Letter 34041

How to remove welding scale without using derusting or sand blasting process  

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How to remove welding scale without using derusting or sand blasting process?

Manish Dhyani
- New Delhi, India

With a hammer and chisel, or a wire brush is the simplest and most basic way unless I am misunderstanding. Sorry, but I think your question is too vague, Manish.

Ted Mooney, P.E.  finishing.com Brick, New Jersey

If you don't have answer then pls keep mum rather criticizing someone. No question is vague. Maybe someone has solution to my problem which you don't have.

Manish Dhyani (returning)
- New Delhi, India

Ted's answer sounds to me like a perfectly reasonable answer (perhaps the ONLY reasonable answer) to a simple straightforward question. What's your problem, Manish?

Bill Reynolds    consultant metallurgist Ballarat, Victoria, Australia

Mr Mooney is correct, your question is far too vague for anyone to give you a sensible answer. What material are you descaling? What is your current process? Why is it now not acceptable? What is the final use of the part?

Without this sort of information any of the experts that contribute to this site could write a book on descaling methods, both chemical and physical.

Sorry to have to contradict you Manish, but much more information is needed.

Brian Terry
helicopters - Yeovil, Somerset, UK

Well, I think it is too vague! You fail to mention if it is gas, arc, tig, mig, laser or electron beam welding. You also fail to mention if it is on hot or cold rolled steel, chromolly, cheap stainless, high nickel stainless or titanium.

Finally, you do not mention if it is a tiny or a massive part.

In answer to your question, the only methods that I am aware of are chemical and mechanical. You appear to rule out chemical, so that leaves mechanical. You ruled out sand blast, so that only leaves shot blast and manual. You did not like Ted's manual, so that leaves shot.

The quality of a response is directly proportional to the quality of the question.

James Watts
- Navarre, Florida

We are manufacturing electronic control panels. (Enclosures)

material : CRC sheet

current process : 9 tank hot spray phosphating system
degreasing/degreasing/water rinse/water rinse/activation/phosphating/water rinse/DI rinse/DI rinse

I know very well that without adding/using a descaling stage in my current process, I can't remove the welding scale. But this is not my problem. My problem is that is there any other solution to solve this problem which is both cost and time effective.

Manish Dhyani (returning)
- New Delhi, India

Hi there,

Maybe you should look for an answer in the kind of welding process you are using. MIG is an option, it can diminish scale. Look better in preventing the problem.

Saludos.

Guillermo Castorena
jobshop plating - San Luis Potosi, Mexico

Being new to this site, I couldn't help but feel that you guys are a little unfair to Manish. Manish asked about removing "scale", a byproduct of metal/steel being heated and cooled causing an oxidized byproduct called scale. The couple of responses regarding using Mig or Tig to reduce the "scale" makes me think that you are confusing scale with slag - a byproduct of most welding processes-which use a flux coating on the welding wire, namely, "stick welding".
Having said this, if you remove the chemical or sand blasting processes, all you have left is mechanical, i.e. power brushing followed by an alcohol based cleaner(fast drying)to wipe away the minute particles. Then you paint either clear coat or color to protect the base metal. Never introduce water to clean as this will cause the rusting process rather quickly thereby defeating the whole purpose. Did I misunderstand the question?

Boyd

Boyd Delk
- Cleveland, Georgia

Thanks, Boyd! You're probably right that my response confused slag with scale.

I don't want to hurt anyone's feelings, and Manish's 3rd posting includes some good detail. But people asking questions outnumber those who answer them by a hundred to one, and if the forum is to be useful, we can't post thousands of questions that remain unanswered; rather, we must ask for clarification so the questions get answered. For the forum operator to "keep mum" when questions are posted which are vague and which are drawing no responses isn't really an option. Thanks again, and please continue to participate.

Ted Mooney finishing.com Brick, New Jersey