Printed Circuit Board Assembly & PCB Design SMT Electronics Assembly Manufacturing Forum

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


Stainless Steel in wash system

Kevin Facinelli

#17573

Stainless Steel in wash system | 12 September, 2001

Ok....this is the last time asking this question. Does anyone know how to clean the dull residue of the inside of a stainless steel batch cleaner. The system has always been DI based and run with a saponifier. I am not sure what the redusue is or maybe it is just oxodization(not sure if that is even possible)....

Any clues...

Kevin

reply »

#17578

Stainless Steel in wash system | 12 September, 2001

Dunno, but if I had to guess, your DI is corroding the stainless. But then again, some saponifier concentrations can be overly caustic

reply »

Sean D

#17584

Stainless Steel in wash system | 13 September, 2001

Hello Kevin,

Have you contacted your equipment manufacturer and discussed the issue with them? Usually they have a method for cleaning their own systems based on the units they will use in their test lab. Based on the system configuration and the chemistry you are using, they should be able to shed light on what the issue may be with your system, ie oxidation, deposition, etc.

Good Luck, Sean

reply »

#17587

Stainless Steel in wash system | 13 September, 2001

Kevin,

Hot DI water will leach ions form stainless steel over time � much like an acid effect on metal. If you have ever seen a Steam Age Chamber after about 6-months use, you will know what I mean. DI water is �hungry� for ions and it will take them from almost anything it contacts.

However, after adding a saponifier, the water is no longer DI, so I doubt if this is the problem.

If you give me a better description of the condition of the stainless steel and the name of the saponifier(s) used in the machine and how long this has been going on, I can give you a better opinion.

Is the residue a �scale� buildup or tarnish? Or, is it more of a �pitting�?

Regards, Bill Schreiber Smart Sonic Corporation Tel: 1(818) 909-6400 E-mail: bill@smartsonic.com

reply »

#17588

Stainless Steel in wash system | 13 September, 2001

Bill: I'm with you on the first thing that you said about DI water, but in the second paragraph, how do you reckon the saponifier affects the DI water?

reply »

Kevin Facinelli

#17594

Stainless Steel in wash system | 14 September, 2001

We have two batch systems here. The systems have worked very well but the interior stainless steel is very dull. We are running a DI based open loop system for cleaning primarily a WS flux. In special cases we have used ArmaKleen E-2001 and Alpha 2110 in the systems. Is there a way of brightening up the insides...removing what appears to be a scale layer??

Thanks,

Kevin

reply »

Kevin Facinelli

#17595

Stainless Steel in wash system | 14 September, 2001

The biggest concern I have is appearance to customers. You open a cleaning system and it looks worse than your shower after a month of scale buildup.

I guess Alpha has two different product to combat this problem. I am going to give them both a try and will let you all know what I find out:

Descaler 926 - Removes scale build-up in aqueous cleaning equipment.

Armakleen Descaler - Essential for removal of scale build on equipment using Armakleen products.

http://www.alpha-frytechnologies.com/products/cleaners/selectorguide.html

Thanks,

Kevin

reply »

#17598

Stainless Steel in wash system | 14 September, 2001

Dave,

The saponifier (or any additive) will supply free ions and contaminate the DI water. If no contamination is introduced (very difficult) or if fresh hot DI water is constantly added as in a steam age chamber, the DI water will begin to obtain ions directly from the stainless steel causing a pitting effect.

Kevin,

Good luck with the descaler. However, the description you give sounds like someone tried to clean the stainless with bleach or similar product. Chlorine will erode the stainless protection and allow it to corrode. The only resolution is to acid passivate the stainless.

Regards, Bill

reply »

Mike Konrad

#17645

Stainless Steel in wash system | 19 September, 2001

Hi Kevin,

Sorry for the delay in responding to your question. I have been trapped in Australia (not a bad place to be trapped I may add).

The scale in your cleaner is not usually caused by the chemical used in the wash cycle (although Armakleen has the ability to leave residue). Scale is caused by DI water (used in the rinse cycle) attacking the finish of the stainless steel. Although it is purely a cosmetic issue, I agree that it would raise concerns with customers.

The best way to prevent scaling is to use a de-scaler. The one you mention in your post is fine. Be aware however, that it is difficult to remove the scale build-up simply by using a de-scaler. You may have to manually clean the chamber with a readily available bathroom cleanser such as Vanish. Be sure to prevent the liquid cleaner from entering the drain lines that connect the chamber to the sump tank as it could cause excessive foam once the machine is operated. Once the chamber�s electro-polished finish is restored, it can be maintained by using a de-scaler once or twice per month.

Call me if you need more specific details.

Michael Konrad Aqueous Technologies 909.944.7771

reply »

#17652

Stainless Steel in wash system | 19 September, 2001

Is this the same stuff that builds-up on the walls of poly washers running DI open-loop? If not, what is that stuff?

We clean with bathtub cleaner.

reply »

Michael Konrad

#17653

Stainless Steel in wash system | 20 September, 2001

Hi Dave,

It may be. DI water alone will not build up residue. It can attack the finish of electro-polished (mirrored) stainless steel though. I have seen a white / chalky buildup on poly inline cleaners, usually isolated in the wash section. The rinse and final rinse sections (with the best water quality) normally do not build up this residue. If the residue is mainly in the wash section (the dirtiest and less de-ionized of all of the cleaner�s water) it is most likely a result of a buildup of organic �stuff� that is capable of leaving a residue. A bathroom cleaner works well at both removing the residue and killing the organic growth causing the residue. If there were a residue throughout the inline cleaner�s sections (wash, rinse, final rinse) then I would question the effectiveness of the DI system. Operating a DI system (resin bottles) even a few days after they are spent can cause a calcium build-up like that in a toilet, shower, bath etc. Hot water make it worse.

Mike

reply »

SP700avi inline stencil printer

SP700avi inline smt screen printer