2-part Polyurethane Paint Expert?

[quartersplash]

I have my 47 foot catamaran on the beach here in Bahia De Caraquez Ecuador, and will be painting with a 2 part polyurethane enamal. There is no one here that is expert enough to ask if you can color sand and buff out this paint if it doesn't turn out as smooth as I want it. I was told by one person that you shouldn't color sand and buff this paint as it removes the hardness that settles at the surface. Please fill me in so I don't make a mistake on this as I never want to do this job again!
Gracias,
Gary on S/V Archies Way

[malbert73]

My sympathies on your project. I spent MANY hours on my 33 foot monohull, so can only imagine the real estate you are covering.

As I understand, if you use IMRON products (like car paint type) they can be buffed, but AWLGRIP and PERFECTION (which I used) cannot be compunded or buffed without ruining the surface. You are best using Awlcare wax and cleaner to keep up the surface in the future.

Good luck.

[Stevens 47]

I used Alexseal 2 part LPU. I had some sweat drips in a couple of spots on the deck. Went back and sanded them with 2000 wet/dry then buffed came out great. I am told by some painters that they have done the same with Awlgrip, I suspect that if you ask Awlgrip they will tell you not to sand it.

If this is your first attempt at shooting you should invest some time in practicing first, it will be much more labor to sand and buff. Of course clean and tenting are a must and watch the humidity. Just my humble opinion.

Jack

[boatsmith]

Awlgrip cures with a skin which is very thin . Under the top skin the paint is of a different molecular structure. If you go through this thin skin it may initially look ok, but in days or weeks the spot will look dirty or flat. The inside of Awlgrip is softer and more porous than the skin. Imron is the same all the way through so patching, sanding, buffing work well. Awlgrip has another paint out over the last several years called Awlcraft. This paint is repairable. Most builders in my area (south FL) have switched to Awlcraft because"perfection" is easier to get close to.We have switched in the lats year and are very pleased with Awlcraft. David

[44'cruisingcat]

First up, I'm no expert. Far from it. I've just (mostly) finished spraying my 44' cat. Big job.

If you're spraying by yourself you'll need to split the boat up into manageable sections. IMO there's no way one man could spray the whole thing and keep a wet edge going.

I ended up with 6 sections, turret, cockpit, 2 inner sheer and 2 outer sheer panels.

Temps were around 25 - 28'C. You could possibly do bigger areas in cooler conditions.

I used Jotun Imperite 300, and looking at results friends have acheived with Awlgrip and other brands, I think the Jotun may be more user friendly. I was able to get a "wet" gloss without runs, with the other paints I saw runs and dry patches side by side. I think there must be a very small "right" window with these paints.

I've been advised the Jotun is sandable and buffable too.

Some pics:

[Jmolan]

Looks great Cruisingcat44, I hope you are happy with it as it looks so good!
I recall seeing a lot of postings by Main Sail and he had a real good handle on what you can or cannot do with various paints. This is a good link to some of what he has posted.

http://www.cruisersforum.com/forums/...long-6469.html

[TaoJones]

Wow, 44CC, excellent work! Big job, indeed. More like:

BIG JOB

TaoJones

[Joli]

Depends on the paint, if it is a acrylic urethane then you can buff it out, ie Awlcraft 2000, if it is a polyureathane like Awgrip then no it can't be buffed. The real pro here is Mainesail.

[quartersplash]

Thanks for the suggestions, and I hope mine turns out as good as the photos posted!
I left out part of the story here. Besides having to do this on the beach and working around the tides, we only have a couple of choices of paint brands. No Awlgrip or any of the marine paints. We just have an automotive 2 part paint here in Ecuador. I suppose I should try and call the manufacturer of the paint and see what they say about color sanding.
Gracias

[clockwork orange]

Absolutely no reason to use awlgrip or any of the other big name marine paints,they are no better or worse than the 3 part car paints from the even bigger name manufacturers such as Du pont and PPG. In our shop we mostly use Awlcraft because the customer has been sucked in by marketing and its a good paint and as others have said,its repairable, however i dont use it on my own boats because of the unimagainative pallette of colors available, i am so tired of doing yet another white or flag blue hull when there is an almost unlimited selection in car paints. The car paint manufacturers have had Acrylic urethanes (which is what Awlcraft 2000 is) for a lot longer because they have always needed repairabiliy,The notion that somehow "marine" makes it special is absurd, car paints have a much harder life,where i live they dump sand and salt on the roads in the winter and then mixed with the snow and then we drive in that crap at 75mph. We painted my sons boat last summer in a VW red using Nason fullthane paint, the boat had last been painted 20years ago when i built it and we used Du pont Centari which is not even a 2 part but it held up every bit as well as Awlgrip,it was dull but we had never polished it in the 20years but there was no peeling or blistering so we had minimal prep prior to the Nason.We painted my 36ft cat in 06 with awlcraft cream decks and PPG Concept for the topsides in Audi TT papaya orange.Thats another thing i like about car paints is you dont need to pick your color from a little color chip,you get the chance to see how it looks on a large object and then you walk in to the autobody supply store and they mix it for you right there in any town anywhere from a formular they already have, its not necessarily cheaper than the likes of awlgrip (which is why i used awlcraft on my decks) but personally i like more color choices and i can get those with car paints with no down side.When we paint my Lindenberg 26 it will be in a very cool color red that VW offered on the New Beetle.A customer of ours has a beetle convertible in that color so i will check the code when i next see him. My kayak is VW turbonium green and my sons is a metalic silver.
Steve.

[quartersplash]

Thanks for the posts. I guess my main question that hasn't been answered yet is:
With an automovive 2 part poyurethane can I color sand and rub out without destroying the hard surface of the paint? And if that is a problem, can I just rub it out with buffing compound without a problem?
Thanks

[clockwork orange]

Not sure what you mean by color sand? if you mean to wet sand through to 1500 or 2000 grit,then buff out the answer is yes although straight off the gun will always be a harder surface regardless of the paint chemistry,same is true with the original gelcoat,once you cut it you are in for more frequent polishing to keep the shine. Many of the car paints want you to clear coat,i never do that step on my boats.
Steve.