Swim Platform install, filling drill holes

tmh

Lieutenant Junior Grade
Joined
Aug 16, 2006
Messages
1,136
Hi. I am installing a swim platform on my boat and want to make sure no water gets to to the inside of the transom. I also have another boat that may have had some water get into the swim platform thru holes. I plan to drill larger holes (3/4" maybe?) then fill the holes with marine tax or glass with poly or epoxy resin. then I'll drill the proper size hole for the bolts of the swim platform. I got that idea a while ago reading here on iboats forum.

My questions are : 1. how big a hole would make sense? Easy enough to fill, etc. 2. What material to use to fill? 3. How to actually fill it? I thought maybe tape wax paper over the exterior of the hole and fill from the inside so it would be smooth where visible outside. But how? Make a putty like mixture to shove in the hole but not run?

Also, while I have holes in there I may inject some CPES penetrating epoxy in there. I think one of the transoms has some moisture, maybe both. How can I get it as dry as possible? Just a fan for a few days blowing through? Shop vac? Heat fan? Dehumidifier under boat cover?

Thx for any and all ideas.

Thanks for any ideas.
 

oops!

Supreme Mariner
Joined
Oct 18, 2007
Messages
12,932
Re: Swim Platform install, filling drill holes

hi bud...

yeah....use a fan to move the air around the transom wood and try to dry it out.

as far as the holes.....over drill them....fill with epoxy then re drill when cured...you might try a wood flour epoxy paste after you have gooped the hole walls with the penetrating epoxy


or you can just shoot 4200 in before you bolt it on.
 

Silver Heels

Petty Officer 2nd Class
Joined
Apr 28, 2008
Messages
125
Re: Swim Platform install, filling drill holes

What I've seen done for balsa cored decks is to drill the correct size hole all the way through and then go back and remove some of the core material only by putting a nail with a short 90 degree bend in a drill. Use this to clean out the surrounding core material and fill that area with epoxy. I have no idea if something similar would work in your situation as you are dealing with thick plywood. Might be something to consider though.
 

Mark42

Fleet Admiral
Joined
Oct 8, 2003
Messages
9,334
Re: Swim Platform install, filling drill holes

The best method of sealing the holes is to over drill by 1/2", then fill with thickened epoxy. Buy a quart of epoxy and hardener and some thickener like EZ Thick. That will let you mix up some epoxy thick as mashed potatoes that just won't run. Then re-drill to right size, and seal bolts with 4200.
 
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