Metal finishing Q&As since 1989

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Electropolishing a telescoping assembly

2005

I am electropolishing some 304 SS telescoping ladder assemblies. They telescope fine before they go into the bath, but when they come out the individual telescoping sections are all racked out of alignment and they no long telescope smoothly.

I am racking the assembly connected to the electrode at the top and bottom of the assembly. My theory is that I need to have the rack contact each part of the assembly becuase the individual sections are pulling together to create a contact between sections to transfer the current.

Could this be possible or is there another reason?

Scott Rowles
- Monroeville, Pennsylvania

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Hello to another Pa. person! Anyway onto your problem.....your theory is a very good one,in fact probably rite on the money! One other possibilty are you building to much of the electropolish onto the parts?

Regards,

Brian C. Gaylets
McKinney Mfg. Assa Abloy America - Scranton, Pennsylvania
2005

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2005

Well. We tried that and it didn't seem to work. Similar to when we weld the assemblies, and the vertical sections pull together. We created a fixture to go into the electropolishing bath to hold the vertical parts apart while they are in the current.

However, what do you mean by building up too much. It seems to us that there is a "fuzziness" to the SS when it comes out of the bath even after washing off in two water rinses. I have inquired a bit about a neutralizer to possibly help with his. Was given recommendations of TSP [trisodium phosphate [on eBay or Amazon]], Hydrochloric and Nitric Acid to try. Any thoughts on those?

Scott Rowles
- Monroeville, Pennsylvania

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What I mean by "build" is,when you dip your part into the elctropolish solution,is it in the solution and current to long? Are you putting more polish on it then what it actually needs? using acid, good idea....maybe? Maybe not,you'll have to watch that you don't make the part to passive in the acid. This is just my theory, I'm not an expert by no means ,I would also check with your distibutor and see if he has any recommendations.

Regards,

Brian C. Gaylets
- Scranton, Pennsylvania
2005

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2006

Uneven surface polish on large parts. I am working on polishing some telescoping SS ladder assemblies. I am getting an uneven finish (i.e. mirror on some parts, pebbled on others and almost lined or striated on still other pieces) across the parts. the whole part is about 7 feet long 16" wide and is made from tube ranging from 2" to 2/4".

Any suggestions? I am under the assumption that it is an uneven distribution of current, but can't seem to rectify the problem. Have tried bigger copper wires to some parts, etc..

Kerry Rowles
- Monroeville, Pennsylvania