I was wondering if anyone has had beading issues with epoxy resin?
I sealed, lam’d, painted and glossed. The gloss coated beaded, I had to brush it out for about an hour to get it to somewhat spread out. I chalked it up as the paint, but I decided to put a light sanding on the gloss coat and apply another thin layer but the same thing happened. I have a bunch of resin and hardener leftover (Resin Research) however I’m hesitant to use it on another project. Also, the board is stringer less so my scheme to strengthen the fin is set it in wood, I seal the wood with epoxy as well, it beaded there as well.
Has anyone seen this beading issue? Any thoughts?
Steve
PS - I gave up on trying to make it look nice… it rides nicely though
I ran a space heater in the room to make sure it was up to temp. It went on nicely but after a few minutes voids started to show up, it was pretty bad. It was a real pain. I don’t want to deal with that again or have anyone else deal with it. Not only was it a pain but the end result was pretty ugly.
Looks like you have got a case of the fish-eyes (why they are called that, you got me).
I have some questions for you:
Did you use AddF in the glosscoat? How much? Did you warm the resin?
What type of paint? Did you seal the paint with a clear?
What was your procedure to clean the board after painting but before glossing (if any)? Or did you wear gloves the whole way through after sanding the hotcoat up until glossing?
How much resin did you use for your gloss coat? How big is the board?
I always keep a squeegee handy when I am glossing. If I get a fisheye or two, I just let a drop of resin from the brush fall into the fisheye, problem cured. If the whole coat fisheyes, I scrape that stuff off the board with the squeegee, pronto. You’ll leave a small amount of resin behind that will cure; you sand that lightly, and your next coat will go on great (in my experience), then you can troubleshoot what got you the fisheyes in the first place and try to avoid it…
The great fisheye causers (in my experience):
oils from skin or elsewhere (like spraying WD-40 somewhere in the same room before glossing)
chemical contaminants (blush from previous coat, millions of others) or incompatible materials (like silicone)
leaving your hot/gloss coat to dry in the sun
My most recent bout with fisheyes was due to a clear acrylic I would seal paint on the hotcoat with. Before glossing I would wipe the board down with denatured alcohol, and the denatured alcohol modified the clear acrylic and spread it all over the board, causing the fisheyes. Now, if I touch a board with my hands after sanding the hotcoat (I wear gloves as often as possible), I wash it with Dawn dish soap and a sponge/green scrubbie deal and rinse really carefully, dry it with a towel to avoid waterspots, and remove the towel lint with a tape pull. No more denatured alcohol wipedowns if I have any acrylic (paint or clear) on the board. And if I wear gloves, no denatured alcohol wipdown needed.
The pic is small, but I’d say you did well for your first one!
looks like the denatured alcohol got you. It took me forever and a few e-mails to figure it out in my case, as the denatured alcohol was dissolving, modifying and spreading the clear, and I couldn’t see it (just to be safe I don’t use the clear anymore if I plan to gloss with epoxy, it was Aervoe brand)…Also, I forgot to mention: if you wear gloves, you cannot touch your face or anything oily, or you have to change gloves…or wash the board later with the Dawn dishsoap. Even with the Dawn, you have to make sure you scan the whole board carefully after you brush on the glosscoat; there will always be a fisheye or two if you have been handling with bare hands, even with the washing. Just drip a drop of resin into the fisheye, and you have a little bump to wetsand after it cures, but no void…
A tip on the washing: when you rinse, look for a clean sheeting of the water. If the water beads anywhere on the surface, it means you still have some washing to do…
Also, if you plan on wetsanding and polishing gloss coats done with epoxy: Use a heat gun lightly on the coat after you finish your walk out (be careful, you can cause fisheyes if you heat the epoxy too much). You’ll see all kinds of bubbles popping you didn’t even know were there. If you would have left those bubbles there, those bubbles would have become holes as you cut into them when you wetsand/polish, and the tiny holes collect rubbing compound and polishing compound and look horrible (especially over color). I take the time I’m using the heat gun to also scan for fisheyes I missed (and fill them), and for stray brush hairs (and pick them out of the coat with tweezers).
Great info. I am using RR and am about ready to gloss coat here in the NE. The room will probably be about 62 degrees. Should I gloss? Heat the resin in a water bath?
I have no acrylic except for pinlines that have an additional hotcoat over them. I have continually rubbed the board down after every sanding (after the lam). Will I have these fisheyes? I like that heat gun trick!
62 is too cold. I had all kinds of problems with those temps. Try to get up to 70 at least, 80 is much better. Adding more Additive F helps with the cold temps, but it will still be problematic. If you are going to go with the cold temp, at least get your resin and hardener nice and warm, and try to heat up the board a little ahead of time too. I use one of those fan space heaters, and put the board under a little plastic sheeting tent to heat it up. But remember that the additive F is flamable, so the fan needs to be away before you crack the addF can. Safety first.
I’m curious what type of wood you are using to set you box?
I tried some RR over Redwood and had some issues with fisheyes. I concluded that oil in the wood was surfacing through the epoxy and continued to cause problems in every subsequent coat regardless of solvent wipedown, sanding, etc. The fisheyes were less apparent as I applied more coats.
If some oils surfaced from your box reinforcements, that might be a potential cause for your problems. When I read of your problem patch, I wondered if that was over the wood or ? If oil did come to the surface, sanding and wiping might have spread it around.
FWIW, I don’t think it’s the resin or the temperatures… More likely contamination. It might be too late for this but you might try spreading a bit of mixed epoxy from your next batch separately on a piece of cardboard or something that you know is clean. Let it set in the same room so the temperature and all that is the same. If the sample panel cures OK without fisheyes you’ll know for sure if it’s something on the board.
It can be done at 62 degrees; I hotcoated a board at 65 degrees 4 days ago with great results, but I did this:
Heated the resin to 110F in the microwave (I have a cheap little IR thermometer, that thing is handy)
Heated AddF in warm water bath to get the solids back in solution
Waved heat gun over board until the surface temp was over 70 degrees (IR thermometer again, but it took forever, next time I’ll just put the board inside for a while).
Since the hardener is at 60 something degrees, when you mix them you get something in the 90s (mine was 92F). You need it this hot so that it will run easily for a few seconds while you spread it, but it cools fast and becomes thicker right away. When it does thicken, slow down your brush strokes or you’ll have bubble city. Finish your walkout, get the heat gun to pop the unseen bubbles and come back in like an hour and a half to pull tape.
Things to watch out for:
DO NOT use a propane or gas or kerosene heater to heat your workspace. Not only is the AddF flammable, but any combustion going on will fill the air with carbon dioxide and H2O, making it more likely that you will get blush in the epoxy coating, even with AddF. I wouldn’t use more AddF than is called for normally in a gloss coat (2cc per fl ounce of hardener).
Make sure if you use a heat gun to heat the board up that it stays at the temp you want it to for more than a few minutes, but don’t overheat it with the heatgun and melt stuff…
I had an issue with a big patch of beading the first time I tried to gloss with RR. I baby-sat it forever, trying to re-spread it, but it just kept beading off like it just didn’t want to stick to that spot. I scraped the whole mess of gloss off, washed it thoroughly with denatured alcohol, and did it again. The second time it stuck good. My research lead me to believe that it was surface contamination from dirty hands. Since then, I’ve been extra-careful to never handle a board with bare hands between cleaning and glossing or even hotcoating. Never had a problem since then.
“More likely contamination. It might be too late for this but you might try spreading a bit of mixed epoxy from your next batch separately on a piece of cardboard or something that you know is clean. Let it set in the same room so the temperature and all that is the same. If the sample panel cures OK without fisheyes you’ll know for sure if it’s something on the board.”
Awesome tip! Great way to find out the cause of problems. I’
Yes I’ve had fish eye problems(beading). It has only happened with acrylic paint on top of hot coat that was getting gloss coated.
I believe that the paint was applied too thick too fast and this caused some sort of reaction.
Why do i believe this?
I airbrushed several pin lines with no problems. I did a fish for a friend and I let him do his own art work before I glossed. He used water based acrylic paint pens. The only place I had fish eyes was where he did art work. If handling the board with my bare hands was a problem I should have fish eyes all over the board. I only have fish eyes over the paint…
denatured alcohol…Used it once. I will never use it again. If you are in the San Diego area you can have this quart of stuff for free.
Temp is everything. Greg L says 75 degrees. Pluseone shaper says 80. learn from the pros!
If you paint on hotcoat, don’t use Future Floor polish to cut the mix, just use water. Future makes the paint rubbery. I don’t know if you did? Also make sure you put the paint on as light as possible, just enough to get the job done. You see the epoxy wets out the paint completely and adheres too it, just not a seal over it. Next time do a color panel lay up with pigmented epoxy instead of paint. Screw the paint on the hotcoat, unless you trying to do a fade of something tricky. if it’s just a straight geometric design in one color, do the epoxy color panel.
Also follow the 10 rules of Epoxy always
Warm room
Warm epoxy
No Alcohol
Don’t wash the board a cleaner
Don’t wipe the board with cleaner
Don’t blow the board off with a compressor, or some other water oil spitting device.
Wipe the board off with a clean paper towel…throw paper towel away after 1 use
Wipe the board off with another paper towel if totally anal compulsive clean freak.
*8a) Expalniation: A little 150 grit dust will not show up in the hot or gloss coat. It’s the chunky resin, dog hairs,
cheap paint brush defoliation, mocking bird crap, and black gnats, and over globing the finish coat brain
slab off orange peal that screw up the finish
Don’t touch board with your greasy jalopy sized mits, once sanded…use paper towels…no gloves
Nothing is cleaner than a freshly sanded surface…don’t contaminate it, don’t risk it.
So what did we learn here?
Nothing is cleaner than a freshly sanded surface…If you paint it, you run the risk of contamination. But if you do the color work on pigmented epoxy, then sand that, then gloss. Guess what, no contamination.
Next time do a test panel on different types of paint…if you must paint, find one that works with RR?
The wood I used was just pine that was nice and dry, I sand the surface. I can remember if I used alcohol to wipe it down on or just a rag. I used a piece from the same board last year. That board I stained the wood first, it came out pretty nice. I don’t have a close up pic but here is last year’s board. The beading happened on both sides so oils from the wood should not have played a roll on the top side
Great tip for testing the leftover epoxy. I think I will be testing painted surfaces as well.
