Sealing transom holes

[zoidberg]

I've removed a cantilevering outboard bracket and a pair of s/s tube 'ladder steps' from the transom, leaving 18 bolt holes ~8-10mm to be filled and sealed.

I'm tempted to affix small woven roving/epoxy patches on the inside, then fill the holes with a Marine Plastic Padding product, then tackle the cosmetics.

Does anyone know of a better way?

 

[Muddy Boat]

Assuming your transom has a ply core, when I did mine (a few years ago), I sealed the exposed core with thin resin and then filled with hardwood dowel to about 3-5mm from each end ( get as tight a fit as possible and sealed the ends with resin). I then used the plastic padding (boat was white) to fill the 3-5mm at each end. Worked a treat.

I would be tempted to use epoxy for the sealing if doing it now, but be aware that regular polyester gelcoat is not keen to stick to it and I am not sure what the options are for epoxy friendly gelcoat.

 

[MOBY2]

Morning, just removed the outboard bracket from mine put eight small circular chopstrand patches one over each hole after removing all the old paint let dry then put a bigger patch over the whole area then two more larger patches each bigger than the last allowing to dry each time, when the weather warms up will fill with gel coat on the outside, seems all good and strong, sure others will be along shortly with other tips.

 

[NormanS]

I've removed a cantilevering outboard bracket and a pair of s/s tube 'ladder steps' from the transom, leaving 18 bolt holes ~8-10mm to be filled and sealed.

I'm tempted to affix small woven roving/epoxy patches on the inside, then fill the holes with a Marine Plastic Padding product, then tackle the cosmetics.

Does anyone know of a better way?

What's the transom made of?

 

[Yngmar]

I've removed a cantilevering outboard bracket and a pair of s/s tube 'ladder steps' from the transom, leaving 18 bolt holes ~8-10mm to be filled and sealed.

I'm tempted to affix small woven roving/epoxy patches on the inside, then fill the holes with a Marine Plastic Padding product, then tackle the cosmetics.

Does anyone know of a better way?

No point doing structural work there (glass), the transom obviously held together without that structure

So you just fill them. Slap some tape on the holes outside the boat (gives you the smoother, splotch-free surface outside where you want it). Squeeze thickened epoxy mixture into the holes inside until full and smoothen a bit with spatula. When cured, remove tape outside, gently Dremel a "pit" into the filled area (countersink bit will do in a pinch) and then fill that pit with gelcoat filler pigmented to match your hull. Sand, polish & wax, done

 

[PaulRainbow]

I would be tempted to use epoxy for the sealing if doing it now, but be aware that regular polyester gelcoat is not keen to stick to it and I am not sure what the options are for epoxy friendly gelcoat.

According to West, poly gelcoat will stick to properly prepared epoxy just as well as it will stick to cured poly.

Morning, just removed the outboard bracket from mine put eight small circular chopstrand patches one over each hole after removing all the old paint let dry then put a bigger patch over the whole area then two more larger patches each bigger than the last allowing to dry each time, when the weather warms up will fill with gel coat on the outside, seems all good and strong, sure others will be along shortly with other tips.

Remember, when laying GRP up you should not allow previous layers to cure. Allowing them to set is ok, but subsequent layers should be done as soon as possible and certainly within the cure time. It is best to apply all coats wet on wet.

 

[Fantasie 19]

No point doing structural work there (glass), the transom obviously held together without that structure

So you just fill them. Slap some tape on the holes outside the boat (gives you the smoother, splotch-free surface outside where you want it). Squeeze thickened epoxy mixture into the holes inside until full and smoothen a bit with spatula. When cured, remove tape outside, gently Dremel a "pit" into the filled area (countersink bit will do in a pinch) and then fill that pit with gelcoat filler pigmented to match your hull. Sand, polish & wax, done

That would be my suggestion too... perhaps a light drill in the holes to provide a fresh surface for the epoxy to adhere to?? One of the guys on here had a genius idea for getting the epoxy all the way into the holes which was to use these - plastic pasteur pipettes from ebay.. use once throw away

 

[Yngmar]

That would be my suggestion too... perhaps a light drill in the holes to provide a fresh surface for the epoxy to adhere to?? One of the guys on here had a genius idea for getting the epoxy all the way into the holes which was to use these - plastic pasteur pipettes from ebay.. use once throw away

Yes, drilling them clean first is a good suggestion. I have some of those cheap pippettes - they're good for fluids (topping up batteries, separating water and diesel), but won't have the suction to get the thickened epoxy into them. A standard syringe works, or you can just put it in a plastic bag and then cut the corner off - like a squeeze bag used in baking.

 

[alahol2]

I have frequently used Milliput superfine white to fill small redundant screw holes. In most cases it needs no gel as a finish but you may need a skim in a 10mm hole. Very easy to use and has many other potential uses on board, lasts for years in the tool box.

 

[zoidberg]

Good - and helpful - answers there. Many thanks, people. I'll do as suggested.