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If you are planning to apply a new top coat to renew a cracked or crazed gel coat surface, look into using gel coat treated with DURATEC additives as opposed to a linear polyurethane paint like AWLGRIP or IMRON.

The Duratec additives are made by made by Hawkeye Industries, and they are a clear additive that is mixed with with the gel coat of your choice. Duratec makes the gel coat spray like paint, lay out,and hardens with a high-gloss tack-free finish. You can make multiple passes all day long to build up the gel coat layer as thick as you want. If you mess up, nothing is easier [than gel coat] to sand and buff out. Paints like AWLGRIP tend to accentuate imperfections, gelcoat is somewhat better at hiding them, so the prep work can be easier as well.

Hawkeye Industries make a sprayable primer which is like an easy to sand, sprayable putty. I used in on a Boston Whaler boat that was heavily damaged and had been painted multiple times by the [commercial fisherman] who owned it before; the boat looked like new when done. Another advantage: if you have to make a repair or fix a scratch, the top layer will be easy to sand, buff, blend, whatever, because it's gelcoat; repairs on AWLGRIP are tough to hide.

There are limitations. You have to get sprayed-on gel couat out of the gun in about eight minutes, or it is goodbye gun. I bought three $20 guns from Harbor Freight figuring I'd just chuck them if the stuff hardened in the tip. This turned out to be a bad idea. The tips of the spray guns were too small, and the gel coat couldn't move the jets fast enough. The solution came from DYNA GROUP, the company that sold me the Duratec; they sold me a gun with a 2.0 tip for $95. You can spray a quart with plenty of time to run a little acetone through the gun and reload the next batch.

On my hull, I went a lightly over the non-skid deck areas and this kept the look and effectiveness of the non-skid pattern. I'm getting ready to restore [silly expression deleted] Boston Whaler boat, and I intend to used Hawkeye Industries DURATEC gel coat additive again.

I am curious to hear if anyone has had a different experience with DURATEC gel coat additive.

[I separated this interesting new topic about using DURATEC gel coat additive from its original thread, which was on a different topic.--jimh]

Are you talking about the Hawkeye Industries product called DURATEC High-Gloss Additive 904-001? I found this data sheet about it:

http://duratec1.com/pdf/DS%20904-001.pdf

Hawkeye Industries has a whole line of products under their DURATEC name, so it would be helpful to identify the specific product you are discussing. They do feature their Duratec High Gloss Additive 904-001. They describe it as follows:

Duratec High Gloss Additive 904-001: Blend with gel coat to create a repair coating or to improve the initial properties of the gel coat. A 50:50 blend with gel coat will air-cure, even at the thin edge of a repair. The repaired area can be polished to a gloss that goes all the way to the edge; prevent the ugly low gloss donut often seen in gelcoat repairs.

This is good news. I will no doubt try this product on my next project boat. I have used AwlGrip for many years with good results, but like you say, what you got when you are done spraying is what you have.

Does [this not yet precisely identified DURATEC additive for gel coat] dry to a high gloss?

Do you need to polish or sand it?

Also, I found a spray gun with a 2.0 tip for about $20.

Binkster wrote:Does [this not yet precisely identified DURATEC additive for gel coat] dry to a high gloss?

Do you need to polish or sand it?

If the additive that is under discussion turns out to be Duratec High Gloss Additive 904-001, then I think your question about high gloss can be answered by the mention of high gloss in the product's name, and your question about polishing answered from the passage I quoted in my earlier reply (above), the one that says, "The repaired area can be polished to a gloss..."

We need Driller to identify the product he is endorsing. He also commented:

Duratec makes the gel coat spray like paint, lay out,and hardens with a high-gloss tack-free finish.

Yes, [Duratec High Gloss Additive 904-001] is the product that I used for the finish coats, and it does cure to a high gloss.

If you need to build up a major thickness of gel coat, however, you mix a higher ratio of gel coat to Duratec for the first few passes, then mix a 50-50 ratio for the final pass for the highest gloss. If I'm refinishing gel coat that is similar in color and is in generally decent condition, I just make several passes with the 50-50 ratio. I've found that if I have my son standing by with a stopwatch (on his iPhone), giving me the 9-minute warning, I can really move along. I premix the gel coat and duratec into one quart containers and add the MEK catalyst as I put the resin mixture in the spray gun. In addition to the high gloss additive, Hawkeye does make several different Duratec products, including some primers that can really be built up heavily where needed. They are all polyester so they're all easy and fast.

Here is a picture of that boat before restoration began. The boat was rough, but it turned a lot of heads afterwards--and caught a TON of salmon. And by the way, the retailer I purchased the Duratec from was Dynagrout in New York, but I'd contact Hawkeye Industries for someone local.

Your restored 21 OUTRAGE looks very nice. I am always most impressed by a restoration that started with a boat whose condition was about a "3" and ends up with a boat at a "9" or "10."

Thanks Jim. That boat was worse than it looks in that picture, probably should have been scrapped but the floors and transom were rock solid so I figured it was worth the effort. Now I'm doing a '73 outrage 21 that had been sitting in a barn for 25 years. It doesn't need to be refinished (just doing the teak and having a new fuel tank built) - and in hopes of a bit more speed, I picked up a pair of 70 evinrudes and hung the Bearcats on the barn wall for a short vacation. I bought a nice Atlantic Towers T top for it but I'm having second thoughts about drilling a bunch of holes and gooping up the deck with 5200, may go with the Mills canvas instead.

This additive does work incredibly well. The finish is high gloss and easy to spray. I restored a15' sport about 2 years ago that came out pretty nice for my first resto. Just an FYI it comes with about 7 pages of warnings and states more dangerous when atomized (sprayed) than when it's rolled or brushed. Definitely wear a quality respirator.