Dear Stephen, This is _really_ interesting. I assume you size with the same thin glue? How long would you let it sit then, before gluing? Thanks for the information. I have a toothing plane iron ... Maybe I should build a body for it! Susan. -------------------------------------------- At 02:23 AM 8/19/97 -0500, Stephen wrote: >> Please elaborate - how DID the old guys do it??? >> >Three things: >1. Tooth all glued surfaces >2. Size everything >3. Use ultra-thin glue. Make thin glue, thin it until it looks like it >wouldn't glue anything, then add more water. Then it's thin enough. > >Why? >Toothing improves the bond and allows the extra glue somewhere to go when >you clamp the joint. Thin glue is very easy to expel from the joint and >requires less clamping pressue consequently. (After all that's why we >clamp.) Old toothing planes are lurking everywhere...they weren't just >used on veneers. In any case you only have to look to see toothed >surfaces everywhere. > >Sizing prepares the wood and makes it behave. Unsized wood will suck out >the water from the glue almost as soon as you put it on, thus requiring >pre-heating as a last-ditch effort to make things last long enough to get >the clamps on. Thin glue can only be used on sized surfaces. Evidence for >sizing is clear on almost any old artifact, piano, organ, furniture etc. >Sizing was often done en masse. The old organ builders sized more wood >than a railway trestle bridge needs. > >Evidence for thin glue is clear on old pianos...you can see the long thin >runs that have been expelled from the joints. Glue that is the thickness >we are "supposed to" use nowadays does not flow in this manner. The runs >are so precise and long that you can even use them to analyse how a piano >case like a Graf was assembled. > >By the way there is such a thing as "bad" glue...and there seems to be a >lot of it floating about on this continent. Take care. Also never heat >hide glue over 60C or it is impaired (see Wolfenden on hide glue)...in >fact any temp. below 60C that the glue is liquid is acceptable. The old >guys didn't use thermometers. > >You can't tell by looking at broken down pianos whether the surfaces were >pre-heated. But there is clear visible evidence for the above three >points. And experience shows that the method works with no heating. >Heating every piee to glue is a royal pain in the butt, so you can bet the >old guys would not have pre-heated. They weren't stupid. > >[No claim to having discovered the method above...credit is due to my >colleague Bill Jurgensen, an ex-patriot US organ, harpischord, piano, >violin maker who lives in Germany. Evidence on organ cases and pipes is >even more obvious than in pianos. There isn't much harder to glue than a >windchest on a cathedral organ...no pre-heat needed.] > >Stephen > >Stephen Birkett Fortepianos >Authentic Reproductions of 18th and 19th Century Pianos >464 Winchester Drive >Waterloo, Ontario >Canada N2T 1K5 >tel: 519-885-2228 >email: birketts@wright.aps.uoguelph.ca > > ----------------------------------------------- Susan Kline P.O. Box 1651 Philomath, OR 97370 skline@proaxis.com "I march to a different drummer, whose location, identity, and musical training haven't yet been established." -- Ashleigh Brilliant
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