Im doing some resin pannels (POLYGLOSS)on top of a hot coat and im getting fisheyes…cleaned sanded hotcoat with acatone…I think it might be the pigments im using cause ive done plenty before never had fish eye problem …I sanded to 220…any help would be nice thank you for your time
Nat,
What was the pigment for or from? Were you just doing a regular gloss coat? If you blew the dust off your board with an air compressor, the air sometimes contains oil residue.
Mike
after sanding my hot coats ive always washed my boards with mild soap (laundrydetergent)and water and then a good wipe down with acetone never had to many fish eye problems and I do resin pins and pannels on a regular basis this is only my second problem it fished so much I wiped it off
Nat,
What percent of catalyst are shooting off the resin? The pigment slows down the gel time of the resin. Also you mentioned sanding the hotcoat with 220 grit sandpaper that maybe a little too fine. The polyester resin needs something to grab onto its not as aggressive as epoxy resin. Here is a link to a catalyzst chart from Fiberglass Supply. Just remember the hotter you shoot it off or the faster it cures the brittler the resin so don't over do it.
http://www.fiberglasssupply.com/pdf/miscellaneous/MEKPChart.pdf
Mike
Its fisheyeing with out catylyst to!! I usualy shoot 1/4 ounce for a quart sometimes a half ounce acording to temp and how fast of a kick I want
try resanding (120 grit)
wipe with a freshly washed white rag ( no acetone)
Apply resin
the acetone may be releasing something off the rag
the residual resin dust will melt into itself
nat,
how big are these panels you are put on the board? Are you using a whole quart? If you are try the same amount of catalyst you would use for a hotcoat approximately 1.5% to 2% catalyst depending on air temperature. Are you putting the resin on a little thick so you can sand it down without going through to the hotcoat?
Mike
With fish eyes the first thing I would check is the lamination, as any problems with this will just carry on down the line. The next thing for me is gel time, set a gloss or hot coat off too slowly and you can watch the bubbles starting to form on the surface of the resin. Then they pop if the resin does’t harden quick enough. The other thing that I know of is humidity. Drop everything at 98% humidity I believe.
Howzit nat, Try using dish washing soap that cuts grease instead of laundry soap. It pretty much gets rid of any oils or other contaminents and you won’t need acetone.Also rinse real good and dry with a lint free cloth, tap water can leave water spots which could cause fish eyes. This is the process I use before glossing.
A little OT but a friend of mine had terrible water spots on his truck and the stuff he needed to use to get rid of them had 2% muratic acid in it. I helped him and the stuff worked great but made my hands peel from the acid. Just shows what it can take to get rid of water spots. Aloha,Kokua