62cruiserinc
Petty Officer 1st Class
- Joined
- Oct 30, 2009
- Messages
- 287
I am in the process of replacing the wood core in the transom (1984 Larson 19').
After removing the engine and outdrive, I took measurements of the transom thickness at the outdrive cutout. The Mercury outdrive manual says the minimum thickness is 2" and maximum thickness is 2 1/4". It also says that the transom outside and inside skin must be parallel within 1/8" The transom on my boat is 2" thick at the bottom and 1 3/4" thick at the top (at the cutout). This is the factory transom. The variation is in the outer skin fiberglass thickness, it is 1/2" thick at the bottom and 1/4" thick at the top. Then there is 1" of plywood across the whole transom, along with an extra 1/2" of ply in the outdrive section.
The factory appears to have violated Mercury's specs for the transom. I think I should rebuild the transom to the factory specs, making it 2" thick everywhere. This would mean tapering the plywood at the cutout so it is 1/4" thicker at the top. It would seem to be easiest to make the 1/2" additional piece at the outdrive thicker at the top (3/4" at top, 1/2" at the bottom. I have a lot of woodworking tools and I could make a jig to allow me to route an angle on a 3/4" thick piece of ply (aqpproximately 18" x 24"). Is there a better way to do it? Has anyone run into this problem before? Can I make up the extra 1/4" at the top another way (glues, etc)?
Thank You
Steve
After removing the engine and outdrive, I took measurements of the transom thickness at the outdrive cutout. The Mercury outdrive manual says the minimum thickness is 2" and maximum thickness is 2 1/4". It also says that the transom outside and inside skin must be parallel within 1/8" The transom on my boat is 2" thick at the bottom and 1 3/4" thick at the top (at the cutout). This is the factory transom. The variation is in the outer skin fiberglass thickness, it is 1/2" thick at the bottom and 1/4" thick at the top. Then there is 1" of plywood across the whole transom, along with an extra 1/2" of ply in the outdrive section.
The factory appears to have violated Mercury's specs for the transom. I think I should rebuild the transom to the factory specs, making it 2" thick everywhere. This would mean tapering the plywood at the cutout so it is 1/4" thicker at the top. It would seem to be easiest to make the 1/2" additional piece at the outdrive thicker at the top (3/4" at top, 1/2" at the bottom. I have a lot of woodworking tools and I could make a jig to allow me to route an angle on a 3/4" thick piece of ply (aqpproximately 18" x 24"). Is there a better way to do it? Has anyone run into this problem before? Can I make up the extra 1/4" at the top another way (glues, etc)?
Thank You
Steve
