LB26

[fallguy1000]

The only painting you can do is priming the bottom. Mask off a line 3" above or in this case upside down (lower) than dwl. Prime to the masking tape a mist coat and do any additional fairing. Then three coat the bottom and sand it and stop.

Flip the boat and build the inside.

When completed deck seam, etc.

Mask off to dwl or the chine; your choice. Feather the primer to the masked line and make the primer on the hull sides even.

Paint the hull colors to dwl.

Mask to 2-3" above dwl and sand the topcoats to say 180 to prep for antifouling and paint the bottom last. Antifoul will not stick to glossy paints.

[les2021]

Afternoon All

Sorry for the delay in replying Dan.

It seems there is a lot more to painting a boat than a wall !!! I have to say I feel really uneducated when it comes to boat painting.... So I will ask stupid questions until I get the idea.

1. Can you get antifouling paint in colours to match your chosen hull colour or does this just show as a different colour. The antifouling range seems to be Grey / Green / White / Dark Blue. I am planning to paint the entire hull in a sort of midnight blue ( dark blue )

2. What is the reason I can not prime the entire hull at this stage. I realise I have a tape joint at the deck and this will need fairing. Can I not miss coat the entire hull so I can fair the imperfections.

3. Does the Antifouling need to be carried out in one hit, Or can I finish paint the bottom and antifoul to the chine. Then antifoul to above the DWL at the end. Or does this show a bad joint...or bad practise !

To my way of thinking if I can paint the bottom in one go it will give a better job rather than trying to paint up to the cradle then move the cradle and fill in. Or have I got that wrong !!!

Let me know what you think.

Cheers

Les

[fallguy1000]

Afternoon All

Sorry for the delay in replying Dan.

It seems there is a lot more to painting a boat than a wall !!! I have to say I feel really uneducated when it comes to boat painting.... So I will ask stupid questions until I get the idea.

1. Can you get antifouling paint in colours to match your chosen hull colour or does this just show as a different colour. The antifouling range seems to be Grey / Green / White / Dark Blue. I am planning to paint the entire hull in a sort of midnight blue ( dark blue )

Generally no. You could match a topcoat to antifoul, but the antifoul will not have the same sheen which makes it look quite terrible.

2. What is the reason I can not prime the entire hull at this stage. I realise I have a tape joint at the deck and this will need fairing. Can I not miss coat the entire hull so I can fair the imperfections.

Yes. I believe I said you can prime epoxy primer.

3. Does the Antifouling need to be carried out in one hit, Or can I finish paint the bottom and antifoul to the chine. Then antifoul to above the DWL at the end. Or does this show a bad joint...or bad practise !

I suppose this could be done for convenience. Just no topcoat over antifouling.

To my way of thinking if I can paint the bottom in one go it will give a better job rather than trying to paint up to the cradle then move the cradle and fill in. Or have I got that wrong !!!

Let me know what you think.

Cheers

Les

Answers embedded.

Painting a dark color has some extra considerations. First of all, the dark colors show flaws a lot more than white. So, you'll want to be real careful with the final finish because everything shows.

And you won't like to hear this next bit, and some joker will post here that I am wrong, but a dark color is a heat magnet. And what happens is the epoxy and fairing compounds heat and change. And the best way to deal with this is to heat the boat which carries some risks... In Greece, temperature of say 100F and hot sunny days will hit the boat and distort the finish and you'll get print through. So, how do you deal with this is to heat the hull up. I did so in a very technical fashion. I put the hulls in 40' shipping can and installed 6 heat probes in the can abd blasted heat into the cans and kept the temp at about 155 for two hours. This is called post curing. And the epoxy is strengthened about 8%. But, there are other approaches. You could black tent the boat under a black tarp outside. In hot sun in Greece, the boat will get hotter than it will in ambient conditions and should not print through. Or, you can just accept print through and fix it all in a repaint...

[les2021]

Cheers Dan

The dark colour seems to be an extra problem. My boat shed is a dark material and in the summer it does get extremely warm, By June we are talking 30 + outside and at least 10% hotter under the cover. So that should help ?

Just wondering how factory boats deal with dark colours ? I suppose they have heated spray shops ?

Anybody else have advice on this one or am I mad going for a dark colour ?

This painting lark gets a bit involved….

Cheers

Les

[fallguy1000]

Probably won't get as hot in the shed as under a black tarp temp post cure oven.

Here is an article. Read down to dark colors.

https://yachtsurvey.com/Paint.htm

[fallguy1000]

Cheers Dan

The dark colour seems to be an extra problem. My boat shed is a dark material and in the summer it does get extremely warm, By June we are talking 30 + outside and at least 10% hotter under the cover. So that should help ?

Just wondering how factory boats deal with dark colours ? I suppose they have heated spray shops ?

Anybody else have advice on this one or am I mad going for a dark colour ?

This painting lark gets a bit involved….

Cheers

Les

Most factories building epoxy core boats charge around 200-250k for a boat like yours..they may use prepegs or they may put the hull in an oven. Not sure how prepegs are post cured or if..

When I made the oven for my boat, I had to make sure no hull compartments were not breathable because I was doubling or better their build temps. Also, the heat should not be sudden. So, you would roll the boat out in the evening and build/cover it. Then the next day, real hot day, would warm up slowly. But no voids are allowed or they will blow up like a balloon. And you'd be hoping for post cure temps probably around 145-155F. Any hotter and you'd vent the enclosure.

Dark is harder. You may get some print through from white. I did not post cure the cabin and it is painted white and I got some movement at the beams on the roof and they all printed through once the sun hit them in the summer.

But if you want to go dark color; you want to tent it outside under black cover. I had old vinyl road signs here and they were actually on top of my ovens to get some solar gain!

Otherwise; I'd go lighter color or plan for some printing thru.

[fallguy1000]

Another thread of opinions for you Les.

https://www.boatdesign.net/threads/post ... 737/page-2

[fallguy1000]

You could also run an electric heater or two inside the shed mid summer in Greece, but make sure none of your supplies are inside. I would not advise heating acetone jugs or black markers or tools like sanders to 140F.

[TomW1]

les dark colors and hi temps do not go well go very well together. Bleed through from the fiberglass is the big problem. If you want a blue go light with something like Sea Foam from Awgripl or another one of there lighter blues. https://www.boatbuildercentral.com/wp-c ... rchart.pdf Well good luck and hoe you find a color you like.

Tom

[les2021]

Hi Guys

Thanks Dan / Tom

I now think I have read enough on paint colours !!! It does seem that there are very differing views on dark colours. I went to the local marina and went on various webcams through out the med and ionian waters, lots and lots of dark hulls.....I admit that I have not heard their views on heat etc.

The main thing is I can not afford to keep repainting !!! So at the moment I am thinking white / Ice blue combo or white / light grey.

The main thing is the bottom will be white so it will not hold me up. I will post my idea on topside paint scheme later and get your views and ideas on how to carry out the right sequence to make a good job of it.

Dan I will post sequence of what I think it is you are suggesting regarding the method of painting the bottom for you to have a look at, anybody else have a view... all will be gratefully received...

No building over the last few days, lousy winter storm.

Cheers

Les