What epoxy to use for jon boat transom?

[presta24]

I am replacing the transom on my jon boat. Plan on getting 3/4in ply and coating it with epoxy. What epoxy should I use? Do I epoxy the ply to the boat? Or just use the bolts to hold it together?

 

[ondarvr]

Just about any of them will work, don't bond it to the transom with epoxy.

 

[Woodonglass]

Epoxy IS the absolute Best sealer for your transom wood. And it is the most expensive method. If you use it you want to use marine grade epoxy like this. U S C O M P O S I T E S

HARDENER>> Epoxy with 3:1 Ratio Medium Epoxy Hardener (Description) Kit Cat No. Resin Amount Hardener Amount Kit Price (includes both parts) EPOX-635311 16oz 5.3oz $15.75 EPOX-635312 Quart 10.6oz $23.95 EPOX-635313 1/2 Gal 21.3oz $39.75 EPOX-635314 Gallon 42.6oz $71.00

An alternative method is to coat and seal your plywood with this...

The Key to ALL transoms is the care and maintenance after installation. ALWAYS pre-drill and precoat ALL screws/bolts with sealant. This will prevent anywater from getting to the inner layers of wood and starting the rotting process.

 

[presta24]

Epoxy IS the absolute Best sealer for your transom wood. And it is the most expensive method. If you use it you want to use marine grade epoxy like this. U S C O M P O S I T E S

HARDENER>> Epoxy with 3:1 Ratio Medium Epoxy Hardener (Description) Kit Cat No. Resin Amount Hardener Amount Kit Price (includes both parts) EPOX-635311 16oz 5.3oz $15.75 EPOX-635312 Quart 10.6oz $23.95 EPOX-635313 1/2 Gal 21.3oz $39.75 EPOX-635314 Gallon 42.6oz $71.00

An alternative method is to coat and seal your plywood with this...

The Key to ALL transoms is the care and maintenance after installation. ALWAYS pre-drill and precoat ALL screws/bolts with sealant. This will prevent anywater from getting to the inner layers of wood and starting the rotting process.

thanks man, how much will a qt cover? My transom is pretty small. Also, what is the best pre drill method?

 

[Woodonglass]

If you're using screws use a bit that's a little smaller than the screw shank size then use some 5 minute epoxy and a tooth pick to poke some epoxy into the hole and then coat the screw with the epoxy before screwing it home. If using a bolt,say 1/4" then drill the hole 1/2" then mix up some epoxy and thicken it with fine saw dust so it's like Peanut butter and then entirely fill the hole back up. Once it hardens totally redrill the 1/4" hole. that way the hole is entirely surrounded by epoxy and if it leaks water can Never get to the wood. 1 quart , 2 quart, 1 quart of each of the chemicals will treat a full sheet of 3/4" plywood.

 

[presta24]

Here are some pics of the project. I have the new one built and one side coated. Can I paint it once its done?

 

[Woodonglass]

Hmmm, I see you used OSB Chipboard to fabricate your transom. That would not have been my first choice in wood. It's not very stable and if any water happens to get to the inner core it will quickly swell and start to delaminate. What did you do to seal it? I see some Polyurethane varnish in the background is that ALL you used? if so, I fear that will not be adequate. If you mixed up the Old timers recipe and really soaked the wood especially the edges then you'll need to let it dry for 2-3 days and then give it a coat or 2 of full strength Poly. After that dries for a couple of days you can then paint it with 2-3 coats of Oil Based Rustoleum Paint. That should make it last a while but again you must maintain and care for it very well especially if you drill any holes.

 

[presta24]

I used the old timers mix and applied it very liberally. Being sure to pay special attention to the edges. What wood would have been your choice? I kept seeing that a lot of people were using exterior ply. That's why its what I chose.

 

[Woodonglass]

OSB is rated for Exterior use but It's not Plywood. There's a significant difference. I would use regular Ext. Grade Plywood, preferably made from Douglas Fir. Or you can ask for Underlayment Plywood. It also uses 100% waterproof glue in it's laminations. With the OT sealant and Several Coats of Paint IF you do a good job of maintenance and care and then keep the transom and boat covered when not in use, this setup will still last a LOT of years. But you MUST ensure to check it all the time and seal any cracks and crevices that might develop over time.

I did a test with the OSB and the Old Timers just to proove it's worthiness to some of the iBoats skeptics!!! I took a 12"x12" piece and coated with the the OT forumula ( I did NOT put on multiple coats and I did NOT do a final coat with fulll strength Poly and I did NOT Paint it) and then nailed it to the west side of my house. This side gets the most abuse from the Oklahoma weather. Really HOT HUMID Sun, Rain, Snow Sleet You name it...It gets it!!! Left it there for about 8 months. When I took it down it had some VERY SLIGHT swelling starting to form around the top edge and that was all. I feel very confident that if I had given it the Full Treatment and followed up with Paint. After 8 months of full exposure to the elements it would have looked like new.

Having said this, I STILL recommend the use of Regular Ext. Grade Plywood for Strength and durability purposes.

 

[ondarvr]

OSB has very little strength and even the supposedly water resistant stuff sucks up water and turns to pulp much quicker than plywood. If it were me I would start over with plywood.

 

[presta24]

Ya, I see the difference now. Ill spend the $10 and start over

 

[jbcurt00]

Great plan.

And now you've got great looking, sealed OSB patterns

 

[presta24]

picked up a piece of ply tonight. Sucks, I was hoping to have have it ready to paint this weekend.

 

[presta24]

So I used the 3M 5200 marine sealant on everything. That was Sat afternoon/evening. It hasn't been the warmest here, but the boat is in my garage. The sealant is still wet to the touch. Is that normal?

 

[Woodonglass]

What exactly do you mean you used it on everything???

 

[presta24]

What exactly do you mean you used it on everything???

all the bolts

 

[presta24]

I did just read online that it takes 5-7 days to cure

 

[jbcurt00]

I did just read online that it takes 5-7 days to cure

Yep.

Cool temps arent helping. Got any work lights you can setup near enough to warm the transom and 5200? Not too close, those halogen bulbs get HOT