How to reinforce a seat?

[Brian J Knudsen]

Hello,

I have a mahogany seat from a 1922 Ideal that needs some help. I am looking for suggestions for how to strengthen the area around where the screw hole is on the underside of the seat. I'm not confident enough to scarf anything onto/into it. Is there a way to add an epoxy or glue that would add strength?

Thank you,
Brian

 

[Nick Dennis]

It should be easy enough to cut a wedge out, plant and glue and then shape a new section and then drill through. The inwale and nut/bolt/washer will all act together in clamping it. On the underside it will be out of sight and out of mind and can easily be matched in.

Nick

 

[Brian J Knudsen]

Thank you Nick,

I am not an experienced wood worker but perhaps this is something I can do. Help me visualize the wedge. Wedge makes me think of a triangle but the shape of the wood I think would best go into this slot I think would be a trapezoid. Also, what suggestions do you have for how to remove wood around the hole? Chisel? Dremmel?

Thank you,
Brian

 

[Fitz]

I drill an oversized hole and fill it with a plug of mahogany cut with a plug cutter. Epoxy the plug in. Drill a new hole for the seat hanger.

 

[dogbrain]

You could probably get away with trying to scrape/carve away all the soft wood and filling the area with thickened epoxy, but epoxy by itself won't flex as well and may break over time, especially on a seat. You may want to try something like this, then scrape or carve away any remaining rot and fill with thickened epoxy. I used thickened epoxy for these repairs since I couldn't get the plugs to fit perfectly. Everything is completely hidden under the inwales.

Mark

 

[Brian J Knudsen]

Thank you all for your replies.

Mark - your picture, is what I envisioned. I have a few questions. Are those thwarts? Do the lighter-colored pieces of wood go all the way through your thwart? I imagine they do not, because you wrote that they are completely covered. What wood would you recommend? my seats are mahogany, but if it is not visible, could I use white oak, cherry, or ash? I have these woods, but I don't have mahogany. I could get it, but if it is not seen... Also, what epoxy did you use? I have lots of 2 ton Devcon. How and why do you thicken epoxy?


Fitz - thank you. I don't have a plug cutter, but that looks like a fun tool.

Thank you,
Brian

 

[dogbrain]

Brian, those are thwarts and the repairs do go all the way through. The new wood is covered by the inwale because it's underneath. With a seat you'll have less wiggle room for the repairs to be hidden beneath the seat drops, although part of the rear seat in some Old Towns is mounted directly to the inwale. If you're certain the repair will be hidden, then any of the woods you mentioned will work. If the repair will show I would use the cherry since it would be closest depending on how dark it is. You can stain the wood to darken it. I use Raka epoxy made for laminating, but I imagine any epoxy will work for such a small repair. Thickening the epoxy is to eliminate any gaps, but if you're good at the shaping you may not need it. Use sawdust from the cherry to thicken it to a consistency of peanut butter.

Hope that helps, Mark

 

[samb]

Difficult to explain but . . .
If you cut a wedge shape to use as your plug as Nick suggested, you can cut the thwart so the bottom view would be what Mark shows and there is a rectangle seen on the thwart end and no cut at all on the topside, sort of cutting a slope out from the bottom. Don't know if you can picture that?

I know what I mean!

Sam

 

[dogbrain]

I like Nicks/Sam's idea better than mine for your seats.

Mark

 

[Dave Osborn]

I would use a belt sander to grind an angle on the bottom side deep enough to get down to good wood. Then cut a mahogany wedge(triangle) to match what is ground away.
Then use epoxy to adhere it. It will be on the bottom. You’ll never see it.
If your wedge is a little off, no problem. Just sand it to fit after the epoxy is cured.

 

[Michael Grace]

Hi Brian,

It sounds like you are very new to woodworking, and that’s OK. Be careful though because you could easily become an addict to both canoes and woodworking. Many people here will tell you that wooden canoes are highly addictive.

Speaking of many people, you surely have some WCHA members around you and any number of them might be willing to lend a hand and give away some woodworking knowledge. If you and I were geographically closer, you could certainly come over to my shop and we would do this together so that you could see the tools and the process. That said, if you do it yourself, the comments here show that there are multiple ways to do most things. The short of it is, just find a way to carve out the all bad stuff as neatly as possible and use whatever method needed or available to fit and glue new wood in place. Wood is forgiving and if you don’t get something the way you want it on the first try you, just try again.

An internet search for woodworking clubs in your area is another way to find help. Groups like that also have lots of scraps so you’ll likely find the kinds of wood you may be looking for. Another good source for scraps would be a local cabinet shop.

I hope this helps,
Michael

 

[Greg Nolan]

Brian -- check your "conversation" messages. I have some experience with repairing one of the seats on our 1922 Ideal (a somewhat different problem), and have some leftover scraps of mahogany which you might find useful, and I'm not far away (Brooklyn, NY).

 

[Fitz]

I should have mentioned that I save old broken mahogany thwarts and seats to cut the plugs from. You can also match the grain to some degree since the plug cuts across the grain unlike the end grain in a dowel. I use thickened epoxy for glue.

 

[Craig Johnson]

Here are a couple of photos of what some are describing.

 

[Brian J Knudsen]

Wow, Thanks, folks! Lots of good information. I appreciate it. I'll get some pictures up when the project is complete. I think the wedge makes the most sense to me.

If I cut out a wedge, should the depth of the wedge ratio to length down the piece of wood be 1:8? Just like an inwale scarf?
Dave - I'm trying to envision how I would use my belt sander to make the wedge opening. Perhaps just using the side of the belt at the angle I want.
Craig - nice work on those thwarts!

Thank you,
Brian

 

[Dave Osborn]

Using a hand held belt sander just put the flat spot over the hole ant an angle and grind away.
If you have a bench to belt sander just grind a angle over the hole...

 

[crosscuts]

If flex and a weak member is the problem a long dado can be cut and a spline be inserted to stiffen up the part.

R.C.