Transom replacement

[idruthrbfishin]

Just bought a 16' Grumman deep vee. Need to replace transom. Everyone thinks marine plywood is the bomb, but in reality the only difference between that and regular plywood is the marine version uses a higher grade of veneer, (i.e. no voids) and waterproof glue. In the past I have used regular plywood with 2 coats of fiberglass resin. Stuff is harder than a rock and completely impervious to water. Considering 3/4" PVC which is available at Lowes or Home Depot. Also considered good old white oak which would probably outlast me.

 

[DaleH]

Never used marine grade, but just exterior grade ... same wood/glue, just voids aren't filled. I coat out with Raka epoxy (1/3rd to 1/2 the co$t of West Systems, www.raka.com) so no big deal. IMHO PVC will flex far too much for a transom application.

My transom refurbs will outlast me ...

 

[idruthrbfishin]

Never used marine grade, but just exterior grade ... same wood/glue, just voids aren't filled. I coat out with Raka epoxy (1/3rd to 1/2 the co$t of West Systems, www.raka.com) so no big deal. IMHO PVC will flex far too much for a transom application.

My transom refurbs will outlast me ...

Yeah, I was wondering if there would be too much flex in the PVC. How much Raka did you need for a transom? I see a 3 quart kit listed. Did you use the thick, Medium or thin resin? I'm thinking thin would penetrate better.

 

[Wrboz]

I used 2 layers of 3/4 exterior grade plywood, screwed and glued with waterproof titebond, sealed with 3 coats of spar urethane. Looks like new after 5 years.
Not so sure that Trex, etc would be good for a transom. It’s heavy and not very rigid.

 

[whobetter]

If using epoxy, how is the transom secured to the boat? You don't want to put holes in the transom after the epoxy is cured right?

 

[lckstckn2smknbrls]

If using epoxy, how is the transom secured to the boat? You don't want to put holes in the transom after the epoxy is cured right?

Make the bolt holes much bigger than the bolts. Fill the big holes with epoxy, when cured drill the proper size bolt holes.

 

[CedarRiverScooter]

I don't fill the hole full, just use a small brush to put resin into the ID. Messy but works. Wipe off the slobber with acetone.

 

[PATRIOT2]

For what it's worth . . . I just cut pieces of solid oak, from an old bedroom set, to match my old plywood transom and then encased the whole thing in aluminum . . . seems to be working okay with the new heavier 4-stroke. Didn't get carried away with sealing and filling. Took some fiddling but I was able to do it without removing the cast knee-brace. Any rivets I drilled out were well above the waterline. The upper edge of the transom was re-enforced internally with channel from an old big screen TV . . . LOL . . . talk about redneck!

 

[idruthrbfishin]

For what it's worth . . . I just cut pieces of solid oak, from an old bedroom set, to match my old plywood transom and then encased the whole thing in aluminum . . . seems to be working okay with the new heavier 4-stroke. Didn't get carried away with sealing and filling. Took some fiddling but I was able to do it without removing the cast knee-brace. Any rivets I drilled out were well above the waterline. The upper edge of the transom was re-enforced internally with channel from an old big screen TV . . . LOL . . . talk about redneck!

This boat requires a piece of wood 79" long, 24" wide, and 2" thick

 

[zekepa]

Yeah, I was wondering if there would be too much flex in the PVC. How much Raka did you need for a transom? I see a 3 quart kit listed. Did you use the thick, Medium or thin resin? I'm thinking thin would penetrate better.

I bought the 3 quart kit. You will have plenty to do a transom. I put multiple coats on mine built out of 3/4 BCX plywood. Transom was approximately 14 inch tall by 81 inches long. Originally I was only doing the transom since then I've also use to to waterproof a storage compartment lid appx 16x68. Currently doing 2 other lids that are 15x22. I'll still have a little left over after they are done. I went with the thin stuff.

 

[BillPlayfoot]

I used 3/4" Birch plywood. It has no imperfections.
I used West System epoxy and epoxied the two sections together to get the 1 3/4" thickness I needed.
Slid it into a vacuum bag set at 750 psi for 12 hours to cure.
Next I cut it to shape and double coated epoxied the edges.
Slid it into the transom and marked and drilled the holes.
Removed it, drilled the holes slightly oversize and epoxied the holes.
Slid it back into the transom and bolted everything together.
Seam sealed the edges to the splashwell and the job was finished.