Hello,
This is my first post. I have been reading this forum for a long time. I’ve tried making a profile many times but was always getting some kind of errors. After about a year and making about 4 emails I finally got it to work. Since I’ve started I’ve always used EPS with Resin Research Epoxy. I’ve been building boards for the last 8 years, but I only do 1 or 2 a year (due to work, family, and the price of building a board). I’m pumped to join in some conversations (and ask some questions).
One question I have is regarding zits/fish eyes on the second fill coat. They are all very tiny and stick up out of the board (I believe fisheyes are concave and dip into the board?) It’s not a big deal since I do a sanded finish on all my boards. Every board I do, the zits are all over the board. Every board I try something new from previous threads. In regards to contamination, I wipe down every surface in the room including lights and ceiling. Mop and lay new plastic tarp on floor. Room is 63-67 degrees (basement and no sunlight). I can’t get it much cleaner than that. I’ve tried on some boards blowing off board with compressor, DNA on some; lately I’ve just been wiping off with a clean paper towel. It’s made no difference on how I approach it from that standpoint. This leads me to believe it’s not due to contamination (or it’s so contaminated it’s a lost cause). I always wear gloves, new brush, new bucket , tape swipe across board. I’ve tried the fill coat immediately after fill coat sanding and I’ve tried waiting a day or two for everything to settle; Same results.
My thought is; could these be caused from the scratches left by the sanded fillcoat? I use my first fill coat basically as a sand coat to completely level and smooth the board. I start with 150 grit on power sander (100 grit on the flats); work my way up to 220 grit on the power sander, then finish with hand sanding to 220 grit. This still leaves scratches (always more on the lap line where the most sanding occurs).
Thanks for taking the time to read and provide any constructive feedback.
Matt
hey man seems like your doing everything right. With your pre sand i only sand with 80 grit as the gloss coat covers it so no need to use fine grits like 220. other than that your method is pretty much the same as i do even in a production environment you will get high spots/zits here and there so don’t stress. More of an issue if the zits go inwards cause you can’t sand them out.
Zits are bits of something that the epoxy forms around.
Lots of times it’s dust. It can be on your bucket. From a brush made in a dusty Chinese factory. From a precipitate in the epoxy. If the epoxy gets old, goes through hot cold cycles.
I’ve never tried it, but I’ve wondered. If you put clean xylene in a good spray gun, and then spray the fresh hot coat. It would only thin the top skin, and leave the lower epoxy to cure like normal.
Thank you for the responses.
Zacko- I could stand to lose the hand sanding 220 portion at the least, bit of overkill. Thank you for point that out.
I always do a second fill coat. Typically because I sand the first fill coat so much I have exposed weave. Also, in this case I put the pin line on the sanded fill coat. My first fill coat doesn’t get as many zits either which I can’t figure out either. And I like heavy boards.
EverySurfer- The hot/cold cycle could be a good start. Its cooler in the basement (63-67) , I warm the resin up in front of the heater I keep in the room and then when I’m done pouring the resin in the bucket, it would begin to cool down to room temp right away. Perhaps, I just don’t warm it up by the heater and just keep it at room temp?
Right before you do your second fill coat pour a little resin on your board and with a squeegee skim the board. Work In an end to end fashion and then scrape what you fave left on the board onto the floor.
This will give you a clean surface. If there were contaminants they were picked up and are now on the floor.
Zits aren’t really a problem since you will be sanding them out anyway. Problems would be fisheyes or pin-holes that can’t be sanded out and must be filled with more resin. As said by Zack, just sand your first hot/fillcoat to 80-100. No need to go further.
Everysurfer - Good point (regarding not heating the whole jug), that should have been common sense. That will be on my list of things to change. So do you just pour the resin in the bucket, heat it up (microwave), then add harderner/ F? I’d almost rather just not heat it up at all, I prefer to keep things simple.
WideAwake - That is a great idea. I may try a 3rd fill coat just for the sake of trying that. If not this board, I will make a test panel and try that.
Are pinholes a result of sanding zits leaving a little pinhole?
Sanding zits should not leave a pinhole. They are just little pieces of dust caught in the resin. Pinholes are from outgassing. Fisheyes are from surface contamination (grease/dirt) so the resin won’t stick to the surface in that area. Epoxy is Expensive. 3 hot coats is crazy. If you must do 2, sand the first one to 100 max and with the second one you can start with 220 and go higher grit from there. 2nd hotcoat should be thinner (less resin overall) since you aren’t filling weave with it. It’s basically the equivalent of a poly gloss coat.
I didnt take any of the bottom, I’ll have to try and take some later. I did a resin pigment so nothing exciting. Just the teal color with single fin box. After sanding all the shine off, the zits were gone with no issues. Someday id like to lay a final coat dhat requires no sanding to keep that shiny look. Im still gonna try and do a test panel this week with some of the mentioned methods
I did run a quick test panel. I took a piece of foam and put a layer of epoxy over. Let it cure, sand with 120. Wipe off worh clean paper towel. One chuck i also wipes with dNA. I poured the new batxh of resin on one half; spread it and let it sit for a bit then scraped completely off. Then finally brushed a thin coat over the whole piece.
Basically testing 3 scenarios, paper towel wipe, DNA wipedown, and epoxy scrape.
The results were fairly inconclusive as no one method appeared that much better than any other. Putting a layer of epoxy on and scraping off did seem to help reduce the zits but also requires more labor and materials. Ill check again tomorrow see if anything changes after fully hardened. Sorry for the bad pictures, not much to photograph,
Hi Whale,
Glad to see you making test panels.
No cloth on the test panels?
What temperature? I think you’d like all this epoxy stuff better at 75-80 degrees F.
Hi jrandy, it was a good test in idea but i dont think it simulated the same conditions as the board well enough. No, no glass. Next board I make i will defonitey run the same test but on the actual board. Will get muxh better results.
As a follow up to my original thread (already a year ago!):
The culprit was additive F. I did one side with the F, got the typical zits. Did the deck with NO additive F and had almost zero imperfections.
Add. F may work in certain conditions, but my results turned out much better by not using.
