Scratch Removal from Stainless Steel

Beginner and pro baristas share tips and tricks.
tjkoko

#1: Post by tjkoko »

I use the following technique for scratch removal on knife blades as well:

1. Rub using a fine grade of wet-or-dry sandpaper at 1000 - 1500 grit. Your own metal will determine the grit itself.

2. Use progressively finer wet-or-dry.

3. Finish using a product called Garret Wade Wonderbars: it's like a giant erasure impregnated with silicone carbide and comes in coarse, medium and fine grits. It's also known as Klingspor Sandflex Hand Block. Less than $20 for a set of 3 blocks.
TJK

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Randy G.

#2: Post by Randy G. »

It depends on where the scratch is and how deep. Large, flat panels are difficult to polish because it can be difficult to get them to look the same across the entire surface. It also takes a lot more elbow grease.

For a mirror finish on metal surfaces, try aluminum oxide powder. I spray some WD-40 on a rag, and sprinkle some of the powder on the rag. For knives, use a piece of soft leather (around 2" x12") and tack it to a strip of like-sized wood a little longer so it has a handle area. The aluminum oxide powder makes it into an amazingly effective strop.

Enough aluminum oxide powder to do a large surface can get expensive. For those jobs I use flour of pumice. This can be used the same way- with water, WD-40, or even Windex and such. I use it with WD-40 to clean the outer shell of my Hottop Roasters when I disassemble them for thorough cleaning. The can I have is from dentistry, but I have seen it in home improvement/hardware stores in large boxes, but I do not know if it is as smooth and fine as the stuff I have which is like pastry flour.
Espresso! My Espresso! - http://www.EspressoMyEspresso.com
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tjkoko

#3: Post by tjkoko »

Aluminum oxide powder, wouldn't that product also be known as jeweler's rouge?
TJK

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Randy G.

#4: Post by Randy G. » replying to tjkoko »

It's possible, but I have never heard of it in those terms. All the jeweler's rouge I have used comes in stock form, and is a deep red color and somewhat greasy feel to the stick for lack of a better description, but I have never investigated its components.. The aluminum oxide powder I have used comes in powder form (as the name implies) and is a light-gray colored powder, VERY fine in texture, flowing almost like water in its container. All just based on my experience with the stuff.
Espresso! My Espresso! - http://www.EspressoMyEspresso.com
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tjkoko

#5: Post by tjkoko »

The jewler's rouge I have comes in the form of a green bar that yields its product when rubbed onto a strop.
TJK

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Randy G.

#6: Post by Randy G. »

From:
http://www.englishcustompolishing.com/usca/myths11.html
"Many manufacturers in the industry... call anything in a bar jeweler's rouge - but 'rouge' is French for 'red'. jeweler's rouge is red because it contains ferric oxide. If it doesn't contain ferric oxide, it's not rouge."

if you go here:
https://02b3ae8.netsolstores.com/jewelers-rouge.htm
There is a chart of the various compounds and what they work best on.
Espresso! My Espresso! - http://www.EspressoMyEspresso.com
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tjkoko

#7: Post by tjkoko »

Whatever the compound I'm using, it's used last in the final finish of the blade including the knife edge. It adds a good gloss.
TJK

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cannonfodder
Team HB

#8: Post by cannonfodder »

The green bars are usually chromium oxide, white is often referred to as white rogue and the red is red rogue, whatever the name the key is the grit of the material and the composition of the grit, chromium, diamond, etc will all have different cutting power. A 3 micron diamond paste will cut faster than a 0.25 micron diamond paste but a 0.25 micron paste may cut faster than a 0.5 micron chromium oxide because of the grit medium.

When I am restoring antique blades I will work a grit progression from 400 wet/dry (depending on how bad the blade is) 800, 1000, 1500, 2000, 2500 then micromesh and finish with 1.0 micron chromium oxide, 0.5 micron CO, white rogue, polish to get that perfect mirror finish. But doing that on an espresso machine would be very time consuming and you need a buffing wheel with different disks for each compound.
Dave Stephens

tjkoko

#9: Post by tjkoko »

Canonf.: I agree, giving a glossy finish to stainless is, indeed, time consuming. I'd just go with the wet or dry and finish by using the wonderbars. They're great for restoring (within limits) brushed finishes on metal. And yes, CrO constitutes the green bars but I love the finish they give.
TJK

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HB
Admin

#10: Post by HB »

I'm surprised nobody has mentioned Wenol Blue/Red. Steve of Olympia Cremina restoration fame and Porsche buff swears by it. It's available at auto part stores.
Dan Kehn