No Clean Flux?

[Mr RB]

Jpanhalt, Australia switched its methylated spirits denaturing chemicals some years back if I remember right, to make them less toxic and more effective to stop drinkers. I expect it's the pyridine which would have been swapped.

From what I know about methanol it's not that toxic when combined wiht a large enough quantity of ethanol. Many red wines contain over 1% methanol and people actually DRINK that stuff (and wonder why red wine gives a nasty headache).

RCinFla, thanks for the info, I use the metho for numerous cleaning tasks including painted and plastic surfaces and have not seen any signs of it attacking surfaces or finished except where they are alcohol soluble.

(edit) I just looked and found a PDF on Australian metho here;
https://www.electro-tech-online.com/custompdfs/2012/03/methylated.pdf
it has 96-99.8% ethanol, 2-4% water and not more than 1% denaturing compounds which officially "will not alter the safety of the product". It also says officially the metho is "a low hazard by skin contact".

I think this may have been after they made the metho safer, ie it shouldn't cause the blindness and brain damage of methanol if swallowed but the denaturing is still enough to make it extremely nauseating and unpleasant to try to drink.

 

[tvtech]

My boards are white and double sided. Meths (coloured now to stop people drinking it) leaves purple stains on the board after washing it.

Water based = bad news.

I have used a product that seems to work OK on my white boards...Expensive though. Called MOMAR "On Board". Does not not strip paint off....but rather cleans flux off (the general idea). You must be patient with it though...little at a time to soften the hardened old flux. Otherwise, you will waste the can.

Not water based = win. Non Conductive to 25KV.

Cheers,
TV tech

 

[jpanhalt]

Jpanhalt, Australia switched its methylated spirits denaturing chemicals some years back if I remember right, to make them less toxic and more effective to stop drinkers. I expect it's the pyridine which would have been swapped.

Thanks for the update. It is good to know pyridine has been removed. I wonder about in the UK?

From what I know about methanol it's not that toxic when combined wiht a large enough quantity of ethanol. Many red wines contain over 1% methanol and people actually DRINK that stuff (and wonder why red wine gives a nasty headache).

The toxicity of methanol is not so much from the chemical itself, but rather from what it is metabolized too. Methanol is oxidized by alcohol dehydrogenase to formaldehyde. Treatment includes giving the patient ethanol, which competitively blocks that reaction and allows time for the methanol to be harmlessly excreted. Antabuse works the other way. Acetaldehyde is produced by the action of alcohol dehydrogenase on ethanol. Antabuse prevents the next step in the oxidation so acetaldehyde accumulates and makes the person feel quit sick.

Unfortunately, alcoholics do irrational things. A patient who is taking Antabuse (or similar) may present after ingesting methanol. You then have a problem.

John

 

[Mr RB]

TvTech, I would not buy metho if it has colouring in it! That's a pain, the whole point of a cleaning chemical is NOT to discolour things... Our stores here have both clear and coloured metho, and people have a choice.

Jpanhalt, sorry i was just guessing it might have been the pyridine that was removed when they made it safer but I really have no idea. Looking at that product safety PDF it looks liek methanol was removed, and the denaturing compound was unspecified apart from that it must be a compound that does not make the product less safe. I assume that means it should be something that makes it taste bad and make you vomit but not necessarily produce poisoning.

As for alcoholics doing "irrational things" like drinking metho, yeah that's pretty nasty. Considering ethanol can be produced for a couple dollars a litre its terrible that people are drinking poisoned ethanol because it cheaper.