Flat bottom warping and bowing up?

[C_Brice]

Hello everyone. It's been a long, busy winter and spring but I'm finally gearing up for boat building season. Last year I started on Matt's Iroquois plans, got the shell put together and installed filets but I have not taped or fiberglassed any of the seems. Then I ran out of time.

Today I went out and set up a solid level frame to set the canoe on while I worked. After setting the canoe on the frame I noticed that the flat bottom had warped up. At the center with the taped butt joints it is dead nuts flat. When the bottom goes towards the stern it starts to bow up about a 1/4". Go towards the bow and it warps up about 1/2" and runs all the way till it gets about 1 ft. away from the tip. Hard to see with the naked eye as it sits now but I'm worried about the looks on a finished boat.

Here is my options as I see them:

1) Don't worry about the warped bottom and finish the boat.
2) Scrap the shell and start from scratch. Only materials I would be out is the epoxy and wood flour for the filets and the plywood.
3) Make a center cut in the bottom all the way from bow to stern and "reform" the bottom panel. This option may be harder and and more time consuming that staring over.
4) Try to force out the warps with screws and wood blocking, tape and fiber glass the canoe and hope that the don't reappear when I remove the screws and blocks.
5) Install ribs. I really don't want too because the areas that need them most are right where I'd like have my feet and knees if I kneel in the boat.
6) Have you master builders come up with a great idea to help me out!!!!

CB

 

[JEM]

have you tack welded anything together yet?

A picture would be useful.

 

[C_Brice]

Hello again Matt. Yep, everything is all welded together. As a matter of fact, I did all the filets last year. I never taped them though. Sorry, but the camera stinks and I wouldn't be able to show much with a pic anyway. To discribe it better, if you hold a level perpendicular to the center axis of the canoe and under the bottom side, the level rest on the edges and there is a gap in the center. Kinda a reverse round bottom.

The other option I have come up with may be the best. I'm thinkin of cutting the bottom of the boat up. I could make a cut about 1/2" up the sides above the filets and remove the bottom. Then I could use the old bottom as a template for a new bottom. However, this option will lower the profile of the canoe about 1/4-1/2" and add about 1/2-1" to the width of the bottom.

??????

CB

 

[JEM]

If it's filleted and you have that warp, I think you might be better off starting over.

It seems that by the time you fight with it to get it straight, you could have started fresh.

You could also cut the seams loose and try re-tacking and the filleting them. But again, by the time you fuss with all that...

 

[Wimperdink]

3) Make a center cut in the bottom all the way from bow to stern and "reform" the bottom panel. This option may be harder and and more time consuming that staring over.
4) Try to force out the warps with screws and wood blocking, tape and fiber glass the canoe and hope that the don't reappear when I remove the screws and blocks.

I like the idea of doing both of these together. I would at least try something so your not completely throwing it away.

Cut 3/4 of the way through the ply along the center bottom of the outside of the boat... then bend it down with bracing blocks from theinside, fill the cuts with dookie schmootz and glass it. At worst you still have to start over. (same position your in now) At best you have fixed the boat and can continue and can give advice to others in this same situation.

Just my 2 cents

 

[C_Brice]

I agree Matt. By the time I do anything to the existing shell I could have a new hull ready for tape and fiberglass. I think I'll just start over. I'll also keep the old shell around and may finish it anyway. No sense throwing it away just because of some warping.

BTW Matt, the shape and size of the Iroquois is exactly what I wanted. It will make a dang nice looking canoe. I'll get a good camera and take some good action photos this summer for ya. Thanks for your help.

Chris

 

[Scooter]

Was it like mine? Used some oak bracing and took the bow out easier than I though it would. Won't be walking around in a 15 ft pirogue, so figured I could live with the extra bracing on the floor.

 

[C_Brice]

As a matter of fact Scooter the bottom of my boat looks just like that. As a matter of fact, I saw your post of in the pirogue section last night while looking around. Your solutions definetly gives me options but I would more than likely need to put in 5 braces since my canoe doesn't have any ribs. I'm gonna keep the original shell around awhile and may end up doing what you did.

BTW Scooter, dang fine pirogue. Saw your pics on the boat bragging board. So whats your next project? :shock:

We all no these things are too dang addicting!!!

CB

 

[Kayak Jack]

If all else fails, make this one into a vertical book case, and build another one