What plywood is used for a transom?

[wire2]

As I prepared to fill the OMC boot hole with 3 layers of 5/8" fir plywood, I poked at the existing plywood with a screwdriver. It's partly rotten around where the screws held the boot on before. Now, I'm thinking the proper fix is to remove all the plywood and put in new.

I'm hearing conflicting advice on good-2-sides fir, or "marine" plywood, supposedly with epoxy between the layers.

Is there such a thing? What should I be using for a proper job?

On a positive note, this makes my vertical X line being off 3/16" a moot point.

 

[Don S]

Re: What plywood is used for a transom?

Moving to the Boat Restoration & Building forum

 

[redfury]

Re: What plywood is used for a transom?

Seacast...that's the way to go, and probably the easiest and most permanent solution.

Otherwise Marine grade plywood is the only way to go to avoid voids in the layers of ply.

Interestingly, my 75 glastron had a plywood transom made entirely out of redwood. After 32 years, the only hint of real rot was down at the very bottom of the transom, but the bottom 3rd was saturated with water.

 

[alloffroad]

Re: What plywood is used for a transom?

My '58 Dorsett Had A Layer Of Ceder And 2 Layers Of Regular Ply. It Was Glassed To The Hull On The Sides And Was Never Coated With Resin. I Am In The Process Of Replacing It With Regular Plywood That I Will Coat In Epoxy Resin After Adhearing The Layers Together With 1 Layer Of 3 Oz Mat And Epoxy Resin. It Should Hold For A Long Time.

 

[wire2]

Re: What plywood is used for a transom?

Where can I get "Seacast"? Is it like a 2 part urethane?

I've also been asking around for epoxy resin, have found only polyester resin so far.

Interesting that you're re doing a '75 V179, I bought one new in '74, traded it on an SX190 in '84, still have it. Am currently changing OMC stringer to alpha gen 2.

 

[wire2]

Re: What plywood is used for a transom?

I found the site, this looks like really permanent stuff!

http://transomrepair.com/zk/fullrepair.shtml

Thanks for the replies, guys.

 

[jspringator]

Re: What plywood is used for a transom?

If you could get it dry, this stuff is a little less radical.

http://www.rotdoctor.com/

 

[wire2]

Re: What plywood is used for a transom?

Thanks, but just today removed the last of the plywood. Took about 3 hours.

All below the waterline was very deteriorated. It looks like water was seeping in almost all the OMC boot screw holes.

Even the factory installed ladder fittings, which had a block of wood inside the ?" fibreglass to hold the screws, the wood was as soft as tissue paper from rot.

I'll be removing the ladder and sealing the holes. Skiers will have to step on the drive cavitation plate to climb back in the boat.