What solvent for ultrasonic stencil cleaning?  - Page 1
Forum section: electronics / general

author: loki42
author_rank: Frequent Contributor
timestamp: August 27, 2023, 12:03:14 am
content: I've recently got an ultrasonic stencil cleaner. I'm wondering what solvent / detergent people are using and how they dispose of waste water. I'm using SAC305 no clean currently.

author: jpanhalt
author_rank: Super Contributor
timestamp: August 27, 2023, 12:16:05 am
content: ZEP heavy duty floor stripper diluted 1 part ZEP to 2 parts water. It's non-corrosive. It is sold worldwide, but unfortunately may not be in Australia. Its magic ingredient is butyl cellosolve (about 30%) with a little ethanolamine to keep it alkaline. It probably fits the Kester definition as a saponifier.* Read the ingredients for "commercial" and consumer acrylic was floor strippers.A higher dilution way work with relatively fresh solder paste.*That 1:3 dilution gives about 10% butyl cellosolve in the final solution, which is about the same concentration as some aqueous flux cleaners from Kester have.

author: Kean
author_rank: Unknown
timestamp: August 27, 2023, 12:59:33 am
content: I've only used solvent based stencil cleaners as I do small volume assembly - e.g. IPA or Electrolube SSC. You obviously don't want to use those in an ultrasonic cleaner... I use a spray bottle and paper towels or Kim wipes.For PCB cleaning I use a saponifier diluted in distilled water in an ultrasonic cleaner, with tap water and then distilled water rinse. Specifically I use Electrolube SWAS Safewash, but I've never tried it on a stencil because it isn't convenient (no tank of a suitable size).I suggest talking to Chemtools or whoever you use for other flux cleaning products - in particular to discuss the safety and disposal requirements. Maybe something likehttps://www.chemtools.com.au/product/electrical-electronics/cleaners-flux-removers/pcb-flux-remover/

author: Mangozac
author_rank: Frequent Contributor
timestamp: August 28, 2023, 06:27:11 am
content: Quote from: Kean on August 27, 2023, 12:59:33 amWe recently bought a bottle of this and accidentally found that it does a surprisingly good job of removing no clean flux residue, so I assume it would also be good for stencil cleaning in an ultrasonic.

author: SMTech
author_rank: Frequent Contributor
timestamp: August 29, 2023, 12:30:54 pm
content: Quote from: loki42 on August 27, 2023, 12:03:14 amYour solder paste supplier should have multiple options, as should any sector relevant chemical suppliers.https://www.zestron.com/en/product-finder/hydron-sc-300-p156.htmlZestron is a popular globally available option. We don't clean ultrasonically so we do use a solvent based cleaner (which is also OK with a handheld ultrasonic cleaner) - this onehttps://bltcircuitservices.co.uk/product/scs1/becausethey supply the paste. I have compared it with Zestron for wiping and handheld ultrasonic cleaning and performance seemed similar, the most obvious difference was on a well used spatula, Zestron easily removed old very dried on paste deposits while the solvent based one does not.I would seek advice from a supplier, some options out there will almost certainly use chemicals you might want to avoid.

author: jpanhalt
author_rank: Super Contributor
timestamp: August 29, 2023, 02:02:22 pm
content: @Kean and others. Attached is the safety data sheet for that Chemtools product. The dipropylene glycol monomethyl ether is a member of the class of ether alcohols as are cellosolves. They are great solvents. The ethanol amin serves the same purpose as it does inn Kester's and ZEP. The dodecyl (C12) benzene sulfonic acid is a detergent. pH is 12, so the sulfonic acid is as a salt.In other words, there are a lot of similar aqueous flux removers that contain the same classes of active ingredients. The difference is more like the difference between vanilla and chocolate ice cream rather than anything special in solvent potency. I did note that the Chemtools product is apparently used neat (i.e., at manufactured concentration of about 30% ether alcohol concentrations). The Kester product is diluted to give a 10% solution, and that's why I dilute the ZEP 1 part to 2 parts water.

author: loki42
author_rank: Frequent Contributor
timestamp: August 29, 2023, 10:01:33 pm
content: Quote from: SMTechAlas some of the suppliers are keen to tell you there thing is amazing and works in every situation perfectly... handy to see if anyone has tried any of the options first

author: BreakingOhmsLaw
author_rank: Frequent Contributor
timestamp: August 30, 2023, 07:46:52 am
content: I use a solution of 10% Tickopur TR14 and 90% demineralized water.Works very well in a heated ultrasonic bath. Affordable too, a 5l canister ist around 25 Euros, which gives you 50l of solution. That will fill my 3 liter cleaner 16 times at around €2,60 per pop with the cost for the demineralized water included.I highly recommendgetting a DIN51 threaded handpump for the canister and a measuring cup, so you don't need to pour it and make a mess with the caustic concentrate. 10 Euros well spent.

author: jpanhalt
author_rank: Super Contributor
timestamp: August 30, 2023, 09:19:17 am
content: Re: Tickopur TR14Here's a link to its SDS in English. A different composition and as noted caustic.http://dr-h-stamm.info/downloads/tr1483034gbenstamm.pdf

author: jmelson
author_rank: Super Contributor
timestamp: August 31, 2023, 12:30:57 am
content: I clean my stencils manually with either acetone or denatured alcohol and paper towels. If the apertures are clogged with hardened paste, I apply a soft toothbrush with the solvent. This has worked quite well.Jon