Too hot to paint???

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GrandadPig

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My new to me boat had been horribly neglected. After asking here I tried compounding the topsides gel coat in a bid to remove scratches. No chance. Switched to 180 wet/dry paper but many scratches and digs are so deep I cut through the dark green gelcoat to the white GRP beneath.

at that point I decided to paint her.

international Toplac over OneUp primer.

two coats of top coat and it looks better than it did but nowhere near as good as I hoped. The paint, thinned with 10% International Thinners, did not ‘level’ as I had hoped.

is this because of the silly temperature the last couple of days? It’s been in the mid 30’s.

should I wait for cooler weather before flatting it back and trying again?

many thoughts?
 
The datasheet for that particular paint has the following:

Ambient temperature should be minimum 5°C/41°F and maximum 35°C/95°F.
Product temperature should be minimum 15°C/59°F and maximum 35°C/95°F.
Substrate temperature should be minimum 5°C/41°F and maximum 35°C/95°F.
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If the ambient temperature is mid 30s, an object sitting in direct sunlight could be significantly warmer than that which would put it outside the specified temperature. I don't know what the effect on that particular paint would be, but if it dries too quickly it could be that it would affect the finish.

Apart from that I don't think I'd want to paint in temperature that hot as it wouldn't give you much working time to keep a wet edge.
 
kwb78 said:
The datasheet for that particular paint has the following:



If the ambient temperature is mid 30s, an object sitting in direct sunlight could be significantly warmer than that which would put it outside the specified temperature. I don't know what the effect on that particular paint would be, but if it dries too quickly it could be that it would affect the finish.
Apart from that I don't think I'd want to paint in temperature that hot as it wouldn't give you much working time to keep a wet edge.
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That’s interesting. Thank you. TBH I just opened the tin and applied it. I used to use a lot of synthetic enamel and the hooter it was the better it went on. Clearly different characteristics. Rats.
 
Higher temrpatures marine paints flash off too quickly, and dont have time to flow to give a really smooth finish before starting to 'dry' This is important to avoid brush marks, and 'holidays' - areas where the paint hasnt ahd time to adhere properly, or is too thin. Current weather being at the upper limit for heat you may have got away with it - or not!
 
oldharry said:
Higher temrpatures marine paints flash off too quickly, and dont have time to flow to give a really smooth finish before starting to 'dry' This is important to avoid brush marks, and 'holidays' - areas where the paint hasnt ahd time to adhere properly, or is too thin. Current weather being at the upper limit for heat you may have got away with it - or not!
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Nope. I certainly didn’t get away with it. Will buy another tin and wait for it to cool down a bit!
 
This has happened, to a degree, on our copper coat. However, this is before burnishing. Pretty sure it will be comfortably good enough. The principle remains though, high temp, not much time for paint flow.
 
Tbh I think you need more undercoat (and sanded back after every coat) before you can expect a decent finish. Until the base is right the finish won’t be. Take this from a man who painted a wooden boat every year…. Also I like toplac but not for topsides. Look at Epifanes paints. Nautiforte is forgiving and gives a brilliant finish.
 
PhillM said:
Tbh I think you need more undercoat (and sanded back after every coat) before you can expect a decent finish. Until the base is right the finish won’t be. Take this from a man who painted a wooden boat every year…. Also I like toplac but not for topsides. Look at Epifanes paints. Nautiforte is forgiving and gives a brilliant finish.
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I am inclined to agree. The flaws in the failed coat will be very difficult to eradicate, and using undercoat/rub down/undercoat rub down etc is probably the only way to get back a decent finish. Dont be deceived by the matt finish of a single rub down. It may look and feel smooth, but gloss coats will reveal the slightest irrgularity
 
Doing varnishing now - start at 7 am with preparation and finish at 9 with coating.

For painting as already noted the surface temperature and the green paint will be higher than ambient which after 11 am oe so in the last couple of days is on the limit for most paints. At least no problems with humidity!
 
GrandadPig said:
My new to me boat had been horribly neglected. After asking here I tried compounding the topsides gel coat in a bid to remove scratches. No chance. Switched to 180 wet/dry paper but many scratches and digs are so deep I cut through the dark green gelcoat to the white GRP beneath.

at that point I decided to paint her.

international Toplac over OneUp primer.

two coats of top coat and it looks better than it did but nowhere near as good as I hoped. The paint, thinned with 10% International Thinners, did not ‘level’ as I had hoped.

is this because of the silly temperature the last couple of days? It’s been in the mid 30’s.

should I wait for cooler weather before flatting it back and trying again?

many thoughts?
Click to expand...

Rather than ordinary thinners, use this stuff:

Owatrol Oil | Rust Inhibiter Paint | Owatrol Direct

I use it all the time, now, on the recommendation of a professional yacht painter (Archie, at Robertson’s, fwiw) but particularly in hot weather with “traditional” one pot finish coats, like Toplac (although I use Epifanes!)

In fact my sons and I were painting this afternoon but in the shade of trees:C12F9370-B2B7-44AD-8F53-900D858279FE.jpeg
 
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Just an example, I've always painted in the summer before, and always struggled with variable rapid drying paint, fly's seeking darwin awards and dust in the air.

Force of circumstances made me paint this last winter spring , choosing days where it didn't go below 5C overnight, but expected to reach 15C later.

It was so much easier, no fly's, no dust, paint didn't dry too quickly, but surface set before evening.
I'll not be choosing to paint boats in the summer again.
 
I tried a small gel coat repair yesterday. Big mistake - way too hot and the stuff went off in the blinking of an eye. I will be dremelling out the blistered and brittle crud and starting again when it‘s cooler.
 
GrandadPig said:
My new to me boat had been horribly neglected. After asking here I tried compounding the topsides gel coat in a bid to remove scratches. No chance. Switched to 180 wet/dry paper but many scratches and digs are so deep I cut through the dark green gelcoat to the white GRP beneath.

at that point I decided to paint her.

international Toplac over OneUp primer.

two coats of top coat and it looks better than it did but nowhere near as good as I hoped. The paint, thinned with 10% International Thinners, did not ‘level’ as I had hoped.

is this because of the silly temperature the last couple of days? It’s been in the mid 30’s.

should I wait for cooler weather before flatting it back and trying again?

many thoughts?
Click to expand...
Add Owatrol oil - your brush marks will disappear as if by magic.
 
I’ve been prepping my boat for a 2 pack repaint last week and the heat has been almost intolerable. Was supposed to start the painting this weekend but my helper (when I say helper, he’s actually the one with the skills) has hurt his foot playing Badminton so has had to cancel which I think was a sensible decision all round. Hopefully temps will drop this week but still stay dry and we can press on next weekend.
 
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