How to clean motherboards?

[jazzbass]

Hi all,

I have tried with industrial acetone, not the one to clean nails from polish , it works great.

Franco

[pompeiisneaks]

I'm still confused that IPA is dangerous. I've used IPA for years to sanitize cuts/wounds. If it's not safe to use on humans, why use it on open wounds? Or is that something related to the concentration, or inhalation? I'm not sitting huffing the stuff, it often takes me 10 to 20 seconds to clean up an area with IPA.

~Phil

[erwin_ve]

Phil: IPA for medical use with a concentration of a max to 70% is safe for skin disinfection, above is considered unsafe.

[pompeiisneaks]

Ahh interesting, I'll have to be careful then, we've used the 91% I have for some of that eek!

~Phil

[pompeiisneaks]

Reading this, it seems that it's more prolonged use of any IPA that can cause skin damage etc. It doesn't seem like minor use, with hand washing in between is much of a risk, I'd think if you were going to do some marathon board cleaning, wearing gloves would remediate any potential harm?
https://blog.gotopac.com/2016/01/06/the ... 20cracking.

Of course a lot of this article is written for industrial heavy duty use too, so it's for industry, not home shop minor use as well.

I'm no doctor, so don't take anything I'm saying as factual, medical, or right, but it seems to me the risk for what I use is nearly zero.

~Phil

[Murrayatuptown]

FYI:

IPC610 solder training in the manufacturing world (involving politics and money) has agreed that a mix of IPA and acetone should not exceed 50% acetone to avoid damage to certain components. That's a little arbitrary, but it does point to the fact that some solvents ware more aggressive than others and some components may be more easily damaged by 100% acetone than 100% isopropyl alcohol. You don't see a lot of polystyrene capacitors anymore, unless you hoard them like do.

The clear axial ones with really skinny leads are pretty solvent sensitive.

I don't know where people can buy 100% (anhydrous) IPA, but it is nice to have available as it doesn't bother much on circuit boards. 50-50 acetone-IPA is really good for flux removal. I know Randolph (same people who make transformer varnish) is one supplier of anhydrous IPA in quart cans.

OTOH, a little water in your IPA is a non-polar solvent that can dissolve kinds of dirt polar hydrocarbons won't. I use 91% at home because we usually have it and I don't have to go buy more stuff. But it takes a lot more scrubbing when you're spoiled by stronger stuff.

Watch out for labels and ink on boards. Once they're unreadable, there's no bringing that info back.

[Murrayatuptown]

Chemical absorption by inhalation, ingestion and absorption are all ways they can get into your body. Different solvents have different TLV's (threshold limit value) over an 8 hour shift (different relative degree of safety).

So we're relatively safe at home with infrequent use. No oppressive Safety Person like at work, but please take care of your health!

I used to clean bicycle parts with gasoline and no gloves! I still have my own liver, but maybe I spoke too soon.

[chief mushroom cloud]

I've used carb cleaner and brakleen...and I ain't dead yet.
Anhydrous Isopropyl Alcohol and soft bristle toothbrush. Dunk the whole thing in a pan of it, let it soak, and brush lightly. Rinse twice in fresh alcohol. Will look 'factory'. Just wear some wrenchhead's gloves and open a window.

[brewdude]

How do you dunk it if you are reworking/modifying a previously constructed amp?… I really try not to remove an already installed board to rework it let alone clean it.

[LOUDthud]

If you look for board cleaners on sites like Mouser, Digikey etc you'll find each product has what used to be called a MSDS or Material Safety Data Sheet. An employer in the USA should have these on file for just about any chemical used including solder.

The MSDS should describe exactly what the product contains chemically, how hazardous or flammable it is, what to do for skin contact or breathing vapors etc. You may have to go to the manufacturers website, but it will be there somewhere.

Some states require that IPA be diluted with at least 30% Acetone. I didn't know that.

To clean small areas such as around a resistor that has been replaced, I use a small brush called an acid brush. It's a metal tube about 1/4 inch diameter crimped on one end to hold black brissels cut to a length of about 3/8 inch. Compressed air or a paper tissue is used to mop up or remove solvent with flux absorbed. Larger areas like entire boards I use a tooth brush and paper or cloth towel to mop up.