1 3/4 inch hole in transom repair

[trendsetter240]

I have a 1 3/4 inch hole in my transom that I'm trying to repair. The previous owner had a drain plug epoxyed into the hole and I'm looking for a more permanent solution.

I was thinking to use a hole saw and cut out a 1 3/4 inch plug of marine grade plywood, coat it with 3m 4200 and tap it into the hole. Would this be a reasonable repair? Does a hole of this size comprimize the integrity of the transom?

I've attached a pic of the hole after I cut out the rubber plug.

Cheers

 

[VeroWing]

Re: 1 3/4 inch hole in transom repair

If that hole is below the waterline, then forget the 4200, and use 5200, better yet an epoxy paste mix. But before you do that, from the pic it appears that on the inside of the hole, there is bad wood or something. How does it look in there, and how deep into transom core is bad wood?

Point is, if you just epoxy a wood plug in that hole, its' only going to be as good as what it is attached to. If transom core material is bad, then plug will leak. Better to enlarge opening to a point that hole is surrounded by firm, dry material. Then measure filler material, and epoxy it in, or maybe even use a Seacast type pourable product to fill area.

 

[trendsetter240]

Re: 1 3/4 inch hole in transom repair

Thanks for your reply, I'm a novice to this type of work!

Yes it is below the waterline, if I don't use an epoxy paste then I will use 5200 as you recommend.

The wood inside the hole was slightly damp but not rotted. I drilled out the hole and managed to get dry wood after only 1/8 inch. I also found the smallest drillbit i had and drilled a couple of test holes about 1/2 inch deep on other parts of the transom. All came out as dry wood.

My plan I think now will be to sand down the entire transom, fill all the holes with 5200 (or epoxy paste.) and then re-paint.

What would you recommend as a brand or type of the epoxy paste? Am I missing anything else here?

Thanks again, your advice is greatly appreciated.

 

[trendsetter240]

Re: 1 3/4 inch hole in transom repair

One more thing to note, the hole goes right through into the bilge. Not sure if that will make a difference on what type of filler would be used.

 

[allpoints360]

Re: 1 3/4 inch hole in transom repair

I would plug the hole as you discussed and glass both sides. You're below the waterline and need to do it right the first time.

 

[trendsetter240]

Re: 1 3/4 inch hole in transom repair

Hey 360, thanks for your reply.

Is it ok to glass only on the outside? The bilge on this boat is sealed with no top side access. I'd have to cut an access way into the floor to get at the inside.

I'm really hoping I can avoid that since the floor is relatively new and was just sealed and painted.

 

[Bob_VT]

Re: 1 3/4 inch hole in transom repair

PC 11 is made for marine use and will even cure if it is damp. Wood plug with a generous coat of PC 11 on the entire plug. You can get a small quanity of PC 11 and for what you are doing the package they sell in the 35mm film canisters will be sufficient.

 

[allpoints360]

Re: 1 3/4 inch hole in transom repair

Is it ok to glass only on the outside? The bilge on this boat is sealed with no top side access. I'd have to cut an access way into the floor to get at the inside.

It should be fine. If you do it right, it will be watertight.

Plug as you were thinking, making sure to inset the plug a bit from the outside. Bevel the edge of the hole out about another inch. Now it's about 2 3/4". Now tape around it to keep from making a bigger mess.

Cut 3 circles of mat, 2", 2 1/3" and 2 3/4", wet each one with resin and place on plug smaller to larger so each overlaps, then tamp or roll out bubbles.

Let it harden, sand and top coat.

Should be as good as new! Good luck.

 

[VeroWing]

Re: 1 3/4 inch hole in transom repair

Being that you cannot access the inside of transom area, then you should be sure to coat the wood plug with epoxy, before installing. This way, it will not be subject to deteriorating from the inside, from moisture in the bilge area.
Then install using one of the adhesives mentioned above, along with the fiberglassing also mentioned, and you should be good to go. Mike

 

[trendsetter240]

Re: 1 3/4 inch hole in transom repair

Thanks everyone. The wood plug is in, sealed tight with 5200. I coated the plug with the 5200 on all sides, inset slightly and I beveled the outer edge of the hole with an angle grinder.

Won't be able to pickup the glassing supplies until the weekend. Should be long enough for the adheasive to cure fully. (it's still tacky 24 hours later).

cheers!