Gel Coat Cracking & Painting

[marksa1458]

I am in process of restoring a 1966 DuoCraft 14' Runabout - Floor, stringers and transom were wood chips and are being replaced - As a result of the bad structure there are a number of gel coat cracks in the hull.

I have been looking at SuperMarine Paint and submitted an inquiry on their products and they responded with:

Quote >>>>>>
The right primer is SM-664 Etching Primer. It will fill the cracks and
spider webbing. Here is your materials list:

SM-695 Etching Cleaner
SM-664 Etching Primer
SM-605 Thinner
SM-1000 Revolution
SM-160 Accelerator/Hardener (optional)

The 160 A/H is optional. In addition to speeding the dry and cure time it
increases hardness and improves chemical resistance.

<<<< Quote

My experience with painting is that all imperfections show right up and my question is if there etching primer will in fact fill the cracks and make a nice surface for the paint to stick to?

 

[saildan]

Re: Gel Coat Cracking & Painting

My experience with painting is that all imperfections show right up and my question is if there etching primer will in fact fill the cracks and make a nice surface for the paint to stick to?

That's the paint company's hope. They want to cater to the human desire for a simple solution. I wish there was a test to determine yes or no before investing in a product. Too often we become the guinea pigs at our own expense.

Without extensive experience in your corner to help you judge with, I think the only way to know for sure is to test a section and see if the products will do the trick. If not you'll need to go old school and either manually open the cracks slightly wider so they'll fill rather than bridge or sand back the gelcoat deep enough to eliminate the surface crazing before fairing/priming and painting.

.

 

[marksa1458]

Re: Gel Coat Cracking & Painting

Thanks for the input - I think you are right on. I hate experimenting with such high priced products - switched to system three epoxy for this project from West systems and haven't been happy with it all - none of my test batches have kicked properly - never had the problem with west...

 

[ondarvr]

Re: Gel Coat Cracking & Painting

If the cracked surface never flexed again it "may" be possible to just paint over the cracks and not have them come back.

The gel coat cracked for a reason, you need to find that reason and fix that first, if you don't you will most likely just have cracked paint in short period of time.

 

[saildan]

Re: Gel Coat Cracking & Painting

Thanks for the input - I think you are right on. I hate experimenting with such high priced products - switched to system three epoxy for this project from West systems and haven't been happy with it all - none of my test batches have kicked properly - never had the problem with west...

Is System Three's hardner to resin ratio the same as WEST ? Is their kick time the same ?

With epoxy you cannot deviate from the H:R ratio set out by the manufacturer and some are diffrent from WEST's 1:1

Just checking, I get used to one brand and sometimes forget when I use another.