Drill and Fill for Transom Holes?

Oct 20, 2014
135
O'Day 23-1 Lake Champlain, Vermont
I've searched the forums here but have not yet seen an answer to this specific question. I'm wondering about whether or not it makes sense to use the same kind of technique on my transom holes that I am using for the deck holes. For the latter I am removing wood between the fiberglass skins using a Dremel router bit (as per Mainesail's method), taping below and filling with epoxy and redrilling. But the transom on my 23-1 may not have an inner FB skin attached to the inside face of the wood.

The gudgeon holes go through the outer fiberglass skin which is backed by a vertical wood plank (factory installed I believe) which seems to be about 7/8" thick. This plank is painted but there doesn't seem to be a fiberglass skin on the other side. I will be using two 1/4" thick aluminum backing plates when I reinstall these.

The new swim ladder (and outboard bracket) holes will go through the outer fiberglass skin, perhaps 1/2" of wood and then what is either another fiberglass skin or paint. I will be using large 1/4" thick aluminum backing plates when I install these.

So should I core out the wood and fill with epoxy even if there may be no inner fiberglass skin? Any suggestions about filling vertical holes.

Many thanks,
 
Nov 6, 2006
9,884
Hunter 34 Mandeville Louisiana
My opinion is that on the ones that have no inside skin, you can seal the outside and the bolt hole sufficiently with Bed It Butyl and chamfered holes per Maine Sail's recommendations.. On the ones bolted through an encapsulated core, the "hog out and epoxy fill" is best ..
 
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Likes: jssailem
Oct 20, 2014
135
O'Day 23-1 Lake Champlain, Vermont
Thanks Claude. That certainly would be simpler although I will use 4200 because the lower gudgeon is sometimes under the water line. I was able to reach a friend of mine who I thought would be unreachable right now. He is retired from professional boat repair but worked on sailboats for decades. He suggested that I go ahead and do the epoxy because it would seal the end grains of the wood. It will be fun trying to fill these holes in a vertical surface but I'll thicken the epoxy quite a bit.
 
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Likes: kloudie1
Oct 20, 2014
135
O'Day 23-1 Lake Champlain, Vermont
It turns that O'Day did put a thin layer of fiberglass over the wooden gudgeon block. I've hollowed it out and tomorrow I'll start with epoxy for the transom and deck holes. If anyone has tricks for epoxy filling of holes in vertical surfaces I am all ears.
 
Nov 21, 2012
587
Yamaha 33 Port Ludlow, WA
It turns that O'Day did put a thin layer of fiberglass over the wooden gudgeon block. I've hollowed it out and tomorrow I'll start with epoxy for the transom and deck holes. If anyone has tricks for epoxy filling of holes in vertical surfaces I am all ears.
I've put tape over the holes and injected epoxy in using a big vet's syringe. Fill from the bottom and make a hole at the top for the air and excess epoxy to flow out of. Helps to have a way to keep pressure on the tape so it doesn't blow out.
 
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Likes: jssailem
Oct 20, 2014
135
O'Day 23-1 Lake Champlain, Vermont
That's a good suggestion, thank you. I saw that recommended somewhere else tonight as well. I have the West System syringes here but have not used them yet.