Epoxy gloss coat

General Discussion
1

Ok i have read thru the all the info here and I have tried to compile all the best tips and this is what i am going to try. I not set up to do 2 pack urethane and I am keen to get the best finish from epoxy for my homers.

A) sand hot coat down to 600 grit

B) run a epoxy thinned witH methylated spirits (70/30)

C) wet and dry to 1200 grit

D) buff with cutting/burnishing compond with cheese cloth under soft sander pad.

I tried spar vanish on my last board with crap results, I havent tried a clear laqure yet.

I will let you know how it goes over the next few days.

any sugestions on above are welcome.

cheers

2

I’ve used an automotive acrylic clear from a spray can recently.

One can cost NZ$12, and i used the whole thing, 4 coats each side. Half the price of 2 pac.

I sanded to 80 grit before applying, and it fills the scratches no probs, just like 2 pac. so easy.

5 minutes between coats, toch dry in half an hour.

After 10 - 24 hours, wet sand with 1500 lightly, then cut with compounding paste, and it comes out almost as good as my 2 pac finishes.

You can get it from any of the general car accesories stores.

Non yellowing, UV stable, hard wearing, flexible.

I just don’t know how it will stand up to the test of time!

In 12 months or so if it’s still looking great, i’m going to change to that instead of 2 pac.

I made sure that there were no pin holes in the epoxy before applying, just in case… with 2 pac i’m happy to let it fill in minor oin holes.

Kit

3

The rumor is there will soon be an epoxy gloss/finish coat that will substantially improve epoxy finishes…

BUT, until that becomes a reality, have you considered automotive finishes? Just today in the water a

local legend “Mouse” (74 years young) showed off his new board. It was finished by a hotrod builder.

The finish blew away anything I’ve seen to date, incredible. A type of new automotive urethane, it

may be water-based. I’ll have to ask around.

I glassed the board using RR, and it was finish-sanded with 220-grit. I understand they did a clear build

coat, then a flowing final clear coat. It was done in a booth. It was neither rubbed-out nor polished

afterwards.

I know of two local paint places willing to “shoot” a board. The booth is definitely part of the secret.

They baked it, and they knew about the EPS core which limited radiated temperatures to 140F.

Maybe if you approach (the actual painter rather than a floor manager) a painter who might shoot a

board in his “off-hours” you could get a finish similar to Mouse’s for a pretty reasonable price?

I think it is def worth looking into…

4

Kit

that sounds like heaps less work…ahh and i am real lazy as well.

Plusone,

Yeah those body shops can do a great job a Mate of mine use to drop his kiteboards into a pannel beaters shop where they would finish them off, paint/laqure. cost about 150 dollars i think. buys alot of acrylic…

thanks for the feedback

5

kiri,

Only thing I would change is that I would not sand the hotcoat all the way to 600. In my experience, a hotcoat sanded that smooth tends to let the epoxy gloss coat ‘run off’ more quickly when applying it and almost look like it is ‘beading’ on the smooth surface. 150 to 220 is good enough.

JSS

6

The only reason you need to wet sand 2pac with 1500 grit before compounding is to knock down the rough finish you get when not using a spray booth.

Fall-out grit from the air means that even a spray gun 2pac will not come out mirror finish.

Plus One is right about the spray booth! With booth, extractor fans, wetted down floor, etc etc you can spray mirror finishes that don’t even need a cut and polish. This is what the automotive guys do.

But I just spray it on thickly, in my shaping bay (heaps of fallout) and let the wet sand sort out the roughness.

Then the cutting paste works a treat for bringing out the shine.

With a rattle-can acrylic, the atomization of the paint is nowhere near as good, so you will definitely need to use a cutting paste, and more than likely 1500 grit wet-sand beforehand, due to fall out.

Hope this helps!

The acrylic stuff I used is meant for cars, surely it’s pretty tough?

Maybe it won’t handle the exposure to salt after a while… we’ll see!

So don’t quote me that lasts forever, but it definitely looks the part!

Kit

7

Tupac?

Were can you get it in California?

What is it?

Is it just automotive clear?

My nephew who lives on the Sunshine Coast of OZ is always telling me about how good the finishes are in OZ while keeping the boards light.

8

well hit it with 220 grit cleaned down then brushed on 30% meths and 70% resin came out shinny, still a few dimples and fall out that will need to be buffed out when dry.

overall happy for a shed hack finish

9

Kiricore,

I’ve been trying to keep an eye open for glossing epoxy. Yours is the first post I’ve found mentioning methylated spirits. What is methylated spirits? Does it go by anyother names?

Nevermind. I just looked it up. It goes by Denatured Alcohol her in California.

So, alcohol as a thinner? Does it improve hardness and sandability or is it just for flow? Have you heard of any down side to using it this way.

I’m interested in what you think after you’ve wet sanded and buffed. Keep us posted.

Thanks.

10

Yeah, it’s an automotive clear.

It’s a 2 part polyurethane, the stuff that you add a hardener to. (hence called 2 pack, 2 part, 2pac, whatever)

The one I use is a “high solids” one, and is mixed 2:1 ratio of paint to hardener.

In a thread a few months ago, I mentioned 2pak, and someone (i’ve forgotten who) from california said that theres some safety rules that prevent you from spraying it unless you have the proper supplied-air respirator setup?

He might have only meant for production, OSHA requirements for a business… not sure what the rules are for home use.

The staff in an automotive paint store will know.

That stuff is pretty toxic, heavily laden with isocyanates, which are bad!

So be careful, wear a mask with the appropriate vapour cartridge… or wear your scuba gear when you do it!

That just reminded me, I was researching home-made “hooka dive systems”, which are a scuba diving setup that has an air hose running from an air pump that stays on the deck of your boat.

You can dive around the boat, and not have to come up due to empty tanks. But watch your nitrogen levels.

Anyway, I thought that would be a cheap way of making a supplied air respirator for spray painting!

I saw plans on the net for one that basically uses a elctric car tyre pump, with a long hose running out to your standard regulator.

Really usefull for cleaning the underside of your boat while it’s still in the water.

Theres a solution if your keen :slight_smile:

OSHA health and safety staff would have fit!

Kit

11

i tried a different method recently

i cant remember who posted this tip but its a goody

before you brush down the epoxy gloss coat

squegee down about 20 grams thined with alcahol or zylene

let that go tacky and then lay down the gloss unthined

you can use the same technique for the filler coat

it prevents ripples and fisheyes

but yeah ive started using 2pac as well

it seems to fill any little pinholes

it leaves a speed type finish cuased by the fallout

or can be wetsanded and buffed

i setup a fan in reverse out the window with a respirator

and a gravity feed spray gun(thanks Sabs for the tips)

12

Ok

Tried the thinned epoxy with meths and it produced an ok finish still had quite a few dimples and brushstrokes, I am after a better finish out of the shed so sanded (again) back down to 120 grit and hit it with the clear arylic. This worked a treat. Thanks KK for the tips, UV stable and at 12 dollars a can its not hard to do once a year if required.

I will let you know how it lasts.

cheers