Removed the black bottom paint and now I see this white layer, is this gelcoat already, good to go with barrier coat or this white paint? Scrubbed with a sanding pad and this is what came off .
Is this gelcoat or paint
- Thread starter newsailor72
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You can see the weave of the fibre glass underneath so I would say it’s gelcoat but hard to be positive without being there.
Looks like you used a pretty heavy grit there. 80 is the lowest I'd go for this job but no turning back now. I'm leaning towards gelcoat as well
Impossible to tell by pictures. Gelcoat is smooth. The glass under it isn’t. If you actually removed ALL of the bottom paint with that sandpaper, I’d bet you destroyed the gelcoat doing that which means you now have exposed th glass mat which would appear white.
So do I need to put new gelcoat or can I just barrier coat it now?
BTW, it feels a little rough, not smooth at all
BTW, it feels a little rough, not smooth at all
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Clean it thoroughly & wipe down with prescribed solvent as recommended by barrier coat manufacturer. Apply several coats of barrier coat epoxy (per manufacturer’s recommendation).May want to paint first coat of anti fouling paint (flash coat) a different color than succeeding coats so in future, when sanding, you won’t sand into your barrier coat.
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It does look very rough .... paint won't fix that. Remediation might require going down to fiberglass, or it might be salvaged by doing a fairing job on the entire boat, then interprotect (6 coats), then bottom paint.... but we can't know what it is with a picture, you need to get hands on the material.
Are you in a yard where you can ask them for advice? Might be worth paying a fiberglass guy to look at it....
From our chair it's impossible to give you a correct analysis. It seems you've got fiberglass / blue / white.... strange, normally the gelcoat would be white, the bootstripe might be painted blue.
How was it stripped ????
Are you in a yard where you can ask them for advice? Might be worth paying a fiberglass guy to look at it....
From our chair it's impossible to give you a correct analysis. It seems you've got fiberglass / blue / white.... strange, normally the gelcoat would be white, the bootstripe might be painted blue.
How was it stripped ????
You haven’t done any structural damage, but you may have reduced the thickness of either a previous barrier coat or the gelcoat. Gelcoat isn’t the most waterproof coating anyway (unless it’s Vinylester - not expected on a Macgregor), so a barrier coat is worthwhile even if you haven’t thinned it. Do what BigEasy says - apply barrier coat and paint per manufacturer specs and go sailing. My guess is the first layer of barrier coat will smooth out whatever is there. If not you could fair it before proceeding.
+1
Having a different color bottom paint under your bottom paint is highly recommended!
dh
Planning to do 5 coats of TotalProtect from TotalBoat. Talked to their support rep, does this sound good? Any tips tricks?
4 coats on day 1, wait 3 hrs between coats, no need to sand in btwn. Temperature here is 70-80.
5th coat on day 2 early morning, wait about 5 hr or so the thumb test, then first antifouling coat.
4 coats on day 1, wait 3 hrs between coats, no need to sand in btwn. Temperature here is 70-80.
5th coat on day 2 early morning, wait about 5 hr or so the thumb test, then first antifouling coat.
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I know you're looking more for advice on what to do next, but I think the white is probably paint. It is hard to tell from the photos, but it has to do with how things are layered. In the upper left corner of the hull image, it appears we are looking at the very top layer of resin with fiberglass directly beneath that. Then, it seems that the blue is on top of that and the white is on top of the blue.
Ignoring the fact that blue gel coat and white bottom paint are both relatively uncommon, just the order of the layers suggests that we are seeing blue gel coat under white bottom paint. I don't know if Macgregor ever did blue gel coat. If so, it would probably have been just from the boot stripe on down, with white gel coat above that. (I believe that Macgregor did this two-tone gel coat, but don't know for sure.)
But, if you verify that the white is on top of the blue, then you can be assured that it is paint - and probably antifouling paint, but not necessarily.
(I am just looking at individual scratches where it appears the low part of the scratch reveals blue. That is what makes me think the blue is underneath.)
The reason that matters is because painting over bottom paint is problematic. Unfortunately, I think this means you need to carefully remove all of that white from below the waterline - like all of it - while preserving as much gel coat as possible.
After that, what others have said about a barrier coat is spot on.
Ignoring the fact that blue gel coat and white bottom paint are both relatively uncommon, just the order of the layers suggests that we are seeing blue gel coat under white bottom paint. I don't know if Macgregor ever did blue gel coat. If so, it would probably have been just from the boot stripe on down, with white gel coat above that. (I believe that Macgregor did this two-tone gel coat, but don't know for sure.)
But, if you verify that the white is on top of the blue, then you can be assured that it is paint - and probably antifouling paint, but not necessarily.
(I am just looking at individual scratches where it appears the low part of the scratch reveals blue. That is what makes me think the blue is underneath.)
The reason that matters is because painting over bottom paint is problematic. Unfortunately, I think this means you need to carefully remove all of that white from below the waterline - like all of it - while preserving as much gel coat as possible.
After that, what others have said about a barrier coat is spot on.
You make a good point about how the layering looks. Could be white barrier coat over blue gelcoat too. That would be less problematic to go over with more barrier coat, but I don’t know a way to tell for sure.
NVM, I just remembered I did some experiments last week on a different spot. The white spot (same texture like this) was next to the black paint and I put Aqua Strip on both places, while the black paint came off there was no white paint at all, so I think I can safely draw the conclusion the white is gelcoat.
Indeed that does suggest that it’s not white paint then. Still strange it’s above something blue. Could be a previous barrier coat. No harm in adding more barrier coat over that though.