Health and safety when TIG welding?

[Chris Stevens]

Noticed that brake cleaner rather than acetone is often recommended for clean up when TIG welding. Realise that a name brand aerosol can or container of brake cleaner, is not likely to contain anything thats going to produce noxious gases when heat is applied.

About a year ago when I had run out of acetone I used some no name brake cleaner (in 5ltr can from Ebay), for clean up, and when I started to weld some quite unpleasant fumes were produced. Whether these were linked to brake cleaner or not I cant be sure of.

However bearing in mind that there is only a price difference of pennies between brake cleaner and acetone, is it a good idea to choose brake cleaner, bearing in mind the adverse effects which might result
from using a no name product?

 

[Pete.]

*Insert phosgene story here *

 

[TechnicAl]

I think the phosgene story is a myth, But breathing in the fumes of any solvent cant be good for you. I always tell people the best prevention is to avoid it.
Use the solvent and then make sure its all evaporated before you weld.

You can try google. I have in the past and not really found anything useful but you never know........and you can check on the Phosgene story ( I think some solvents may produce it but not all.......I seem to remeber they have to be Chlorinated but it maybe the opposite or completely wrong)

 

[Chris Stevens]

Get the feeling I would probably be dead if brake cleaner had produced phosgene, but whatever it was didnt seem very nice!

 

[Swift&Bold]

Phosgene gas is produced when chlorinated hydrocarbons are subjected to high temperatures that's how it's produced for the military, it's not found naturally in the environment. Solvents typically used in industrial cleaning also contain them so It really depends on the content of the no name brake cleaner as to whether there is the danger or not.

 

[Jim Davey]

Depends how fast whatever you use evaporates, acetone goes pretty quick as do most brake cleaners. As long as it's gone for sure by the time you start welding it shouldn't really matter.
I do use a blow lamp to run over the weld seam sometimes if I'm not certain all the cleaning fluid has evaporated, I get a tiny puff of flame from residual acetone that has trapped itself which I'm sure would've affected my gas shield if it had happened during welding, but it's never needed on flat plate joints where there is nowhere to trap the fluid.

 

[Richard.]

Most of the time I have acetone on the shelf simply because it evaporates that little bit quicker
Ive a drum of brake cleaner too which I obtained locally at a motor shop and it's almost as good at what it needs to do. Al said it really it's a subject that's gone well OTT and just like the thorium tungstens it spreads like wild fire and people think these things are like atomic bombs. In all walks of industry whether it's using a solvent, grinding a tungsten etc etc you should not be breathing it in no matter the type or flavour. They are not dangerous if used properly and the precautions to protect our selves. Silly stories make people frightened to use things when in actual fact the best approach is to educate people to use things properly.
Pickling paste will do you far far more harm than any brake cleaner or tungsten yet that that's never a problem.

 

[voipio]

Brake cleaners using petroleum spirits and alcohol are less of a hazard, when heated, than methylene chloride (also known as dichloromethane) based products which give off chlorine. Carbon tetrachloride as another solvent with chlorine as a decomposition product.

The chances of phosgene being produced from methylene chloride during high temperature workshop processes is negligible. The conditions are just not right in terms of reaction kinetics. Chlorine will be the most hazardous decomposition product and, inflammability aside, is another good reason not to smoke around this stuff. Although it is the least toxic of the simple chlorohydrocarbons, breathing large quantities of plain old methylene chloride vapour is not a good idea, either.

 

[Wozzaaah]

This has been done to death on here, all the info anyone needs is available by doing a forum search.