I'd approach this like the common bowed up bridge on a steel-string acoustic guitar. So, first I'd separate those two pieces. Then use steam to straighten them out and re-glue them back together under pressure. The glue joint will keep them straight if you do it right.
I've never tried this, but I think you can use a microwave as a steamer. I saw a video of someone doing that on youtube the other day. If you steamed it, and then clamped it to a flat board (perhaps with a milimeter of shim on either side to give it a little extra curve for "springback") you might have a pretty good shot at straightening it.
Also, if you steam the glue seperating the parts, you might end up with three less crooked parts. Straighten each one and then glue them back together flat. You might have some success that way.
Good luck
Paul
Steaming has its risks, besides glue ... you might raise serious tannin stains unless the wood was ammonia-fumed long ago (don't try that at home, folks).
Remove the finish, steam it, clamp it overbent slightly (something like a penny under each corner with the clamp in the center). I would not put it in the oven. Just let it sit clamped for a week or so while you work on other parts of the camera. Should be fine.
Hi Ian,
I am no woodworker but I would say it was due to incorrect craftsmanship at the build time.
Gluing 2 different thicknesses of different woods with a strong continuous glue joint (I presume hide glue ?) could hardly be expected not to warp, and maybe this started early in the life of the camera. From the photo the thick piece on the bellows side has shrunk slightly more than the front piece as it all dried.
I have an interesting book " "The New Science of strong materials" by J.E Gordon writing about his experiences in design of wooden aircraft and boats up to WW2
Quote " Wood is not a material which suffers fools gladly.."
According to him, Casein glues, ancient but re-introduced in 1930's were better at gluing wood because they were weaker when damp and could shear to reduce stresses somewhat.
I just looked at some old 1920's furniture here, they knew where to glue and where to leave different pieces unglued and free to move.
The results are "creaky" but less warping.
If I can't fix this piece I'll either make a new one myself or failing that I'd use a local cabinet maker. I prefer to keep everything close to home and the costs to a minimum.Originally Posted by Alan Curtis
I'd already decided to strip the shellac and paint and steam the part (post #16 of this thread) and that seems to be the general consensus of other posters opinions.
Steven Tribe's comments about the wood grain made me look closely at the piece and unusually it's one solid bit of wood, the two guides for the lens board are inconsequential, on other vintage wood/brass British cameras I own the part is composite from a fiew parts glued and screwed together.. The warp on this follows the grain, it may have been caused buy someone using water to remove adhesive where the bellows attach as there's evidence of some sort of repair or re-glueing.
Ian
I hadn't intended to start on this camera so quickly but I've now straightend the part. I guess starting this thread and getting so many replies made it a challenge
Surpringly it didn't need steaming, I had to soak it in hot water to remove the residual glue from the bellows and soften the glue used to hold the two lens board guides, I'd already removed the screws. I then rubbed it down to remove the french polish/shellac varnish and black paint on the back. The small parts aren't thick and had bent with the warp but returned to flat once removed.
The main piece was warmed in the oven (after a good soaking) at about 75°C and resoaked in hot water then pressed gently in a reverse curve to the warp, this was enough to straighten the panel after a few cycles, and it stayed flat when I dried it in the oven. I've stabilised the wood so it shouldn't warp again and looking at the end of the bellows I removed it confirms that the warping probably took place because of a repair as I'd thought. The hole in the centre of the panel is cut accross the wood gain and rough finished and the area highly was porous so any water used to remove glue would have been drawn in and it's like sponge when wet.
So the piece is re-assembled and finished.
Ian
Well done!
My wife is a willow work artisan (sounds better than basket maker!) and we have a very large zink container for softening the basic material. I have tried to convince her to try steam treatment rather than cold water (better when its -10 deg. C outside), but with no success.
The traditionalists won't like my proposed solution, but if this was mine, I would look into machining some of the wood away and inserting a machined aluminium (not aluminum) piece to hold it straight. Hopefully it could be inserted from the rear and hidden with a veneer of matching wood.
Might be easier to just make a new one though.
EDIT: However. If I bothered to read to the end of this thread I would have realised that neither method was now necessary!
Steve.
A minor tip - remove the wood front and to separate the glued parts, microwave for about a minute. It will all pull apart with no effort. Then decide whether you wish to remake or straighten via steaming and flattening.
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