Epoxy or Vinylester Barrier Coat

[HankOnthewater]

I agree with Jedi in post #10, Although I have not use the product Interprotect, I would not use a polyester resin, and then epoxy: Straight epoxy.
Not a problem if the hulll is dry, and the (lack of) dryness is often the offending issue. It may take months or a year for a hull to dry out depending on temp and humidity.
I have done a few hulls like this, never a problem (not my boats), most owners were not very happy initially as I suggested to wait another 6 weeks, and.... again another 6 weeks for the hull to be dryer, but the end result........ owners were happy, no issues.

[Allied39]

Remember that epoxy resin covers a broad spectrum.
I am a system three man. Have used hundreds of gallons of the stuff and am absolutely satisfied with every aspect.
When doing a hull job six months or so back I was ready for the seal coat on bare glass.
System three has two resins most suited to for this application, silver tip and clear coat. Clear coat is way more expensive, but a small expense when considering the whole scope of the job.
I did several test patches, the clear coat easily showed a better "bite" on the glass. So thats what I went with.
Just something to consider amoungst all the info you are digesting.
This is for the OP, not interested in arguing or dealing with the trolls

[Scrimshaw4]

The color of the Sherwan Williams is somewhat irrelevant since you will be covering it with bottom paint. You'll probably want to sand it when done (fair it) so put on thick coats. If you're using an ablative you'l probably put on 3 coats, with the first coat being a "marker" coat of a contrasting color to the outer two coats. This way when the marker shows you'll know when your bottom paint needs to be done again.

[cburger]

Originally Posted by Scrimshaw4

The color of the Sherwan Williams is somewhat irrelevant since you will be covering it with bottom paint. You'll probably want to sand it when done (fair it) so put on thick coats. If you're using an ablative you'l probably put on 3 coats, with the first coat being a "marker" coat of a contrasting color to the outer two coats. This way when the marker shows you'll know when your bottom paint needs to be done again.

I asked about different colors of the barrier coat so better able to see coverage when applying different layers.

I have not been able to find the product you utilized do you recall the exact nomenclature? It comes up as a low VOC product, not sure this is what you used.

[Scrimshaw4]

Here are pics of the Sherwan Williams Barrier Coat Parts A & B




Hope this helps

[kenbo]

Originally Posted by cburger

I asked about different colors of the barrier coat so better able to see coverage when applying different layers.

I have not been able to find the product you utilized do you recall the exact nomenclature? It comes up as a low VOC product, not sure this is what you used.

Google Sherwin Williams Formula 150, Type III. Formula 150 is a steel and aluminum primer, green only. Formula 15x are the top coats.

These products are low VOC paints with only about 60% solids. System 3 epoxies and some other brands are are 100% solids. Blister repair failures done with epoxy are usually caused by not drying the hull adequately or improper measuring and mixing of the epoxy itself.

[cburger]

Originally Posted by kenbo

Google Sherwin Williams Formula 150, Type III. Formula 150 is a steel and aluminum primer, green only. Formula 15x are the top coats.

What are the negatives of using this product on fiberglass?

These products are low VOC paints with only about 60% solids. System 3 epoxies and some other brands are are 100% solids. Blister repair failures done with epoxy are usually caused by not drying the hull adequately or improper measuring and mixing of the epoxy itself.

Did you add some type of flake to the epoxy to make it a barrier coat or just roll on straight?


Thanks to all who have contributed here

[kenbo]

Originally Posted by cburger

Did you add some type of flake to the epoxy to make it a barrier coat or just roll on straight?


Thanks to all who have contributed here

The negatives of using the Sherwin Williams epoxy paint is that it is not as impermeable to water as 100% solids epoxy. I've used that product on cast iron keels but I found it to be less satisfactory than a high quality moisture cured urethane (MCU) paint. POR 15 is a good but pricey MCU there are others.

I would not add anything to the epoxy that I would be using as a barrier coat. It seems like you're refering to Interlux's marketing brochure of using "micro platelets". Look at the data sheet https://www.international-yachtpaint...4_20190726.pdf. Interluxe's epoxy base is 45% solids.

Let your hull dry, clean it thoroughly with dewaxer then acetone again. Don't skip the dewaxer it's expensive but it's essential. Repair the pox with epoxy with milled glass fibers and fumed silica. Sand all repairs fair and wipe the hull with acetone again. Roll on a coat of 100% solids epoxy and hot roll a second coat. Let the epoxy fully cure and wash hull with soapy water to remove the amine blush. Sand and bottom paint. Be patient, a good result takes time.

[cburger]

Originally Posted by Happydrv

Vinylester is junk. Barrier coats are epoxy for a good reason.
Must be done correctly like Wingless says.

Very broad statement, I thought the best hulls are vinylester not polyester

[cburger]

Originally Posted by Allied39

Remember that epoxy resin covers a broad spectrum.
I am a system three man. Have used hundreds of gallons of the stuff and am absolutely satisfied with every aspect.
When doing a hull job six months or so back I was ready for the seal coat on bare glass.
System three has two resins most suited to for this application, silver tip and clear coat. Clear coat is way more expensive, but a small expense when considering the whole scope of the job.
I did several test patches, the clear coat easily showed a better "bite" on the glass. So thats what I went with.
Just something to consider amoungst all the info you are digesting.
This is for the OP, not interested in arguing or dealing with the trolls

You have peaked my interest in using the System Three epoxy, if I understand your application is to hot coat two to three coats as a barrier coat.

Certainly a lot less involved than 5 coats of Interprotect.

[cburger]

Originally Posted by Allied39

Remember that epoxy resin covers a broad spectrum.
I am a system three man. Have used hundreds of gallons of the stuff and am absolutely satisfied with every aspect.
When doing a hull job six months or so back I was ready for the seal coat on bare glass.
System three has two resins most suited to for this application, silver tip and clear coat. Clear coat is way more expensive, but a small expense when considering the whole scope of the job.
I did several test patches, the clear coat easily showed a better "bite" on the glass. So thats what I went with.
Just something to consider amoungst all the info you are digesting.
This is for the OP, not interested in arguing or dealing with the trolls

First application of System 3 clearcoat today, typically how many coats have you applied for good results,

Thank You

[cburger]

Two coats of System 3 Clear coat epoxy was rolled on, second coat was applied while first coat was slightly tacky and the first coat of Petit Hydrocoat was rolled on when the final coat of epoxy was still tacky.

After the work was completed by chance I came upon System 3 instructions for using their epoxy as barrier coat that indicates 4 coats of epoxy minimum should be applied and that the final coat of epoxy should be dry and sanded
before applying bottom paint and that if this direction is not followed a
nd the bottom paint "Hot Coated" to the epoxy you risk having the bottom paint and epoxy fall off after the boat is launched.

The vessel will remain on the hard for many months before launch.

What are the chances that the coatings will actually fail?