Ultrasonic cleaner

[Vertigo]

Is it safe (for the board and components) to clean a freshly populated board in an ultrasonic cleaner with an alcohol solution? I know it isn't necessary, but can it be done without fearing that it would ruin the board?

[roberto]

You want to soak the full pcb in a cavitating bath of alcohol?
No, it isn't safe. No reason to do it.

[pompeiisneaks]

I am not sure why it would be unsafe roberto?

I know it's a common tool to clean solid state circuit boards that have corrosion etc.

What specifically would be bad for this situation? I clean my leftover flux from the board with alcohol?

Or is soaking the entire thing in an alcohol solution and causing ultrasonic vibrations dangerous in some way and a different cleaning solution should be used?

~Phil

[sluckey]

You risk losing the labeling and colors on some components. And some components may absorb some alcohol. I would not advise soaking a board in alcohol.

However, I wash all my loaded boards in mineral spirits. I just use a 1" paint brush and liberally apply, scrubbing at the same time. Then tilt the board on edge to quickly drain. Blow off with an air compressor. This get's rid of all the flux splatters. Then I repeat the whole process using denatured alcohol which removes any traces of the mineral spirits. This whole process only takes a few minutes. Nice clean board and the solder even has a polished look (or so it seems). Both of these chemicals are pretty gentle. Don't use anything that takes your breath when you sniff.

[roberto]

I am not sure why it would be unsafe roberto?

You risk losing the labeling and colors on some components. And some components may absorb some alcohol. I would not advise soaking a board in alcohol.

Exactly as sluckey is saying.

[pompeiisneaks]

Thanks to you both!

I'm guessing the ultra sonic cleaners likely don't use alcohol in their solution then? (This is something I've never used but seen many videos I watch on YouTube about electronics repair etc)

~Phil

[Vertigo]

Thanks all. I'll try the spirits and brush. I've been using a trimmed acid brush and 99% alcohol but all that seems to do is push the flux around and redistribute it over the board, leaving it a sticky mess. Over the long term, it's likely to look like a carpet.

Phil, I can't speak to electronics but I use alcohol and acetone all the time in my ultrasonic. The machine itself is filled with a distilled water mix but I keep small glass containers for cleaning various titanium parts before welding.

[pompeiisneaks]

Thanks all. I'll try the spirits and brush. I've been using a trimmed acid brush and 99% alcohol but all that seems to do is push the flux around and redistribute it over the board, leaving it a sticky mess. Over the long term, it's likely to look like a carpet.

Phil, I can't speak to electronics but I use alcohol and acetone all the time in my ultrasonic. The machine itself is filled with a distilled water mix but I keep small glass containers for cleaning various titanium parts before welding.

That may be the reason alcohol works so well, I doubt it has an impact on titanium other than cleaning it.

I'm a complete noob to ultrasonic cleaning so very curious about it.

~Phil

[sluckey]

The mineral spirits or turpentine will dissolve the flux, making it easy to brush off. That's why I use it first. But just one wash/scrub with mineral spirits often leaves a film on the board that doesn't look good. The denatured alcohol wash/brush takes all the residual film off, leaving a clean looking board.

[Vertigo]

I just tried it and it worked very nicely. Thanks for the tip.

Do you have a tip for gently removing a wad of silicone from a circuit?

[roberto]

I've always used it for metal parts with water and 2% of nitric or 5% of citric acid (I think I bought it in 2010 or so).

[Vertigo]

I've always used it for metal parts with water and 2% of nitric or 5% of citric acid (I think I bought it in 2010 or so).

I bet that works great but I have rather specific needs for what I do. I need titanium parts to be ready to weld shortly after they come out of the bath. The fast evaporation of alcohol and acetone get that done. Any detergents I've tried need a rinse and anytime I introduce water into the process I get spotting. Since I do all of my finishing pre-weld, I need everything to be as close to perfect as possible or I have to go back and do a significant amount of work post-weld.

79B39454-09AF-443E-BB50-E118853381F9_1_105_c.jpeg

[roberto]

Very nice welding!

[SoulFetish]

I've always used it for metal parts with water and 2% of nitric or 5% of citric acid (I think I bought it in 2010 or so).

I bet that works great but I have rather specific needs for what I do. I need titanium parts to be ready to weld shortly after they come out of the bath. The fast evaporation of alcohol and acetone get that done. Any detergents I've tried need a rinse and anytime I introduce water into the process I get spotting. Since I do all of my finishing pre-weld, I need everything to be as close to perfect as possible or I have to go back and do a significant amount of work post-weld.

79B39454-09AF-443E-BB50-E118853381F9_1_105_c.jpeg

Acetone is a great quick evaporating degreasing agent on machine parts, but DO NOT use it on electronic parts. It will break down most composites, and I would not recommend using it on circuit boards either.
99% Isopropyl alcohol works great for this application. It is my preferred cleaning agent, and will break down flux on it's own. It's been used safely on electronics for decades (in fact, Tektronix used to specify that only isopropyl alcohol should be used when cleaning any contacts or switches so as to not affect the HF characteristics of the contacts).
We used to use Denatured Alcohol in the shop for cleaning boards and electronics, but the manufacturers have recently been putting in additives, making the fumes so nauseating that it is unusable, even with a mask. The label states that it should not be used as a cleaner, so perhaps the additives were included as a deterrent.

[Vertigo]

Acetone is a great quick evaporating degreasing agent on machine parts, but DO NOT use it on electronic parts. It will break down most composites, and I would not recommend using it on circuit boards either.
99% Isopropyl alcohol works great for this application. It is my preferred cleaning agent, and will break down flux on it's own. It's been used safely on electronics for decades (in fact, Tektronix used to specify that only isopropyl alcohol should be used when cleaning any contacts or switches so as to not affect the HF characteristics of the contacts).
We used to use Denatured Alcohol in the shop for cleaning boards and electronics, but the manufacturers have recently been putting in additives, making the fumes so nauseating that it is unusable, even with a mask. The label states that it should not be used as a cleaner, so perhaps the additives were included as a deterrent.

I would never use acetone on anything but metal parts and even then, I only use it when there's a contaminant that's too much for alcohol to handle. The original question was alcohol and the ultrasonic, never acetone on electronic parts.