Two-part paint issues

Are you painting wet on wet ? or allowing one coat to cure, sanding and recoating.

 

I could not even think about wet on wet! The roller would drag the previous coat. I am giving it all the time I can (over 20 hours min.)

 

Yes...the coat needs to harden... then be sanded, scuffed up, the recoted.

Wet on wet ...say three coats per day, is valuable when you need to build film thinkness.. but the finish will be poor.

Buildup coats with 2 part varnish are normally wet on wet then sanded flat after cure

 

Some paints will permit an over coat window without sanding. You paint apparently doesn't, so it needs to fully cure, get toothed, then recoated.

The bottom line is film thickness. Bulk it up, no matter how many coats it takes. Consider you'll likely wet sand 1/2 of the previous coating away. Keep this in mind when trying to figure out how much material is down.

75 degrees is fine, but you'll need a time window sufficient enough to permit application and flow out. 3 hours should do.

 

If the forecast to be trusted, between 6 and 8 it will not go over 80, and the boat is not getting direct sunlight till 10.
That's my window.

 

New developments.
I let the boat stay for the last 3 days. The forecast for the next week looks better.
However, I just went over the hull with the rug with some acetone. It picks the paint up. Not like washing it away, but still dissolving the 2-part paint that is supposed to be fully cured?

 

Why are you washing down with solvents? Wash with water, maybe some mild soap, rinse and dry. No need for solvents.

 

I wanted to see if the paint is cured well. I need some understanding what is happening. Should I go on with this paint? Get myself a spray gun, compressor etc? Or if I decide to repaint with Interlux Perfection, do I need to sand off completely or just cover with primer?

 

Kick the solvent, acetone, rag rubdown habit. Its bad, bad and bad. The solvent dissolves impurities and deposites them into your freshly toothed surface. The rag sheds micro fibers and deposites them into your freshly toothed surface.

Washdown with water and a soft brush...air dry.

If dust recontaminates your surface remove it with a special " tack rag" and a very light touch.

Google tack rag...be sure to use a 2 part compatable tack rag.

My experience is that if you can sand paint..it is cured.

I dont know your brand.

 

Your paint is designed to spray not roll. You will probably never be able to roll it good. You can try thinning and thinning and try rolling at cooler temps but some paints just won't brush/roll. Your paint is an acrylic. it won't stay open long enough, it will bubble due to other science stuff.

Cut your losses. Buy a proper roller/brush paint eg International Perfection or Awlgrip. They are both available in your colour. You will have a base colour at least with cheaper material.

Watch out what is said about sand paper. The grades are normally stated as dry sand paper eg 3M 255 grade. 'Waterproof" ie black paper grades are rougher. eg 600 waterproof is equivalent to 400 dry approximately.

You will need 400 dry grade...or equivalent on dark blue. Anything else is too rough and will show scratch marks after a month ie when paint has fully shrunk back. This is good enough for adhesion. The finer the sanding marks the more surface area you get. It isn't all about the grit. The abrasive people will bore you silly with the science. (eg thibnk about the SHAPE of the profile and how this affect the adhesion/ surface area)

 

I was recently supplied International Interprotect primer for a roll and brush job. I found that Interprotect , with a splash of the recomended thinner, generated a respectable primer finish. Just enough wet edge.

If you get frustrated with your primer, give Interprotect a try

 

Guys,
the biggest regret I have now is, I did not got this advise before all the hassle (and the paint dealer's rep is to be blamed).
I just got the Interlux Perfection, one blue, one white and their 2-part primer. Yesterday I've sanded everything with 320, (some real rough parts with 220).
This week it is supposed to be milder weather.
I hope I will get it right this time.
Thanks