How much does it really take?

[rebars1]

I am restoring a 1959 14' Wizard runabout. I getting ready to install a new transom using two layers 3/4" marine grade plywood against the original outer shell. Each surface is about 6.75 sq.ft. of area. How much epoxy resin should I mix for each layer?<br /><br />Layer 1: Plywood against outer shell. Pre-soak plywood with thin resin then use thickened resin to bond to shell. Can I thicken the same batch I used to pre-soak or should I mix a separate batch?<br /><br />Layer 2: Plywood to plywood. Presoak both surfaces then bond using thickened resin and clamp with screws.<br /><br />Layer 3. Fiberglass inner (boat side) face on second plywood layer, with extra glass at bottom and sides.<br /><br />I held the wood about 1/4" in from the sides of the boat shell. Should I pack the gap with fiberglass and resin or just thickended resin?<br /><br />Finally, is this a small enough transom that I can install the layers in one event, or will the resin go off too fast?

 

[STAGE3]

Re: How much does it really take?

I went through 3 cans for my project. I can't remember how big the cans were..sorry/

 

[JB]

Re: How much does it really take?

I would add a third layer of at least 1/2" to that transom, Rebars.<br /><br />Good luck.

 

[G DANE]

Re: How much does it really take?

Rebars<br /><br />I found that adding a layer of wettet mat between layers of plywood gives mush better bond and lots of extra strength. I wouldnt dream of trying to bond wood layers without.

 

[rebars1]

Re: How much does it really take?

JB: Thanks for the reply. The original transom was one layer of 3/4" plywood full depth with an additional strip of 3/4" plywood just at the top 6" down to the splash well. I am going two layers full depth. Also, the inner face of plywood below the splash well was only glassed up about 2" from the bottom of the boat. The motor is the original 35hp Johnson.

 

[JB]

Re: How much does it really take?

I understand, Rebars.<br /><br />I would still do it stronger than original.<br /><br />Good luck.

 

[rebars1]

Re: How much does it really take?

JB: I'll check the motor clamp width and the boat top piece to see if a 2" thick transom will fit. I like the idea of stronger.<br /><br />G Dane: I've seen recommendations here both ways, with the glass and w/o the glass between the plywood layers. I would think that thickened epoxy (like mayonaise) between plywood that was pre-soaked with thin epoxy resin would bond pretty well. But your experience with the glass makes sense also.

 

[rebars1]

Re: How much does it really take?

But the question is do I mix a quart for each laver or more?

 

[jheron]

Re: How much does it really take?

I just did mine and I think I used about half to 3/4's of a gallon total here is what I did... I used system three epoxy with the #2 hardener, then I spread resin on the existing fibreglass back then a layer of 6oz cloth to help fill in any irregularitys (hehe spelling was never my strong point) then a layer of thickened epoxy with cabosil over the cloth and on the first piece of the transom, with that in place spread the next layer of peanut butter on the remaing piece and the front of the last piece and then I through bolted it all together where I could and clamped it where I couldnt. After all is said and done it is one solid transome I kept mixing the batches as I went keeping them small so they wouldnt go off in the pot I spent more time mixing then I did spreading but I had no waste and it all turned out great <br />regards Jon

 

[JasonJ]

Re: How much does it really take?

The thickness you are building to is fine. My original transom wood was only an inch thick with filler to fill out the rest just at the splashwell, and this was on a boat rated for 145 hp and had a 125 hp motor on it. I built my transom with a layer of 5/8 and a layer of 3/4, that filled me out. I have towed a 21 foot bass boat with the transom eyes, nothing creaked or groaned, it is plenty strong. Your setup will be plenty strong as well...Good luck...

 

[rebars1]

Re: How much does it really take?

JasonJ: Thanks for the input. My son and I have been admiring your conversion project for some time now, especially the fishing platform you installed. That will be our next project on our other boat (18.5' trihull, merc 888)

 

[rebars1]

Re: How much does it really take?

Project update: I have the two layers of plywood epoxied in place. I'm ready to glass in the plywood to the inside of the boat and then reconstruct the splash well.<br /><br />Question: Is one layer of glass enough on the inside face of the inner layer (facing the splash well). Should use white pigment in this layer or will the gel coal material be white enough? I guess that's two questions.

 

[cc lancer]

Re: How much does it really take?

Well If it was mine I would consider 3 layers and stagger the layers. It will sand out to a nice job. Then put on a good coat of gel coat. So far you have "glued" the transom to the sides, now make it strong enough to pull a yacht.