Barrier coat disaster

[kko]

And what about the Coppercoat over the solvent based products?

 

[kko]

I ask to know possible options, just in case. But in fact, we will rather sail as before, repair only what is necessary and don't worry when we scratch the boat, like when mooring to the cliffs in Norway

 

[srm]

And what about the Coppercoat over the solvent based products?

See my previous post - 54. Coppercoat over industrial solvent based high build epoxy in 2009, still sound after touching up in 2019.

 

[kko]

I remember now, when looking for appropriate products 6 months ago (and contacting the manufacturers/distributors), the decision to use a solvent-free option was because of possible problems with solvents mentioned, mainly longer time to wait before applying the Coppercoat (after the barrier). But nobody mentioned two things. One is the surface tolerance for adhesion. So much important! Another is application. As I read now, it is much easier to apply the solvent based products (yes?). Many companies have both. Painting the solvent free resin caused many runs, not very even surface and finally 4 days sanding to smooth before applying the Coppercoat (which was quite easy to apply in comparison). Total time of our work is 5 weeks, 10h+, 7 days. Even if solvent based barrier needs to evaporate for e.g. 7 days, it does not change much. Better 7 days doing nothing than 4 days more sanding... Or is this longer for the solvents to evaporate? Any other pros/cons?

 

[dankilb]

Solvented epoxy products are fine underwater (many are designed for big ships, oil rigs, bridges etc.). The solvent is merely as a thinner and a medium by which to get the paint onto the surface - it evaporates early in the drying/curing process and will be completely gone by the safe ‘recoating’ times specified in the instructions. Once the primer has cured, Coppercoat doesn’t know whether it’s on West or Jotun!

Before you splash the boat and go sailing, it is worth considering that a Jotun job could be completed in a couple of weeks (inc. coppercoat). The cost per 5L is around £60/€65 inc tax.

 

[Yngmar]

If you've sanded the barrier coat with the same sandpaper discs as the hull, contamination from the discs (which was unlikely anyways) can be ruled out, as the Coppercoat evidently stuck well to the barrier coat.

 

[kko]

Now I would need to scratch everything just to know where exactly there is no adhesion, i.e. do everything again. Also, buy the Coppercoat again... As it is, I may have water anywhere under the coat after some time. And the osmosis will just show where I need to do the repair. It should't destroy the boat in 2-3 years. The laminate is thick and healthy. And I don't want to spend all my holiday scratching, sanding, painting and scrapping plastic :/ may be better to repair some osmosis and the coat after next few years of sailing. I can loose the boat by lots of other reasons than a wrong coat (e.g. last year the chain wrapped the anchor and we were back last moment). For us it's just sailing, not painting boat for an exhibition at any cost (including our holiday time).

 

[kko]

I have found this story. Another two West barrier failures with waisted Coppercoat on top.

Linnea Sailing - West System barrier coat failure and what we learned

I have got the West barrier recommendation from the Coppercoat actually.

 

[kko]

Linnea Sailing says that the Coppercoat knew the situation. And still recommended the West barrier when I have asked them :/

It is not funny when you are super happy after a month of hard work, that you have this "barrier for years", and you peel it off with the masking tape. And someone who sells this, knew two other such stories and mentioned no word.

 

[kko]

Back to the technical discussion, Linea mentions solvent based products possibly incompatible with bare GRP (they share knowledge which they got in the same situation). Covering bare GRP will be my case. Are there any solvent based products risks?

 

[kko]

Probably the Coppercoat guys like when their product peels off before 10 years and it is someone else's fault

 

[Restoration man]

Ok just to confirm this peeled off back to the bare original gelcote / fiberglass ?

If so here’s a thought know-body has come up with.

The boat is 40 years old and its been drying for 10 months but the hull might very easily still have a high moisture content (the pre curser to osmosis) I haven’t heard anyone mention a tramex or sovereign moisture meter being used. From what I’ve read Epoxy coating should only be used on surfaces that display a certain level of dryness this is a different reading for tramex or sovereign meter, could it just be that the coating just wont Stick properly for this reason ???

 

[kko]

In the one of the pictures (beginning of the thread) you can see how it was peeled off. White spots is the original gelcoat. Gray is the bare fiberglass (under the dust). As you can see, it is 70-80% bare GRP under the coat. It is because the original gelcoat was thin and we wanted really to get rid of any other coats. Thus, sanding to bare GRP in many places.

The meter was not used. But the laminate is osmosis free. We sail only for holiday, about 2 months every year. Another 10 months the boat is in the shipyard, already for 7 consecutive years. Last 2 years in the dry side of the Canaries (practically desert, recommended place for such work).

 

[srm]

Ok just to confirm this peeled off back to the bare original gelcote / fiberglass ?

If so here’s a thought know-body has come up with.

The boat is 40 years old and its been drying for 10 months but the hull might very easily still have a high moisture content (the pre curser to osmosis) I haven’t heard anyone mention a tramex or sovereign moisture meter being used. From what I’ve read Epoxy coating should only be used on surfaces that display a certain level of dryness this is a different reading for tramex or sovereign meter, could it just be that the coating just wont Stick properly for this reason ???

It is possible there was a long term build up of moisture in the hull over 40 years. However, the usage over the last seven years should have dried the hull somewhat. When I successfuly coated my current boat (described in earlier post) she was 15 years old, had been ashore for two years but had only ever spent one winter afloat shortly after launching. Survey report was that moisture content was minimal to negligible so I felt confident in applying epoxy.

Before I coated my boat in 2009 I spoke to someone at Coppercoat UK about the anti-osmosis properties and they said it would reduce water absorption, but recommended an epoxy base coat as well and supplied the industrial solvent based coating that I used. However, if I read the Linnea article correctly (linked earlier) then more recently they are saying that Coppercoat being an epoxy is sufficient by itself. Interesting.

 

[kko]

Before we bought the boat, it was also stored in the shipyard, but don't know for how long. If it should work, is there a better, reasonable way of drying an old boat than 7 years, 10 months in the shipyard?

When I have asked the Coppercoat about using barrier coat (according to their web page), they mentioned 2 brand names and recommended solvent free to apply the Coppercoat faster. No other risks or disadvantages were mentioned.

 

[kko]

The Coppercoat recommended, the West System advertises best ever barrier using their product, both are extremally expensive... but show you cost advantage over 10+ years. Not including your work or shipyard. No special precautions or risks mentioned... And already 3 complete failures since 2020... I wonder what is the true MTBF assuming no mass usage of these products.

 

[kko]

In my case, the failure time was zero, just "out of box".