brokenn

Member

Registered: 11 Jan 2026

Posts: 2

Epoxy coat peeling

I’m building a Chesapeake 14 with my son and we’ve recently completed the fibreglassing and epoxy of the hull. The 4th thin coat has started peeling though, with a few big sheets that come off easily in a few patches, like picking badly sunburned skin.

I’ve tried to attach a picture. I've asked elsewhere, who suggested it was due to me waiting too long between coats. I had waited probably a week before applying the 4th coat, so it didn't bond correctly.

Also, the garage I did it in is usually quite cold, but when doing the epoxy we had it heated to above 15 for at least 10 hours or so.

I have now started sanding it with 80-grit to remove any bits that I can that might seem remotely loose. It is making the epoxy look white and waxy, but that seems to go away when I wipe it down with a wet cloth.

Is this the correct thing to do? Sand it all down to 80-grit, and then epoxy over the top with a fresh coat? Will the epoxy be able to hold on to that texture?

Thanks!

Paul

Employee

From: Gatebeck Cumbria

Registered: 4 Aug 2011

Posts: 134

Re: Epoxy coat peeling

I think that it is very likely that the cause was leaving it too long between coats.  Epoxy sticks to almost anything save plastic and itself when cured.  If the layer was cured then you should have washed the surface with warm water containing a little washing up liquid and then sanded: I realise that it is too late now but I mention it because you will have to do the same thing before you apply paint or varnish.

Don’t worry you have not compromised the strength of your kayak. You have given yourself more work but you are doing the right thing. Wash the hull, avoiding any areas that are still bare wood,  then sand the whole area with 80 grit paper until the surface is white.  Note that this requires very little sanding and do not sand down to the glass fabric.  If you do go as far as the fabric these parts should be coated again with a thin coat of epoxy.

We offer free email and telephone advice during the build.  It is possible that you have already applied sufficient epoxy.  If you contact us we can discuss what you did and give more detailed instructions about how to repair it as well as re-assure you that there will be no problem with the finished boat.

This is from our FAQ

Can I put another coat of epoxy over cured epoxy?
Yes. Since the epoxy has cured a chemical bond is not possible so what is called a mechanical bond is needed. This simply means that the cured epoxy has to be lightly sanded before the next coat is applied: the first coat should have a matt, almost white, surface. Use glass paper of between 80 and 120 grade, no finer.

brokenn

Member

Registered: 11 Jan 2026

Posts: 2

Re: Epoxy coat peeling

Great, thanks for the detailed response.  We have sanded through to the epoxy on two small spots when trying to get rid of what I thought was the weak layer, but otherwise it sounds all good. I've only sanded one half of the boat thus far, so another half to go still. I'll keep the phone support option in mind if anything else comes up.

sailingfree

Member

From: Wareham, Dorset

Registered: 15 Feb 2022

Posts: 34

Website

Re: Epoxy coat peeling

Hi, I had exactly the same problem a couple of years back. See post #23 here https://forum.fyneboatkits.co.uk/viewtopic.php?id=751

As posted, I found that most of the faulty layer came off quite easily.

I’m pretty sure it was a combination of cold, damp and leaving the first coat too long and a build up of amine blush.

Anyway good luck with the build, the situation is recoverable with a bit of care.

Pete