Ouch.  It is marine plywood which isn't supposed to delaminate under severe conditions. Forget heat, unlike epoxy the glue used to laminate marine ply doesn't let go under heat until the wood roasts.

Usual solution is cut out scarf and rescarf. The time for perfectionism is while planing/sanding the scarf bevel - get it right, get it square, and test the scarf fit before slobbering glue on it.

B&B Rare Woods sells mahogany veneers that might match.

http://www.wood-veneers.com/

Or you can just accept the dark area. You'll be the only one who notices, everyone else will be too busy asking if that's a wooden boat, did you build it yourself, how long did it take, how much did it cost, how much does it weigh, etc.

Hokey's right, the best fix is to get the scarf right in the first place so you don't have to do the sanding. A butt joint could give you trouble if the boat's not designed for one and it's just as easy to mess up as a scarf.

Good luck however you go, and remember, it'll be a real fun boat no matter what.

Laszlo

NHbuilder,  I think you will NEVER find veneer to match so forget that.. I suggest cutting the scarf apart, turning the pieces end for end and CARFULLY re-scarf. This will leave the oversanded end or ends at the bow or stern of the panels where, with creative placement of the patterns, they may not be a problem. This assumes that the newly scarfed panles will be long enough. Measure it up and give this a shot. SEEYA Jack

At the CLC demo on Monday at Lake Natoms someone brought a boat where they used veneer to cover the joints. They did not try to match but used a wide contrasting stripe, at angles, to cover the joints. It looked very nice. I wish I had a photo or that the owner would post photos.

 Ralph

I wasn't happy with my scarfs so I covered them with something I found at Rockler called Traditional Inlay Banding.

http://www.rockler.com/product.cfm?page=1229&filter=Traditional%20Inlay%20Banding

If I had to do it again, I would have sanded the banding as thin as possible. It is about 1/20th of an inch thick, so I put extra layers of fiberglass tape on either side of the banding to make a smooth transition from the okume to the raised banding. One side of the boat came out fine, but on the other side, you can see the extra layers of cloth when you look at the side of the hull from an angle. I'm not sure what happened to cause this. If I had sanded the banding to be as thin as possible, I probably could have skipped the extra cloth.

Mark