Yes, without hardener, AE is isocyanate free. There will be marginally less gloss without hardener, and be a little softer. Hardly noticable. It will still look good. It will take longer for the paint to cure without hardener. This means that you would either have to shoot all your coats the same day, or wait a week or two in between coats. With hardener, you can recoat within 24 hors. Try that without, and the paint will lift. You're right that asthma and isocyanates don't mix, unless you have a respirator with an outside air source.

 

Take a look at this MSDS of urethane activator. The content of Hexamethylene Diisocyanate shows a value of <1% by weight. From that, please tell me how many grams (or micrograms, or whatever) of isocyanate compound exist in 4 oz. of hardener. You can't and that is my point.

In my opinion and apparently Steve's, to even insinuate activated AE is safer than urethane is reckless when you consider the fact that OSHA's permissible exposure limit (PEL) for TDI is 0.02 part per million parts of air (0.02 ppm).

Stevef100s
Since isocyanates have an affinity for water, what do you do to protect your eyes, when using a chemical respirator?

Personally, I won't use a chemical respirator when using isocyanates. I use a forced air respirator with a hood. I don't have to worry about mask leaks and my eyes are protected. I have gone one step further by using a paint suit to protect myself from splash-back. Wish I had done that before I developed the itchy welts on my arms.

 

This thread has turned into an isocyanate discussion so I have a question regarding protection. I am going to use the acrylic enamel and I am going to paint outside (a few pieces just inside the garage with the door open too). I bought a 3M Dual Cartridge Respirator 07193 (Organic Vapor/P95 Assembly - 3M recommended for paint spray applications). That's a mouthful. With a name that long they probably could have charge more. Anyhow, is this OK for what I'm doing? My son is going to paint his truck too and I don't want to take any chances with him. Thanks.
jor

 

So no hardner with an AE paint is okay with a quality respirator?

How long should someone wait, after painting their vehicle without the use of hardner, before they drive it?

Is there anything that can be done to keep dirt out should this be done outside, during the curing process, such as run water over the paint?

Are there any AE paints that stand out quality wise over others?

The shine comes from the hardner is there a clear AE that could be added for depth?

I watched a show the other day where they were applying a new house of color paint, it was a BC/CC paint, they used a respirator only, was that just a bad display of safety practices?

I know, a lot of questions, I am wanting to paint my old truck but wanna be confident of what is done, before hand.


Thanks

 

<cr>
The stock answer is, no, you should not spray isocyanate products without a fresh air respirator.

If the question was, do I spray isocyanate products without a fresh air respirator, I would say, no I don't.

If the question was, do people spray isocyanate products without a fresh air respirator, I would say, yes they do.

If the question was, can you spray isocyanate products without a fresh air respirator, I would say, that's your call.

jor
I have a friend that is in his 60's and has painted for about 40 years. Besides that, he is a smoker. All he uses is a chemical respirator. On the other hand, I have read OSHA docs of painters that have died after exposure. Personally, I would feel comfortable using a chemical respirator, if I was painting outside. By the way, this is not a recommendation that you do it.

jwtaylor
Yes, AE (without a hardener) is safe with chemical respirator. I have limited experience with Dupont Centari and PPG DAR (AE products). The Centari docs say that it is "tack free" in 2-3 hours and "tape free" in 6 hours @ 77F. Using a hardener will decrease these times. DAR docs say you can put it into service after drying overnight @ 70F. Add an additional 24 hours during inclement weather. If you ran water over these products before they were dry, you would have one giant mess.

 

Thanks. I figured the water idea was a long shot, but being they aren't water based I wasn't sure.

If these have been defined before then bear with me, if not then I have a couple more questions.

Define "tack free" and "tape free". Thanks again

 

<cr>
Tack free is when the paint isn't tacky anymore. Dust free would be another term.

Tape free is when you could apply tape, to do a 2-tone paint job.

 

Appreciate it.

 

tack free is when you add the flames

 

There are many different opinions on what to use for a respirator. A supplied air system is recommended. I've read that a charcoal respirator is effective in filtering out isocyanates. I've also heard of painters that have had too much exposure can't even go near them. The father of an old boss of mine sprayed too often without a respirator and heard he was in really rough shape and his nervous system was all messed up. I believe they effect everyone differently. None of the shops I worked in years ago cared enough to have a supplied air system for us to use, and no they didn't have a well ventilated downdraft booth. If they made it law for shops to have them , thats great. The autobody industry needs a lot of changes in my opinion. Thankfully I don't paint steadily any more, because what shops normally pay it is not worth risking damage to your health. I have also painted at home many times with only a charcoal respirator and probably got more exposure then I care to think about. As soon as I can afford to buy an air supplied respirator I will. Make sure you get as much ventilation as you can, cover exposed skin and eyes, and make sure your mask has a good fit and fresh cannisters if using a charcoal respirator. Even if you aren't someone who is effected right away, you can be over time. I wouldn't want to spray a paint without a hardener, but the isocyanates in them are not something you want getting into your body.