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Ultrasonic cleaner for cleaning coolant off parts

Matt@RFR

Titanium
Joined
May 26, 2004
Location
Paradise, Ca
We are making some parts that have holes small & deep enough that our plater had to modify their clear alodine process. (Ø.028" x .745" deep with a .015" air bleed toward one end.) They can't etch the parts. If they do, we end up with nasty hard white buildup in the holes that scrap the parts.

So we need to up our game as far as cleaning these parts prior to plating. We did some testing with a shitty harbor freight ultrasonic cleaner to test the theory, and tried straight water, simple green, windex and dawn additives and the straight water did just as well as the rest after plating, so that's the obvious choice. Our coolant washes off pretty easily, but these parts are delicate and I do NOT want anyone trying to mechanically clean them in any way. They are just going to ruin the parts. Also, this job is supposed to run in to 2024 uninterrupted, so the less handling, the better.

I envision putting the parts in a room temp water rinse straight out of the machine (as we already do), then measure, then in to the ultrasonic cleaner with straight hot water for a cycle. This would happen every 14 minutes, 8 hours per day.

Any machine recommendations? I'll be buying new, and I want to buy quality. The tank can be as small as about 4" x 6" and maybe 2" deep. See picture for part size, max two parts per cycle.

Any other recommendations on this process?
 

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We have a Crest brand that we got from Ebay about 5 years ago.
Works great! Some tricks people use is to put your parts in a ziplock so the filth doesn't contaminate the rest of the fluid. But it's easily drained and refilled so it's never been an issue for us. https://crest-ultrasonics.com/

One thing to note is that ours is 220v, and when we moved our shop to a new location the only 220v outlet that we had was outputting like 208v. We noticed a performance decrease from the lower voltage. The sonic waves aren't as powerful as they could be with a full 220v outlet.
 
You have to be careful with ultrasonics and raw aluminum. If left in too long (just a few minutes), or too high of frequency, it will make little white "blooms" all over your parts.

Years ago, I had a 15 gallon rectangular polypropylene tank that had a little giant 750 gph pump attached to it. Temperature rating on the pump was around 200 F, IIRC. I plumbed the pump outlet to PVC coiling in the bottom of the tank that had a bunch of 0.0625 holes drilled in it with scattered orientation. Used a drop in Titanium heating rod controlled with a PID. The end result was a hot tank with vigorous agitation that would get the parts extremely clean. Deep holes were not a problem. I believe I used 1:3 simple green/distilled water ran at just about 140F in that tank that did not harm the aluminum parts.
 
I don't think ultrasonics are very good at cleaning deep holes. You have to flush them with a small hose or needle to get stuff out of the bottom.
I should have been more specific. The holes are not the issue, the outside of the part needs the cleaning. Dipping them in hot water doesn't do it, so we need to 'scrub' the parts without touching any of the delicate features. Ultrasonic is the only way to do that that I know of.

EDIT: To hopefully be even more clear: When properly cleaned prior to plating, we have no more issues. So it's just a matter of finding which machine to buy to make life easy again.
 
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Maybe a call to the MFR of the coolant to ask to speak to their Chemical engineer about the best way do clean your parts.

Our plating shop calls suppliers regularly to ask about new opps or new materials.
 
Maybe a call to the MFR of the coolant to ask to speak to their Chemical engineer about the best way do clean your parts.

Our plating shop calls suppliers regularly to ask about new opps or new materials.
Oemeta only offers a cleaner meant for washing down machines for storage. Too many additives in it for our use. Beyond that, they said to try an ultrasonic cleaner. So we did. Which works great. Like I've said a couple times now. I'm just looking for machine recommendations and any pointers on using it.
 
We use Crest Ultrasonics with DI water and simple green for stainless parts with deep holes. They get washed in hot water, put in the ultrasonic with simple green mix for x time, and then go in a 2nd ultrasonic with just di water for a rinse, then they are blown off, inspected under a microscope, and packaged. We had another name brand (I cannot remember the brand but they make parts washers and whatnot as well) and went through 3 units in a year. They eventually warrentied them, but we switched to the Crest machines and have been running the same two all the time for 4+ years.
 
Multiple small machines might be best to guarantee continuous uninterrupted cleaning. Keep the water fresh in each tank. I’d think about using DI or RO water and no chemicals added.
 
Hi Matt:
Like many others here I run a Crest Ultrasonic and have had no problems at all.
A couple of cautionary notes though.

- As others have implied, run scrap parts through it at various settings until you can get them consistently as clean as they need to be.
- Beware the crap that leaks out of the holes after you think you've dried them, and ruins the Ano.
- Find a way to hang the parts in the tank so they can't rattle around and touch each other if they're truly as delicate as you imply.
Letting them bang around on the mesh basket or against each other is the surest way to fuck them up that I know of.
- Change out the solution on a regular schedule and test it's pH often if you care to try for perfection.
- Find the right stuff to put in the tank and mix it in the proper ratio so it can't discolour or corrode the parts.
-Toss it out and replace it once too much of the water has evaporated out of it...don't just add water and pretend it's good as new.

Cheers

Marcus
www.implant-mechanix.com
www.vancouverwireedm.com
 
A note from the distributor I wanted to buy from: "Crest has suspended shipping of their tabletop ultrasonics models due to supply chain issues."

So they helped me choose another brand and model, and I ended up buying two Branson CPX2800. About the same price but with fancier electronics than the Crest, which I didn't want. Hopefully they will hold up to daily use.

A quick shoutout to sonicsonline.com. Dave was very helpful with answering my dumb questions, and they shipped my order the same day.
 
Ultrasonics from China can be cheap and run a long time, but you can spend the big bucks on the Big name brands that don't do any better. To do a quick check on ultrasonics throw a piece of aluminum foil into the water (always load fluid to the fill line of the tank), the foil should have holes blown through it like swiss cheese.

I would try isopropyl alcohol 99%

Water has contaminants in it that can cause surface issues. You could also try distilled water that is processed to deionized.

Orange cleaners don't do any better than plain old granulated sugar and water.

I would not use cleaners
 
if water is working, the offending contaminant is readily washing off with plain water. if the passages don't have angled turns or cavities, and the throughput is that small, do you really need ultrasonic?

I think a Resturant prewash with hot water might work.

if you had hundreds per hour and batch processing was mandatory, yea big ultrasonic like my Branson 7000, but for 4 parts per hour, (32 per day?) just put them in water with a little mild dish detergent off the machine, rinse the days production at the end of shift with the prewash individually, place on towel to dry. all done.
 
Have you looked at vapor degreasing? I remember we threw out our ultrasonic cleaner because it was leaving black wear marks on the parts, we primarily used vibratory tumblers for rough deburring, a magnetic stir deburring machine (sPINner I think it was called, it did an amazing job cleaning too) for really light stuff, and then a volatile solvent vapor chamber for final cleaning.
 








 
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