Hi all,
Im having an issue with both my filler and finish coat going milky/cloudy on my current build.
Ive not had this issue before and cannot find any definative reason for it in the archives.
For the lam I used 6oz cloth with some resin tint splash effect. Colours worked really well. Cut laps. No issues with the lam.
I use UV Cure poly resin but added some catalyst to ensure the tints kicked. Learned that one the hard way…
My problems begin here:
Hot coat on deck didnt kick properly? Never had that happen before either. Gummed up my paper. I let it sit overnight. No change. Applied a second coat. Kicked fine. Sanded fine. Happy days. Only reason I can come up with is I used my styrene tin instead of waxed styrene by mistake. As they are sitting together at the time.
Bottom coat kicked and sanded no issues.
Resin Leash bridge and fin box installed. All sanded. No dramas. Ready for finish coat.
Applied finish coat to deck using lam res with wax and catalyst to kick it as I always have. It went milky all over as soon as it kicked.
I left it overnight. Bottom still looking good waiting for finish coat. Deck looking cloudier than yesterday? I sanded the entire deck down to cloth. Wipe down. No clouds. Problem solved.
I flip board to now see that the filler around the laps has gone very milky… almost opaque… 2days later?
So I will have to sand all that out also.
I dont want to apply the finish coat and risk repeating the problem again until I figure out the most likely cause of what has happened.
Possible reasons?:
over brushing.
Though I dont think this to be the case. once long, once across, walk away. Uv kicks and out in the sun to cure.
Can you over mix the wax into resin?
Moisture.
Its quite hot and humid at the moment. Maybe sweaty board handling, oils from skin, or sweat drips while applying?
Sanding Dust. Perhaps not a thourough clean after sanding? Not likely as dust usualy goes clear soaking the resin up.
Over cooking. Too much catalyst in UV res or not mixed thourough enough creating uneaven heat and cooking in areas. Is this possible?
Some other contaminate in the resin or tools like Acetone in the brush perhaps. I did reuse a brush cleaned with acetone. That is something I dont usually do.
Anyway. Im sure its a stupid error from negligence or lack of knowledge. My punishment is sanding it all off!
I once had a poly resin coat go milky on me when a fog bank rolled in…so possibly moisture is your culprit. Although I can’t Imagine that being a cause two days later. Old resin? Or some contamination.
Cloudy poly resin is typically caused by moisture. But as keith said, it’s unusual for it to go cloudy after a couple of days. If it’s a mosture issue it will be cloudy as soon as it hardens.
Overbrushing?? No! Can you over mix(i.e. Put too much wax/styrene) in your resin??? Absolutely. A couple of cap fulls is all you need per quart to quart and a half. Moisture??? Yes possible. But I would expect this problem to occur in cooler temps and as Keith mentioned; moisture in the air or fog. Dust?? No. Over cooking??? No. you didn’t see any smoke did you?? Acetone? No. contamination??? Yes! Most likely the resin itself. Moisture in the can? Could be from the humidity. But nothing you have stated otherwise would be the culprit. Get a gallon of fresh resin. You should be using Gloss resin for a “Gloss” finish anyhow.
I’m guessing moisture or too much sanding additive. Only time I ever had anything like that was when I was first starting out glassing outdoors in the afternoon and the evening due set in before the resin had cured.
Moisture seems to be the general consensus on this one.
I need to create a better environment to glass in so I’m not sweating all over everything!
Got a fresh tub of resin for good measure. And now using exact measurements instead of eyeballing.
I read elsewhere that if you are using UV cure, you must let the coat sit for 5mins to allow all the wax to rise to the surface before kicking it. Else you end up with the tacky finish I had to deal with also. Same deal when over brushing with catalyst. Needs to sit for 5 after the last brush stroke before it kicks.
I use uv resin on almost every board I make - color (I add cat too) or clean. Skim coats and hotcoats.
Brush your hotcoat as normal (45 one way 45 the other - then length wise) Let is sit for a minute - flash in the sun for 15-20 secs - let it sit inside for another minute - stick back out in the sun for a minute.
I have never had a tacky hotcoat.
I clean my brushes with acetone and reuse - a well broken in gloss brush is gold.
I’ve had one gloss patch go milky on a quick n dirty finbox install - moisture (probably still had beach water on it hahah). - it’s also gotten more milky as time has gone on.