Filling holes in transom

Cope

.
Jun 19, 2011
78
Catalina 22 South Lake Tahoe
My boat has an old factory motor mount on the transom.
I would like to (will be) remove all this dead weight and seal up these holes.

what is the best process and material to make this happen?



Im thinking tape over one side and thickened slow set epoxy forced into the hole then tape over the out side and let cure?

Thanks for all the time and advice.
 
Dec 11, 2010
486
MacGregor 26x Hayden AL
Best? Easiest... I put some 5200 in the holes and reinstalled the bolts. Done.
 
Jul 21, 2013
333
Searching for 1st sailing boat 27-28, 34-36 Channel Islands, Marina Del Rey
Best way and the correct way is to fill with what the transom is made of originally, probably wood.

Insert wooden plugs soaked in resin into holes after cleaning the holes out. The plugs should be just shy of the gelcoat on both sides. Now fill holes with thickened resin and gelcoat over it.

You and the next owner will appreciate a truly professional job and finish.
 
Feb 28, 2005
184
Catalina 22 1909 North East, Md.
Are you just removing the two slide tracks or the tracks and motor mount? Are you planning on having an auxiliary outboard motor?
 

Cope

.
Jun 19, 2011
78
Catalina 22 South Lake Tahoe
I just want to remove the two side tracks. The mount in the center is staying. I hang my honda 5Hp off of it.
I like the idea of wood plugs, That seems like a good way to go.

Thanks for the ideas.
 
Dec 11, 2008
1,338
catalina C27 stillwater
Placing "stock" material in the holes because that is what it was built with is not wholly rational. That is the same logic as if someone never updated the stock chainplates because they are stock, despite proof that older C22's need to have their chainplates updated. Lets talk about this before you go wood plugging those holes. Original is not always right.

If you wood plug the holes, are you going to then fair out the gel coat so that a gelcoat patch extends well beyond the originally drilled hole? Or are you going to simply leave the hole at its current OD and pop some gel in there? IF left at current OD and gel coat to fill in only on top of the wood plug, you WILL crack and you WILL get water in which WILL rot the wood, both the plug and the plywood.

Any time we drill a hole in a boat, we should attempt to remove the wood at a larger radius between the inner and outer skins of the panel in order to fill that region with synthetic material to prevent water intrusion and wood rot. The same should be done here. I think if I were doing this I would take the old mount rails off and with an allen wrench in a power drill, spin the short end of the allen wrench between the inner and outer skin in order to remove some of the wood all around the hole. then tape the inside skin all over to seal it and pack in thickened epoxy filling not only the hole, but extending in all directions a short distance all around the hole, inside between the inner and outer skin.

This will be the corect way to fill these holes, as there should be at least a somewhat solid mechanical bond of the epoxy between the inner and outer skins, effectively sealing the wood from any chance of getting wet from these holes. Then at that point fairing the holes out or not for a top coat of gelcoat is totally a cosmetic issue, not a mechanical one.


Even if you remove the rails and simply replace the old bolts/screws with new stainless scrwes to seal the holes for a fresh, aluminum-free look, I recommend over-drilling, reaming out, re-filling, and then re-drilling. Any time you have a hole open through a cored panel for any type of service, you owe it to the boat to seal the wood from water intrusion...

My $.02
 
Feb 28, 2005
184
Catalina 22 1909 North East, Md.
Phil has the right idea, but before you fill the the widened out hole with thickened epoxy you need to fill it with just straight epoxy and let it sit for about 5 minutes than drain it out before you inject the thickened epoxy. This is called wetting it out and allows the wood core absorb some epoxy, if you don't do this first the core can absorb epoxy from the thickened epoxy mixture leaving a weakened plug in the hole that could leak.
 
Feb 28, 2005
184
Catalina 22 1909 North East, Md.
Check out West System's web site or pick up "The West System Way" at a marine store, it explains the whole process in detail with pictures and diagrams, it used to be free, most likely still is.