Duratec: anybody with experience

So the hull of the boat I'm building has been faired with epoxy mixed with a fairing filler and pigment [US Composites brand]. I was going to prime and paint with a 2 part poly, but during my internet searches I found a website for Duratec, a thining agent for Gel Coat, so you can spray with conventional equipment. On some of the forums I browsed, some people say it goes on great and dries hard, and some say you can remove it when it's cured with your fingernail. Does any body have any experience with this product, or should I go back to plan "A" with the single stage 2 part poly. Thank you in advance...

Joe D.

 

Have sprayed gallons of duratech and the only thinneris ever used is acetone nothing else
Its goes so hard in 48 hours you lucky to even scratch it and if its left in the sun you wont be able to even sand it.

 

By paint with poly- you mean polyurethane, right? I used their vinylester product so I could gel coat over epoxy. Which isn't the product you are thinking of, I don't think (it worked great and customer service/sales/tech help was great). If you are using a urethane above the waterline, I think many people will tell you it isn't necessary.

For what it is worth, the product I used said not to use over epoxy/microbaloons. I did anyways and it worked fine.

 

I'll second Tunnels on Duratec, I have sprayed dozens of plugs with Duratec and love the stuff.

My sequence goes: (over timber)
Crystal Clear Sealer (only need for timber to seal it)
Base Primer (Sand with 400 grit)
EZ Sanding Gray Primer (top coat, sanded down to 1200 grit)
Buff Polish

Just reread the original question, I would use Duratec on moulds or plugs but I wouldnt use it on the actual hull, 2 part poly would be better suited for that

Hope this helps

DAVE

 

Thanks for the replies. On the other forums I browsed most said they used Duratec for the gel coat finish on their boats and loved it. I gonna buy some and do a test panel, than make my final decision. Thanks Again...

Joe D

 

Hawkeye has several products in the Duratec range. Perhaps it is best to first determine on which Duratec product we are talking! I have the suspicion that you are talking about 2 different products.

Here is the product list:

http://www.duratec1.com/Product Names & Codes.html

 

Yes you can use it on a hull or a deck what ever !! i have a small boat with a bad case of mud cracked gelcoat and sprayed and squeeged the durateck into the cracks and let it go hard then a spray a second time left it and spent time with 180 sand paper and gave it a good sand and made sure all the cracks had been filled 100% then another fine spray with acetone as a thinner and 400 wet sanded making sure not to go through to the deck below then a final check and a industrial 2 part polyurethane and it came up really good that was more than 5 years ago and to this day not one mark from the mud cracking has ever shown up . Its spent quite some time out in the sun and its as good as the day i sprayed it .
The other thing i like its able to have q cells added and use as a fairing coat with a pressure pot can build 1.5 mm to 2 mm quite easy ,after its sanded then use the straight duratech over the top and what ever paint you want to use .
Its consistant !! it predictable , its dependable and i dont know of any one ever having any kind of problems with it for any reason . As a barrier coat between other things theres nothing better !!

 

Which Duratec!!!

 

duratech black & grey primer with guide coat

I like it too, pretty easy to use, only probs I've had(my fault) was to shhot it on too cold a day, tented it the next & heated & back to good.
I've used the high gloss gelcoat additive as well, makes gelcoat more like paint to apply, also good stuff but only on tooling repairs & some small touch ups, I'd imagine that UV resistance might be lower butthe only basis to that line of thinking is that its a little less opaque than plain gel. Jeff

 

Polyester gelcoat over epoxy can be used, but you have to be sure to remove all the amine wax. It will not have the best adhesion though. Since you used epoxy, a polyurethane paint would be a better choice.

 

Thanks gonzo. I had'nt thought of that. I really wanted a Gel Coat finish, but it appears I'm probably better off with paint...Thanks Again...

Joe D

 

Like Gonzo said, gel coat doesn't bond all that well to epoxy, so use a paint.

As far as the Duratec clear additive (if that's the product you are talking about) it works well to reduce the viscosity and allow the gel coat spray, flow to level better. The problem you run into is it will also reduce the UV and water resistance of the gel coat, the amount of reduction depends on how much you add

 

most of my customer is working on Duratec are for plug. But this is an good idea for finish boat. Great surface property, special those black gelcoat, fantastic!

 

The moment you start mixing things with other things you are changing the structure and what you started with is no longer going to do what its surposed to do .Simple dont do it !!

 

"I really wanted a Gel Coat finish, but it appears I'm probably better off with paint...Thanks Again..."

I used the vinylester duratec product as a layer between epoxy and gel coat. It seems to work fine. Call them to ask, they are very helpful.