As I recall, the old K&B epoxy paints weren't exactly safe. How safe is Klass Kote? I did not see safety info on their website.

DavidR,

Basically, which products contain isocyanates ? exopy glues ? epoxy paints ? cyano glue? dope ? polyurethan paints / varnish ? How to make sure ?

I'm afraid when I read your lines [&o] that I went wrong ...

What is the long term impact of isos on human body ?

Doug,

I use the non mask option, call the guy at autobody store he was really helpfull with me and recommended the combination I got. Make sure and get at least 80' of hose that way the air is cool when it gets to the hood.

I agree with your statement about the cost of your health, that's why I have advocated the forced air respirators for the last couple of years.

Strykas,

The only way to be sure what you are dealing with is to ASK the supplier of your product for the MSDS sheet. Here in the US at least it is a law that any chemical has an MSDS sheet.

Thanks David, I just picked one up, I really appreciate threads like this. Also got a new Jet Haulin Trailer this morning to pull behind my new 6.0 liter Diesel Excursion! So better to stay off the highways coming from TX to the Jet Meets this year, I'm likely to topple over on anyone of you guys

Merry Christmas and Happy New Year etc!

Sean

Here's another site selling them prices are pretty good:

http://clmcenterprises.com/hobbyair.htm

David, I was not trying to down play the importance of proper personal safety, I was only replying to the original question about a modeler priming his jet hopefully not a full size one, however small the job should be protecting your self is upmost importance, and yes I know this unfotunatly I,m in the buissines I own a fully equipted body shop for about 19yrs, fetureing PPG materials I stock their system, and have all the informacion available to me and my employees, Ron Ballard"s post #25 is the proper way of protection, you suggested the use of THICKSTER gloves, that is incorrect they are made of latex wich offer little or no protction because they rapidly degrade after being exposed to many chemicals found in paint, Nitrile gloves , in contrast, provide a better barrier to paints and organic solvents, maybe you should read this WWW.epa.gov/dfe/projects/auto. I will offer some info from the CDC DHHS(NIOSH) publication No. 96-111
BACKGROUND
Diisocyanates are a group of low-molecular-weight aromatic and aliphatic compounds. the most common of these are toluene diisocyanate (TDI), methylene bisphenyl isocyanate (MDI), and hexamethylene diisocyanate(HDI)they are widely used in the manufacture of flexible and rigid foams,fibers,coatings such as paints and varnishes, and elastomers. diisocyanates are increasingly used in the auto industry,autobody repair and building insulation materials. in this report. diisocyanates as group will be referred to as isocyanates. The world production o ISO is estimated to be 3 billion puonds annually, and 280,000 US workers are potentially exposed, EXPOSURE LIMITS OSHA, the current permissible exposure is 0.02part per million parts of air. HEALTH EFFECTS OF ICOCYANATES they are powerful irritants to the mucous membranes of the eyes and gastrointestinal and repiratory tracts, Respiratory irritation may progrss to a chemical bronchitis with seveis re bronchospasm and also sensitize workers to asthma attacks wich can lead to death. CASE REPORTS HIGHLIGHT OF 1 DEATH of a 37 year old car painter in 1988 with on going asthma hospital visits continued painting after being warned several times, and wearing only a mask went to work sprayed a car with two part polyurethane and died the following morning, sounds like your frends story all this info is available thru the U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES this is meant for occupational safety, originaly I was only refering to the response of a relatively small primeing project I'm sorry if I caused any confussion, and I agree if $450. for peace of mind is worth it then by all means buy a freash air positive pressure respirator, specialy if you also paint your models, because you know that most basecoats contain lead wich is also a hazard of painting.. dave I wonder what would happen if I introduced some ISO inttravenously to you maybe we can try it at a jet meet noon time event, would be educational dont you think... just kidding okay george

Guys
I have learned quite a bit reading over this thread. Thanks for the information! All in all I prefer a professional spray booth.
BRG
Greg Anixter

Hi guys,

I would like to dispel some incorrect information about isocyanantes, their mode of operation in out bodies and how the selection of PPE comes about. To give you some background, this area is my carrer - I'm a Certified Industrial Hygienist and got my masters in Environmental Sciences (Industrial Hygiene). Disclaimer: This in no way means that I'm NOT full of _ _ _ _ on other areas of jet modeling. Anyways - this I do know. About 2 years ago, I did a bunch of research (and a paper) into the medical/toxicological study literature on Iso's and Cyanoacrylates. As luck would have it, Bayer Chemicals and 3M was doing a high-level technical class on iso hazards at a professional development seminar I went to. I participated in that as well. Here's what I found out and know:

Isocyanates are not technically !QUOT!cumulative!QUOT! like lead poisoning, but are in a class of hazards called !QUOT!sensitizers!QUOT!. They do not collect in your body, but rather your body develops an allergic reaction to them over repeated exposures. There's no specific number of exposures that leads to a person becoming sensitized. Once sensitized, you will have a systemic allergic reaction (not the typical runny nose/sneezing). The reaction is just as was described earlier - bronchoconstriction, etc. can't breathe. As far as is known from studies thus far, once sensitized, you're always sensitized. there appears to be no other long term affect known yet (always subject to change). Most adverse reactions described in the literature do not involve death - but there have been a very few. A person's tendency to react is varies due to age, health and most markedly due to race for some reason.

Not all Iso's are created equal. TDI is the worst actor and the paint companies have by and large have moved away from it. The poly-isocyanates demonstrate the least sensitivity potential from those I've reviewed. Skin sensitivity has only been demonstrated in animals with direct painting of TDI on the skin and never demonstrated in humans. Could it happen? Who knows, but I'm not going to test it. Some of the other health effects on the paint cans are not due to the iso's, but rather the solvents and carrier chemicals which have a detrimental effect on liver, kidneys and nervous system.

PPE:
3M did a study in which they took their respirator cartridges and forced air w/typical iso concentrations through them and had sensors on the other side to see when breakthrough would occur. Bottom line was that a chemical (specifically an Organic Vapor) cartridge alone showed very quick break through but an OV cartridge with a HEPA pre-filter gave very good protection on the order of hours. Here's the rub: you can not smell iso's at the ppm level that they are considered to be potentially hazardous so you have no warning properties. NIOSH respirator decision logic then dictates you use supplied air with such chemicals if the cartridge has no end-of-service life indicator. Paint companies will not go against the NIOSH recommendations. David was right on the money about your cartridges to - you open a chemical cartridge and it's got at best a week's life span under perfectly low chemical exposure and super low humidity (say Arizona?). In the Gulf Coast, where I live, the life span is measured in hours with little to no chemical exposure. 3M is very confident that a HEPA pre-filtered, fresh OV cartridge provides protection, but they can not recommend it due to the technical limitations and so they don't.

Gloves - As a chemical safety geek, I'm proud of you guys; Nitrile gloves ARE the way to go for almost all of your painting needs. Latex is porous and absorbent of solvents. You can buy the nitrile gloves researchers use in laboratories that are as thin as latex exam gloves and they'll do just fine as long as you're not dunking your hand in the paint. Just make sure they are the type that have SOME chemical resistance.

What about residue after painting? After mixing, Iso's polymerize fairly rapidly and loose activity. They basically turn into plastic. Humidity also causes iso's to polymerize without mixing. The tests 3M/Bayer and others have done showed no free isocyanates basically within a few hours after painting. This, they think may also be one of the reasons why we don't see more very bad reactions to the stuff, kind of limiting the exposure.

Chuck Carlisle, CIH, CSP, CHMM

Intersting how the tone of this thread has changed, I'm glad to see it. We often take the little safety matters for granted.

I do know the thickster gloves are Latex but they are a much thicker latex and seem to hold up much better, but I also keep nitrile gloves on hand in the shop, maybe I need to adjust my technique some.

Chuck,
I'm glad you cleared up the cumulative affect of the Isocynates but it is not the sensitization a cumulative affect? The more that you are exposed to the chemical the more likely you are to become sensitized to it?

David,

I entirely see your point/perspective and that can be true from a lay perspective. From a pure toxicological/human biochemistry perspective the difference is important: where a cumulative toxicant such as lead, cadmium, mercury is concerned the body eventually excretes it, though it may have a biological half life of 40 years. Also most of the cumulative toxicants have different target organs (e.g. lead and bone marrow; cadmium and kidneys) and health effects which are typically chronic in nature. On sensitization, you have an overall systemic, acute reaction which may or may not be life threatening. Sensitization might occur in as little as one or two high doses with lesser adverse reactions (or almost none) and then wham! a bigger reaction.

From our modeling point of view, we want to avoid multiple exposures (as in prevent the "cumulative effect", whether it's technically cumulative or sensitization) and take typically the same precautions. So it's 6 and 1/2 dozen as far as we're concerned.

Chuck Carlisle, CIH, CSP, CHMM

BEWARE : For those in Europe using "G4 polyurethan varnish" by SOLOPLAST (very good fuel proofing varnish) :

http://www.soloplast.fr/resultat.asp...e=39&Submit=OK

It DOES contain dipenylmethane isocyanates ! [X(][X(][X(]

I used to remember my early modeling days when I was 14, using this varnish in NON ventilated areas, with no mask at all, working with bare hands (very sticky). I 'm still here today, 15 years after, but perhaps not for long, go figure.
Take care.

chuck

thanks for chiming in. i will be addressing these issues before the next round of painting.

Wow! Soloplast, huh? I wonder if that's even available n the states. I've never seen any over the counter type hardware store polyurethanes that had Iso's in them. The iso's do make the paint tough though. Kind of diametrically opposite to polycrylic, which is water based and looks pretty darned safe.

Strykaas,

I think you'll be around. Also, most known effects of isocyanates express themselves upon exposure - note the asthma-type symptoms. If you cut off your exposure, you should live (barring car wrecks, skydiving accidents, prostate cancer at 70, freak cooking accidents, any good tasting food, etc.) a nice long life.

Build safe, fly often - enjoy life without the worry - it's a precious gift to be savored.

Chuck

Chuck:

I think you mean no free isocyanates, as in PPG hardeners......

All Polyurethanes(foam, varnish, single part paints, etc.) by chemical definition, are isocyanate polymers.......all of the spray and brush products must meet strict, free-isocyanate, off-gassing standards at varying temperature and pressure........ basically zero off-gassing permitted here in the U.S.......don't know about Euro products like Soloplast.....

Tom

HI all, you guys kill me, You dress up to the hilts when painting and then go to Superman and breath Jet fuel for a week.
On a serious side,I too will be ordering one of them dare air pumps.
Rcpete

CHUCK
It's nice to have someone with your personal knowledge in this subject. Thank you for taking time to share it with us.
george

You're absolutely welcome and ask me anytime - if I can't answer off the top of my head, I have the resources to research it. E-mail or PM me as I drive a desk most of the day I usually can usually answer pretty fast.

Tom -
You are probably right, I do not profess to be an expert in urethane or polymer technology. I just know how to research and asses relative hazards of chemicals, radiation, etc. It's funny though, for all the msds' I've researched on the standard hardware type urethanes for wood, they never list Isocyanates as an ingredient.

And you have hit on a good point "free isocyanates" were the center of attention in much of the research performed out there as "bound" Isocyanates don't appear to offer the hazard. It's not to difficult to measure in the air or from wipe samples and the evidence suggests there's not much of a ligering hazard from Iso's. The suspended (in air) solvents from the paint spray are another story, though they aren't the same class of hazard. Take home point - that can of hardener is the really bad stuff, not the other part of the 2 part/3 part paint.

I appreciate the banter - need the mental exercise.

Hi Chuck:

Your observations are correct....if the stuff in the hardware store can was properly manufactured, there should be no isocyanates in the can.....once the isocyanate is hydroxylated and polymerized at the proper temperature and pressure, in the presence of proper catalysts, all the isocyanate molecules are converted to a long chain of urethane molecules, hence Polyurethane on the label....no one gets scared that way.......once the stuff polymerizes, it is very stable in either the liquid, foam, hardened paint or plastic form at room temperature or slightly above, but if it starts to get very hot or burn, it can break down and give off free iso's......we have all heard of the toxic fumes given off when full scale planes crash and burn and the polyurethane seats cushions light off........one of the toxins is free isocyanate....mixed with smoke, bronchospastic suffocation is almost certain as in ValueJet 592.....

During 30 years of medical practice, I only saw one case of severe bronchspastic reaction to iso's......it was a young guy, about 20 years old shooting PPG in his garage, with only a small exhaut fan under his nearly-closed garage door.....and he did have a history of childhood asthma.....yet there are literally hundreds of guys locally who have shot iso's and epoxies, even lacquers with just a paper or poorly fitted charcoal mask for years.....mild reactions do occur regularly with guys who elect not to wear proper protection, but life-threatening reactions are rare...

In no way am I suggesting not to use proper safety equiptment......I own an AXIS/CITATION twin turbine HVLP unit and Hazmat suit...kinda pricey BUT DON'T FORGET....if you live in the north country, spray a little anti-fog on the clear face plate, and the hood makes the best snow blowing headpiece around......keeps the frostbite off my nose and cheeks when the wind swirls at 25 kts right in my face, no matter which way I turn, when blowing 12 inches of fresh powder at 10 below zero......


Tom

Some techniques I've read suggest brushing on the primer (K36) and then sanding it back when dry.

Is there still the same hazard when brushing (from the vapours) rather than from the atomized paint during spraying?

Thanks

Paul

I have a question about the K-36 primer part 1. I have noticed it hardens up on the lip of the can and things like stir sticks. I do not believe it could be removed with any thinner after 24 hours or so. Is it necessary for fuel/oil proofing to use the catalyst at all? How about for spraying on things like wings?
BRG
GA

Burning of polyurethanes and plastics is nasty and Isocyanates are only part of the concern as it also produces cyanogenic compounds (like hydrogen cyanide). A few years back now, there was a typical car-b-que in Dallas. Usually the guys stand back and do not don SCBA's since it's outside. This time it was a Pontiac Fiero (remember the plastic body?). There was a wind shift and several fire fighter received "minor" smoke inhalation - and died relatively quickly. Subsequent/forensic analysis showed elevated levels of hydrogen cyanide and was confirmed with some test burning. Test burns are pretty interesting - if you're interested I could related a forensic where the Texas Department of Insurance (that's where the fire marshal's reside) caught a woman committing a homicide and covering it up with a fire - by burning a 450 pound pig carcass (it's gross), but I'm digressing off paints and jets.

How about designs of home-built paint booths? I'm about to turn a 3rd garage bay into a down-draft booth that will quickly convert back to storage for my Cobra. I'm interested in what others have done as well.

Brushing is MUCH less hazardous, by orders of magnitude, but you still have to take precautions. If you do not catalyze the primer, you will not like the results.

Hi guys,
I was wondering if any of you could help me?.
I 'discovered' K-36 and K-201 whilst reading Pat McCurry's Dornier build over on RCSB, never heard of the stuff before, as you all probably know he swears by it. I have tried to obtain it over here, we have a local supplier of PPG Paints,..... who had never heard of it,.... he contacted PPG UK,..... they had never heard of it!!!!!!. I printed some pictures of the tins of paint from the web, to prove it existed. Only then..... did they tell me it must be only available in the US...... So question is do you know of anybody who will ship me some to the UK?

Thanking you in advance
From STONE AGE ENGLAND
Andy D