After sanding the laps I cleaned the board with a brush and vacuum cleaned the surface. Pulled fresh new tape along the board and wiped it with a bit of paper. (never touched the board without wearing gloves)
Same problem as with the other 3 epoxy boards I made while doing the hot coat. Lots of zits on the surface. I cant tell if its dust or small microscopic bubbles.
I tried to sand them out but I hit the weave in several places and the micro craters are still there, filled with white sanding residue.
The board needs a second coat and I made a small test panel where I sanded with 100 grit and then did an epoxy coat. After 5 seconds the epoxy pulls away from where the zits are like fisheyes?
Made a similar area but used polyester with UV cure. Lay down smooth and I cured it in my tanning bed. Looks really good.
BUT as with any other problem, I run into I started to search the swaylocks archives and there seem to be two camps with the Poly on Epoxy thing.
Some say it works and others say it won’t.
What would you guys do?
My last longboard I made with PU/poly never had any problems with fisheyes/zits but all my epoxy boards have.
Epoxy is finicky. If you search the archives for “epoxy fish eyes” you will find a lot of discussion. Search also “cheater coat epoxy”, this is what has worked well for me. I don’t have a clean shop, because one space serves all purposes, but I clean it as best I can before fillcoating and finish coating. I don’t do all the elaborate wipe down cleanup stuff others do, I sand the board and that’s it, if there is a bit of sanding dust on the board I don’t worry about it. I apply a very very thin coating, as thin as I can get it, and when that starts to gel I apply the fill coat. I don’t claim to get a flawless mirror finish every time, but it has largely eliminated the fish eye problem for me. I use Resin Research epoxy, and find that additive F doesn’t make much difference for me, one way or the other, so I don’t use it much anymore.
I dont know if my resin is advertised as blush free, but its “suited” for surfboard lamination and is UV stable.
I am working in my garage that is right now around 20c. Heated by a construction fan, its about -2C outside here right now. I guess that is not optimal for laminating with epoxy.
The resin was heated a bit by putting the mixing cup in hot water to get it closer to body temperature. (not hardener but I keep all my epoxy in the house)
2% Additive F that I also heated with hot water before pouring it in the epoxy mix.
The test “panels” was me trying epoxy on one side of the nose and on the other side Polyester. Same sanded hot coated finish. 100 grit. unfortunately, I do not have any compressed air to clean the board with at the moment. Maybe investment (just ordered a new planer hehe)
Yeh the cheater coat was in my mind when i was preparing the hot coat as I’ve been reading that people been successful doing their hot coat that way. I don’t know why I decided not to try it this time
Every board seems to have at least one problem along the way… For me it seems to always be the hot coat/sanding! gah!
Proper temp helps too, I forgot to mention it, but glad to see others did. Quicker setting epoxy also helps, seems the longer it sits the more likely for fisheyes to appear. Like I say, I have found epoxy to be finicky. But it has it’s upside, epoxy is all I glass with now.
I know your frustrations well. There was a post in Swaylocks that described how this builder in Puerto Rico did his beautiful Epoxy gloss finishes. What I got out of that post was to squeegee some epoxy over the surface first using it like a cleaner. You don’t need too much epoxy to do this. Squeeze it this just about dry removing all of the contaminates from the surface. After, you can lay down your second hot coat. This really helps to make that 2nd hot coat lay down really nice.
Yeh I think I will do that for sure next time.
But I am not sure how to solve the situation i am in now since the the Epoxy won’t lay flat on the already hot coated surface.
I could leave the small zits alone and just brush Epoxy on with my finger to seal the places I hit the weave on and admit defeat on this build.
Or gloss it with polyester
Gonna repeat what has already been said. Had the same issues as you with boards 1-3 (epoxy, but just one single fillcoat). boards 4 and 5, I applied a really thin coat and after that the proper one. sure, wasn’t perfect, but i didnt expect that with epoxy on my first boards. also worked in winter in a heated garage. not too good of a combination i am afraid, but i also did everything on one room, shape, glass, sand.
I have glossed with poly over epoxy. Its do-able, and I didn’t have any major bonding issues, but if you get a ding it will chip off all around the ding area. I have also battled with fish eyes, and ended up sanding the fill coat down, making sure to scuff inside all the divots, and re-fill-coating the board. I generally use several thin fill coats now, light sanding between, rather than one thick(er) “hot coat”, as with poly resin. But with the cheater coat you can do a thicker coat, if desired.
Okey so I will give Epoxy another try. Have to remove the dust that is stuck in the small zits first. It should be safe to hose the board with water even if I’ve hit the weave a bit while sanding right?
Have to remove all all the dust or I will have thousand of small white dots under the next hot coat.
Squeegee a thin layer of Epoxy, let it get tacky and then brush another layer of hot coat on!
If that looks horrible too I will gloss it with polyester.
I will update the thread with how it goes.
Thanks everyone
You don’t have to remove all the dust, it turns clear with resin, the problem is when there is enough dust, and the little puka small enough, that resin doesn’t penetrate down into the bottom, and some dust remains dry under the resin, then you have a white dot.
Yes, that’s correct. I first made 3 boards in EPS/Epoxy. I then decided to try polyester and PU blanks to see de difference.
I only use 1-time brushes. I am trying to clean the garage up as much as I can after I am done with sanding and so on, but the dust is everywhere anyway.
Been trying to pursued my girlfriend to let me hot coat my boards inside the house (epoxy) where its cleaner… haven’t really won that battle yet.
Are polyester more forgiving when it comes to fisheyes and zits? seems like its way easier to get a even coat with.
You can do poly finish on epoxy with no problems, but as all need to be make correctly. Many guys do it with success for long time, others only have problems… Even well done poly finish is not as tough as epoxy one, so when ding your finish will spider crack like all poly board.
use a compatible epoxy, let it fully cure.
it’s a finish coat not a hot coat, sand thorougly the last epoxy coat with not more than 80grit.
be really concervative with cata and styr p.
best, use a real nautic isophtalic top coat or at least a low réactivity isophtalic resin.
I came up with a thing to try. I still got like 200g of the tinted resin that I will try to squeegee out just to fill in the white voids and hopefully make them darker. If necessary I will then do a final coat over that.
The plan with this board was to give it a satin look. So will scotch brite it to a matte/satin look. Maybe more forgiving than trying to go for a glossier look?
I been spending a good 30 min with the water hose and got some of the white dots out but most of them are still there. :(
hey man, the craters or zits are most likely caused by a dry lam, which can be due to the epoxy’s slow gel time or not leaving enough resin in the weave. Once you hotcoat the board these dry pockets will release air , which will leave you with low spots in the fill. If you sand over the craters and dont have a good air compressor to remove the trapped dust youll get the white dots. Also like le-mat says you can do a poly gloss ideally on an epoxy fillcoat without to much issue, the board below was done with the following method.
It felt that I laminated with too much resin actually but the zits appeared maybe after 2hours after hot coating.
Will do a thin squeegee coat next time and then the real hot coat.
I squeegeed out a thin thin layer of tinted resin yesterday and it made 90% of the white dots disappear. My fear is that they will show again once I start to sand it smooth again.
Already looked into buying a compressor. Read that it needs some kind of oil filter?
Maybe investment (just ordered a new planer hehe)
