# Electropolishing Welds on Stainless.



## rwm (Feb 17, 2020)

I am interested in doing this. After some research it seems like Phosphoric acid would be the best electrolyte. 85% H3 PO4 is pretty cheap on eBay. I have ordered some carbon fiber to make a brush. Does anyone have experience with this?

Check this out:








						DIY Stainless Steel Weld Cleaning / Electropolishing
					

DIY Stainless Steel Weld Cleaning / Electropolishing: When stainless steel is heated to welding temperatures, it turns lots of pretty colors - gold, red, purple, blue - depending on the temperatures. These look nice, but if you want your stainless steel to look like stainless again, a polishing...




					www.instructables.com
				



Robert


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## Rootpass (Feb 18, 2020)

I’ve done it at the house with a car battery charger. Works well generates heat! I’ll see if I have a picture.


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## Rootpass (Feb 18, 2020)

It’s been rolling around in my desk drawer. 304 3/4” round stock. It works pretty quick. As a side note, I’ve seen where it’s said you can electropolish aluminum too but I never had any luck with it.


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## middle.road (Feb 18, 2020)

rwm said:


> I am interested in doing this. After some research it seems like Phosphoric acid would be the best electrolyte. 85% H3 PO4 is pretty cheap on eBay. I have ordered some carbon fiber to make a brush. Does anyone have experience with this?
> 
> Check this out:
> 
> ...


Adding to my 'Wanna-Do' list - you are. . .


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## vtcnc (Feb 18, 2020)

Make sure you consider a neutralizer and then rinse the neutralizer from your work. You will leave a residue if you don't neutralize and rinse. Sort of like a sticky salt build up and it can stain your work-piece.

If you are going to do this as a matter of trying to make money, use separate rags to neutralize, rinse and dry. Cross-contamination can happen pretty quickly when weld cleaning in volume.


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## rwm (Feb 19, 2020)

I ordered some Phosphoric Acid and some carbon fiber cloth to make a brush.
Pics to follow....maybe...
Robert


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## homebrewed (Feb 20, 2020)

I'm puzzled on why you need to make a carbon fiber brush.  The Instructables article uses a stainless steel cathode with fiberglass or a special sponge around it to hold the electrolyte.  You don't want direct contact between the work and cathode, that will just short the power supply out.  Am I missing something?


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## rwm (Feb 20, 2020)

homebrewed said:


> I'm puzzled on why you need to make a carbon fiber brush.  The Instructables article uses a stainless steel cathode with fiberglass or a special sponge around it to hold the electrolyte.  You don't want direct contact between the work and cathode, that will just short the power supply out.  Am I missing something?


I agree! I saw the instructable setup. I see that the commercial units use carbon fiber brushes. I think the fiberglass wrap does not conduct well enough. Does anyone know the best solution?
Robert


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## vtcnc (Feb 20, 2020)

This is the wand we have on our Walter Surfox Weld cleaning system at work (or at least something that looks very similar to this one):









						Walter 54B029 Highly Conductive Carbon Fiber Flow-Through Brush 5Pk : Weld Cleaning Accessories - $213.75 EMI Supply, Inc
					

EMI Supply, Inc :  Walter 54B029 Highly Conductive Carbon Fiber Flow-Through Brush 5Pk - Ideal for tight corners, narrow surfaces and hard-to-reach areas....




					www.emisupply.com
				




The carbon bristles burn up over time. The way it was explained to me is that the electrolyte flushes any debris away and the bristles allow for flow through conductivity and the bristles conduct into the little wrinkles and crevices of welds.

With a felt pad, the pads have to be dipped into the electrolyte solution. The felt conforms around the weld bead. So I don't think there is a worry for a shorting problem here, it is more about using a conductor that conforms to the contours of the weld you are cleaning.

EDIT: perhaps there is something different going on when using the carbon brushes. I'll take a look at our model tomorrow and tell you which one we are using exactly and you can look up the specs.


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## rwm (Feb 21, 2020)

I cannot believe the prices of the Walter stuff.
Robert


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## vtcnc (Feb 21, 2020)

rwm said:


> I cannot believe the prices of the Walter stuff.
> Robert


Yeah, its nuts, but they offer exceptional support and onsite training at no cost. (Well, its built into the retail price, of course)

But their equipment is very good quality.


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## homebrewed (Feb 21, 2020)

I can see the need for a good quantity of electrolyte at the work surface.  I wonder if you could adapt one of those stainless steel "scrubbies" to hold more of the electrolyte?


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## rwm (Feb 21, 2020)

I don't think you would want the stainless in direct contact with the work. I plan to try the carbon fiber brush as well as felt over a stainless electrode.
R


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## homebrewed (Feb 21, 2020)

No, you'd still want to use the fiberglass or a sponge with a pocket in it.  A sponge would be easier.


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