Boat Forum / Building / December 2007

Only a note that wood is usually softened with steam in order to bend
it. That way the wood doesn't absorb a lot of water. There are books.
There is this magazine, Wooden Boat, that is devoted to that kind of
thing. I do prefer aluminum myself, as a boat building material. It is
easy to drill and rivet, and doesn't need paint. Maybe antifouling
bottom paint, but it doesn't need to be protected from sea water.

Casady

Clear mahogany can be bent nicely with steam. Be careful not to
oversteam or it will tear, under, it will split out. I trust you are
talking about real mahogany and not that crap they sell for decking.
Anyway, as to soaking first I suppose you can however, if you steam it
properly you should not have to. Any water that does soak into the
wood only serves to help move heat through the part, as heat is what
makes the wood cell walls soft, not moisture or steam. Steam just
serves to carry the heat as it were.  Anyway, proper steam application
should make it so you don't need to presoak, at the same time, I see
no problem with it either, just extra steps...

I would try a test piece first, but 15 min per 1/4" is a good starting
point iirc, hopefully someone will correct me if I am wrong on that
one.

Later, good luck, post pics. I will see if I can dig up some pics of
my turkey frier steamer, I have several size steamboxes I can hook up
to it.

get one of those steam wallpaper removers (not expensive) and hook the hose up
to a fitting on your "TUBE" and covert it to a steam chamber. There are plenty
of online hobby sites that describe steam bending, and some things to be aware
of. It's not that hard to do. The biggest problem is that excessive steaming or
soaking permanently weakens the wood.

I have used castoff aluminium guttering to heat / steam wood. By
folding the ends up just so to retain the water and using two pieces,
one as a lid, sitting on a couple of camp stoves, I was able to boil
teak.  Then I found out that teak does not benefit from steaming.
Still, the method was satisfactory in principal.

Terry K

My first question to you is what specie of mahogany are you trying to bend?
When we build the 17' runabout we needed to make the 1/2" African Mahogany
planks more supple where we had to roll around the barrelback of the hull.
I used a 30Ga garbage can with a drain valve in the bottom to make it easier
to drain.  I wrapped the can with some close cell neoprene for insulation
and cut a flap door in the top.  we filled the can with 180 degree water,
placed the end we needed to bend into the water, wrapped a towel around two
feet above the can, wrapped plastic around that with the bottom of the
plastic tucked into the can so water would return to the can and used a
quart container to take hot water and pour it down the upper section of the
plank.  All you need is about fifteen to twenty minutes in the soak.  Have
all your clamps staged and ready. We used the towel to wrap the plank in
transit to the hull to maintain temperature as best as possible.  After you
have clamped it in place use a heavy duty heat gun, such as you would use to
strip pain, and apply heat to both side of the plank for about ten minutes.
This not only dry the wood but helps set the bend/twist needed.  We left the
boards clamped for twenty-four hours the sanded the inside to remove the
raised grain, completed the fitting of the plank and installed it. We also
used this method in a 4" PVC pipe to bend the shear clamp.

My experiance, hope this helps.

Tom