After using 2K clear...
das_auto
06-03-2009, 09:32 AM
Hi!
Sorry, another 2K question. But I´d really rather be safe than asthmatic.....or 6ft under.... :rolleyes:
How long do you leave your 2K cleared parts to harden after you´ve sprayed them. And also where do you leave them, since they give off those nasty isocyanate vapours while curing......if I´m not wrong?
Is it enough to just leave them in front of the extractor (I have a Graphic Air AS-300)
Also, there is a 3M cartridge style respirator mask that is NIOSH approved for use with Isocyanates. Anyone that has used one and if so is it any good?. The airfed ones sure are very expensive.
Thanks!
Emil
Sorry, another 2K question. But I´d really rather be safe than asthmatic.....or 6ft under.... :rolleyes:
How long do you leave your 2K cleared parts to harden after you´ve sprayed them. And also where do you leave them, since they give off those nasty isocyanate vapours while curing......if I´m not wrong?
Is it enough to just leave them in front of the extractor (I have a Graphic Air AS-300)
Also, there is a 3M cartridge style respirator mask that is NIOSH approved for use with Isocyanates. Anyone that has used one and if so is it any good?. The airfed ones sure are very expensive.
Thanks!
Emil
Didymus
06-03-2009, 11:30 AM
How long do you leave your 2K cleared parts to harden after you´ve sprayed them.
You can leave your parts for any length of time after they're sprayed. Just put out some food and water; they'll be okay all by themselves. :biggrin:
Seriously, what do you have in mind after spraying? Sprayed properly, 2K will give you a mirror-like finish that won't need sanding or even polishing.
It dries almost instantly. In the unlikely event that sanding is necessary, I'd wait overnight. For decals, maybe a couple of hours.
And also where do you leave them, since they give off those nasty isocyanate vapours while curing......if I´m not wrong?
It's the spray that you need to worry about, not recently painted models.
My guess is that 95% of the vapors are gone from the newly painted model in ten minutes, and the rest are released over the next year or so. Just looking into a bottle of the stuff, you'll probably breathe in more toxic chemicals that you'd get from ten "curing" models. Keep in mind that urethanes don't harden because of evaporation, but because of a chemical reaction with the hardener. That's why you can't store pre-mixed 2K urethane. It will harden in the jar.
Because I think the urethane gloss looks artificial, I don't "do" 2K any longer, but when spraying 1K urethanes, I wear a respirator designed for painting. The labeling on respirators sold by FinishMaster (my automotive paint store) doesn't anything about urethanes. I'm not a chemist, but I think you're okay if you paint near an open outside door or window and wear a respirator intended for painting.
By the way, since it seems like you are just getting into 2K urethanes:
Dupont and other manufacturers recommend against thinning. That's fine if you are painting a full-size car. But, IMO, unthinned urethane is way too thick for models. It rounds off sharp edges and thickens near panel edges, making the car look like it's been dipped in Karo syrup. (Models built in the UK look like they've been dipped in Tate and Lyles.)
2Ks are best thinned with a low temp reducer like BASF RM UR40. I recently discovered that hardware store lacquer thinner will sometimes curdle the paint. It's fine for clean-up, but don't thin your urethane with it.
Ddms
You can leave your parts for any length of time after they're sprayed. Just put out some food and water; they'll be okay all by themselves. :biggrin:
Seriously, what do you have in mind after spraying? Sprayed properly, 2K will give you a mirror-like finish that won't need sanding or even polishing.
It dries almost instantly. In the unlikely event that sanding is necessary, I'd wait overnight. For decals, maybe a couple of hours.
And also where do you leave them, since they give off those nasty isocyanate vapours while curing......if I´m not wrong?
It's the spray that you need to worry about, not recently painted models.
My guess is that 95% of the vapors are gone from the newly painted model in ten minutes, and the rest are released over the next year or so. Just looking into a bottle of the stuff, you'll probably breathe in more toxic chemicals that you'd get from ten "curing" models. Keep in mind that urethanes don't harden because of evaporation, but because of a chemical reaction with the hardener. That's why you can't store pre-mixed 2K urethane. It will harden in the jar.
Because I think the urethane gloss looks artificial, I don't "do" 2K any longer, but when spraying 1K urethanes, I wear a respirator designed for painting. The labeling on respirators sold by FinishMaster (my automotive paint store) doesn't anything about urethanes. I'm not a chemist, but I think you're okay if you paint near an open outside door or window and wear a respirator intended for painting.
By the way, since it seems like you are just getting into 2K urethanes:
Dupont and other manufacturers recommend against thinning. That's fine if you are painting a full-size car. But, IMO, unthinned urethane is way too thick for models. It rounds off sharp edges and thickens near panel edges, making the car look like it's been dipped in Karo syrup. (Models built in the UK look like they've been dipped in Tate and Lyles.)
2Ks are best thinned with a low temp reducer like BASF RM UR40. I recently discovered that hardware store lacquer thinner will sometimes curdle the paint. It's fine for clean-up, but don't thin your urethane with it.
Ddms
Some_Kid
06-03-2009, 01:26 PM
As far as the respirator goes any automotive respirator should be fine. You can check its specs to be sure, but if you can't smell the urethane with the respirator on then its probably doing its job. You should ask someone at an auto paint store just to be sure.
gionc
06-03-2009, 02:22 PM
I got one of those 3M "100 hours life" respirator, normally guys in a body shop use them for a week, I have it by years and still is OK with 2K and even worst stuff (try a Lechler styrene-safe acryl and you'll feel the 2K smell increbibly good :D), only advice is to store the mask in it's bag, so carbon powders wouldn't work with the whole shop's air.
About the curing question: wouldn't be a great idea leave the 2K paint in front/inside the fumes extractor: in fact it remain soft for much time and may (but read do...) collect powder: I normally use an upside down box, over the table, I don't feel so much smell after application, much less than a Tamy laquer over curing.
About the curing question: wouldn't be a great idea leave the 2K paint in front/inside the fumes extractor: in fact it remain soft for much time and may (but read do...) collect powder: I normally use an upside down box, over the table, I don't feel so much smell after application, much less than a Tamy laquer over curing.
matador88
06-03-2009, 02:27 PM
this debate has been here several times.
but my one comment...
when using 2K and open window is enough (even with the mask).
it is not
its heavy particles tend to go down, not up and they can go thorugh doors - under them
your family can breathe it in next room.
its really serious health concern here with this stuff.
when its good `ol 2K its relatively usable, but what to do with new waterborne stuff (in EU you can buy ONLY this stuff). its even more dangerous, after "coming" into body (through - when you have mask - bare skin areas and even eyes!!!) it wont go away. never.
but my one comment...
when using 2K and open window is enough (even with the mask).
it is not
its heavy particles tend to go down, not up and they can go thorugh doors - under them
your family can breathe it in next room.
its really serious health concern here with this stuff.
when its good `ol 2K its relatively usable, but what to do with new waterborne stuff (in EU you can buy ONLY this stuff). its even more dangerous, after "coming" into body (through - when you have mask - bare skin areas and even eyes!!!) it wont go away. never.
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