US 2k Spraymax two-part cans

Re: US 2k Spraymax two-part cans

Dick Coers

I thought you needed an air supply mask to spray 2k product. Something about the isocyanates?

Re: US 2k Spraymax two-part cans

David Weaver

I spray that stuff outside with ov mask. That along with the super tough overspray.

I guess I'll make sure to spray it only outside.

Re: US 2k Spraymax two-part cans

Bill Tindall, E.Tn.

From the MSDS sheet it is more like 10% solids. The only chemical nonvolatile is the diisocyanate (nasty stuff). Its 50% dimethyl ether! Flammable!!! This stuff sets the bar for flammable, well , maybe not as flammable as natural gas.

What does 2K mean?

It is just an aliphatic urethane. Won't yellow.

Re: US 2k Spraymax two-part cans

Bill Tindall, E.Tn.

I guess I'll make sure to spray it only outside.

That would be a very good idea.

Re: US 2k Spraymax two-part cans  *LINK*


http://finishing.tips/catalyzed-polyurethane-finish/

ISOs

David Weaver

Appears to be a long-known long-studied topic in two part finishes, especially automotive.

What I can find of the isocyanates is potential or probably carcinogen, but perhaps falsely attributed in one of the animal studies because of toluene presence.

But spray outside only. I vaguely recall spraying my car hood in the driveway (but with the garage door open), and when nobody was home (to avoid grief with the mrs). Amazed at the hardness and toughness of the finish, though, and it looks like there are "ISO-Free" 2k finishes, but not in cans.

No interest in dealing with the stuff for small projects in a gun that would need to be cleaned. Until it's warm out, I'll be using shellac on guitar bodies, anyway. It doesn't care that the back end of the shop is 45 degrees.

Something missing

Bill Tindall, E.Tn.

This stuff seems to be a 2 part finishing system. One part, the resin, is missing from the link you provided. There will be a resin, the film former. This component is not part of the MSDS you linked to. The second component is the crosslinker, the diisocyanate, described in the MSDS. When mixed the diisocyanate reacts with the resin to cross link it. The details of how this chemistry is initiated is not explained on your post. Can A and can B of this stuff? But how mixed?

Diisocyanates are highly reactive. That means they react with almost anything- finish resin, DNA, most every component of a cell, skin, etc. To make them safer the isocyanate is created on each end of a big non-volatile molecule that won't create much vapor pressure to create a breathing hazard from the vapors. But the aerosol is at least a sensitizer and may be deadly if enough is inhaled.

Re: ISOs

Bill Tindall, E.Tn.

To get the crosslinking to go at typical temperatures requires a highly reactive substance. Any chemical that can cross link a resin will cross link most every component of a cell.

Toluene is benign. It is a common industrial solvent because its primary hazard is flammability. Fretting over toluene in the company of an isocyanate is like worrying you might trip going down the stairs in a house afire.

Re: ISOs

David Weaver

Not fretting over toluene - just noticed in a study that they mentioned animals were given high doses of isos and cancer was the result. I went and reread some parts of other studies. When you don't know anything about chemistry, then you're guessing (like me).

I follow-up read suggests the following - toluene diisocyanate was listed as carcinogenic in a study (I think it was fed to animals), but no carcinogenic link found for inhalation.

That's not exactly reassuring, nonetheless.

Reading about isos in general (and potential misinformation on guitar forums from some folks suggesting that the isos will persist in a vented garage for weeks and contaminate a house and everyone in it, for weeks) probably isn't instructive to a level I'd like to see, so all I can conclude from all of this is that the best idea would be to just look elsewhere. It worked fabulously on a car hood, but I don't need the same guessing just for the desire to put a hard high-gloss resistant (permanent non-repairable) finish on a guitar.

I sprayed at the edge of my garage with a respirator on and the garage door open, and the door between house and garage blocked (towel under gap, etc) after reading warnings about it back then, and then went back into the house through the front door so as not to open the basement door. I thought I was maybe being a little over the top at the time (now that I recall), but probably not.

The aromatic nature of nitro lacquer leaves it out for me, too - I'll just look elsewhere, which is kind of a bummer. The toughness of the finish and the convenience of a trick two-part can (you puncture an inner cylinder in the can when you're going to use it, and then it obviously has to be sprayed within a short period of time or it'll just harden in the can) so that you don't have to clean spray equipment was nice.

I also see now why some of the two part foams were always warned against as not being appropriate for "playing around". Due to isocyanates.

The iso-free 2k poly is available and looks like it has been for about a decade with a comment that it can lose lustre over time (everything probably does) faster than the iso-containing prior versions, but I'll keep my eyes peeled for an offering of the iso-free stuff in cans. It looks like the spraymax-ish version of the 2 part clear in a can is sold under a bunch of different labels (eastwood, spraymax, etc) but is the same thing everywhere.

The trick can...

David Weaver

...the reason I think there's one type of this that appears to have different brands on it is because it comes in a trick can. There's a can within the can, and a mechanism to puncture the inner can to mix the two parts, and then one must spray the contents of any punctured can within a relatively short period of time (for obvious reasons).

I'm going by memory, but the instructions request that you shake the can for a very long time, and I've seen a few posts of guitar finishers suggesting that theirs never cured (they blamed it on the finish, but probably didn't follow the instructions).

It was easy to use on the car.

Your mentioning of a lack of ingredients makes sense - 10% solids didn't (elsewhere in literature, it says 33-35% solids total) based on how much I wet sanded the car before buffing the hood out. Incredible quality as far as hardness and toughness, but it was useful to ask this because had I not, I probably would've sprayed a few guitars with it, and perhaps some at the edge of the garage with the door open - it's just not worth it.

I have asthma pretty much since birth. I see that isos are associated with causing acute asthma or seriously harassing folks who have asthma already and making things worse, and fortunately, I didn't notice anything, so I probably didn't ingest much.

Reading further about the isos suggests that longer term, a setup like mine isn't appropriate because it'll just be absorbed through skin and eyes.

Many accounts on the guitar forums also of people stating that they have no ability to spray outside, but they felt safe because they sprayed in an enclosed garage instead with same precautions they'd use with nitro. Only one poster provided appropriate warning that it links with skin, eyes, etc and most others disregarded.

Re: ISOs

Bill Tindall, E.Tn.

toluene diisocyanate

The bass ass of the bunch. It is volatile so it can move from finish to everywhere. Special labs are required to use it. My daughter makes polymers from diisocyanates and she won't go near this stuff. Wicked sensitizer. I have a friend that worked with it and if he gets a few molecules of it on or in him he turns bright red and itches.

The stuff used in finish now days is not volatile. It will not leave the curing finish. The only hazard is skin contact before cure and aerosols.