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View king_nickizzle's profile

Not getting a smooth epoxy finish

by king_nickizzle
posted 08-15-2017 02:29 AM


17 replies so far

View TheFridge's profile

TheFridge

8882 posts in 1391 days


#1 posted 08-15-2017 03:03 AM

I tried wet sanding epoxy to 2500. It didn’t work too well. If you want glossy you’re gonna have to pour it that way. I don’t know what you used but I hear west systems makes some great epoxy.

-- Shooting down the walls of heartache. Bang bang. I am. The warrior.

View Gilley23's profile

Gilley23

488 posts in 287 days


#2 posted 08-15-2017 03:34 AM

What kind of epoxy did you use?

View TheFridge's profile

TheFridge

8882 posts in 1391 days


#3 posted 08-15-2017 04:17 AM

I’ve only used bar too epoxy once and tried a variety of things to repair it with little success.

I just hear many speak of west systems when it comes to epoxy because it is versatile and a pretty reliable product.

-- Shooting down the walls of heartache. Bang bang. I am. The warrior.

View MrUnix's profile

MrUnix

6348 posts in 2104 days


#4 posted 08-15-2017 04:17 AM

Yup – what epoxy are you using? Neat epoxy (sans any fillers or additives) will flow pretty well. Sounds like yours is way too thick. You can decrease the viscosity for a better flow with heat… heating the epoxy and/or substrate you are applying it to will help.

Cheers,
Brad

-- Brad in FL - In Dog I trust... everything else is questionable

View TheFridge's profile

TheFridge

8882 posts in 1391 days


#5 posted 08-15-2017 04:20 AM

What he said

-- Shooting down the walls of heartache. Bang bang. I am. The warrior.

View king_nickizzle's profile

king_nickizzle

25 posts in 816 days


#6 posted 08-15-2017 12:06 PM

Thanks for the responses! I’m using the brand Famowood. The reason i was thinking sanding would work in my case, is because I’m going for a matte finish anyway. I realize that if I want a high gloss, any sanding is going to scuff away that sheen. But since I’m going to be muting it quite a bit anyways, I figured sanding might be okay for this look. Here is an example of what some guys in town use, who use the same product I’m using.

http://decg5lu73tfmh.cloudfront.net/diyforums.net/images/fbfiles/images/traditional_trestle_bench_pine_top_with_matte_epoxy_v_1402774202.jpg

View LittleShaver's profile

LittleShaver

267 posts in 524 days


#7 posted 08-15-2017 12:47 PM

I had good results wet sanding up to 1200 then switching to auto buffing compounds. First a swirl remover than a polish. Used a HF 5” buffer for the auto compounds. There are auto compounds available that do not have silicone in them.

-- Sawdust Maker

View king_nickizzle's profile

king_nickizzle

25 posts in 816 days


#8 posted 08-15-2017 01:41 PM

Do you wet sand right from the start? Or do you sand it regularly with low grit in order to get it flat, and then move to wet sanding to really fine tune? I feel like getting it flat is going to take a while and using only wet sanding techniques will make the process even longer.

View Monte Pittman's profile

Monte Pittman

28170 posts in 2243 days


#9 posted 08-15-2017 02:19 PM

I have poured a fair amount of epoxy and never had blotches. Lots of other problems, but no blotches. It’s not completely self leveling. It will puddle and not flow. I use a plastic trowel to smooth it out. The warmer it is in the room makes a difference in viscosity when pouring and also how quickly it hardens. I don’t like brushes because you will wind up with bristles embedded in the epoxy.

Epoxy is a merciless teacher. Easy to make mistakes and very difficult to clean them up.

Good luck.

-- Mother Nature created it, I just assemble it.

View Monte Pittman's profile

Monte Pittman

28170 posts in 2243 days


#10 posted 08-15-2017 02:21 PM

If you want something other than high gloss finish, I use spray lacquer over it for my sheen.

-- Mother Nature created it, I just assemble it.

View tomsteve's profile

tomsteve

753 posts in 1124 days


#11 posted 08-15-2017 04:14 PM



Do you wet sand right from the start? Or do you sand it regularly with low grit in order to get it flat, and then move to wet sanding to really fine tune? I feel like getting it flat is going to take a while and using only wet sanding techniques will make the process even longer.

- king_nickizzle

imo, wet sanding would be the way to go-using backing blocks to make sure the surface gets flat and sanding in different directions for each grit. sand in an ////// direction with one grit then\\\\\\ for the next. that helps to see that the scratches from each grit has been removed. you can keep going down( or is it up?) in grits until you achieve the sheen youre looking for. sandpaper grits go up to( or down to?) some seriously fine grits, which get called polishing paper after a point.
personally id start with 800 grit and see how that cuts and flattens. its easier to go down( or up?) to 400 if it isnt cutting fast enough then the other direction.
HOWEVER
IF there is anywhere that could possibly sanded through to bare wood, i would stick with dry sanding.

View TheFridge's profile

TheFridge

8882 posts in 1391 days


#12 posted 08-15-2017 04:20 PM

I was able to achieve a consistent matte by sanding with higher grits. I just couldn’t get any better than that.

-- Shooting down the walls of heartache. Bang bang. I am. The warrior.

View DS's profile

DS

2855 posts in 2325 days


#13 posted 08-15-2017 04:44 PM

I use micro mesh 5 in. discs to get a good polish. Once you get it flat, you are looking at a lot of work. Stepping through 1800 grit, 2400 grit, 4000 grit, 6000 grit, 8000 grit and finishing with 12000 grit. (No joke) Then applying a finishing compound.

Polishing compounds do something similar, but with less finesse and control.

I know you said you want a matte finish, but if you want to take it to a shine, lots of elbow grease is required.
Just FYI

-- "Hard work is not defined by the difficulty of the task as much as a person's desire to perform it.", DS251

View mitch_56's profile

mitch_56

18 posts in 378 days


#14 posted 08-15-2017 11:10 PM

Depends on what “blotch” means. Are you getting amine blush? Fisheyes? Might be best to post some pictures.

There are lots of things that can cause finish issues with epoxy, especially in shop and garage environments. Lots of surface contaminants can easily be deposited on your work, many people mix epoxy in containers that were previously used for all kinds of nasty stuff and then wonder why their epoxy looks like a train wreck. Oily hands, leaky compressors in the shop, spraying varnish or laquer nearby, porous or open-grained woods (like walnut) can cause air bubbles, even furniture waxes and car polishes—I’ve seen a million different things cause finish problems for epoxy over the years.

Sometimes guys use a propane torch to get rid of bubbles, but don’t use it well, and they scorch the epoxy. Some people mix their epoxy incorrectly and get too hot of a batch, or heat the part A too much (or heating the part B at all!) to make it flow better and the batch smokes as it cures – definitely going to get an ugly finish in those cases.

As for sanding, it can be done, but as mentioned above, it’ll take a fair bit of work, and you’ll have to go into some very fine grits and then polishing compounds, otherwise the finish will look dirty or hard to see through, sometimes hazy.

View Andybb's profile

Andybb

752 posts in 508 days


#15 posted 08-15-2017 11:24 PM

If you r seeing trowel marks it could be that you are applying it too thick or is too thick to begin with. I would think that the blow torch or better yet a heat gun would be your best bet right after applying your third coat to get a smooth surface. I use either Total Boat or West System epoxy and have never had a problem.

-- Andy - Seattle USA

View papadan's profile

papadan

3584 posts in 3273 days


#16 posted 08-15-2017 11:31 PM

I’m wondering why you used a Walnut slab if you want a matt finish on the epoxy. You could have built it out of MDF if you don’t want to see the grain.

View Andybb's profile

Andybb

752 posts in 508 days


#17 posted 08-16-2017 07:37 PM



I m wondering why you used a Walnut slab if you want a matt finish on the epoxy. You could have built it out of MDF if you don t want to see the grain.

- papadan


I think he means flat vs glossy, not opaque.

-- Andy - Seattle USA

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