I have been experiencing problems when I use epoxy over acrylic pin lines. I’m using RR epoxy. The epoxy does not level over the pin line and leaves very small areas in which it appears the epoxy has not bonded. Has anyone else seen this? Has anyone done ploy pin lines on epoxy? How does it work?
Hey tuna, I’ve had a similar experience with my acrylic pins. I assume you are using the Rich Harbour technique? Sanding the pin with 320 has worked ok but I’ve also gapped up my pinline doing this… not dry enough I guess–I’m not patient.
The best way in my opinion: lam, hotcoat, sand to 220, pinline with acrylic, wait, sand with 320 to remove any glaring ridges, UPOL, polish. UPOL = great gloss but I hear it is super bad for you. I use a full face respirator and have read that even that is inadequate without forced air.
I saw a board this week that had acrylic under the hotcoat, it had the same dimpled appearance and needed another thin layer right over it.
This might be a time to try “epoxy” appliance spray can paint for the pins or mix water color paint for the airbrush or try it straight out of the tube
Hey Tuna,
I have experienced the same problem along with a bleeding effect at time when I apply epoxy over acrylic based pin lining. The 3 things that seemed to help the most are 1) letting the lines dry for at least 8 hours before applying epoxy ~ 2) puting enough material on the lines so they can be lightly sanded with 220 grit ~ 3) wearing rubber gloves during the whole process so no body oils get on things.
No Worries, Rich
I have run into similar problems with acrylic pinlines and epoxy. I have found that I have to “babysit” the gloss coat and keep checking on the board looking for the seperations on the pinline. I use a small fine tip paint brush and keep adding a drop of resin where it separates. The epoxy has a slow set time so in most cases the extra drop added on the separated spots has time to settle out.
An alternative to this is to put your gloss coat on thick. Don’t seem to get quite as much separation off the pinline. Downside is you end up with a heavy gloss or you just sand/polish more.
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Hey Tuna,
I have experienced the same problem along with a bleeding effect at time when I apply epoxy over acrylic based pin lining. The 3 things that seemed to help the most are 1) letting the lines dry for at least 8 hours before applying epoxy ~ 2) puting enough material on the lines so they can be lightly sanded with 220 grit ~ 3) wearing rubber gloves during the whole process so no body oils get on things.
No Worries, Rich
rich has it! that’s how i’ve always done it, and have never run into any problems. pinline one night and then just leave it alone… the next afternoon give it a light pass or two with some finer-grit sandpaper and slap on your final coat of epoxy.
Howzit Tuna, I think the problem is caused by the paint lip left after you pull the pinline tape, this impedes the gloss resin flow over the pinline. One thing I do is use a small plastic seam roller to flatten the lip so the resin can flow over the pin line. Another thing is the gloss may still be thick enough to sand with 400/600 and rub out with out hitting the pin line. Another trick is to use a razor blade and cut the paint along the tape on both sides which might remove the lip when you pull the tape. This would be a tricky step but if you have a steady hand it could work.Aloha,Kokua
I’ve done poly pinline over epoxy with an epoxy gloss. I lightly scuffed the pinline with a 3M pad followed by light tack rag with acetone - it worked out OK. A poly gloss over the sanded epoxy and poly pinline would also work.