oh the humanity! (epoxy filler coat problems- revised)

General Discussion
1

just glassed my second timber board. the lam came out really good but when i applied the filler coat it all went pear shaped!

there’s more fisheyes than a god damn trout farm!

looks to me like silicone but im not really sure. now the problem im facing is, i cant seem to sand it out. the sanding discs just clog up. even sanding it wet doesn’t seem to help.

have i phucked my board or is there a way out of this?

im not happy!

if i leave it to dry for a while longer, will that stop the discs from clogging up?

not quite sure of the epoxy’s name but it came highly recommended!

remember this disaster? well, thanks to the help of the swaylocks family i actually brought it back from the brink.

a big thanks to those that helped. for a minute there, i thought she was a goner!

2

Try sticking that epoxy in the microwave and zap it pretty good before hot coating next time. Put your hardener in and mix first as well. That way it all comes to the same temeperature. Somewhere on Sway’s someone said that epoxy will draw into itself and leave empty pools on fill coating if you don’t do this. Did it start contracting when you put it on? Otherwise what grit are you using? The coarser the grit the harder it is to clog and I’ve used 60 grit on epoxy without too much fuss. When I’m desperate that is. So basically my only suggestion is to sand the f$@k out of it and reglass and rehotcoat unless you think you can level it with polyester and get it to stick.

3

Yucky it is…

Classic separation dramas. Its heartbreaking is’nt it.

A few things I’ve seen making shit happen like that:-

Lam surface with any contamination : - Did you polish something else anywhere near the board, or on the same stands? Your guess could be it - Traces of silicone. Cutting compound sometimes has it.

Lack of wax in Filler coat : - Did you add wax in styrene to the filler coat mix?

Heat : - Did you try to set off the filler coat with heat while still wet?

Its painful, but you are going to need to scratch up the interior surface of all those pits with some sandpaper by hand. Fill each of them with a little dollop, and sand them down flat before maybe going another coat.

The best epoxy filler coats go down thirty seconds after the board is sanded…even need to watch out for moisture in your airline when you blow the board off!

Josh

4

Oh man. I hope that those pics were taken after you tried sanding…If not, I would be wondering what the cloudiness is…and the clogging of the sandpaper sounds very strange…almost like a wrong ratio problem, or worse…

I think speedy has it right…contamination or heating up after walkout but before cure…I have never used wax/styrene, but I usually use AddF (same effect, I guess).

That sucks, I feel your pain. Can you think of anything that would have introduced contamination? Did you do anything differently than before?

On the bright side, once you get it fixed, it looks like it will be a great one! Is that a real leaf in the resin?

JSS

5

this is something i did that may have caused the contamination.

after i laminated the board i made the fin. which basically means the board sat around the panel shop for 3 or 4 days before the fin was ready to glass on. then fill coat. i guess it could have picked up all kinds of contaminates by just sitting around too long. GOD DAMN IT!..

I did add heat after i finished. is this not a good thing to do?

i glassed it in a spray booth and then baked it for 3 hours at 50 degrees c.

it looked this bad strait away anyway so…

the cloudyness you see in the shots is just where ive tried to sand it. its actually quite clear. which is one positive, i guess…

also, i know the mixing ratio is correct. and yes, that is a real leaf.

can you add styrene to epoxy? what does it do?

6

thats a long time

give it a sand as well

wipe it down first with a solvent

a guranteed flat filler is if you put down a thinned coat of resin first

let it tack off then put on the bulk of the fill coat

yeah 60 grit is pretty much the go

80 is okay with a good sander

epoxy sands like shit

7

Hey Shifty

I had the exact same thing happen to me.

I haven’t quite fixed that board yet, but you will need to gum up a few sanding discs and sand it almost right back to the cloth and start again.

I have since constructed another board with exellent result.

I rang the guy from the resin company (ATL Composite) and this is what he said about the resin.

After your lam has cured, scuff with a scoth pad with water and rinse thoroughly to remove any blush or contaminants.

Give your lam job a quick sand with 80 or 100 grit.

IMPORTANT: Make sure you scotch scrub BEFORE you sand.

I made that mistake. Resin guy told me if you sand first, you sand any contaminants into the resin and makes it harder to remove before fill coat and will result in what you have now.

Make sure your temp is right. (I put a little blower heater on and get it to about 27 degrees C. then turn it off before I coat so it doesn’t blow dust around.

I give my boards a good clean with “wax and grease remover.” Gets rid of any contaminants.

Sounds like you are in the auto panel business so you will know what i’m talking about.

ALWAYs use new mixing pots and sticks. I get mine from woolies. (chinese take-away containers. 5 for about $3.50)

ALWAYS use new brushes. I get them from bunnings for $1.99 each then toss after one use.

Make sure your mix ratio’s are correct and mixed thoroughly.

Fill coat as normal but get it spread evenly then LEAVE it alone to cure.

If you keep trying to fix little imperfections, you end up making it worse.

That should keep you out of trouble for next time.

As for your situation now, you have already sanded so give it a good sand, give it a GOOD clean with the wax and grease remover then re-fill coat.

One thing I have learned about epoxy is that you CAN’T take short cuts.

Good luck

Cheers

8

I can’t bear to look…

It’s…hideous…and disturbing…

I’d get out the grinder with some 50 grit… and lots of it. Go at it really slow and even with the hardest pad you have.

Good luck, brother.