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On my post last week I showed the trunk bottom sill replacement I made from a piece of 2″ ash for my ’35. The question was asked if I cut or bent it. I cut the 3 dimensional curves primarily on a bandsaw. The original body wood was pretty much all cut from solid pieces finger jointed and glued together. Often the problem with old finger joints is the wood is fine but the glue joint is loose. If I remember correctly I think they used animal “casein” glues (like titebond) that doesn’t stand up to moisture very well. On my Packard years ago I went overboard and used resorcinol glue such as was used on the “Spruce Goose”. Long after the wood rots away, there will be funny strips of glue left. I am mainly using West epoxies now, they are easier to mix and fill gaps better than resorcinol.
There is a really interesting product out there which apparently can be used like steam bent wood without the steam bending. link: puretimber.com
They supply wood (including ash) that has been treated with some process that saturates the wood leaving it easily bendable into shape at room temperature. It is shipped in sealed bags and as long as it stays sealed in the bag can be stored for weeks or months. It can be cut and pushed into severe curved shapes. Let it sit for a couple of weeks to dry out and it will retain the shape like steam bending. Not practical for a lot of body wood replacement bits but but might work for some. I am thinking of trying it to replace the top bows on my ’35. They are mortise and tenon joints and to replace without disassembling the whole top wood structure you pretty much have to either have splice joints in the replacement bows or cut the top out of the mortise of the side rail wood.
The “bendy wood” provides the interesting possibility of maybe cutting the tenons on each side of the replacement bows and bend them up enough to fit into the mortise and pull them down into position. A 2×4 doug fir cut to the correct curve could be clamped underneath to form the curve for the bows and left to dry out for a couple weeks.
Anyway, has anyone else have experience with the “bendy wood”?
Jim
I’ve used a bendable plywood before, I don’t know if it was called “bendy wood” or not, about 1/8″ thick 3 ply. I made a convertable top bow for a L-29 Cord Cabrolet and worked on a Tourist body that was formed from it. No need to moisten it and it came in large sheets. Jim
Top bows in James ’35 sedan. On our ’29 Club Brougham the top bows while morticed & tenoned together, the mortices are machined with the early version of a “biscuit”” cutter which makes a partial circular slot. This allows the tennoned bow to be installed on a diagonal after the body frame is completed. The bow is then glued & screwed into position. The system is a clever timesaving dodge allowing the main body framing to be completed & the bows can be inserted later. Maybe your ’35 is done differenty.
I have a friend who is in the business of replicating early aircraft, more specifically Wright flyers. They bend a lot of wood, have used steam in the past, but now trying the method of soaking the wood in an ammonia mixture. I don’t know exact details, but it’s a high concentration of ammonia, and after soaking wood in it for a number of hours, the wood is like a workable plastic and bends very easily…
For those of you needing top bows bent, there is a guy in Chambersburg PA, trade name Oak Bows, who steam bends oak bows for various cars. He will work from his patterns or your old material. Neat process. The guy works out of a 20’s vintage dealership with a number of antique cars on the second story. We went in February (that’s winter here, Jak!), and the guy had a dozen or so really nice classics, like a beautiful 20’s Rolls drophead, in an unheated space. He kept a bucket of water next to the radiator to gauge the effect of the cold on the pure water in the radiators. If you are in the area, it is worth a visit.
As I have said before, I am building a new (hopefully) zero energy home here in the DC area. In order to build the house , I had to take down an 80 foot ash tree that was 45 inches in diameter. I saved the main trunk in two pieces, about 25 feet or so. The house is almost finished, and I need to do something with the ash, some oak, and maple trunks I saved. If someone would convince me to have it milled, I will see about making that happen. I was trying to get someone to take it for baseball bats, but that didn’t pan out. I do have pics, but can’t dumb them down sufficiently to get them to load here.
David, any idea on the long term affects of the ammonia on the wood fibers and/or strength?
Thanks, hadn’t thought of the biscuit idea for the mortise and tenon joint, that is pretty straight forward and could work really well. One of those “why I didn’t think of that””? thanks!
The thought of ammonia to soak the wood leaves the worry of whether it will leave a bad smell for a long time in a closed car. That might be the process the company I provided the link to uses (I haven’t yet bought any to try it out).
Jim”
James
Question for the chemists out there
I worked on a couple of airplane seats that they did, had a wooden trim piece that followed the curves of the aluminum seat skin. They used ammonia to make the wood “bendy”. There was no residual ammonia smell, and it was directly against the aluminum with no apparent problem. Anhydrous ammonia evaporates quickly at room temperature, the method they use is to put wood in a closed container with the ammonia, such as a length of PVC pipe.
The real tricky part of doing this is to learn how much to bend the wood. There is always some return to the bends after it dries out completely. One must overbend just the right amount. In 2 decades of messing about with wooden boats I began to get good enough to be ‘close’ sometimes!
Dave
I notice that the photo I posted does not have the “click to enlarge”” feature & so cannot be enlarged. What have I done wrong?”