Reinforcing dinghy gunwale

[Gabe Long]

Hello! I’ve got a small dinghy that I use as a tender to my sailboat. The dinghy is lightly built, which is fine for its purpose, but when I’m rowing the gunwales flex so much I’m worried I’ll crack them over time.

I’m guessing the proper fix would be to fully replace the gunwales with more solid wood, but I’m daunted by the idea of getting the old wood separated from the fiberglass (and since it’s just a putter around boat I don’t need it to look perfect). I’m thinking I could glue 3” strips of plywood just under the gunwale to stiffen it. Good idea? Bad idea? Other ideas? Apologies for the bad photo, I’m not currently with the boat. Thanks!

 

[montero]

Hello!
You can use wide strip of glass fiber fabric and just reinforce gunwale by more layers of laminate. Or use strip of foam beneath gunwale and as above . Second way maybe need only one layer of glass.

 

[Gabe Long]

That makes sense, thanks!

 

[fallguy]

You ought to be able to remove the wood from the glass. Then add blocking to the areas and double the thickness of the inwhale, or change the inwhale wood to something better. Or jist screw new inwhale wood to the poorer wood. Some white oak, though heavy it quite stiff.

 

[Tops]

The nice thing about a laminated solution versus bending on a new solid wood strip/wale is less tendency for the new pieces to 'spring' the hull out of its current shape.
One could use 6 c-clamps to a 3x36" piece of plywood under the gunnel centered about the oarlocks and see if the sheer behaves better. If that helps, gluing it will help even more. A little flex might be better than overall too stiff.

 

[Tops]

View attachment 202805

I do like scuppered/slotted gunwales too. I have yet to do one myself, it might happen on the current project...

 

[Gabe Long]

Thanks! Would I need to steam solid wood? One of the things I was attracted to about plywood is that I’m thinking it’s bendy enough to just glue and clamp.

 

[Tops]

Thanks! Would I need to steam solid wood? One of the things I was attracted to about plywood is that I’m thinking it’s bendy enough to just glue and clamp.

My guess is that most likely one would need to steam solid wood.

 

[fallguy]

Thanks! Would I need to steam solid wood? One of the things I was attracted to about plywood is that I’m thinking it’s bendy enough to just glue and clamp.

I think you could try about 1/2” oak and see what it does….bend looks pretty slow to me

 

[kapnD]

Laminating thin strips can form the desired curvature without putting excessive pressures on the hullsides.
Brace the inside with stick braces across the boat where needed.

 

[fallguy]

You could glue two rips of 1/4” white oak with titebond..

 

[gonzo]

A 1x2 of pine will stiffen it enough. The stiffness increases with the cube of the dimension. Twice the thickness is 8 times stiffer.