Question on laminated woods

Frank Wekenmann · January 2010

As many feel that laminatited backs and sides are an important ingredient to the Selmac tone, I have a few questions about it, especially since an old Dimauro I once played had totally different back and sides (rather soft and light) than e.g. the modern Gitanes.

1. Which woods were traditionally laminated in Selmers?
2. Do the woods used in the laminates matter? If they do, which layer is most important soundwise?
3. Which glue was used in original Selmers?

Thanks,
Frank

djangoed · January 2010

The wood used for the majority of the original Selmer guitars were Indian rose wood for the external veneer, french poplar for the veneer used in the centre of the laminate and then mahogany for the inside veneer.

Regarding the choice of veneers I think it would be a good idea to talk with a luthier who has experimented with different woods for laminating the back and sides on selmacs.
But if you want to try to copy the sound of an original Selmer then the logical answer is to use the exact same wood as they did ! Bear in mind that many people will have their own oppinion about these things and not all luthiers will agree...sometimes there is never one answer !

The veneers that were available then were thicker than the veneers of today though....

Poplar takes the glue very well and is a soft wood that acts as a hard wood, its also very elastic which maybe why it was used. When I was in France for a couple of years I did notice it was very cheap and and extreemly common. Its used for many things and in building like rough flooring in all the barns and old houses.
Maybe it was origanaly used because it was readly avalible and cheap who knows....?

Im not sure that Selmer did everything thinking about tone etc Im sure they also chose wood that was cheap and available... and bear in mind that the guitars were produced on a production line in a factory and the guys working there were not luthiers. Selmer a business too so some decisions must have been about cost....

Another thing thats interesting is that the inside of the guitars were also treated with a laquer or varnish which is not really the norm in guitar building.

The glue was most probably animal glue, not nice to use if your a vegeterian

Most of the info should be in Francios Charles book by the way !

Are you gona make one your self or have one made ?

Jazzaferri · January 2010

Many wood instruments were given a coat or two of shellac on the inside to minimize moisture transferral (hence movement)

Hide glues were and still are used in violin family instruments as they are designed to be disassembled from time to time which hide glues allow without breakage. Not sure if or why a guitar manufacturer would use a hide glue in that time period. It's a real PITA to use.

Frank Wekenmann · January 2010

Thanks for your answers!

Are you gona make one your self or have one made ?

No, I will not make one myself and I am really happy with my current guitar! I was just wondering, why, if laminated woods are commonly considered to be essential for achieving the typical sound, there is not more discussion about the type of laminates. The afore-mentioned Di Mauro had in fact a very elastic back that could easily be moved by my thumps. Surely such wood must reflect the sound differently than the laminates on e.g. a Gitane.

The veneers that were available then were thicker than the veneers of today though....

That is interesting, I would have sworn the DiMauro had a very thin back.

The wood used for the majority of the original Selmer guitars were Indian rose wood for the external veneer, french poplar for the veneer used in the centre of the laminate and then mahogany for the inside veneer.

So no Brazilian on the outside like many modern replicas? Any idea if the sound-reflecting properties of mahogany in the inside are still discernable?

Im not sure that Selmer did everything thinking about tone etc Im sure they also chose wood that was cheap and available... and bear in mind that the guitars were produced on a production line in a factory and the guys working there were not luthiers. Selmer a business too so some decisions must have been about cost....

+1

Hide glues were and still are used in violin family instruments as they are designed to be disassembled from time to time which hide glues allow without breakage. Not sure if or why a guitar manufacturer would use a hide glue in that time period. It's a real PITA to use.

If they really used Hide glue, this must make a big difference and could also explain the weight difference in vintage vs. modern guitars. Hide glue can be applied very thin (thus not adding weight)and when it dries it becomes hard as glass (no damping). I know that it is difficult to work with Hide glue. My guitar (with solid back and sides) was build by legendary luthiers Rudie Blazer and Willi Henkes, who use hide glue exclusively. Here is a link to a funny video that show how Rudie works with hide glue (starts in German, continues in English):

bjewell · January 2010

The Martin guitar company has demonstrated conclusively that hide glue makes a substantial improvement in the volume and tone of an instrument. This is especially true in regards to the bridge-to-top, bracing-to-top, and body construction.

Hide glue is not so difficult to work with once you know how. I wonder what Dupont uses?

Craig Bumgarner · January 2010

I have no doubt that hide glue is good for a lot of reasons, but have been concerned that for laminating, there isn't enough working time. I use a mold and clamping caul, but it uses 20+ clamps and this takes while. In Francois Charle's book, there are pictures showing a jib with just three clamps. I should think that would work much better with hide glue. If anyone has thoughts on this, I'd be very interested to hear.

I've used Titebond in the past and while it worked out okay in the end, the wood does absorb a lot of moisture in the process. It takes weeks for the back and sides to stabilize. I've been considering using Weldwood Plastic Resin (urea formaldehyde) glue next time. I might also consider epoxy but having used it a lot in boatbuilding, I know it is messy and difficult to clean up.

Craig

Jazzaferri · January 2010

titebond has changed over the years ... it was and probably still is the glue of choice for Bob Benedetto

I have not heard of Martin guitars study of hide glues giving better sound. Where do I find this info. Sounds really interesting to me.

bjewell · January 2010

Martin is building a guitar under the so-called Authentic moniker. It is made much closer to the specs of a '30s guitar, including using hide glue. In their pre-production phase, they built the guitars with hide glue as well as (sp???) alephetic resin glue. The hide version sounded much better in terms of clarity and volume.

I have a 2005 D-18 Authentic and it sounds hands down better than an almost identical 2003 D-18 Golden Era, i.e., red spruce, real mahogany, ebony, Brazilian specs. Thle GE was made with modern glue. It was a nice guitar but the difference in tone and volume was substantial.

Bob Holo · January 2010

Hide glue is wonderful if you know how to make, store & use it properly and if your woodworking skills are good enough to allow you to make extremely tight (perfect or near-perfect fitting) joints.

Why is it great? Well, unlike aliphatic resin, it doesn't just form a mechanical bond, it forms a molecular bond between the pieces of wood which is referred to as 'specific adhesion' ... literally an electromechanical bond by valence forces. So, at some level of abstraction you could even say it makes the two pieces of wood 'one' And while you can completely reverse joints with heat and water - dry hide glue is one of the most heat resistant glues out there... (unlike aliphatic resins - most of which will begin failing around 140F... so never ever ever leave your guitar in your car...)

However, hide glue is not at all forgiving. If you're using old or overcooked hide glue or you don't know how to make it or use it or if your woodworking skills are a little sketchy so your joint is loose fitting... hide glue will give you horrible results. In other words, with hide glue there's really no in-between - you either own it or it will own you.

Also, hide glue is brittle, so it's not appropriate for all joints on a guitar, as a guitar is not meant to be taken apart (as a violin is) You can reduce the brittleness of hide glue by extending it with a small percentage of urea (which also extends the working time and makes it a little easier to use) but generally when instrument makers are using hide glue they're using straight fresh hide glue ~190 grain - and they're using in on joints where there is a good fit and no need for flexure... a joint where the tightness of bond must be maximized and acoustic/mechanical dampening must be minimized.

So, I'd never use it for bindings/linings - things that are under flexure and/or might take a whack... but yes, it's a heck of a brace glue... but for most other applications I find that a good aliphatic like Titebond or the stuff from Luthier's Mercantile are about the best you can get.

Oh, and there were several types of back/sides for traditional Gypsy Jazz instruments. Consider Selmer: they made gypsy jazz model guitar back/sides from... Solid Mahogany, Solid Maple, and laminates of Rosewood/Poplar/Mahog ... Mahog/Poplar/Mahog ... Rosewood/Mahog ... and those are just the documented types. Selmer often did three piece laminates, but occasionally did two piece laminates with the significant piece of wood being a softer interior wood such as Mahog with a Rosewood veneer over it. Several top makers of gypsy (and classical) guitars laminate their sides even when they use solid backs because side rigidity is so incredibly important and it's tough to beat the stability of laminated sides. As for the backs - well... there are many aspects to making a back and this post is already long enough... but to make a long story short - if you find an amazing GJ guitar with a solid back - don't pass it up just for that... a well made solid back is way better than a cheezy laminate... and most GJ laminates made these days are exactly that... cheezy... gummy heat-press glues... thick glue lines... thuddy... yuck. As for what Selmer used? Probably urea+hide or urea+formaldehyde... the fact that they lacquered the interior makes me think hide... because hide is hygroscopic.