Stem bending advice needed

[fisherguytoo]

:shock: :roll: :oops: I am ready to bend my stems on the Prospector-ranger that I
am building. The idea comes to me that I have read that the heat gun can be used for
this purpose. I have the heat gun and using it would be a lot simpler then putting
together the steam set-up. This is my first canoe project and I need the advice of people that have bent the stems both ways or had success using the heat gun.

Am I about to goof up a lot of work or is this a good idea ?????(using the heat gun).

Thanks in advance. fisherguytoo in Nor. CA.

[lkiffner]

Hi!

I used the steam method and had very satisfactory results. I bought an inexpensive electric tea kettle and a 5 foot length of schedule 40 pvc (4" diameter). I followed the directions in Ted Moores book. Really quite simple. Plus, I worked alone and had no problems at all. Sorry, I've not heard too much about the heat gun method. But, as a 1st timer like you, I went with the given procedure by Ted.

Good Luck!

[KARKAUAI]

Aloha, FG2,
I first steam bent my stems, screwed them up enough that I redid them with the heat gun...MUCH easier and quicker. Next time I'll use 1/8" laminations and bend without steam OR heatgun.

[IslandStripper]

Only done it once so far, but we bend ash for a ranger last year with a real cheap set up. scrap plywood for a box, a $3 kettle from the trift store, 15 min in the box (i think) bend real well.

I would think that moist air would have to make the wood more flexible than just plain heat, but I'm not an expert in the impact on wood moisture and temperature regimes on a woods modulous of elastity or bending strength.

Later

Dave

[Juneaudave]

I think you can probably do it either way... but I personnaly found building a cheap steam box and bending my stems per Canoecraft to be a lot of fun...and following the instructions gave me some confidence. I use a teakettle on a Coleman stove as a heat source and a beat up piece of metal downspout from a gutter as my pipe. If I was to use the heat gun, I would get some moisture into the wood first. My experience using a heat gun to bend wood and relieve stresses on strips has been so so because I always seem to scorch the wood (and burn the edges on the strips!)

[Glen Smith]

I have used both steam and a hot-air gun for bending stem laminations. The hot air worked fine with 1/8" strips but I use steam with 1/4" strips. I use a piece of abs pipe and an old kettle that doesn't turn itself off once the water boils.

[Steve Lansdowne]

Seems to me that steam heats up the entire piece of wood at once, whereas a heat gun would not do this all at the same time. I'd be surprised if it worked, but I've had no experience with this. I laminated my stems around a jig and didn't worry about using heat or stem, as they bent OK without heat.

[Bill from Louisiana]

I didn't use the hot air gun, but I am sure it will work just fine. I used a hot iron, the kind model airplane builders use, although a regular iron will surely work. I soaked my 1/4" thick stem material in the bath tub for about 30 minutes. I then clamped the stem material to the top of the stem mold, appliied the iron, and slowly bent the stem around the mold, clamping with "C" clamps as I went along.
I do not know what material you will be using, but I used white pine, which was available. I also used this method to bend 1/4" walnut for a cap over the outer stem instead of a metal band. I think you will find you can do a very good job with the hot air gun. Good luck

[patrick pfeifer]

we steam bent our stems using a funnel, metal bucket, and a peice of 3 inch PVC pipe. We filled the bucket up about 2/3 full and put the funnel upside down on top of it, using a few wet sponges to seal the joint, and then put the pipe on top of this with the funnel spout going into it, sealed this joint with sponges, hung the strips inside of the pipe, used a glove to seal off the top, and set the whole thing on top of the grill with a meat thermometer inside to check how hot it got. since our grill is not inside of our garage, we just removed the PVC pipe, keeping it straight up so we didnt loose any steam or heat, and carried it into the garage to bend. It worked great, we had more than enough time to bend it and clamp it.

[KARKAUAI]

Aloha, all,

When I first bent my stems using a home-built steamer, I left them clamped for 36hours after gluing up with MAS slow epoxy, they sprung back way to much to use. With the heat gun and 1/4 inch strips, they sprung back only a little and were usable. I remember reading recently on another thread that moisture in the wood can affect the epoxy bond. What about steaming them using thickened epoxy to glue up the stems? Seems like a lot of moisture in the wood.
When I glued up my iako (the double ama setup uses 11 ft. iako) I used 1/4" thick laminates and bent without using steam or heat gun. There was NO springback.

Guess I just don't quite get it yet.

[Erik, Belgium]

Here 's my two Eurocents

steaming:
Ideal for thicker strips, like Glen said from 1/4" upwards. Reackon 1 hour per inch of wood thickness. Leave enough room for the air to flow through the steambox (don't cover it up completely). Most sort of wood can be bent this way. Don't burn yourself.

Heatgun:
Does the job for thinner strips (1/8"). Soak the wood in water for at least an hour, and then slowly heat up while dispersing the hot air (don't keep it on the same spot too long) and steadily bending the area more and more. You 'll notice the moisture 'boil' in the wood, that's the moment to bend the wood.

Tip
Always have the bent wood tied up in the correct form for a long enough period (some days). Also let it dry out completely before gluing the pieces together with either epoxy or 1 component PU glue (works just as fine as epoxy for this purpose). While drying, you should overbend the strips just a little 'cause they 'll spring back a little. Once the strips have been glued, there will be no springback anymore.

Erik

[John Michne]

See my web site, http://michneboat.com, click on builder’s Corner, and then select Making Stems. I use 1/8” spruce laminations for stems and can almost tie knots in it with a heat gun. They can be glued as soon as they cool – a few minutes. No drying time required.

- John

[Pete in the Deep South]

Once you get setup for steam bending, it's an easy process. I use a discarded helium balloon tank with my fish fry cooker...works great!

[Bernie in Illinois]

Don't be intimidated by steam bending, it sounds worse than it is. As already pointed out, it only takes a tube or box and a steaming pot or kettle. The heat gun idea is ok on short and thin stock but poor for something like a stem. If you soak 1/4" ash strips in warm water overnight, you can almost bend them without any heat. Again, be sure to leave the stem on the form for several days, and tie the ends together to prevent any spreading when off the form. Although not mendatory, it will be easier for you to have a friend do the clamping while you do the bending.

[shawnwaite]

Personally I liked steaming...

pvc, kettle, hot plate...

about the funnest part of the whole project!

Serious side.

S.