Need advice on how to fill in 4 bolt holes on the Stern

[Rodneys]

Im thinking about changing motors on my boat from a bolt on motor bracket to a clamp on mount. What advice do you have to fill in the 4 bolt holes.

 

[trucktramp]

Re: Need advice on how to fill in 4 bolt holes on the Stern

I have the same issue with my boat and after talking to my local marina, I was told that the way their guys repair larger holes like bolt holes in the transom is to first plug it with some dowel rod from your local lumber/home supply store and then seal with some 3M 5200. You may have to make the hole larger as the dowel comes in standard sizes. I am going to coat the sides of the dowel on my job with the 5200 for an extra layer of sealant and adhesive in addition to the ends. Make sure that everything is good and clean so that you get good adhesion and sealing. Hope this helps.

 

[Rodneys]

Re: Need advice on how to fill in 4 bolt holes on the Stern

Hey, That might work and would be cheaper than trying to plug it with fiberglass.

 

[TopGunn]

Re: Need advice on how to fill in 4 bolt holes on the Stern

Yep thats what i ended up doing. Well my first plug job was done at the marina when I put the boat in the water and heard the water pouring in. Didn't notice 2 bolt holes from the other motor were open (got excited to hit the water), so to get by for the day i found 2 sticks on a tree that fit tight in the bolt holes and pounded them in and broke them off. It sealed the holes water tight and worked for the day. I popped the sticks out when i got home and replaced with dowel rod and silicone. She's water free now

 

[oops!]

Re: Need advice on how to fill in 4 bolt holes on the Stern

the dowell idea will work just fine.....

HOWEVER......all the transom rot i hase ever seen, is caused by holes in the transom not properly sealed.

when you insert the dowells, fully coat .....no...over coat the hole and the dowell with 5200. then insert the dowell.

you can also fill the top of the hole with marine tex or gell coat.

the important thing is to make sure that the hole is totally sealed from all water intrusion.

 

[Yacht Dr.]

Re: Need advice on how to fill in 4 bolt holes on the Stern

Hello m8s..

I would strongly suggest that after you fill your hole ( with whatever dowel or glass filler ) that you bevel around the hole til you can put a few layers of mat over the area. Approx 3"-4" round for a 1/2" bolt hole.

It will incapsulate the hole. Just plugging it is kinda risky IMHO.

However..IF you do decide to just to the dowel thingy then please chamfer the hole.

YD.

 

[109jb]

Re: Need advice on how to fill in 4 bolt holes on the Stern

Are we talking about a fiberglass boat or an aluminum one?? I didn't see where the original poster specified. If fiberglass, I agree with Yacht Dr that you should bevel and apply some glass to the outside.

If aluminum, you can do what I did on my Starcraft. I first sanded the aluminum around the hole down to bare metal. Then I took the cone shaped pilot from my steering wheel/harmonic balancer puller and used it and a hammer to flare the aluminum into the hole. I then cleaned the aluminum and filled the hole and flared portion of the aluminum up level with epoxy mixed with short strand loose glass fibers. You could just cut up cloth for the amount needed. Sand level, shoot some rattle can paint on it and done. Below is a little sketch showing the cross section of what I did.