Hardner-Shelf Life

[lsabourin]

Hi guys I've started clearing my own work and I see that the hardner label says that it's good for 2 weeks after opening. Is that for real? How long will it really be good for?

L

[OzDesigns]

I went to my my local shop yesterday to buy some more clear and hardner they recommend using pints or less because of what you mentioned. I have a bottle that has been opened for 1 month and i haven't noticed any probs. I am sure the experiened guys no more about this though.

It seems everytime someone mentions doing clear coat, it must be mentioned that it is the nastyiest little poison on earth (contains cyanide?), protective gear is a must!

Oz

[Bahamut]

Most hardeners react wit air. So buy in small amounts and keep it tightly sealed. BTW it's usually a chemical called diisocyanate. 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). Not that they aren't dangerous substances, because they are, I just wanted to make sure you guys know that it isn't cyanide gas your spraying around everywhere. Isocyanates are used for a ton of things. They are most likely in the insulation in your house if it's a newer one. The Isocyanates are a stablized by adding a catalyst that causes a bond to another type of molecule rendering them harmless for the most part. It's the free form of these types of Isocyanates that creates harmful effects.
TDI and other isocyanates are powerful irritants to the mucous membranes of the eyes and gastrointestinal and respiratory tracts. Direct skin contact with TDI can also cause marked inflammation. Respiratory irritation may progress to a chemical bronchitis with severe bronchospasm with prolonged exposure. Sporadic cases of hypersensitivity pneumonitis (HP) have also been reported in workers exposed to isocyanates. Individuals with acute HP typically develop symptoms 4 to 6 hours after exposure. Symptoms are often flu-like, with fever, muscle aches, and headaches. Symptoms may also include a dry cough, chest tightness, and difficult breathing. Individuals with chronic HP often experience progressively more difficult breathing, fatigue, and weight loss. If you begin to expierence these types of symptoms it means you need to check your work area and equipment. The ventilation in your work area may not be adequete to keep the PPM down to a number that your respirator can safely filter out, OR your respirator protection is inadequete. If you so much as think your respirator is not protecting you it's important that you stop using the 2 part urethanes until you can get filters that are at least P100 compliant. Better yet is a fresh air supply mask. This is simply a hose apratus connected to your mask to draw prefiltered air from a source that has been isolated from the work area. This is the easiest, cheapest, and best way to avoid exposure to Isocyanates.

I hope my Blabbering has helped clear up some confusion about these substances.

[OzDesigns]

It's ironic that clear coat would seem the least harmless, doesn't even smell that bad, and at the same time will kill you. I was in a rush once and put on a final coat withot a mask (mui estupido). About 4 hrs later I pucked like a rock star. I wasn't in there for more than 5 min.
After that i knocked out two holes in the walls for my monster fans and I invested in a real mask. Not the crappy cloth ones. Ever since then no probs.

BTW, nice tech info on chemical composition.

Oz

[lsabourin]

Thanks guys. Mine is about 2 weeks old so should still be good. I'll know for future use.

L

[landsbro]

Yepp,that's true have a bunch of containers with dried hardener..
it can be little tricky too,,it can look OK but still be bad,,,
when you mix the clear with the hardener and stir it should look like water
(clear) if the mixture get little milky/muddy in color the hardener is bad.
i use to keep it in metal containers with a lid but found that it last longer if
i keep it in a empyt thinner bottle,
/kimmo

[Bahamut]

Any way you can store it so there is the least amount of air in the container is the best. Just a small amount of ambient air can render it useless in just weeks. I keep the portions I don't use in those expando containers that are made form PETE plastic. Then i can extract all the air from the container.

[Diaz Dezine]

I pretty much avoid all the risks and storage of clear by going to an area autobody and paint shop to the final clearing for me.
I just do not want to deal with any of the hassles that come with shooting clear, plus I don't want it around the house or the neighborhood. The neighbors complained a few times and those few times were only when I shot clear.
Takin it to a paintshop assures for me that they do it safely and also get a primo finished surface.
Just my two cents...
DIAZ

[Bahamut]

Cost is an issue with having it done by a paint shop though Diaz. That's the only reason I shoot clear. If I was doing a job for someone that was paying me $$$$ to paint his car then I deffinetly would have the Pro clearing figured in the budget. But helmets and computers and other small things are usually too costly to bring to a paint shop. I think most of the time they charge a lot just because they don't want to deal with it and if you agree they are making it worth their hassle.

[Diaz Dezine]

Actually they are quite fair and $$$ was never an issue if you want the perfect finish, especially when the customer demands it.
Plus the paintshops love it when I walk in with some artwork that needs to be cleared, they display it, and it produces a type of work they normally don't do but would like to attract. In turn produces work for me, which has actually been quite beneficial for me and anybody trying to make a living in this field.
Can't really afford the property taxes to own a shop and really do not want to deal with zoning and environmental issues either.
You said it yourself Baha how dangerous clear is,, and for myself,, having it and spraying it where I live and breathe is not an option for me.
But that is me and the way I have dealt with clearing issues and I have adjusted financially and it has worked out quite well.
Not telling anybody how or what to do just giving my two cents...
DIAZ

[lsabourin]

Thanks again guys for all the insights. I will have to consider all the options I think. Right now I don't do very much clearing and as a biochemist I know what's in that stuff. I'll finish the snowmobile but I'll have to probe a couple of local paint shop and discuss this.

L

[motoxguy]

This conversation definitely interests me. I really want to clear my own work. The biggest object I really would need to do would be a helmet. I do not have the facilities for that stuff which is why im using AA. Aside from health issues which can be avoided with respirator/suit, I would be scared of the flammability of the fumes etc. I know alot of people do it in these conditions too, are they just rolling the dice? I dont know whether to try and find an auto body to clear my lids or put up tarps in the shed and do it out there. That would also mean that if its too cold, you cant do it anyway correct? Clear is the one thing I havent figured out yet.

[Bahamut]

Temprature is deffinetly an issue with clearcoating. Most must be within +/- 5 degrees of the reducer you're using. There's deffinetly more to clearing than just shootin paint.

[oats]

Should be about 65 degrees or more for clearing-If you have an old fridge , putting the container in it will prolong it's shelf life. When it goes bad it will harden up.

[airshock]

Isabourin, I realize this tread is a few days old but anyways, a old painter fellow told me once, (older than me, and I think he was normal) that if you have a mig welder with argon gas (compressed tank) just spray a few fumes into the can of hardener, shut the lid quickly and it will last for years. Another note, I have had hardener last for over a year in a old sealed fridge, just remember to shake it well before using. Just my 2 cents.

[lsabourin]

Good tip airshock. Never too late.

L

[Bahamut]

If you get all of the Oxygen out of the can it will last forever. I think O2 is what causes the reaction. Argon is inert and heavier than O2 so the welders tactic is sound.

[Diaz Dezine]

Hmmf...learn somethin new everyday! Have to pass this on.
DIAZ

[dungeonworks]

Originally Posted by airshock

Isabourin, I realize this tread is a few days old but anyways, a old painter fellow told me once, (older than me, and I think he was normal) that if you have a mig welder with argon gas (compressed tank) just spray a few fumes into the can of hardener, shut the lid quickly and it will last for years. Another note, I have had hardener last for over a year in a old sealed fridge, just remember to shake it well before using. Just my 2 cents.

Some places sell canned Argon for this purpose.

I have only had a couple cans go bad and that was House of Kolor catalyst. Their bottle type containers are cheap as hell. Heck, the el cheapo brands seal better when re installed! LOL I have stretched the shelf life out for longer than I'll admit here just by ensuring their is a good seal and looking at the clarity of the clear as Landsbro pointed out. If it is hard or clumpy, toss it and if it is clear like distilled water, it's good to go.

[dungeonworks]

Here you go...*LINK*....scroll down about 3/4's down and look for "Bloxogen". That's the stuff I was talking about. Also, check out the brewing and wine making sites. They sell stuff to keep opened wine and beer fizzy and fresh for weeks and I believe it is just argon as well. They stuff they use does the same thing, blankets the liquid with a heavier gas and pushes out the ambient air.