Fiberglassing Transom...

[play2win]

When laminating the pieces of transom together, is glassing required? I just removed old glue off of the back of outer skin. Do I just put epoxy against outerskin and first piece of plywood, and work my way up....OR do I place a piece of mat in between each piece of ply....OR, do I go - mat, cloth, mat, ply, etc. Do I drill holes in transom before I put in? If I dont, will it be difficult to penetrate epoxy and glass when drilling holes after it is all assembled?

 

[crab bait]

Re: Fiberglassing Transom...

i hand built two boats.. both the instrutions never called for cloth in-between.. but guess it's fine.. but don't see the need or really what it's for..except to suck up imperfections in the mating surfaces..<br /><br />my boats just called for 'thicken epoxy'.. <br /><br />take thin type.. add fillers such as silica, microbaloons, milled fiberglass powder is best..<br /><br />in this case.. a thicken mixed slurry.. like a wet wall paper glue consistency.. not a putty .. <br /><br />but first apply thin epoxy to both surfaces.. than apply another coat.. <br />than apply the thickened..<br /><br />do this so the ply soaks in epoxy an doesn't suck juice from the thickened .. as it'll be a dry surface bond if not done..<br /><br />holes.. what holes.. drain.? motor.?<br />let me know..<br /><br />also ,, by-the-way.. never NEVER NEVER use thin epoxy for any bondin' of two things.. it'll never hold.. cause its to thin.. <br /><br />always thicken for/to bond things together..

 

[ob15]

Re: Fiberglassing Transom...

Like crab bait said, always use thickened epoxy when glueing. Use either wood flour of silica (cabosil). Mix it a little thinner that peanut butter. The wood will fail before the glue.

 

[play2win]

Re: Fiberglassing Transom...

Any of the holes, motor, drain, towhooks, ladder. When, precisely, do I drill holes into wood? Before installing? After putting in wood and epoxy? After I glass it in on the inside?

 

[ob15]

Re: Fiberglassing Transom...

I would wait until you're ready to install them. Drill the holes a little oversized and coat inside with thickened epoxy. Use 4200 or 5200 to help seal when installing item.

 

[thehermit]

Re: Fiberglassing Transom...

play,<br />I believe that mat could be used between the hull skin and the first layer of wood as a filler of voids. I am going this way on my 22 then with thikened epoxy between wood. I guess what you do depends on how bad you skin is (wasnt it cracked?) if real bad some cloth or mat cant hurt.<br />hermit

 

[BillP]

Re: Fiberglassing Transom...

Think about this...99.99% of all factory boat transoms are done the following way.<br />1. Glass the hull<br />2. After the glass has kicked enough to be hard, set the plywood transom against the hull and glass. The mating faces MAY be coated with resin before glassing. Multiple layers of ply are screwed or glued together with ordinary polyester resin or Elmer's type carpenter glue before setting in the hull. Transoms built this way last forever if kept dry. Do more work if it makes you feel better but the above method is proven beyond doubt.

 

[play2win]

Re: Fiberglassing Transom...

Going to start working on cutting pieces, etc. today (tomorrow, should be in 50's wa-hoo!, so it will be a good day to use the epoxy). My Checkmate was originally 1.5 inches. Any need to give additional support, getting many suggestions to go 2.25. Any suggestions?

 

[JasonJ]

Re: Fiberglassing Transom...

You can only go as thick as the splashwell will allow. Thicker than that and the top will not go on properly.

 

[BillP]

Re: Fiberglassing Transom...

If you want to add strength there are several options. Don't forget that you are automatically increasing the strengh by using epoxy instead of polyester. That's approx 25%-35% more glass strength. <br /><br />1. Like Jason says, the spashwell may get into the way for another layer of 3/4" ply but a thinner sheet may fit the gap. Or you can run a 3/4" sheet up to were it hits the splashwell. This would give massive strength even without having the upper motor bolts going though it.<br /><br />2. You can also run a fiberglass web from the bottom of the splashwell to the transom. Very easy to do and spashwells add a lot of stiffness.<br /><br />3. The easiest would be a knee glassed in on the centerline...like they used to do on wood skiffs.

 

[JasonJ]

Re: Fiberglassing Transom...

Bill, originally there was two fairly large knees. I am assuming he will be glassing new knees in, but he hasn't said or asked about them.

 

[play2win]

Re: Fiberglassing Transom...

Thank you Jason & Bill. Is an additional piece of ply necessary? If I'm using epoxy, it should be stronger than origianlly built. After I cut out pieces of wood, wet out with epoxy, then let dry, and sand, then use thickened stuff? I repaired crack in hull this weekend as well as holes from towhooks (cut out holes and glassed from inside. Roving was last layer I used to patch holes and crack. Going to use mat for the remainder of the back of inner shell. After it fully cures, should I sand, then put a few coats of epoxy over glass, let dry, and sand again. Wont this give the cloth/wood a nice bonding surface when I am ready to laminate transom?<br />Oh yeah, as for knees, I plan on rebuilding them to the top of splashwell, and eliminate the pre-existing crossbrace that held an additional 3/4 piece of plywood for the top 6 inches of transom

 

[ob15]

Re: Fiberglassing Transom...

Wet it out and then glue together with thckened. Don't let the wet coat cure. If you did, no problem just sand real good, apply another wet coat & then glue. The idea of the wet coat is to wet the wood so it doesn't absorb the resin from the thickened mixture and create a weaker joint. It is always better to work with wet epoxy if you can. the bond is better. If you can do it all at once, that would be the way to go. Even if the epoxy is still tacky, it is still good to go.