GEWA Air 1.7 Shaped violin case

January 5, 2017 at 05:51 PM · I have had 3 Gewa cases, 2 of them shaped (1 violin and 1 viola). The rectangular (budget model) is still in use for my baroque violin.

What I dislike about the shaped cases is material used. It is light indeed, but thermal protection is zero and I even do not want to speculate about their ability to withstand any physical impact.

Buy a winter cover, such as "Mooradian" . The reason is twofold:

1. additional zippers will remind you to close your case.

2. better thermal protection

January 5, 2017 at 07:38 PM · Good review. I've had one of these Gewa Air 1.7 shaped cases for over a year. No regrets. A classy case, light, elegant, very strong, well crafted and well designed -- great for stowing in an overhead bin in an aircraft, or for taking on a long hike to a session or an orchestral practice. There's not a lot of room inside the case, but everything essential fits, including two bows, rosin, tuning fork, nail clippers, glasses, etc., and a Kun shoulder rest. Thermal protection is exactly what as you would expect in a high-tech case of this kind. It's just fine for a 20 minute walk at -12°C, i.e. normal winter weather in Ottawa, but for any longer or colder than that I'd take my car or buy a cover. I like its appearance much better than its more popular rival, the BAM case. I have an oblong Negri Milano as well, very nice case, better thermal protection, which I use when I want to lug around a lot of gear, but I leave it home at home now for airline travel.

January 5, 2017 at 11:46 PM · I should add, GEWA AIR and Jaeger(the one I got instead while checking both) has less-than-optimal thermal properties in the summer(especially if you get non-white AIR case). The interior of the case heats up to and over 50 degrees celsius if you walk out in the sun in a non-windy condition in for 30 minutes. This is due to lack of circulation(comes with water-proof-ness)

I bought a cover to use with my Jaeger in the winter, but I am yet to put it to action because I still am afraid of slipping on the ice and falling on it. According to what GEWA representative told me, it should work well for insulation in the winter at the very least.

January 6, 2017 at 02:21 AM · Steven, I am curious about where your information comes from on the Gewa Air thermal properties since you never had one. Gewa reports the thermal conductivity of the Air cases synthetic material to be 0.025W/mk, while wood factors between .055-.17W/mk (http://www.engineeringtoolbox.com/thermal-conductivity-d_429.html), i.e. its material insulation property is reportedly twice better as wood for the same thickness... in theory. Not every synthetic materials created equal, and some of the world's best insulation materials are synthetic. No denying the "pressure cooker effect" as labeled by Mr. Musafia own observations and the qualities of wood, but the same can be said for any non ventilated case.

I am not defending the Gewa Air case per se as I have not measured its thermal properties myself, but certainly would not want mis-information spread around. Hence wondering, are the thermal properties of the Gewa Air case you have given from your own observation, someone else's observation specific to the Gewa Air, or that measured for another synthetic material case by a third party?

January 6, 2017 at 03:06 AM · The Gewa Jaeger case does not resemble the Air in terms of quality, whatever its thermal qualities. I bought one a few years ago and had to return it, since I discovered that there was insufficient space between the lid and the top of the violin, with the effect that the bows rubbed on the top plate of the violin when the lid was closed.

I have myself walked around in the summertime sun with my Gewa Air case, quite often for more than 30 minutes, and it has never heated up noticeably. I keep a small digital thermometer/hygrometer inside the case, just to be aware of heat and humidity. So I am very skeptical of Steven's alarming figure of 50°C. It could only happen, in my opinion, if the case were left lying in in a hotspot like a car seat in direct sunlight for half an hour. Never a good idea, with any case!

Ottawa is very hot in the summer and cold in the winter. Because I was curious about its resistance to the cold, I actually recorded the temperature readings inside my case, both before and after a 20 minute walk to a local jam session on a windy night in December at -10°C. Before the walk, the temperature inside the case was 20°C, the same as my living room. When I arrived at my destination, the thermometer read 15°. Kind of what I expected -- not a serious change. So I am satisfied that the thermal properties of this case are really quite good.

January 6, 2017 at 08:21 AM · Roger, the thermal insulation IS the reason why the case heats up so much in the summer, because the heat stays in. The sun heats up the case, especially if the case is dark. It's not the outdoor temperature causing the heating, it's the sun!

For AIR, I bought a colleague lunch for going for a walk with me in a hot summer day with low wind, and we had thermometer inside and outside the case during the walk.

Parker, in particular I walk about 30 minutes along the canal in Ottawa everyday(for those unfamiliar with the city, the canal has a walk/biking path that stretches about 13.4km from the parliament building to a river/lake, there is almost no shade other than from trees and overpasses). When there is no wind, my case went up to 53 degrees celsius and my colleague 54, my Jaeger exterior is Brown, and his AIR is black.

January 6, 2017 at 08:26 AM · As for Winter, as I've said, I am yet to test my Jaeger, and my colleagues doesn't walk with his violin either. I've taken all precautions for damaging my violin while walking, but I'm still hesitant. Parker, did you record temperature on a day like Yesterday? 5th Thursday (not Friday)? I'm actually very curious because I'm thinking of giving it a try this winter.

January 6, 2017 at 11:33 AM · "Gewa reports the thermal conductivity of the Air cases synthetic material to be 0.025W/mk"

Roger, can you provide a link to this information? I am unaware of any rigid and protective synthetic case shell material which has such a low TC index. That is less than styrofoam! (0.033 according to your source).

I'm interested for my research. Thank you.

January 6, 2017 at 11:54 AM · A few days ago I did a cold-weather exposure test between two ultralight violin cases of similar weight and characteristics, a wood-laminate one and a carbon fiber one.

If anyone's interested, I can post the results (no brand names will be disclosed). These results will be published in the journal of the Italian Violin making Association (A.L.I.) in the fall.

January 6, 2017 at 02:21 PM · I would love to see your results, Dmitri.

Steven, my fellow citizen -- no I didn't try it yesterday. But I have no hesitation for short periods carrying my violin in its case in the average cold temperatures in Ottawa. A 20 minute walk at -10 or -12 is o.k. However, if it dived to -20 or -30 as it sometimes does around here, no way! I'd take the car or get a cover. No case could protect the instrument in those conditions. (Well, a Mustafa would probably give you a little more time!)

January 6, 2017 at 03:14 PM · In case you are looking for a cover, the representative told me about this one:

https://int.gewamusic.com/product/100/gewa-rucksack-for-form-shaped-violin-cases-sps.html

it works for Jaeger, and considering the shape and size, I think AIR would fit perfectly also.

Cdn supplier I bought it from is

https://www.violins.ca/cases/cases_backpacks.html

I do have to criticize however that I am not the biggest fan of the fact it doesn't have a "side-strap" so that I can carry it on one shoulder. I usually already wear a backpack, and only have the case slung on one shoulder, but the case cover doesn't seem to let me do that without modifications.

January 6, 2017 at 04:07 PM · Steven, thanks for the links. It is 1/2 the price of a Mooradian cover. Does it have a handle?

January 6, 2017 at 04:48 PM · Hi Rocky, no problem, and no, it doesn't have its own handle. Apparently the handle from the case is supposed to stick out. You are supposed to zip them up to the handle, but not really designed to zip over them.

January 6, 2017 at 05:22 PM · Dimitri, Gewa states the thermal conductivity value right in their web site (Gewa Air 1.7 Spec). Very low indeed if true.

January 6, 2017 at 05:47 PM · Tx Steven for clarifying how you got the 50C+ figure it is useful and important information to know so we can contextualized it. One other difference between your Jaeger case and the Air case beside the color was the fact that the Jaeger is protected by an outer canvas layer, which could also account for the 1C degree difference you and your friend observed and perhaps not so much so the "pressure cooker effect". I agree though, Black isn't the best of colors if you are going to be in the sunshine during hot summer days.

Extreme temperatures (and sunshine) as you have in a typical Ottawa summer day (35C, high humidex... I lived there 9 years) would be challenging for any case, sealed or not. I suppose one would be best to use a white insulating bag cover in the summer, and black in the winter if extreme temperatures and sunshine is an issue, but luckily for me I live in Victoria :-)

January 6, 2017 at 06:06 PM · I think I'll try a simple cold test this afternoon on my two cases by putting them outdoors (empty) for 20 minutes and measuring what happens to the temperature inside them. It's currently -11°.

January 6, 2017 at 06:09 PM · I am actually thinking about (sweat-equivalent)wetting my case exterior in the summer. Or walking with a spray bottle to make it wet every 10 mins or so.

The cheapest, least work solution for it.

January 6, 2017 at 06:11 PM · Parker, have you had the (mis)fortune to crash-test your cases? I think with the cover and all, my case may be okay humidity/temperature wise for my walk to work, but I am very worried about slipping on the ice and falling on it. I did break a laptop in that fashion.

January 6, 2017 at 06:17 PM · Thanks for the link, Roger.

If the TC index data claimed by GEWA is true, it would be interesting to know what this "thermoplast" really is. But I say "if".

That figure is rather difficult to believe, to be honest. The tables you provided in the other link don't show any rigid material with an index even approaching 0.025.

Air is listed at 0.024!! I guess I don't believe in miracles any more ;-)

January 6, 2017 at 06:18 PM · Steven --once I dropped my rather heavy Negri Milano oblong case from full shoulder height onto a marble floor in the Rideau Centre. Full protection - nothing out of place, & the violin even remained in tune. Never had an accident with the Gewa. The Negri is wood laminate covered with canvas.

January 6, 2017 at 08:27 PM · I thought "thermoplastic" usually meant plastic the become softer when hot, while "thermosetting" materials are "cured" by heat. My Gewa cases are "thermokern", "kern" meaning core, but I have also seen "thermo-formed" in the descriptions. This shell is a fine honeycomb structure with a hard skin on both surfaces, slightly flexible but surprisingly strong, at least until the plastic ages. Perhaps the trapped air will provide as much thermal insulation as wood?

January 6, 2017 at 10:10 PM · Steven, if I had to carry my case for extended period of time in the bright hot summer sun and was concerned with heat build up in the case, I think I'd find a way to wrap it with a car window heat shield; they're cheap, light and pretty effective in reducing radiant sun light heat buildup. Wouldn't be pretty... and shiny, but I am guessing better than a regular shower ;-)

January 6, 2017 at 10:29 PM · Roger, that's a good idea, and I can actually tailor some when I can find a supplier for that. I can tailor the reflective shield to the case, and tape or sew velcro tapes on key points. Any recommendations for the reflective fabric supplier? I don't care much about thickness or shape, because I intend to cut and sew ends, as far as reflective panels work.

I should add that I am on a very thin budget right now and I intend to do most shopping ASAP because I estimate a big drop in our economy thanks to some political reasons.

January 7, 2017 at 05:51 AM · I'd probably just buy the largest windshield sun shade I could get at Canadian Tire and cut it out. I doubt you'll find the reflective material anywhere. An alternative I suppose would be to use a heat emergency blanket which consist of aluminized polyester, very similar material and very cheap, you just won't have the insulating material (but that can easily be bought at a sewing material store), but it would be effective in reflecting the sun light.

January 7, 2017 at 06:12 AM · Roger Ebay and Amazon are pointing me at some really cheap sources directly from China(let's be fair, isn't 21st century made in China?[perhaps not specialized items such as violins, science equipment]). The problem is that they are giving me way too much of it, and my bachelors apartment is already very crowded.

January 7, 2017 at 06:33 AM · I have a rather long review and comments to add as well:

I have an Oblong Gewa Air case. They have a video of how their Air cello cases are made on YouTube, both in German and English.

Their Air cases are made with a sandwich structure of thin, vacuum-formed ABS plastic shells (i.e. the "thermoplast") with a bulkier injected polyurethane foam core between them. Polyurethane foams are typically used as an insulation material so their low thermal conductivity isn't surprising. The gas in PU foams isn't just atmospheric air - it's usually a product of whatever foaming agent they used - such gases could include CO2 or Pentane. It's also important to remember that thermal conductivity is not the only measure of insulation - while an empty air gap has low thermal conductivity via conduction, filling that gap with foam significantly reduces convective heat transfer. The low density of the foam (most likely in the range of 3-5 pcf) allows the shell to have significant thickness in the top and bottom panels, which lends a lot of strength and stiffness to the structure.

As a note - Bam's Hightech cases are made with a similar structure (ABS/Foam/ABS sandwich) though they use a different foam (Airex brand, though they don't specify which type or grade) and manufacturing method (they don't use foam injection).

The shell of the Gewa Air is quite rigid - I can stand on the center of the lid with minimal deflection (<1 cm) and I'm over 200 lbs. The back of the case can also support my weight. To me this is pretty impressive since most other cases I've looked at, including a Hiscox that I own, which (in my opinion falsely) boasts a 500 kg crush strength, have relatively heavy-duty arched lids but extremely thin and flimsy back panels. That's like expecting the case to never be upside-down in an accident.

As others have noted above, the clearance between the instrument and the case shell is quite generous. For my particular violin, the clearance between the shell and the back (under the soundpost) is about 2 cm - I can easily slip my fingers under the back of the violin while it's resting in the case. The bridge clearance is about the same, and the scroll hovers about 1.5 cm from the bottom panel. At the widest point along the lower bouts, there is about 1.5 cm of clearance on either side from the side panels. The rounded edges on the outside make the case look a lot smaller than it really is.

The hardware is riveted through the shell and backed with 1 cm diameter metal washers. The oblong version has a strap to keep the lid open at just slightly less than 90*. The handle's contour is a bit awkward for me but the case isn't heavy enough for that to be a significant issue. However, the lack of a subway handle is inconvenient.

They are quite different from the "thermokern" shell that's used on their Maestro or Venetian cases, which is not honeycomb but a rigid, skinned foam - possibly made via structural foam injection molding. The Maestro case (I also have one of these) is significantly inferior to the Air in almost every aspect. Worse weather seal (just a butted closure with zippers), worse hardware attachments (not through-riveted), worse structure (I can bend shells significantly just with my hands), and worse interior (poor clearances and the "suspension" padding misses the whole point of suspension padding).

Finally, I think it is inappropriate to lump all synthetic-shell cases into one category. The material properties of CFRP (carbon fiber reinforced plastic) or GFRP are extremely different from that of an unfilled plastic such as ABS. Compound this with the fact that some casemakers (including guitar case makers) are switching over to a sandwich structure design to optimize bending stiffness to weight while others are still using single layers or solid laminates (for cost and manufacturability reasons) and you'll find that trying to lump all synthetic shells together is about as useful as confusing cardboard with plywood.

January 7, 2017 at 07:30 AM · Jeff, that was very informative, thank you. Do you think my suspicion is correct for saying Jaeger and AIR uses the same shell with different cover,latches and interior?

I must say that this thread somewhat resembles http://www.violinist.com/discussion/response.cfm?id=21807

January 7, 2017 at 08:04 AM · Steven,

I'm more inclined to think the Jaeger shares the same (inferior) shell as the Maestro and Venetian models based on the overall shape and the edge profiles.

The Air cases have a more pronounced arch on the bottom panel. At the edges of the lid and base, the inner and outer shells are formed so that they "pinch" together and then an EPDM rubber profile is fitted on top of that.

The Jaeger and Maestro/Venetian cases have a flatter bottom panel, and the edges of the lid and base are simple butted closures. Moreover, the interiors of the Jaeger, Maestro, and Venetian are identical save for different patterns on the fabric. In contrast the Air cases are more spacious/minimalist.

If someone were to ask me for a recommendation between these different Gewa cases I'd suggest the Air over the Jaeger/Maestro/Venetian by far, mostly on account of it being better designed for instrument safety (weather sealing, interior clearances, padding location, shell rigidity & strength).

I'd also like to point out that while the Air cases have a good seal against weather, the EPDM seal is by no means airtight. When I tested my case's strength by standing and slightly bouncing on it (with the contents removed, of course), I could hear the air hissing/escaping from the seal. In addition, a truly air-tight case would be prone to pressure-locking; if the interior air pressure were lower you wouldn't be able to open the case without a crowbar. If you look at [respectable] industrial carry cases or shipping cases they all have pressure purge valves to prevent the case from imploding or pressure-locking during transit.

January 7, 2017 at 09:40 AM · Jeff, thank you for confirming that the GEWA Air has a shell made of ABS plastic and polyeurethane foam.

ABS plastic has a TC index of 2.33 and polyeurethane foam has an index of 0.030. So how can the finished shell have a TC index of 0.025 as GEWA claims? Simple. It cannot.

Sorry if I am insisting on this but I believe that all manufacturers of violin cases must provide truthful information about their products so that musicians can choose from an informed standpoint and puchase according to personal preference.

Otherwise those manufacturers that do provide truthful information (especially regarding weight of cases) are unfairly handicapped, to the detriment of the buyer as well.

January 7, 2017 at 10:04 AM · Jeff, thank you for detailed informaton. I can confirm your description in my (shaped) Maestro (Thermokern) violin and viola cases. I have customised the interiors extensively, as I have a high-ribbed violin, and a high-arched viola.

Ironically, my Maestro double violin+viola case has a 5-ply wooden shell. I am still modifying the interior which I am tempted to replace entirely. It was the only affordable double case with sufficient clearance for my tubby viola (except a flimsier 3-ply one from Sebim). And it weighs around 10lbs..

Ageing:

- Thermokern become brittle over the decades, and the little round feet sink into the foam!

- The outer ABS skin of my previous case became paper-thin from daily rubbing on my clothes!

- BTW,do BAM plastic cases seem to have outer clasps which age badly?

Subway: I have added a strap at tha top end of my cases, and a softish rubber sausage (from a car accessory shop) at the bottom end, as I can't always perch the vertival case on mu foot.

January 7, 2017 at 04:26 PM · The interesting thing is that images of the GEWA Air cases on Japanese web sites do show a Subway strap.

January 7, 2017 at 04:51 PM · That's not surprising. Different markets have different needs, hence most manufacturers will make adaptations to their models to best fit those needs, resulting in different specs according to market area.

January 7, 2017 at 05:35 PM · Dimitri,

Where are you getting the values for the PU foam's TC index?

According to this source the TC can be as low as under .022 to .35, depending on the foaming method (freon vs. CO2).

http://hyperphysics.phy-astr.gsu.edu/hbase/Tables/thrcn.html

It's also important to note that the thermal conductivity of a material (especially foams) can vary with the temperature of the material, since that affects the gas pressure inside the cells and subsequently the insulating qualities as well.

http://www.lsta.lt/files/events/28_jarfelt.pdf

Because polyurethane foams can be closed cell or open cell, filled with a variety of gases (freon, pentane, CO2, etc.), and made with different densities, there is no single TC value for PU foam. In addition, there is a sub-class of PU foams known as polyisocyanurate foams (PIR) which are stiffer, and have higher insulation values, but are more brittle.

It's also useful to remember that the majority of the thickness of the Gewa Air shell is the foam core, and only a thin layer of ABS is on either side. The foam takes up about 80% of the panel thickness if not more, and it's likely that Gewa simply published the TC index of the foam itself since it makes up the bulk of the volume of the shell.

It could also be that Gewa didn't test the thermal conductivity of the foam material themselves - they could have used the value given to them by their supplier.

Regarding testing/publishing values - most major industrial case manufacturers (many of which also make guitar cases) subject their products to a standard set of tests to get standardized ratings such as ATA 300 (which requires a pretty rigorous series of drop tests, impact tests, abrasion tests), and IP 67 (waterproof for 30 minutes under 3 feet of water, no dust ingress).

A lot of false advertising for synthetic shell cases comes from a combination of the typical consumer's ignorance when it comes to material science, and in some instances the manufacturer's ignorance as well. Examples below:

-I've seen a distributor try to market Bobelock's fiberglass cases as having superior insulation because fiberglass is used as an insulation material. However, what they missed is that fiberglass batting is a good insulating material because it traps air pockets, and solid fiberglass laminate is not a good insulating material.

-Hiscox tries to market its ABS plastic outer shell as being extremely impact resistant. It isn't - even impact-modified ABS plastic has a mediocre notched Izod rating of 5 ft-lbs/in. For comparison, polycarbonate typically has a rating of 14 ft-lbs/in when notched, and a rating of NB when unnotched (NB indicates no-break; the pendulums typically used can test up to a maximum of 120 ft-lbs). Also, most car bumpers nowadays are made with a polypropylene copolymer (which is far more impact resistant, even at low temps), not ABS.

-Almost everyone has a misconception that tensile strength or tensile strength-to-density ratio is the dominant factor for shell material.

The actual limiting factor is the specific flexural modulus, or ratio of the flexural modulus to the cube of the material density - the stiffness of a panel increases with the cube of its thickness. So, a more flexible material can be made into a much stiffer case overall if its density is low and you can build bulk with it. This is why for non-sandwiched and non-corrugated construction, plywood is unbeatable for shells - it is quite stiff (flexural modulus ~ 10 GPa) and its density is quite low (.5 g/cc to .7 g/cc). Typical 50% by weight carbon fiber has a flexural modulus of 45 GPa and density of 1.5 g/cc, so intrinsically it is 4-5 times as stiff as plywood. However, plywood is only 1/3rd the density, so you can use 3 times the thickness and get a 27-fold increase in stiffness which washes out carbon fiber's innate stiffness advantage. But, this changes significantly when a low-density core is used to build bulk between CF skins. In this scenario the dominant factor shifts towards the elastic modulus/density ratio. Sandwich structures provide some interesting properties such as shells that can be globally stiff (For crush resistance) but locally flexible (For impact dissipation), and are being used in military applications for these reasons.

January 7, 2017 at 05:50 PM · Hi Jeff, thanks for your detailed response on this. The source I quoted for the TC indexes was the same quoted in one of the posts above, just to keep things on the same plane.

That said, the acid test is how things work in the real world, which is why there is this ongoing violin case safety testing being independently performed by a FAA-accredited branch of the Milan Polytechnic. It involves professional-grade cases made of various materials by a number of manufacturers, brand-name and not.

The results will be published by the university in a couple of years once all the testing has been completed. In the meantime I've mentioned some prelimnary results in another post of mine some time ago.

January 7, 2017 at 05:51 PM · (double post, sorry)

January 7, 2017 at 06:08 PM · Wow. A lot of food for thought here. I must say I do admire Jeff's fortitude in standing on his Gewa air case, especially at 200lbs. Much as I'm tempted I don't think I'll try that, though ... and I only weigh 170. Mine is a shaped case and probably not as strong as an oblong. I think there was a thread about that issue not too long ago, where Dmitri weighed in with his usual blend of information and good sense. (I have finally , alas, given up going to gigs where 200 pound musicians threatened to stomp on my case, or drive a tractor over it).

January 7, 2017 at 06:12 PM · Thanks, Parker, for your kind words. I do think it's important to discuss things, rather than simply accept them as advertised.

There are many posters on v.com who have a lot to teach us all. That's what discussion forums are all about!

January 7, 2017 at 06:21 PM · funny thing is that if I look at my Jaeger case, it has different button pattern for the flaps than most of the Jaeger cases advertised online, and also the curvature and shape of the hard shell is identical to the AIR from comparing to my colleague's AIR and the AIR at the store when I was buying it. One other thing is that Jaegers are sold with the string tube, and mount, mine just never had them.

I recall Parker mentioning that Jaeger was made in China, but mine is made in Germany, at least it claims to be. Also, I'm curious why GEWA makes Jaeger more expensive it they use cheaper shell for it than AIR.

I have a feeling that Jaeger may secretly have sub-variants of the case, with newer models being the cheaper.

January 7, 2017 at 08:59 PM · Hi, All,

I have been following this discussion with interest, as I purchased a shaped Gewa Air 1.7 case a few months ago.

I agree almost 100% with Roger's review in his initial post. I have been very satisfied with the design and performance of the case, with my main criticisms being the lack of any restraint to keep the case top from folding down flat, and also the attachment of the accessory pouch. I also have been frustrated by the total absence of any reviews about the Air cases on the various violin dealers' and internet retailers' websites!

I am a fiddler, not a violinist, so I am often playing at outdoor festivals and in less-than-optimum venues (pubs, living rooms, etc.).

I wanted to replace my previous Bobelock oblong, non-suspension, plywood-shell case with something more compact and protective (and definitely lighter!). I was very interested in protecting the fiddle from heat and cold. I chose a white matte shell, mainly as the best way to protect against direct sunlight when I have to carry the fiddle around outdoors.

Superior thermal protection is one of the "selling points" of the Air cases, and I have been curious whether my shaped, white Air case would offer better thermal protection than my old brown-exterior plywood Bobelock.

Last summer I placed both cases (lying flat) in full, direct sunlight, with laboratory thermometers suspended midway in the interior of each case. I checked the temperatures after 15 minutes, 30 minutes and 1 hour. I can't remember the exact temperatures recorded, but I do remember that the temperatures registered inside the Air case were almost exactly 10* Farenheit lower than inside the Bobelock, at all three times.

The 10* difference was almost certainly due to the white vs. brown exteriors, rather than any difference in insulation effectiveness. I don't know what, if any, effect the difference in internal volume would make. But I do feel somewhat better now about any inadvertent sun exposure.

I also have been wondering about whether my Air case's "thermal" shell would delay the internal temperature drop relative to the plywood shell in cold weather.

Coincidentally, last night I got my chance to experiment!

It was exactly 0 degrees Farenheit here last evening, so I placed both cases (sitting handles-up) outside with two thermometers (F and C)suspended inside each case. Both cases were initially at 71*F. I checked the temperatures after (timed) 45 minutes.

The inside temperatures for each case were exactly the same, 18*F and -8*C.

So it seems there is no thermal advantage for the foam-injected sandwich with interlocking edge of the Air case over the Cordura-covered plywood with nylon zippered Bobelock.

Again, I'm not sure if the internal volume difference between the cases matters, or if any air leakage through the zipper might have occurred.

Disappointing, but still interesting!

January 7, 2017 at 10:52 PM · I haven't successfully completed my cold test comparing my Gewa air and my Negri Milano cases, as I was using two different kinds of thermometer and I found that the digital battery powered device more or less failed in the cold and give extremely faulty readings. Will do a comparison again with the same thermometer. It's -13° outside now, so I'll give them each 20 minutes . . .

January 7, 2017 at 11:58 PM · Completed my cold test. Done between 6 and 7 pm at an outside temperature of -13°C (which is chilly, but mild compared to how low it often goes around here at this time of year).

Both cases had an inside temperature of+ 21°C when I put them outside for a 20 minute timed exposure, out of the wind. The temperature inside the Gewa Air dropped to +5°C, and inside the Negri Milano it fell to a balmy +7°.

Both are excellent quality cases and do not come cheap. The violin-shaped Gewa Air we all know from the discussion above, and the Negri Milano is oblong, well-padded and made of laminated wood covered with canvas. The wooden case gave slightly more thermal protection, but not enough for prolonged exposure. But I guess the moral is obvious. Any case without a special thermal cover won't offer much protection from extreme cold or heat.

I guess it would also be a good idea to find out what really happens inside a case with one of these special covers!

Incidentally I used a standard red-alcohol based indoor-outdoor thermometer from the hardware store. I don't know how accurate it may really be, objectively speaking, but it seems to work much better than my digital case thermometer, or my three dial-type analogue devices. The former goes utterly wonky in the cold, and the latter respond erratically, if at all, below 0°

January 8, 2017 at 12:28 AM · I've quickly added a couple of stick-on Velcro pieces to my accessory bag, it seems to help holding it a bit tighter and more to my liking.

On the temperature test, it would be really nice if one of you would measure every 10min to see the rate of decline over an hour (or to the time when the same temperature as outside is reached), with another thermometer on the outside as a baseline and show us the curves.

January 8, 2017 at 12:37 AM · I would really like to try that, Roger, but my wife is starting to threaten me with dire consequences if I do any more of this dashing in and out of the house in the freezing weather with my fiddle cases. . . .

January 8, 2017 at 04:05 AM · Some comments about the thermal tests:

1) It's useful to keep in mind that both Parker's and Kenneth's tests are comparing a shaped Gewa case to oblong plywood cases (Negri and Bobelock, respectively). The surface area to volume ratio of a shaped case would be slightly higher than it would be for an oblong case, so there is relatively more area for heat transfer to occur for a relatively smaller internal volume.

2) The nylon covers on plywood cases likely add a measurable amount of insulation - similar to how a single napkin or paper towel is enough to protect your hands when holding a hot plate or dish (provided both are dry).

4) The interior fabric of the Air cases is quite sparse and has very little "loft" to it. I do not own any Bobelock or Negri cases, but I would suspect the Negri cases have a considerably higher-quality interior lining with longer fibers. Similarly, the Bobelocks I have seen also have lining that is much more plush than that of the Air case's. This may also contribute insulation, as well as better humidity stability.

5) One of the design flaws (in my opinion) of the Air case's shell is that while the top and bottom panels have a good amount of thickness to them, the shell thickness tapers down to the edges where the rubber profile is fitted. If you apply enough pressure on the lid or back of the case, the side walls actually bow out slightly before the top or bottom panels bend. The ABS shells remain the same thickness but the PU foam core is significantly thinner. Thus, the insulation is dramatically reduced along the edges of the Air case.

6) Both the Negri and Bobelock cases have a significant amount of foam filler in the interior to match the instrument's shape and also form the interior geometry of the case. This would provide a small amount of insulation. In the Air case there is almost no foam filler except for what's necessary to keep the instrument in place.

The tests above don't lend too much credence to Gewa's claim that the Air cases have "exceptional insulation properties." They also do not show a direct comparison of the relative insulation properties of the Air shell vs. a plywood shell because of the reasons above. What they do show is that the cases as a whole are at least not significantly worse in temperature insulation compared to respectable plywood cases.

It's interesting to note that the Air cases' structure is quite similar to that of a Pelican or Yeti ice chest - plastic outer and inner shells with a PU foam core sandwiched in between. The difference is the coolers have over 7.5 cm of PU foam all around compared to the ~1.0 to 1.5 cm for the Air case, and less than that for its side panels.

Unrelated to insulation, but another point on false or misleading advertising: Gewa touts that their injected PU foam is more robust than their competitors (who I assume must be Bam - no one else makes thermoformed plastic violin cases with foam core construction) because their competitors have to heat and bend their foam core around corners. The fact is that almost every grade of Airex foam that can be thermoformed is a type of vinyl foam (technically an IPN of vinyl & polyurethane but that's a different topic). Weight for weight, vinyl foams have almost twice the strength and rigidity of polyurethane foams. Per the thermoforming guides for Airex foam (and also for Divinycell, a competing product), thermoforming the foam causes at most a 5-10% loss in properties. Basically, it's highly likely the PU foam that Gewa uses even with their foam injection process is significantly weaker in compression & shear (two of the most important mechanical properties for a sandwich core) than the vinyl foam that Bam probably uses. Actually, most serious sandwich panel & composite design guides will tell you that PU foam has the lowest mechanical properties to weight ratio of all the commonly-used sandwich core materials such as plastic honeycomb, PVC foam, end-grain balsa, Nomex honeycomb, etc.

I keep coming back to this thread because there's a lot of interesting findings being made and it touches on some material science and manufacturing topics that I spend (and have spent) a lot of time reading about.

January 8, 2017 at 09:10 AM · Parker's and Kenneth's tests both show empirically (i.e. in the real world) that a typical wood laminate case will provide at least as much thermal protection as one of the newer high-tech composite cases touted for their "execptional thermal protection", when not more.

If somone can kindly tell me how to post a jpg onto this page, I'll post a graph of a 100-minute cold stress test between two ultralight cases, a wood laminate one and a carbon fiber one. (no brands will be mentioned)

Cheers!

January 8, 2017 at 02:46 PM · Since this is a bit of a Canadian influenced trend, why don't we use the knowledge of our Inuit brothers from North?

They learned over a long period of time that no (natural) material itself is sufficient against extreme cold, but adding layers brings air pockets, which in turn can keep you warm!

A few years ago we had an extremely cold winter here in Toronto and I added another wrap for every -10 degrees Celsius. I did not do any objective measurements, but my violin was warm to the touch upon my arrival. Typically, a few minutes outside before subway and up to 20 after.

It looks like Matryoshka dolls; silk bag to start with, Gewa oblong case (plywood with its own cover), fleece blanket, violin winter cover, another blanket, viola winter cover.

January 8, 2017 at 02:47 PM · Thanks Jeff for your detailed comments. One other factor I should have mentioned is that I placed the two cases outdoors in sequence, because I possessed only one reliable thermometer. The Gewa was put out out first for 20 minutes, then I brought it indoors and measured its inside temperature. Waited until the thermometer returned to 21° (room temperature). Then the Negri went out. So about 50 minutes for the whole process. The temperature was slowly falling, maybe as much as one or two degrees during this time between 6 and 7 pm. I didn't have an accurate way of measuring the outside temperature curve -- this procedure was all very ad hoc -- but I believe the Negri was exposed to an extra degree or two of cold. The window thermometer (other side of the house) gave a rough confirmation of this, as I checked it before and afterward. (The dial-type thermometer I had placed outdoors alongside the cases was too inaccurate.)

So it seems to me that the Negri was actually giving somewhat more protection than my measurements indicated. Possibly a degree or two. This may be of interest to Dmitri.

January 8, 2017 at 05:20 PM · Dimitri, to post a JPEG do as follow (V.com instruction):

•If you would like to embed an image, please upload and store your photos on Imgur.com. Then use the "Direct Link" to get the image location to embed it in your post with this code:

<

img src="http://i.imgur.com/XXXXX.jpg">

NOTE: delete the paragraph return after the < character.

That's a sample image code. Please do not embed images more than 560 pixels wide.

January 9, 2017 at 02:02 AM · Dimitri,

In the study being conducted with Milan Polytechnic, will the eventually published results also include the brand and model of the cases, or will the results be grouped into construction categories (3-ply wood, 5-ply wood, ABS, ABS/PU foam, Carbon fiber, CF/foam, etc.)?

Also, it'd be interesting to see the how much heat is accumulated or dissipated within the case via conduction (heat transfer between environmental atmosphere and case) versus radiation. For instance, if the heat transfer is predominantly through conduction, then a thin layer of Mylar (aluminized Biaxially Oriented PolyEthylene Terephthalate, the shiny stuff windshield screens and emergency blankets are made of) won't help much since it only insulates against radiation heat transfer, and convective heat transfer if it traps air pockets.

January 9, 2017 at 07:09 AM · Jeff, the published results of the studies performed by the Milan Polytechnic will not include brand names, only the types of cases. There are photos, although I don't know if they will be published.

Our cold stress testing regards heat transfer between the environment and the case interior, however our heat stress tests, where the case is subjected to direct sunlight in a high temperature ambient (32°C+/ 90°F), also include the radiation factor.

To what extent is difficult to determine. Again, our testing is devised to better simulate "real world" conditions, which the musician is more likely to encounter, rather than industrial oven or freezer testing which offers more control over the environmental conditions but scarcely reflects everyday reality.

January 9, 2017 at 11:56 PM · Dimitri,

My comment on radiation vs. conductive heating was more of a question on whether or not the cases currently on the market are putting their efforts in the right direction for insulation. For instance, some (maybe most?) unfilled plastics are transparent to infrared light - if for some reason your case interior is heating up or cooling down due to IR heat transfer (just as an example) then no matter how much more plastic you put there to try to insulate it, it won't really help.

Regarding the studies:

How specific are the types/categories? The reason I ask is that while a "plywood case" covers a few types (e.g. 5 ply vs 3 ply, steam-bent vs cold-bent, dried/aged vs. new wood, etc.), the term "composite" or "synthetic shell" covers many more possible constructions (ABS plastic vs Polycarbonate for unfilled plastics, carbon fiber vs fiberglass vs Kevlar for composites, solid laminate versus sandwich structure, continuous fiber vs long fiber vs short fiber reinforcement, thermoplastic vs thermoset, etc.) and the structural and thermal properties of each of those possible permutations can vary by orders of magnitude.

Here are some example material' flexural modulus and density figures as an example:

Unfilled ABS Plastic:

1.00 to 1.20 g/cc, 2-3 GPa depending on proportions of Acrylonitrile to Butadiene to Styrene (ABS is technically a copolymer)

Carbon Fiber reinforced Nylon-6, 50% by volume, continuous fiber:

1.44 g/cc, 45-50 GPa.

Carbon Fiber reinforced Nylon-6, 50% by volume, long fiber:

1.44 g/cc, ~22.5 GPa.

More spec sheet data can be found on MatWeb. The two CF examples highlight my point - they seem very similar on the surface but one will support over twice the load of the other.

You could build a 7 lb carbon fiber case using solid laminates that can support only 40 lbs of weight and has no thermal insulation, or you could also build a 7 lb carbon fiber case using a foam core that can support 200+ lbs of weight and has thermal insulation in the ballpark of most plywood cases.

As someone who reads quite extensively on material science, I would like to see the study be as specific as possible about the case constructions. To do so otherwise (i.e. lumping them into simple "wood vs synthetic" categories) would be extremely misleading and only enables further ignorance on the subject.

As I said earlier, treating all synthetic materials as one monolithic group is akin to grouping plywood and cardboard together just because trees are necessary for both, or calling a Musafia or Bobelock case "composite" just because it has a nylon cover over a wood shell.

In a similar vein, there is a huge difference between 3-ply vs 5-ply or 6-ply wood, due in part to anisotropy and wood quality. With 3-ply you have 2 plies in one direction, and 1 ply at 90*. The material properties change drastically with the orientation of the panel. With 5-ply or 6-ply the number of plies oriented in each direction are more even and the panel properties become more consistent with different orientations.

January 10, 2017 at 02:35 AM · Jeff, sounds like it would be nice if Dimitri could put you in touch with the study team. We're certainly all curious about it, but unlike most of us, you have the knowledge to have an intelligent discussion with them and perhaps have input in their approach even, whatever it might be.

January 10, 2017 at 07:38 AM · Jeff, quite honestly I don’t think most case manufacturers are really interested in this. My take is that since synthetic (i.e. plastic, composite, thermoformed, etc.) shells are easier and cheaper to industrialize, most companies go for that and then advertise supposed superiority of this or that material without thinking twice about it, since they believe no one will ever check.

I can state this with some authority as I experimented at length with synthetic shell case shells: fiberglass (uni- and multi-directional), Kevlar, carbon fiber, sandwich (Coremat), and others. Molded plastics like ABS or high-density polyeurethane were rejected from the start because of their basic properties.

We built over 120 cases with these materials, and they were offered to musicians to test in the real world. As my company didn’t have the necessary expertise, we outsourced the engineering, development and production of the shells to a reputable company. After two years of comparison of different solutions with wood laminate shells we threw in the towel, wrote off the investment, and went “back” to wood, despite laminate being more difficult to craft into a good case shell than molded plastic.

The fact is, I have yet to see any independent studies in which a violin case shell in wood laminate, if correctly designed and built, is not superior in virtually every way to a synthetic shell, including weight vs rigidity.

RE the studies being performed by the Milan Polytechnic, we took a selection of professional-grade oblong violin cases of different manufacturers which represented most of the categories you mention.

The research is however not intended to determine the best material to make case shells, but a preliminary exploration to compare how much overall violin protection this selection of mainstream higher-end cases offers, and which are the areas to improve, and how. This includes not only resistance to temperature changes, but also crush resistance and crash testing.

The variables are thus not only the case shell material, but its design and dimensions; as well as the design and method of construction of the interior, including internal clearances, and kinetic energy absorbing and transmission to the content.

This project is, to the best of my knowledge, the first independent study of its kind. In addition to what I am myself learning from it, my hope is that a result of the published research will be to make violinists more critical and informed about how much protection they are buying, as opposed to dogmatically believing, as some advertising suggests, that if you make wind generators and space shuttles a certain way, then you should make violin cases that way too.

Heisenberg stated that to simply observe a phenomenon is enough to modify it. :-)

February 1, 2017 at 01:51 AM ·

February 2, 2017 at 03:26 AM · Hi Peter, I've sent you an e-mail at the address you've provided.

February 13, 2017 at 11:05 AM · I've just received Gewa Air 1.7 case, and I have a BAM high-tech contoured. I can comment on the ergonomics and design, but have not conduct any thermal insulation test yet, which I'm not going to do so anytime soon. Anyway, here are my impressions, which mainly focus on weight and design.

Upon first handling of the Gewa, it's actually quite hefty, including 2 straps and the mini compartment pouch and blanket. I was expecting it's at least as light as the BAM, but no, BAM is definitely lighter, although not dramatically so. If the Gewa is 1.7kg, this the BAM feels more like 1.4-1.5kg. I took out the straps and removable stuffs, and compare again, the BAM is still lighter.

Then I started to put on the straps and load my violin inside. The Gewa is more compact, which makes the shoulder rest almost unable to squeeze it. BAM has more space and more liberal on the choice of shoulder rest. Though both are only suitable for KUN style rests. Weight wise, it goes to BAM.

Both case has good design on instrument placement, which allow some space between the shell and indtrument. However, I do worry about the cushions surrounding the lower bout in the Gewa, there's actually NO cushions, just fabrics, so when an impact occurs over there, it'll most likely a much harder hit compared to BAM which is cushioned. So on cushioning, it goes to BAM.

Bow locking mechanism was tighter and more secure on Gewa, with very firm lock, compared to BAM which is only a faint hint of click on center. But BAM reversed the bow holder, which seems safer. So both are a tie on this.

The Gewa feature number lock, and BAM provides key lock. I like the BAM latch more, but the Gewa seems to have stronger lock/latch. Both allow one handed operation so it depends which one you like. Not going to cover others things which to me doesn't have significant advantage over the other.

Last but not least, one thing that really makes me prefer BAM over Gewa, is the ergonomics of the straps. You can set the straps to be very comfortably carried on one side or both. The Gewa wasn't very comfortable and it doesn't stay hanging at my back when carried on one side/strap. On top of being lighter despite having bigger space, the BAM is a winner.

Can't comment on the thermal insulation which I usually don't walk under the sun for prolonged period. I'll perhaps update if I encountered any of these situations.

Oh, I do have a Musafia momentum z, which is a little heavier than Gewa. You can safely say that if you are to buy a Gewa, maybe save up for a Musafia. They now make case ranging from 1.9 to 2.2kg, which will be a great alternative to these shaped case if compactness isn't your concern.

February 13, 2017 at 05:55 PM · For cushion, I do have to agree that GEWA seems different. At the lower bout, I feel there is almost no cushion.

February 13, 2017 at 10:50 PM · Good feedback Casey tx. To be fair when comparing, one should note that the Gewa Air 1.7 shaped case is less than 1/2 the price as the least expensive Musafia case (for me in Canada that is), but similar in price to the Bam High tech Contour, which is its closest comparable IMO. Something to keep in mind when shopping.

February 14, 2017 at 12:53 AM · Roger, when I was case-shopping. BAM High Tech at the best deal was ~$800Cdn and GEWA Air was ~$550 Cdn. I wouldn't call that quite similar.

February 14, 2017 at 05:14 AM · Oops Steven, my mistake, you are right. I based my post on prices at the Sound Post where it listed the Bam for $578 but failed to notice the USD currency ($680 CDN), while the Gewa is $525 CDN, a significant difference when applying the exchange rate.

February 21, 2017 at 07:49 AM · Roger,

It's true, the price is what makes me want to give it a try. Apart from the limited space inside the case, there's nothing much to complain about.

I seldom use my BAM case as the violin usually sits in the musafia. My Gewa carries another violin that I now plan to use everyday. The airtight seal does have impact on the humidity inside the case - I actually had more loose pegs instance than pressure cooking the violin. Not a bad thing in where I lived, which is summer all year. But loose pegs does give problem if I want to use it for some performance and the string would need a retune every now and then within an hour.