I am not sure if "void" is the right word but after I laid the fiber and let it cure, I sanded and then applied a coat of epoxy (is this called hot coating?). The final product looks like the pic even though I used the brush to cover all those voids. I even torched it to get rid of all the bubbles. What is causing this issue?
I am thinking about sanding and then applying more epoxy but not sure if that would fill those voids; I could even fill those voids with epoxy and filler. I just want to make those repairs airtight. there is one tiny pinhole and that repair but there are several patches on this board. Maybe I can just spray paint and be done (as you can tell, aesthetics is not my forte). Thoughts?
btw, I'm using West System, 206 slow cure hardener, and the vent plug is off (I'll switch brands when I have no more resin/hardener because I have read here there are better products for boards). I am doing the repairs inside so the temperature is fairly constant.
Fisheyes caused by contaminants and its almost impossible to hotcoat perfectly. There is an additive that is basically a detergent and prevents it (but no don;t just add detergent)
Hotcoat not necessary anyway, thats a surfboard thing. If your laminate is good, just fill with a blading / knifing putty and paint.
Mark as usual, is correct. The fish eyes are caused by contaminants of some sort.
So you'll need to sand that right back and get rid of whatever is causing the fish eyes.
If it then needs a fill coat use a bog of some sort
Thanks, I'll fix this and report back.
BTW, I'm not very confident about those repairs. I have been wrapping my patches with plastic film and let it cure that way and the end result is much better. For these ones, due to the location, I was not able to use plastic film and I think I went too light on the epoxy (I used the same amount of epoxy on the rail, where I wrapped it with plastic foil and the end result was WAY better). Note to myself: when not wrapping with film (poor man's vacuum) use more epoxy.
I have a question. So when I epoxy hot coat my rails , ( instead of painting over , i prefer to see the natural ingredients ) , I get some annoying fish eyes. Im using an additive that is supposed to stop fish eyes . Doesn't work.They range from 3mm up to 10mm. I'm sure they are not from pin holes. I believe the surface to be super clean. Finished with 240 grit dry. No finger prints , I don't even directly look at the rails let alone touch them. In the old days when making windsurfers with polyester resin , I never got fish eyes. I never was worried about contamination. The finish was perfect. Could have left it like that. Minimal fine wet and dry was all that was needed. Is that because polyester resin is self cleaning because of it thinners base ? Why is epoxy so ****ty to work with. Could I use polyester resin to finish my rails ? Suggestions?
For fish eyes free epoxy coat:
Brush on tacky (B stage) lam.
If you want, have to, sand: wear clean gloves, use fresh sand paper and only use a clean brush to dust free surface just before resin. From here to reduce risk:
1) whipe the board with a bit of epoxy mix, squegge on and squegge out, let surface tacky and brush main hot coat.
Or
2) squegge a thin layer of epoxy cabosil past then brush main coat.
Use enough resin to have a thick coat depend viscosity of resin but need an enough thick coat to self level without separation. No voc's epoxy have low tensil surface (= ready to fish eyes).
Even if with this way you can hotcoat modern epoxy with less problems, i often use polyester finish coat like we do 30 years ago when i start work with epoxy, near impossible to hot coat. On well prep fully cured epoxy lam no problems even if most polyester finish are brittle so spider web and can lightly peel out on real impact dings.
Epoxy finish before sand:
Polyester finish before sand:
I found for me the key to successful gloss coats are.
Only touch with gloved fingers before applied (after sanding no higher than 120-240grit).
Controlled temperature, preferably falling.(20d is optimal)
Certain resins are better or less sensitive than others (I like XCR or R/R)
Run some masking tape over to pick up any dust after brushing or hoovering.
Squeegee on a tight super thin first layer, let that go tacky and then brush on as normal.
Select to expand quoteSurfing Uk said..
I found for me the key to successful gloss coats are.
Only touch with gloved fingers before applied (after sanding no higher than 120-240grit).
Controlled temperature, preferably falling.(20d is optimal)
Certain resins are better or less sensitive than others (I like XCR or R/R)
Run some masking tape over to pick up any dust after brushing or hoovering.
Squeegee on a tight super thin first layer, let that go tacky and then brush on as normal.
Yes same for me, max 120grit. Alternative is to squegge a thin layer of resin+cabosil before main brushed coat.
