Forced air paint curing (not drying)

Discussion in 'Luthiery, Modifications & Customizations' started by LiveOVErdrive, Aug 25, 2017.

  1. LiveOVErdrive

    LiveOVErdrive SS.org Regular

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    So I'm a pretty impatient guy. When I paint a guitar, I don't want to wait two weeks or more for the paint to cure before I wet sand and buff it out, and yet I have to if I want it to look good. Probably.

    I've been trying to find info on whether using a heat gun or a hair dryer or a space heater would speed up the curing process on paint or not, but nobody seems to talk about it. A LOT of people talk about DRYING paints with forced hot air, but little to no info on CURING them (the second step where it sits for a while and gets harder).

    Anyone done it?

    I'm using water based enamel and water based poly. Both Acrylic.
     
  2. 7 Strings of Hate

    7 Strings of Hate Mid-Level Asshole Contributor

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    In my experience, the paint drying is a quick process. The clear coat is the part that takes weeks to cure.
     
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  3. LiveOVErdrive

    LiveOVErdrive SS.org Regular

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    I guess that's mostly what I was asking about.
     
  4. KnightroExpress

    KnightroExpress Guitar Nerd Vendor

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    It depends on the product you're using. Nitrocellulose has a long cure time but if you're using modern polyurethanes, you should be good to go after 24 hours. Even faster if you go the UV route.
     
  5. Mr_Mar10

    Mr_Mar10 SS.org Regular

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    Any hints will help me here too.. I've a guitar I clear coated 4+ weeks ago (with too much 2k, granted :p ) it still leaves clothing texture in the clear on 2 patches when i play it. I just want to play the damn thing now . ... don't really want to strip it again this guitar has been a giant pain lol I wish I would've stuck to finishing oil
     
  6. KnightBrolaire

    KnightBrolaire Sunbro

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    some of the home improvement polyeurathanes really suck and take forever to cure. It took over 2 months for on of my builds to finally harden. Spraymax 2k shouldn't have that problem though...My neck and body I sprayed with it were hard in a day or so.
     
  7. MikeNeal

    MikeNeal SS.org Regular

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    i usually just use automotive paint/clear for everything. i can usually wet sand the clear after a few days.
     
  8. LiveOVErdrive

    LiveOVErdrive SS.org Regular

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    Everything i read is leading me to believe i need to use automotive paint. But i really want to make water based stuff work because it is just way less nasty.
     
  9. MikeNeal

    MikeNeal SS.org Regular

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    get a respirator :D and make a small spray booth with old painting drop cloths. thats what i do.
     
  10. LiveOVErdrive

    LiveOVErdrive SS.org Regular

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    I actually have both of those things. I just really hate cleaning my tools with mineral spirits. Guess i should just suck it up :)
     
  11. MikeNeal

    MikeNeal SS.org Regular

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    to be honest, i rarely use my gravity feed gun, as i hate running my compressor. 99% of the time i just use aerosol cans haha
     
  12. Killemall1983

    Killemall1983 SS.org Regular

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    UV cured finishes can be sanded in less than 5 minutes.
     
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  13. Petar Bogdanov

    Petar Bogdanov SS.org Regular

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    I believe it's a mixture of curing and drying. I have some 2K poly in a water bottle, and it's been sitting gummy and white, while similar thickness in a paper cup crystallized within a day. Same ratios and everything. It wouldn't hurt to try.
     
  14. MoonJelly

    MoonJelly brainless and deadly Contributor

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    In my experience, even 2k gets temperamental in high humidity. I live in the devil's armpit, and while the heat is OK for most paint, when it's 50%+ humidity out there, I get an annoying orange peel texture to the paint as it cures. 70-80 degrees F and low humidity, and I see that Spraymax stuff work like it's supposed to.

    Also when you use Spraymax in the cans (which is all I've done), make sure you mix the catalyst for at least 2 minutes before you spray. If you think of it like a 2 part epoxy, that catalyst is the hardener... i.e. if it's not mixed properly the curing will take a lot longer.
     
  15. LiveOVErdrive

    LiveOVErdrive SS.org Regular

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    I'm going to experiment on scrap with water-based poly over water-based enamel and a hair dryer or space heater and see what I can do. I don't think I've ever done enough clear coats to actually build properly, so maybe a few more coats will help.

    I've also got some Aquacoat Waterborne Lacquer in the mail - another water based clear to try.
     
  16. KR250

    KR250 SS.org Regular

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    I'm going to give the General Finishes water based poly a try. Supposed to be the hardest consumer poly that I can tell so far. Also supposed to dry very fast on its own. Arriving today, and going to use it on my current build once the dyeing is complete.
     
  17. Walshy

    Walshy SS.org Regular

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    Eager to see your results as I'm an oil guy at the moment due to uncertainty with poly finishes.

    Anyone doing UV hardening? Just wondering how expensive it gets if you go that route.
     
  18. LiveOVErdrive

    LiveOVErdrive SS.org Regular

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    So I tried out a hair dryer with varathane water-based floor poly a few days ago and it worked GREAT. I loaded up my gun with the poly and a little water and just alternated spraying a coat and drying it with the hair dryer, and continuing to blast it with hot air even after it was dry to the touch. Put on several coats this way within a half hour or so and then hung it up for a few days to cure.

    A few days later I wet sanded and buffed and it came out GREAT. Holds a nice gloss and although I have to go back and work through the grits a little slower (I skipped some and you can still see some swirling) it still looks great. Definitely doing this again in the future. I really like only having to clean my spray gun once.
     
  19. KR250

    KR250 SS.org Regular

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    Cool! I was thinking the same thing about clean up and spray guns, going to order a proper HPLV gun soon and give this a try with the water based finish I've got on hand. It already dries super fast.
     
  20. LiveOVErdrive

    LiveOVErdrive SS.org Regular

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    Here it is all buffed out.

    [​IMG]

    Still not quite professional quality but I think that's just my lack of wetsanding skills.
     

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