View Full Version : Arrgghh... Stopping solvent pop...
Skiddz
07-03-2010, 07:54 PM
had almost an entire day to myself today, so broke out the paint and HVLP gun so I could get base coats on 2 canopies I've been repairing from past crashes and another brand new one I just worked over for the usual manufacturing boo-boos. All are fiberglass and all were repaired with epoxy finishing resin and glass cloth. Gelcoat that was cracked was chipped off and "divots" filled with epoxy and microballoons then sanded smooth.
2 coats of Bulldog adhesion promoter were applied 1st, allowed to dry overnight then a coat of sandable primer to bring up the pinholes and any "errors" in my repairs. Testor's White putty was used to fix any major issues and high buildup primer was used for pinholes and very minor scratches followed by a 400 grit wet sanding and a wipe down with denatured alcohol (same process I've used on every lid I've painted)
One more coat of primer 2 days ago was the last thing before I started mixing paint this morning..
Washed my hands good then donned vinyl gloves and wiped all the canopies down with PPG wax remover/degreaser then after 20 mins or so, tacked it all off..
Paint is HoK BC26 White. Brand new can which got a good 10 minute stirring and then a good shake (until my arms were tired hehehe) before mixing. Mixed 2:1 with medium reducer.. Fogged a light coat on all three canopies after shooting some test cards to make sure paint flow and atomization was good.
2nd coat was a light covering coat but on the 3rd one, (shot just as the 2nd started to flash - stringy pull up with the finger test from inside the lid) I got a couple spots of significant solvent pop on both repaired canopies. The new one was fine. None of the spots was over a repaired area...
I let those dry for a couple hours, then sanded down to primer, degreased, let dry for 30 mins, tacked and tried again.. Same friggin' spots popped again...
I'm going to let the lids dry overnight and try again tomorrow - anyone got any ideas how I can stop this?? Any issues with my work process?? I've shot about a dozen lids like this and never had a problem...
Kustom
07-03-2010, 09:29 PM
hey i check that pic you mailed me it's solvent trap air it and use what i said it should work fine if not i told you plan b uc35 FTW
helipainter
07-04-2010, 10:25 AM
That is the part of uc35 i do not like. The dupont is idiot proof. Get it wet, looks the same as when i walked away. I've had that stuff get really weird around dirty air, as in no huge condescent filters would make the stuff useless to me. One redo is one too many. It dries so fast, i feel is half the problem. Never tried retarder but it might help or at least a high temp reducer. Slows it down.
One other thing i learned, make sure your clear has time to settle back down after mixing. Don't use it when it is full of bubbles in the cup. I let everything sit 15-30 minutes after stirring for 5-10. Some paints mix easier than others
When i mixed gallons daily, i used shakers for 5-10 minutes after mixing. It makes everything much more consistent, especially in volume
Kustom
07-04-2010, 12:19 PM
umm his problem had nothing to do with the clear or the brand it was Solvent traped in the primer layer.Cause he was not even spraying clear yet at the time. My comment on the use of uc35 was a tip on fixing a another issue if it came up. besides never had a problem putting uc35 in the hands of a novice and have any problems.
helipainter
07-04-2010, 12:33 PM
I'd still go with something in his air source. I've never used weird stuff like he is talking about underneath so i guess the products he's mixing are not compatible?
Kevin, do you feel moisture hit you when you unplug the gun from the air hose? We have had a huge amount of humidity the last few days since the high pressure went away. I'm getting a gallon a day out of my compresor right now. and am seeing water getting through my driers
The letting sit after mixing also works for everything from krylon rattle cans to sterling.
Skiddz
07-04-2010, 12:56 PM
I don't think it's an air issue at all. I run an oil/water separator at the compressor, the hoses are for painting ONLY (I have 2 circuits off my compressor, the other is for airtools only) and I have another oil/water separator about 2' from the gun. I've never seen any moisture at the gun separator, but do get some at the compressor end once in a while. (Teaspoons, not gallons) Tank is purged fairly often as I use the compressor a lot.
I've used this same "mix" of products for a dozen or so canopies - fiberglass, plastic, that gawd-awful crap Raptor canopies are made of, even polycarbonate once.. Never had an issue - even with some other fiberglass repairs. Odd that the new canopy didn't have an issue. Same with the airsoft gun stock my son had me shoot while I had the squirt gun out.. Same process with that one.. Sand, clean, tack, Bulldog, primer, sand, clean, tack, basecoat... Came out beautiful.
As for the UC35, I've never had anything but great results with it.. The few runs I've had were my fault and it's always glossed up very very nicely. I do a very light 1st coat, let it flash for a bit, then a light coat, let it flash, then a medium wet coat and let it dry for 24 hours. If it's got some orange peel or runs, I wet sand 'em out with 1000 grit then do another medium/light coat over the top..
helipainter
07-04-2010, 02:17 PM
Is the issue resolved?
do you see anything different in any of the materials? A slightly different look. Some crap leftover in the strainer you never seen? Possibly something got a splash from something else like cross contaminated? Just throwing out ideas to get you to the show.
helipainter
07-04-2010, 02:34 PM
Are you using the kustom brand compliant gun cleaner?
Skiddz
07-04-2010, 03:47 PM
Out of the 3 spots that popped, two are good now.. the third (and of course the largest) popped again on me, even after sanding down to the original gelcoat and re-priming..
Gun is getting cleaned with copious amounts of laquer thinner and lots of clean rags... Getting ready to re-shoot that area as I've sanded it down once again and am going to break out the airbrush to try fogging on several light coats before hosing it down...
Kustom
07-04-2010, 05:57 PM
you and them big words.. well 2 out of 3 are fixed not bad i messeed with a cano i have here so see if i can make it pop. still doing a 2-1 what primer/sealer you using? I doubt your overdoing the cat in it but just checking. most people like to blame brands then a simple error like trash. if you brought it down to the orginal glass work coudl it be some old mold release wax.. long shot but who know what the orginal cano are based with. For all we know if could be a old laq stuff they can still use over there and if you messed with that stuff you can paint over dog do and it will lock it in. does the orgin glass have a green tint to it? I have a simple back up plan if need be. I guess if you have time later call me i'll be around been workign on a mural in the basement and on your cano.
Skiddz
07-04-2010, 06:52 PM
Got it... Wet sanded the entire lid with 600, took the "hot" spot down to bare glass (through the gelcoat) and then laid on some high-build primer, let it dry then blocked the whole area, followed by a thorough washing with soap 'n water, a wipe down with dentatured alcohol, another washing with soap/water, then blew it all dry, hit it with the DA again and reprimed...
Let that sit for almost an hour then broke out the airbrush, fogged on the BC26 in 3 light coats, then went to town with the spray gun.. Been 10 mins since the last coat and no pop.. 30 more mins or so and I'm gonna start dropping tape on it... Waste of the day.. I could be done and ready to shoot clear tomorrow....
Kustom
07-04-2010, 07:30 PM
hey did you get that email with the stuff
Skiddz
07-04-2010, 07:53 PM
From last night? Yep...
Got the platinum/yellow down on the Logo 400 lid I'm doing... Had a damned bug fly into the yellow so gotta let that dry a bit and see if I can sand it out.. Hopefully I'll have enough time to do the highlights before we take off to go see fireworks...
Kustom
07-04-2010, 08:22 PM
did you test out the tape trick it works for that as well too
Skiddz
07-04-2010, 10:00 PM
No, didn't notice until I was done cleaning the gun... No big deal. I was able to wet sand it off with some 800.. Can't even tell it was there...
Kustom
07-04-2010, 10:03 PM
sweet
I know I'm a bit late to the game here but had a similar issue a few years ago when painting a car. I think it was some "porosity" for want of a better ways to describe it, in the mud trapping solvent. I backed the car out in the sun for a bit to "cook" all the trapped solvent out of the mud. No issue after that.
Skiddz
07-05-2010, 07:13 PM
Welp, it's GOT to be something with this canopy.. Got it all taped out and color shot but when I went to pull tape off my original layout, the effing paint came up with it in a few places... I've *never* had tape lift paint off before... I think I need to stomp this canopy back into the stone age and call it quits.... Pisses me off 'cuz it was actually looking pretty decent....
Guess I'll be "naked" at this weekend's FF...
Kustom
07-06-2010, 09:31 AM
WAna trade cano's I'll trade you a clean one for your dirty one
Skiddz
07-06-2010, 03:03 PM
Well, I kinda need this one for a FF this coming weekend...
I think I know WTF is going on...
This particular lid has been flown for over a year with just the white Gelcoat on it and it's taken a few licks during that time. I'm thinking a combination of hot exhaust gasses and Jet-A/Turbine oil has impregnated the glass and all my washing hasn't removed it all..
What I laid down yesterday is nice and hard so I'm going to try and wetsand the whole thing and repair the boo-boos when I get home tonight. Barring that, I'm heading to the Auto Paint store for some 1/16" trim tape and will cover the boo-boos up and clear over the top of it all.. Should work ok for a temporary fix - at least it'll look decent for the FF this weekend... I hope...
Kustom
07-06-2010, 03:31 PM
hell bud if you had spare resin i'd tell you to coat the whole thing with a thin layer with a brush then sand it smooth and go on top of that bu i'd do that as a last resort
Skiddz
07-06-2010, 04:05 PM
Not worth the effort. Faster to order a new lid from Bergen, get it trimmed and mounted and then start over...
kevinww
07-07-2010, 05:37 PM
Skidz, was this the canopy that you repaired with epoxy, as the quicker drying epoxies can cause this sort of problem.
Skiddz
07-08-2010, 02:23 AM
It was repaired with resin... I fnially got it painted up and everything's sticking. hated to rush it, but I've got a FF to go to this weekend and wanted some "clothes" for the turbine so rushed through it a bit. Not my best work, but i'll look decent from 10'...
Still have to do some quick 1000 grit sanding to knock down some paint lines and clear it, but it should look ok once it's done.. here's a crappy cell phone pic of it fresh out of tape.
http://www.helifreak.com/picture.php?albumid=2819&pictureid=40351
This particular lid has been flown for over a year with just the white Gelcoat on it and it's taken a few licks during that time. I'm thinking a combination of hot exhaust gasses and Jet-A/Turbine oil has impregnated the glass and all my washing hasn't removed it all..
..
You hit the nail on the head:thumbup: