Ultrasonic cleaning solutions

[orion242]

So I got a 10L ultrasonic cleaner coming.

http://www.ebay.com/itm/291236823191?_trksid=p2060778.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

My main reason for this is cleaning flux and water damage from PCBs.  Secondary uses will be the wife's jewelry and firearms.

I have heard everything from soapy water, IPA, and special (expensive) solutions to use.  For PCBs, flux and mineral buildup (water damage) removal what is the general consensus?   Soapy water sounds cheap enough, but soaking a PCB in hot water seems counter productive in the long haul.  I have hot air stations so drying promptly is not a problem with water.  IPA is workable, but sounds like it gets dirty fast.  10L is not a small amount of 99% IPA to flush regularly and I move enough PCBs that this will see several 30sqin boards with light repair (and the original hand work) weekly on the light side.

Thanks in advance

[Richard Head]

I have no ultrasonic cleaning experiance but I've found that if a PC board has water damage it's generally best to first clean it with water.
I think water works best because most of the crud on the board was probably water soluble anyway.
As I understand it water disolves more compounds than virtually any other liquid, probably because its a highly polar molecule.

[apelly]

I've had good success with a healthy dose of dish washer detergent

[metalphreak]

I have used:

100% Isopropyl Alcohol - works well, removes flux quite quickly. Downsides are quick evaporation, slight white residue after drying, and it'll leave the flux residue right back on the board if you don't freshen up the liquid often. However, isopropyl is cheap!

Water + dishwashing soap - didn't remove flux very well. Works well as a final/second bath after isopropyl or another cleaner.

Chemtools General Purpose Flux Remover - works as expected, but leaves a sticky residue on boards if you don't rinse them afterwards. It's also not as cheap or readily available as isopropyl alcohol.

Chemtools PCB Wash Defluxing Solution (Water Based) - not yet tried this, but it's available locally (same place I get my alcohol, Altronics). I have a bottle on standby for my next set of PCBs.

[mazurov]

Bob Pease mentioned  washing boards in the dishwasher in his "Troubleshooting Analog Circuits" books as a troubleshooting aid.

I wash boards in ultrasonic the following way: 2x30 min. runs in IPA  at ~70C cleaning the residual IPA from the boards with compressed air between runs.  One run ( possibly of lesser duration even) could be enough but 2 allows me to stretch IPA and 30 minutes time can be set with a single press of a button :-). I found this particular process to work especially well opening dry joints so that they fail QC 100%.

Whatever solution you end up using don't pour it directly into the bath (especially Ed's Red for the guns). I fill the bath with hot water and place  boards/IPA in a glass beaker. My bath fits 2 1L beakers so both washes after the very first one one can run simultaneously.

If you want really good cleaning you can tune the bath to resonate with IPA vessel by gradually increasing the volume of water in the bath and observing the results. Don't use plastic vessels as they absorb ultrasonic quite well.  For guns check places selling equipment for catering, they carry rectangular stainless steel pots used to heat up food in the field. Glass is the best material though.

[robrenz]

Alconox is an especially effective in an ultrasonic cleaner.  Many labs use this to clean all the labware. This is the generic version but they have many specialized versions

[David Hess]

I prefer using hot distilled water plus a little bit of TSP or dish soap for general purpose cleaning.  This is also what I specifically recommend for contaminated or water damaged printed circuit boards because salts will be water soluble.

I do not clean gun parts often in my ultrasonic cleaner but when I do, hot water plus a little bit of TSP or dish soap usually works.

I would use IPA for flux removal.

Naphtha and lacquer thinner are my choice for heavy duty jobs but distilled water with a little bit of TSP or dish soap plus some acetone and IPA are cheaper.

[wraper]

As of cleaning water damage citric acid water solution is pretty good in most cases but can tarnish some parts like metal screens. Don't seem to affect soldering and parts. Of course then you need to wash it again in ultrasonic bath with clean water. When I worked in mobile phone repair service a while ago, we used some cleaning fluid for ultrasonic baths and it worked very well. Unfortunately can't remember it's name, otherwise would buy it for myself. But you must be careful with such fluids, many of them dissolve solder and smd varistors but leave corrosion intact.

[tautech]

A mate uses water and White Vinegar for his rifle brass, sorry do not know ratios, but PM me I will give him a call.

[eurofox]

I have a small unit and use warm water and green (green stuff to wash the dishes).

It clean very well glasses, jewels, instruments knobs and any other object I want to clean 

[orion242]

Thanks for all the replies.  Certainly points me in the right direction.

Whatever solution you end up using don't pour it directly into the bath (especially Ed's Red for the guns). I fill the bath with hot water and place  boards/IPA in a glass beaker. My bath fits 2 1L beakers so both washes after the very first one one can run simultaneously.

Ahh.  So your using the water just as a filler and putting the cleaning solution in the beakers.  Brilliant.  I wanted to make sure the basket was big enough to handle most of what I deal with.  Most times I don't need the whole volume.

[orion242]

I do not clean gun parts often in my ultrasonic cleaner but when I do, hot water plus a little bit of TSP or dish soap usually works.

That's good to hear.  I don't plan on it much, but the wife's .22 pistol has what seems like 1,000 parts to it.  After all the rounds its a bit gritty and the sonic seems a lot easier than a full disassemble.  Sounds like most suspend anything with a finish from the top so they don't contact metal and rub during cleaning.

[orion242]

A mate uses water and White Vinegar for his rifle brass

Never crossed my mind.

Might have to clear a space in the lab for reloading...

[tautech]

A mate uses water and White Vinegar for his rifle brass

Never crossed my mind.

Might have to clear a space in the lab for reloading...

Never bothered with going that far myself, but he is shooting rabbits @ 800+ yds 

[SeanB]

Guns are easy to clean if you strip them apart. You can get most off with some paraffin and a cloth and a brush, and then rinse in clean paraffin. Final rinse in mineral oil diluted with thinners to protect the metal and slap it back together. Rifles we used to wash with a high pressure hot water and aircraft detergent to get the grease out from storage, light oil and then shoot. Clean again same way and pack with grease for storage again.

[G7PSK]

The best thing to clean guns is brake cleaner, which is fairly pure naphtha.
When I used to clean watches and clocks many years ago in an ultrasonic bath it was toluene. Leave metal in to long and it pits and gun blue is damaged in a few minutes.

[orion242]

That's my only reservation about sticking any gun in it, destroying the finish.

I got this guy today.  The chinglish is spectacular but a quick peek inside and I'm somewhat surprised on the build.  Not nearly as awful as I thought.  I'll take some pictures this weekend and do a quick tear down.

Have a pound of the Alconox coming tomorrow to test out also.

[robrenz]

In my experience you need to be careful with the elapsed time in the ultrasonic bath. I have a small Crest Ultrasonics unit with swept frequency. If you leave an anodized part in the bath for a few minutes, no problem. But I have left black anodized parts for a couple hours and the dye in the anodize was almost completely removed to the point that the jet black part was now very light grey.  This was with Alconox as the detergent.  Another thing I notice about ultrasonics is that you are better off not just throwing parts in and expecting it to remove thick deposits quickly. I have a beaker next to the bath full of various paint brushes, tooth brushes, acid brushes, etc. that I use to get any thicker deposits off the parts as soon as they loosen up.  Even lifting the basket up and down to get some agitation will help immensely. I also use an old Water Pic dental unit that I fill with the hot cleaning solution and then use the pic to pulse jet the solution into tapped holes while in the bath (messy but very effective). My last advice is run the bath HOT. I run mine where I can just stand to manipulate parts with my gloved hand. Heat is a huge part of cleaning speed and that allows a shorter time in the ultrasonic action. My typical part time in the bath is about 2 minutes.

[orion242]

  on the Alconox.

I'm pretty happy with this stuff.  Boards come out clean without residue.  Little heat and it removes flux in just a few minutes.  Boards look better than when I got them.

Thanks again.

[ConKbot]

I have used:

100% Isopropyl Alcohol - works well, removes flux quite quickly. Downsides are quick evaporation, slight white residue after drying, and it'll leave the flux residue right back on the board if you don't freshen up the liquid often. However, isopropyl is cheap!

White residue is dirty IPA, either flux in it, or a low percentage solution with contaminates.   IVe done a bit of hand assembly production at work, and a good 3-step process was 2 bins of alcohol, and a wash bottle.  Scrub and remove all the residue in the first bath, take it out, shake it off, put it in the second bath to remove flux/alcohol solution from the first washing.  Quick scrub with a second brush, then rinse it with the wash bottle, over top of the second bin, so the alcohol drains into it.   Blot dry, and re-rinse if needed. 

When the 2nd bath starts getting full, dump most of it into the first bath.   All the heavy junk stays in the first bath, and the 2nd bath is kept pretty clean by the alcohol you use to rinse running into it constantly topping it off.  And youre always rinsing with pure alcohol, but not being too wasteful with it.

The boards would come out looking just as clean as when I got them from the board fab. 

[David Hess]

on the Alconox.

I'm pretty happy with this stuff.  Boards come out clean without residue.  Little heat and it removes flux in just a few minutes.  Boards look better than when I got them.

Is that their Detergent 8 cleaner?  That is what they recommend for removing rosin flux.

[jlmoon]

A mate uses water and White Vinegar for his rifle brass

Never crossed my mind.

Might have to clear a space in the lab for reloading...

I wouldn't suggest putting any gun parts in a U Cleaner unless you have them in single piece mode and suspended by isolation hangers.  The vibrations from ultrasonics will damage the machined surfaces rather quickly. 


opps.. I quoted the wrong post.. sorry

[orion242]

on the Alconox.

I'm pretty happy with this stuff.  Boards come out clean without residue.  Little heat and it removes flux in just a few minutes.  Boards look better than when I got them.

Is that their Detergent 8 cleaner?  That is what they recommend for removing rosin flux.

Nope got the "generic" cleaner for now, Alconox 1104 Powdered Precision Cleaner.

http://www.alconox.com/Resources/StandardDocuments/TB/techbull_alconox.pdf

It seems to strip off flux in ~5min @ 60C.  It is somewhat reactive to solder, if you leave it in much longer (10min+) it seems to take the sheen off solder joints.  At 5 minutes it has little effect to metals.

Its easy on skin, no smell, leaves the boards looking like they just came from the fab.  Only 2.5 tbs per gallon, its cheap enough to flush a batch when your done.

[metalphreak]

I have used:

100% Isopropyl Alcohol - works well, removes flux quite quickly. Downsides are quick evaporation, slight white residue after drying, and it'll leave the flux residue right back on the board if you don't freshen up the liquid often. However, isopropyl is cheap!

White residue is dirty IPA, either flux in it, or a low percentage solution with contaminates.   IVe done a bit of hand assembly production at work, and a good 3-step process was 2 bins of alcohol, and a wash bottle.  Scrub and remove all the residue in the first bath, take it out, shake it off, put it in the second bath to remove flux/alcohol solution from the first washing.  Quick scrub with a second brush, then rinse it with the wash bottle, over top of the second bin, so the alcohol drains into it.   Blot dry, and re-rinse if needed. 

When the 2nd bath starts getting full, dump most of it into the first bath.   All the heavy junk stays in the first bath, and the 2nd bath is kept pretty clean by the alcohol you use to rinse running into it constantly topping it off.  And youre always rinsing with pure alcohol, but not being too wasteful with it.

The boards would come out looking just as clean as when I got them from the board fab.

I only have a very small ultrasonic cleaner, so the alcohol gets dirty with flux fairly quick. I really didn't want to resort to doing multiple baths in alcohol.

http://www.altronics.com.au/p/t3180-chemtools-pcb-wash-defluxing-solution-1-litre/

I gave this a try yesterday, and it works just as well as all the other cleaners. However, since it's water based (some kind of detergent in it), there are no annoying fumes. After cleaning boards in this in the ultrasonic cleaner, I just dunk them in a container of water and give them a quick scrub to remove any trace of the cleaner. So far, it's been the nicest option to use in terms of fumes and skin irritation.

Also, if you have any holes in your PCBs, you can blow bubbles with it 

[nukie]

The chemtools flux cleaner is the best I have ever used. It's also economical.