I’m beginning to think it is impossible to do a hot coat without pinholes, waxbumps and general crap! Broke one of my own rules today and paid for it. Didn’t have a paint strainer to strain wax solution with so I just shook it up good and mixed it into my resin. Was cool here last night and there was some suspended crystals…Should warm it up…Well I’ll just mix the hell out of it and it should be fine…wrong…wrong…Wrong!!! I don’t know which is worse, the pin holes or the wax craters! I guess it serves me well since it was on a board for me! Seems like there was an excessive amount of pinholes though. Does using UV catalyst aggravate this problem??? Seems like there are more imperfections when I use the stuff for some reason. I have to admit I don’t usually let a batch sit for the reccomended hour before using. Could this be causing a problem??? Going to get some strainers tomorrow, won’t do that again.
I don’t know? I sometimes get hotcoats so good that I can just pull the tape and sand the edge down and polish it out. Sometimes, everything lands, sags, and poops on it from 8 miles around. So many variables, temp, humidity, % kicked, etc. I know I don’t like using UV on hoatcoats that much. It seems to kick off in different areas that are painted or tinted different colors that cause sagging sometimes. When I use catalized resin I will thin it out with a cap full of acetone per qt. of resin. This helps just enough to let it flow, level, and pull off the board for a better thinner coat. Some guys add a little styrene to do this also.
Yep, I use a bit of styrene sometimes also. I have noticed that when the UV cure kicks it tends to get globby instead of the smooth gel like MEKP kick. Once it goes it’s best to leave it be. With regular MEKP I will keep at the lap to work it super flat but if you try this with UV it will get globby and roll up and you end up with a rougher lapline to deal with. I like the speed but it definitely has its quirks. Did some funky color changing to an orange spray I did recently. I hate working on a board for 10 hours just to screw it up with a funky resin quirk! Trust me. those little wax flakes will come back to haunt you when you get ready to spray on some clear.
I may be be wrong here because they didn’t have UV cure when I was making boards.
Seems I NEVER get pinbubbles on the hot or gloss if my lam job is well saturated, whether it was squeegeed next to dry or wet lumpy. I’d say about 70% of hotcoats after board #12 were good to rub and polish.
When using UV for hotcoats I find it best to catylize the resin like a normal hotcoat (say 30cc) and let it jell before puting it out in the sun.You have to give the resin a chance to flow out and let the wax rise.Thanks to Kokua and Tom Sterne for this little trick.
Do you really strain your SA? I’ve noticed mine seems to have more lumps in it lately, but I figured those were neccessary… well not the lumps, but the wax itself. Guess I figured the resin would help smooth it out or something.
Do you find you need to use more SA if straining out wax?
I used UV w/Silmar for hotcoats on a couple of boards and had some funky results. Likewise I didn’t let the UV catalyst sit for the prescribed time before using it…also unreliable. I always liked to mix my UV powder in and let my bucket sit for a few hours and come back and shake a little more befor using it even later on. I mixed SunCure in all of my resin batches but added MEK on hotcoats and gloss coats to cure similar problems you are having. I would dust the board well, maybe a once over with the compressor air tip, then drag a strip of tape over the board before my glossing to keep as much crap off the finished surface as possible.
Kind of hard to beat having a trusty broken in brush that was past losing bristles. Yeah, there were always those unforgetable times when a bird was loose in the glassing bay, stomping around on my gloss coat, or a moth or some other disaster.
Go the route of MEK in your hotcoat (either with or without UV catalyst in your resin) and see if that helps any of your problems.
You might be right. I wasn’t having any problems…even gettin a bit cocky that all was going so well then I went on a quest to get super light lams. I have been pouring resin, one good pass with the squeegee both lengthwise and crossstrokes then a firm, tight pull to get all excess resin out. I might not be letting the resin soak in quite long enough. I always use MEKP on hot coats. I think I might not have left it long enough before throwing the door open. Everything looked great when I went out and when I came back…pin holes everywhere! I am going to be very meticulous with the SA from now on. Warming resin and SA to make sure all wax is dissolved (melted). Actually measuring SA! Got lazy and just splashed some in. As Dave would say Diverse is good Deviation from sound technique is NOT! Thanks for the imput…will post next results as they happen. Board did come out super light though…now to back step a bit!