steaming wood

[blades]

howdy
I am in the process of steaming my inwhales and I had to glue 2 pieces of wood to get a long enough board. I would like to steam the outers in one shot. does anyone have any insight as to wether you can steam over a resin glue joint or will it fall apart on me.
Steve

 

[smallboatshop]

Hi Steve,

Epoxy generally doesn't stand up to the heat generated in a steam box. Usually long rails from shorter length stock are joined away from the ends. This way you can steam just the length that you need to bend and the scarf joint from the two shorter pieces is positioned where it will have less stress than were it on an end curve.
Dan

 

[dboles]

Ive steamed them and the glue usually fails but sometimes you get lucky and it holds, you can usually clamp all on before it does or reglue afterwards.

 

[blades]

have any of you used resorcinol or know if it will hold up to the heat. A friend of mine used to make fly fishing rods and would steam them to straighten them. he only held them over steam he did not put them in a steam tank.
steve

 

[dboles]

Last time I used it in the steambox it failed.

 

[blades]

update

Last night I made a 20 foot steam tube out of 2 inch pvc and inserted my B&D wallpaper steamer in the back end HA! HA!. I only had it tilted about 5 degress it took over an hour to get hot and never got the last 5 feet hot so I was only able to bend one end of my outer gunnels. I think if I tilted it more it would get hot all the way but 20 feet is not the easiest to deal with. I used resorcinol on the outers and had no problem with the glue joint. I also finger jointed the joint to get max. surface. I got a little agressive in the bend and broke 2 feet off of one of them in a cross grain. made another one today and all should be ready by the weekend to try again.


P.S. CLAMPS

This is my first canoe so how many clamps are too many I had about 50 going at one time and my clamp rack was about empty.

Steve

 

[Dan Miller]

Couple of thoughts on your steamer set up. You only need to steam the last few feet of gunwales, so a 5 or 6 foot steam box is plenty long. You probably also need a more robust method of generating steam. You want the steam box to be a minimum 180 degrees F to be effective, and hotter is better.

 

[smallboatshop]

Hi Steve,
You really only need to steam the wood that you're going to bend. A few years back we made a temporary steam box from one sheet of 1' foil backed insulation board and duct tape. 7' long with sides of 10" and top and bottom of 14". One end was closed with a piece of the board and the other left open. To keep the stock from laying on the bottom we inserted 1/2 or 5/8 doweling in the 3 places - 2 pieces going from side to side and two from top to bottom so get a grid like tic-tac-toe. We taped all the seams with duct tape, cut a hole on the middle of the bottom and taped in a tomato paste can with ends removed as a gasket to receive the plastic pipe from the old gas can that sits on the gas burner. The box was but on saw horses. The box is nice and light, easy to move and to store in the rafters. Our temporary box lasted almost ten years.

The lengths of gunwale stock can be taped together with elephant tape and then inserted in the steam box once you have steam. The open end of the box is covered with towels through the whole process to keep the steam heat in. (You have a broken gunwale so you can use this to establish the amount of time necessary to steam your stock.) You have to work very quickly once the gunwales are removed from the steam box so you need to have your mold and wedges and mallet and metal strap ready to go. I usually do this on the floor as it's easy to handle there.
Attached are two views of one method to make a mold. This mold requires no clamps. I have shown it with a piece of old gunwale so you can see how it works. It is wide enough to do a pair together. The wedges are driven in under stove bolts that are inserted as you bend the stock. The first stove bolt is in place when you take the stock from the steam box - you put your metal strap on top of your stock, place the end under the stove bolt and tap in the wedge with your mallet. That holds the mold to the stock. Working quickly you bend your stock and metal band down to the mold and insert the second wedge facing it toward the rear of the mold, then you do the third the same way and you're done. You need only one wedge for each if you measure well ahead of time.(The photo shows two in the middle but this is usually not needed. And the mold in the photo is for gunwales for a war canoe so you have to picture in your mind a larger piece of stock.) On the more radical bends you sometimes need to insert another wedge on the end to force the stock down to the mold.

Now you do the same with the other end of the stock. This is of course more awkward with the mold attacked to the other end but the process is the same.

There are other ways to go and better explanations for the process, but I hope that this helps.

Dan

 

[blades]

Thanks dan & dan
sorry to take so long to respond:
since this is my first canoe and have had nothing other than the instructions that came with the plans. also these instructions were for a different canoe. my knowledge is limited. you have given my some good info.
To let you know I was in a hurry to finish since I am leaving for vacation friday and wanted to take it with me but sorry to say it won't be going.
I am bending the gunnels on the side of the canoe to fit the bend and the twist at one time is this considered a normal practice. when I get back I will try and post some pictures.
Thanks
Steve

 

[Dan Lindberg]

Steve,

If you do decide to steam the full length, put a "tee" in the middle, so there are 2 - 10 ft sections on either end. Run the steam in the bottom of the tee and out the ends of the 10 ft pieces. Cap them but be SURE to drill a small hole in each so you don't build pressure.

When I did this, I used a Coleman camp stove, 2 burner, to provide the steam, I did run out of fuel once or twice though.

Also, the plastic pipe will sag and expand with the temp, so support it, full length is best, every 4-5 ft is doable.

With my strippers, I like to steam or soak the gunwales and then fit them to the canoe, kinda like you describe. I suspect (but don't know) this will only work with low end designs, as it takes a lot of time to get it out of the tube and on the canoe.

For high end canoes, I bend only the last few ft as others have described.

Dan

 

[blades]

does this know make 3 dan's ''ANYWAY''
Dan
how does it make a difference on quality if you bend just the ends or the whole thing??
I ask this because I have at least enough wood for 4-6 more canoes although I may do a nice row boat in there some where. I do want the best look and quality I can get.

I have to say my wallpaper steamer puts out a lot of steam. It got 16 of 20 feet of 2inch pvc very hot in fact the last 4 feet was not mounted and after I finished clamping I turned around and it had bent and twisted at 90 degrees. The idea of a tee in the middle may fix the problem.

I will be on the road at 5:00 am and be gone for a week to 10 days so I may not respond for for about 10 days but thanks for the info.

Steve

 

[blades]

dan
Sorry I just read your post again and I think you were talking about the height of the bow not the quality of the boat.

I am building a 17'6" redbird and it has very high ends and is how I broke 2 outwales but I also have plans for the 15' hiawatha and can re use them
Steve

 

[Dan Miller]

Whether you steam one end or both at a time makes no difference in quality, per se, but remember you've got about 60 seconds once you remove the material from the steam box to make the bend. That can be a handful when dealing with gunwale length material.

I sitll highly recommend putting a thermometer in your steam box. One of those small rapid-read meat thermometers work well. This will help two ways - first it will ensure your steam box is hot enough (it needs to be a minimum of 180 degrees) and second, it will let you know when it is ready to receive stock. There is a lag time between when steam billows from the box and when it is really ready to receive your stock.

 

[Dan Lindberg]

)

Yes, high end dimensionally, not quality.

And for the Redbird, I'd only bend the ends, I think it would take too much time to get a piece out of a full length tube. I'd also only bend one end at a time.

If the canoe is very narrow at the ends, and the gunwales have to be bent in also, (ie, a reverse bend at the end) I sometimes add "control" blocks on the form so the I can add that bend also, (ie, making the path of the gunwale move across the form in addition to over the form) this bends the gunwales in 2 directions at the same time.

As for bending the whole gunwale, when I install gunwales, I try to have them bent, prefitted (and farnished) such that they are not under any/little stress when installed. That's why I'll either soak or steam the whole gunwale. If there is a lot of curve at the ends, I'll steam the ends and get that bend in, and then soak (or steam) the rest so it fits the canoe shear without a lot of stress. This takes a lot longer but then for me playing with canoe is just a hobby, and when I finish one isn't too important.

Dan

 

[Dave Wermuth]

Hi Blades

"I am bending the gunnels on the side of the canoe to fit the bend and the twist at one time is this considered a normal practice"

Not sure if it's 'normal' but I've seen it done. A long sock is made of plastic sheet and duct tape and steam goes in one end and out the other. The ends are worked on as they soften.

I pre-bend mine on a jig after soaking in the pond for a few days and boiling the last six feet in the boiling tank. I don't have a steam box. I've not had any sharply bending high stem canoes to do---yet.