Bringing up a shine with epoxy?

General Discussion
1

Heyall

I’m laminating, and hotcoating with epoxy. When the hotcoat dries, it has a few little pimples and dust specks, but overall a pretty glossy look.

When i try to sand these little pimples and specks out, the epoxy starts to turn a milky white colour, and all though the spots do sand out, i’m left with a matt finish in some spots, and some spots are glossy…

Just wondering how people get a nice good shiny epoxy gloss finish?

Doc has said that a source of the milky colour is the water, when im using wet n dry sand paper…

Benny agreed and has suggested waiting a week for the epoxy to fully cure, and then sand… or use acryllic spray gloss afterwards…

Some of the bert’s boards have a super shine, is that epoxy or a different coat on the top?

Any info would be a great help!

Cheers

Ant

2

if you want to do a “gloss and polish”, lay down another coat of epoxy thinned out with denatured alcohol…very thin…shouldn’t have any dimples and whatnot. if needed, sand to at least 1000 grit, and then polish it out…should come out lookin’ good.

3

Or, you’ve got a compressor and gun, spray it with clear 2 pac polyurethane.

Denatured alcohol = metho… Soulstice’s idea will work too…

4

true true… all good advice,

but i used to use a sneaky shortcut, for customers concerned with weight…

if you know what youre doing with the airbrush, load up some fairly generous coats of premium clear acryl laq (still with flatting additive, but tone it back a shade)… then just let it hard off for an hour, hit it hard with 1200 wet… then smash it with cutting compound and the sander (on low speed)with a polish sponge on it…

all up i could get a 9’6" epoxy pig lookin like a full gloss/ polish, in about 10 mins

sorta just polishing up the spray coat… sounds dodgy, but

by crikey does it come up grand

5

soulstice,

We went to 2000 grit on the last one & then used regular surfboard polish - the surboard polish really did a better job than the car wax/polish approach. It seems that my first board is getting a chalky look to it - we thought it was the car wax/polish getting old… The car wax/polish seems to give a shine by “wetting” out the finish (kinda like when you rub it down with alcohol, the board looks nice until it drys) but the surfboard polish seems to microsand the finish to give a nice “dry” shine.

How much alcohol did you add? I’d like to try that on my next board.

Thanks for your help!

6

OK, so if i was to spray it with the 2 pac poly, when would I spray that on?

After the hotcoat?

After I sand the hotcoat?

Because if i sand the hot coat to get the pimples out, then it leaves milky epoxy… which would show through the clear 2 pac right?

Thanks for all the help guys.

Cheers

7
Quote:

How much alcohol did you add?..the surfboard polish seems to microsand the finish to give a nice “dry” shine.

i tend to just eyeball that kinda stuff. maybe a couple cap-fulls?? basically, you want it to lay on thin…thin = smooth. the denatured alcohol rises to the surface, and then just evaporates.

what kind of polish are you using???

8

thanks for the reply - it was the stuff from fiberglass supply:

http://www.fiberglasssupply.com/pdf/shaping/SurfPolish.pdf & its under the shaping tools section:

http://www.fiberglasssupply.com/Product_Catalog/ShapingTools/shapingtools.html

9

Hey Lavz

That milkyness is scratches from the sandpaper. Sand it fine enough and they will disappear with either 2 pac or a thin coat of epoxy and metho.

Try wetting a bit of where it looks milky, you’ll see what I mean.

2 pac goes on last, remember what Sabs’ boards looked like only clear…

10

HI Lavz!

I’ve been working on the epoxy shine myself… I made a few fins a few months ago and found out something about how I WAS doing it wrong. It tried to go too fast and skipped steps. I now do it like this…

Sand with 220 till it’s even, then 360, then 500, then 800, then 1000 THEN… Rubbing compound (from auto store) then the FH Polishing compound. A lot of work but it sure turnes out nice.

Les

11

Hey les…

So with all your sanding, did you get the milky effect happening too?

So I guess what your saying is, is you sand and sand and sand, its super smooth and then you rub out a shine?

L

12

The 2pac that Bert uses is made by upol. They also make a 1 pac that is supposed to perform like a 2 pac. It doesn’t have the isocyinides and has a much shorter health warning. This is the one that I use. The first board that I used it on I used the version that comes in a spray can. It took 2 cans (very expensive) and turned out awful. The next two boards I bought the one that is supposed to be sprayed from a sprayer. The results were much better, although not perfect. Next time I’m going to try a nozzle with a much finer spray opening (I used 1.4). It is much cheaper to go this way ($6 per board compared to $30). I think its a better way to go, but its going to take a bit of effort to get it right.

13

Hi Ant

You cand polish up epoxy it comes up very shiny see my old red beach pics

But the big but, you really need a good polisher with a wool pad

Makita one come at about $5oonz you can get cheap ryobi but they dont last

The 2 pac i use comes from a friend that makes carbon

car bonnets and imports all his stuff from asia

The cans dont have labels!

and the msd sheet is in chinese

Its super clear and really pulls tight when drying

Cant say i would recomned breathing the stuff

Ive tried brushing it lately and it seems to still pull nice and tight

There is a lot less chance of breathing it that way

Back to epoxy sand it with wet and dry through the grades down to 600 grit

Its long and boring then get some cutting compound put it on a rag and put the rag uder a random orbital this will give you a nice semi gloss

Got a new board just about finished

i will put a pic in when its done

Mike

14

Hey Lavz!

Don’t remember getting milky white but there are a lot of scratches with 80 grit (dry). It looks kind of whitish. Then less scratches with each higher grit (wet for the rest) of sand paper.

I used (still use, after 10 boards) a Harbor Freight ($30?) and it works just fine! The hard black rubber surface I glued a 3" foam (like for cushon on a chair) and then use sticky glue to attach sand paper. Then the bonnet it came with for rubbing compound and I bought an extra one specifically for the polishing compound.

Les

15

my process with epoxy gloss is as follows:

sand the hotcoat with 80, then 120.

pin lines, then gloss coat - thinned with acetone(about a cap ful - we don’t have RR or addtives here in brazil)

let dry overnight, then i put it in my oven(my black car with the windows cracked) for about 1 1/2 hour to help it cure super hard.

then the fun part, wet sand with 320/400/600/1000 then polishing compound, then a wipe down with car wax.

its a lot of work, but now i can polish the board in about an hour.

once you get the hotcoat sanded flat(and clean) the gloss lies pretty flat. also, make sure your brush is completely clean(no solvents at all) - this was my original problem. a really fin bristle helps too.

hope that helps,