PCB flux residue

[ppppenguin]

AFAIK there is a standard formulas for meths.

https://www.gov.uk/government/publicatio...ed-alcohol

Curiously it says that methanol is not the same as wood naptha. I don't quite see how they can be different. Either way, it can make you go blind.

[alanworland]

Interesting topic, we used to use rosin fluxes during the assembly of petrol pump circuit boards which used to get cleaned in a vapour laden tank, can't remember the product.
There was an 'incendary' incident with one of the boards (not good in a petrol pump!) and water based flux solders were introduced into our flowsolder machine which were washed off in an industrial type dishwasher.
Used to come out spotlessly clean - we used to measure the waste water.

Alan

[Nick]

Interesting - never read the standard before, however section 2.2 says that whilst there's a standard for UK produced CDA (Completely Denatured Alcohol), CDA approved and produced by any other EU state is also allowed.

So, good luck with that! There's 27 other EU states, each potentially with a different standard (assuming that they have a standard), but if a version of CDA is allowed there, we have to allow it.

Thus, unless the bottle says it's produced in a specific country, you just don't know, i.e. "Produced in the EU" is not helpful.

Anyway, this is all rather moot, as has been mentioned, industrially flux is now water-soluble to avoid the need for organic solvents. Not all components are dishwasher-safe (or can be protected against washing) so they have to added post cleaning or the board designed to only use components that can be cleaned this way - generally a problem for switches, connectors, inductors etc.

[reset]

Interesting - never read the standard before, however section 2.2 says that whilst there's a standard for UK produced CDA (Completely Denatured Alcohol), CDA approved and produced by any other EU state is also allowed.

I have used Ever Clear for board cleaning but it may not be available outside the US??

   


https://en.wikipedia.org/wiki/Everclear_(alcohol)

[Nick]

Interesting - never read the standard before, however section 2.2 says that whilst there's a standard for UK produced CDA (Completely Denatured Alcohol), CDA approved and produced by any other EU state is also allowed.

I have used Ever Clear for board cleaning but it may not be available outside the US??

Essentially the same stuff as Methylated Spirits/CDA - i.e. mostly Ethyl Alcohol (Ethanol), except that it's explicitly made from grain (or corn) - I don't think that the specs for CDA stipulate where the ethanol comes from, just that it's ethanol!

CDA in the UK normally contains a small amount of IPA as well, so you're getting a hit of a secondary solvent too.

[reset]

CDA in the UK normally contains a small amount of IPA as well, so you're getting a hit of a secondary solvent too.

I guess I should have stated it is sold in liquor stores and made for human consumption. No concern about unknown content.

Drinking it will cause blurred vision but will not blind you.

[BusyBee]

I use IPA if to hand, or otherwise some lens cleaner I have (alcohol based on menthanol I think). I generally liberally swab on and then scrub it off taking the flux with it using an old toothbrush.

[Cleggy]

You can sometimes find out some information on the constituents of proprietary formulations by searching out what used to be called the Materials Safety Data Sheet (MSDS) - which I think are now referred to simply as SDS. Doesn't always work, but is always worth a look.

I have to admit that I care little about flux on a board, so have never used removers.