Adding epoxy layers on hull

[Patricks Dad]

Hopefully this is a quick question:

We'd like to add a couple additional layers of epoxy on the bottom of our hull over the stem area to protect it from abrasion. I assume that the right approach is to lightly sand the current epoxy layer in an area slightly larger than where we will add the new epoxy layers. Then apply the new layers within that sanded area and feather it out (staying within the sanded area to ensure a good bond). We'll then sand over this area along with the rest of the hull when we're ready for the overall hull sanding.

Any precautions we need to keep in mind to ensure we don't have any problems and the resulting finish is clear and consistent?

Thanks!

[Glen Smith]

Do you just want to add extra epoxy or also bias-cut glass strips?

[Patricks Dad]

Just Epoxy. I put on 1 strip and didn't like how it looked so we took it off and decided to go with just epoxy. Advice on making the strips really disappear would be welcomed (the edges were lumpy on the strip we cut and tried to apply).

Thanks!

[Rick]

Epoxy alone won't add much abrasion resistance - you can apply another layer of fiberglass and probably won't be able to see it's there afterwards, as long as there isn't any air trapped underneath. Give it a generous overcoating of epoxy and sand the rough edges to fair in with the rest of the hull carefully. Several layers of glass might start to take on a milky appearance, but two layers shouldn't be noticeably different.. If several layers for added resistance are wanted, a test panel should show how much fiberglass can go on before transparency and color are affected.

[Glen Smith]

If you just want to add a few sacrificials coats of epoxy on the stems, I would make each new coat narrower than the last one. This will produce several small "steps" in the epoxy instead of one big "step" and make it easier to feather in the new coats to the existing epoxy on the hull. For feathering I would start with a cabinet scraper and finish with hand sanding with 120 grit paper.

When I add bias-cut strips to a stem, I position the dry cloth so it has no folds or lumps then I apply the epoxy with a brush using a sponging action instead of a brushing action. I add enough epoxy to completely saturate the cloth and work out any bubbles with the brush tip. When it is to my satisfaction, I carefully squeegee out the excess epoxy. It is very easy to move the cloth at this stage so you must be careful with the squeegee. Keep an eye on it as the epoxy begins to set and use a brush tip to push down any cloth that wants to lift away.

Some builders lay out the strips on a piece of plastic and soak them with epoxy. Then they transfer the whole thing to the stems and peel off the plastic. Get the strips in position and squeegee. I tried this once but I did not have much success with it.

I normally add these strips after doing the saturation coat on the hull. Then I feather in the strips and apply the rest of the epoxy coats to the hull and stems.

[KARKAUAI]

I saw a post on G's kayak forum that was suggesting a coat or two of epoxy with cab-o-sil to protect against abrasion along the keel and stems. Too much cabosil would make it milky, and there was no suggestion as to how much would still leave the mixture clear. It would take a little experimentation, but I may try it NEXT TIME, or if I find more abrasion than I anticipate. I have to agree with the poster that sanding a fillet made with cabosil and a little wood dust is MUCH harder that sanding pure epoxy, so maybe it would work. Anybody ever try it?

[Its Me]

Color may be an issue but if not and abrasion is a major concern it seems that an additive/filler could be used. Maybe Raka or west can suggest a filler.