Letter 34041

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

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

Manish Dhyani
- New Delhi, New Delhi, India

With a hammer and chisel, and a wire brush? Your question is far too vague, Manish.

 
Ted Mooney, P.E.
finishing.com Inc. - Brick, NJ

If you dont have answer then pls keep mum rather criticising someone. No question is vague. May be somoeone has solution to my problem which you dont have.

Manish Dhyani
UL - 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
Tasmet Systems - Melbourne, 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
Westland Helicopters Ltd - 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 rulled 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
- FL

We are manufacturing electroic 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 cant 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
- India

Even though I apologized, I was still feeling shame on myself for an inadecuate and embarrasing letter some days ago. Though not the same situation, reading this correspondence made me feel a little better. Impossible not to hurt someone´s feelings ever. Thanks, Ted for this educational and at the same time, amusing site.

Guillermo Marrufo
Monterrey, NL, Mexico

You have contributed tremendously to this site, Guillermo, and myself and all of the readers greatly appreciate it. You are right that it is impossible to never offend anyone :-)

 
Ted Mooney, P.E.
finishing.com Inc. - Brick, NJ

Hi there,

Maybe you should look an answere 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 minut 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 therby defeating the whole purpose. Did I misunderstand the question?

Boyd

Boyd Delk
- Cleveland, GA, USA

Thanks, Boyd! You've drawn yourself a comfortable mental image of the situation and proposed a good solution. But what if I now told you that a dozen of the parts Manish was talking about would fit in a thimble? Maybe that's the case, maybe it isn't -- he didn't say.

I certainly don't want to hurt Manish's feelings or anyone else's. But people asking questions outnumber the people who will answer them by a hundred to one, and my obligation as system operator is not to attract thousands of questions that remain unanswered, but to see that enough of the questions are answered that the forum is valuable. I believe that raising the quality of the posted questions is key to that, and for the forum operator to "keep mum" when vague questions are posted is not an option. Thanks again, and please continue to participate.

Ted Mooney, P.E. 
finishing.com
Brick, NJ

I want to answer or follow-up on this subject publicly (in non-commercial fashion).

 

My company is a supporting advertiser at finishing.com and we want the contact information to reach the inquirer privately.

 

I want to post a new question or inquiry of my own on a different subject.