Ultrasonic Stencil Cleaners

[Reckless]

We have been hand cleaning our stencils and my workers are complaining they want an ultrasonic cleaner.  The ultrasonic cleaners I have come across have been very expensive ($30k+).  I finally came across an old 1994 smartsonic formerly branson precision cleaning unit in my price range.  I have seen some units have bad transducers from other companies which cost many thousand to repair.  Smartsonic was claiming they never had a transducer fail and have been making units since early 1990s (over 1000 units in the field).  I don't know much about brands for pcb stencil cleaners.  The same company makes an alternative to alcohol for stencil cleaning, 440-R non alcoholic detergent that looks interesting to me: https://smartsonic.com/chemistry.html

If anyone has any experience, please chime in.  We are looking for the simplest machine to clean stencils thoroughly.  This is a similar machine to what we are buying:" alt="" class="bbc_img" />.  I don't have experience with ultrasonic stencil machines but have smaller versions for cleaning jewelry/watches which I never learned how to use effectively.  We are looking at old machines in order to save money as long as they still work.

[Mechatrommer]

I don't have experience with ultrasonic stencil machines but have smaller versions for cleaning jewelry/watches which I never learned how to use effectively.

how to use it effectively? other than the provide on/off switch and timer button? i just bought 4.5L Ultrasonic Cleaner Digital Timing Heating Jewelry Cleaner 240HTD 120W @ $75 maybe there are bigger version. never thought to try it on stencil and i dont have one to try. if it works, it works, if not then its not... 10L

[fcb]

We use a handheld ultrasonic cleaner on stencils. Works pretty well and saves having to have a large machine with all the $$$.  That said we keep an eyeout on the auctions.

Big ultrasonic machines tend to be built from lots of small transducers, so they are somewhat fixable.

[Reckless]

Our stencils are framed 29" so little box style machine wouldnt work. 

Fcb, do you use something like this
[url=https://www.amazon.com/dp/B07X9BR63N/ref=cm_sw_r_cp_apa_glc_fabc_YNBK1ZVWV314PXDKEF0A]https://www.amazon.com/dp/B07X9BR63N/ref=cm_sw_r_cp_apa_glc_fabc_YNBK1ZVWV314PXDKEF0A

[fcb]

More like: https://www.gen3systems.com/gensonic-stencil-cleaner

[Reckless]

Forgive me ignorance but what is the difference?  I have a feeling its alot more than $55 amazon unit.  They look similar.  Amazon unit is 50khz and gensonic is 40khz.  I do know 40khz is the norm.  Not sure if more is better. 

[fcb]

I don't think the frequency will make much difference.

The one we have has smooth stainless steel base and you gently push it around the top of the stencil with the stencil cleaning fluid - only using a small horizontal force.  Essentially like a ouija board.

[Rat_Patrol]

Every time I look at the price for framed stencil cleaners, I turn around and go back to my vat of IPA and nylon brush and keep on keeping on. Put stencil in vat, soak a few minutes, scrub with nylon brush, rinse, air dry, put back on the shelf.

I don't do super fine pitch components though, 0805 and SOIC are about as small as I get.