Removing gel coat and spraying Awl Grip

[wet-foot]

I need to remove the gel coat from a slightly curved hull area. Is it possible to rip it off with a router or some similar tool? The area is about 7' long and 1' wide.
I guess the other option is a dual action sander and a belt sander. Looking to refinish a small 12' hull, is it hard to spray awl grip polyester urethane? I know it takes a long time to cure, so perhaps awl grip acrylic urethane is the answer. Can you spray these products with a good mask or do you need an air supply?

[Jimbo1490]

Why do you feel you need to remove the gelcoat prior to refinishing? Is it blistered? Sound, aged gelcoat is an ideal substrate for painting, so why remove it if it's OK? Just smooth it down with a DA sander with P150-180 and paint. If the gelcoat is NOT sound, and you must remove it, that is another job altogether.

Jimbo

[wet-foot]

Getting the gel coat off was fairly easy, got the base nice and smooth too. I had to get down to the glass resin base to reshape the hull with epoxy and glass. Wondering what a good paint system to use is? This is a trailer item so it won't be sitting in the water for any extended period.

[Jimbo1490]

AWl Grip is a good system. Sterling is very similar but handles and cures better in cold weather application. Pricing is almost identical. Some of the Sherwin-Williams industrial dealers have started carrying Jet-Glo which is also excellent. The selection of primer is AT LEAST as important as the topcoat. Use a good epoxy primer that is tough and chip resistant. The tougher primers are also more difficult to sand, but that's life

Jimbo

[wet-foot]

I can get Awl Grip but will look into Sterling also. Anything I should know or do before spraying these products?

[Jimbo1490]

These 'fleet' type finishes are formulated for painting big things like boats and airplanes. To that end, they are formulated to 'flash off' much more slowly than typical automotive spray paints. They also cure much slower. Painters who have only shot auto and industrial coatings have a tendency to apply too much paint too quickly, especially on the first coat, and get plenty of runs and sags. One way to cope with this is to shoot a 'dusty' first coat followed by a 'full wet' second coat after a 20-30 minute wait. Another method that works well when spraying a smaller area is to substitue MEK for the reducer. NOT lacquer thinner, NEVER acetone, but ONLY MEK. Then the flash-off time will be similar to the more familiar auto finishes. Awl-Grip has recently begun advocating a three coat method with three medium coats rather than one 'dry' coat and one 'full wet' coat.

Many painters (myself included) do not care for Awl-Grip's T0003 'Medium Reducer'. It is really slow reducer. Yet if you try to use it in hot ambient conditions (common here in Orlando) it often causes solvent popping. Awl-Grip has admitted this fault and recommends switching to fast reducer or MEK during hot conditions (WTF ??!!)

The Sterling 1014 reducer does not have this fault, or any others, and many painters use it in all paints regardless of manufacturer.

Measure the viscosity of the paint and remember that it's easier to shoot thin paint than thick. There's no need to hurry; in moderate temperatures, these paints will provide a very long 'wet edge' time so you do not have to worry about losing the wet edge. Fleet finishes tend to be a bit harder to atomize properly, so use atomization pressure at the top of the range, about 60-70 psi with conventional air-atomizing guns.

Fleet finishes cure more slowly, taking as much as 24 hour to go to the 'tape-free' stage in cool (but not cold) shop conditions. This WILL be a problem if you are painting outdoors. The careful use of a cure accelerator like Pro Cure X-98 can reduce this by an amount proportional to admix percentage. You really should measure the accelerator accurately as the max mix ration is 256:1 (1/2 OZ/Gal). Get a disposable pipette to measure for a small batch, otherwise a medicine measureing cup works nicely for a quart mix or more. At 'full accelerator' Awl-Grip will go to 'tape-free' in 2-3 hours compared to about 12 without in standard conditions.

Jimbo

[wet-foot]

Can you spray this material with a siphon feed automotive type gun? Do you spray boats professionally, you are obviously very knowledgeable on this subject? appreciate the input, thanks!!!

[Jimbo1490]

Siphon guns are OK with the usual limitations for siphon guns; heavy and tiresome, can't spray upside down, low material rate, and etc. Gravity or especially pressure feed is always better. I spray airplanes professionally, but have sprayed a few boats over the years.

Jimbo

[JR-Shine]

If you are not an expert with a spray gun, you will probably get much better results rolling and tipping. Here is a page we made describing the techniques. We use Sterling paint, but the technique is the same with Awlgrip...

http://www.boatbuildercentral.com/he...g_roll_tip.htm

[wet-foot]

Very nice instructions plus the results look excellent. When I see the price of a complete paint kit with all the prep required I believe I could get the bottom in shape in the same amount of time with gel coat. The area is about 35 sq feet. Gel coat will cost me about $30. I guess if I can't get the results I want I can still go with paint. I am also considering doing the bottom in epoxy with black pigment. Even without the UV protection I think this is a pretty good option. A while back I built a cedar srtrip canoe and left the epoxy unprotected. No problems even 5 years down the road, plus I could just sand and recoat with no varnish to worry about. Black is probably the only color that would work as it yellows rather fast.

[Jimbo1490]

Notice that he was able to get a nice coat of paint on while the boat was located in a busy warehouse complex, with his and other vehicles close by. This you could NEVER do with spray application (at least not withot fistfights and lawsuits ). We tipped and rolled a Boeing 707 fuselage once because creating overspray was not an option. Came out pretty good and we didn't even use brush catalyst, just the brush reducer. But we had about 8 painters and everybody knew what they were doing.

Jimbo

[wet-foot]

For a small hull bottom would poyurethane paint stand up as well as gel coat?
Is it possible to touch up scratches or would the entire bottom need refinising?
I am really big on upkeep but would not want to redo the entire surface every other year!

[catmando2]

This is the paint job I did on my last cat. A few of us builders won't use Awlgrip or Sterling as it can be difficult to repair.

I've always used on my own boats Ameron coatings for highbuild, a fraction of the cost and the topcoat I used was urethane not polyurethane. Easy to repair, buffable and cheap. The stuff we use has pictures of mining equipment on it and is used by some airlines in Australia.

I've worked on cats with 14 year old paint jobs and a cut and polish brings it up like new. I don't think you can buff polyurethane as you burn the surface.

pics of my last cats paintjob. she is 10 years old now and the paint is fine.

Dave

[wet-foot]

The exposed top side I'm dealling with is only about 20 square feet so a good automotive paint could work. Will try my epoxy coated bottom for ease of repair and touch-up. Great to see it is possible to lay down a nice smooth coat spraying and even brushing out a rolled on coat. I like the brushing idea for the bottom as you would certainly laying down more paint. Thanks for all the expert advice.