Stainless Stove finish 1

[mikeo56]

Hello
Is there any method available to refinish the type of stainless sheet used on fridges, stove and oven hoods?
Seems like 400 grit paper is close or even finer than the original. However, the original finish has some diffaction of light(if I look closely I can see greens and reds)and runs perfectly parallel to the legth of the sheet.
I can't sand straight enough by hand and do not know what could recreate the slight color diffraction.

Any ideas?

Thanks, Mike

 

[MikeHalloran]

We do it on generator housings for yachts. The machine comprises a long Scotchbrite belt (~6" wide x 16' or so) running on two drums so that the lower run of the belt just clears the panel being finished. A handheld pressure pad pushes it down on the panel a few square inches at a time.

You might be able to get close to duplicating the finish with a Scothbrite belt in a belt sander. You'd have to have a very steady hand (or a drafting machine type arm) to keep the grain straight, and you might need to use a speed controller on the sander to keep the heat down and help the belt survive.

Or, you could stack a couple inches of Scotchbrite discs on the spindle of an angle grinder. I think we have a spindle extension that allows that, for finishing edges. I don't think it was homemade.




Mike Halloran
Pembroke Pines, FL, USA

 

[mcguire]

The original finish was probably made using a 220 grit and a water soluble oil. This is what mills do to make the #4 polish which most appliances have. Some processors use a dry abrasion which looks less bright.

It's unfortunately virtually impossible to duplicate the original finish because you must match pressure, alignment, lubrication, and especially pitch, which describes the length of the grit line. The original finish was made with a belt rotating on a back up roll of maybe a 12 inch diameter. A belt sander makes a long grit line, the orginal is about 1/4 inch long, or so.

Sorry to sound discouaging, but this is a long-standing problem with that damn finish. The only duplicable and blendable finish is a long grain type. In Japan it's called "hairline". Allegheny makes it in the US.

Michael McGuire

http://stainlesssteelforengineers.blogspot.com/

 

[tripleZ]

Not exactly. For some refrigerators, the brushed finish as we call it uses a series of steps. You brush between 120-220 grit then follow with a Scotch-brite aging belt. We don't brush with oil; we do it dry. Some customers have very stringent requirements on how the finish is made. For instance, standard belt sanders will develop imperfetions which can be translated to the part. For that reason you use much longer 10-foot long belts on specialized sanders. The Scotch brite aging process sometimes uses a belt, and sometimes uses a flap wheel. Pressure is prime. For long flat surfaces, special fixtures are developed (if a robot isn't being used) to get a consistent finish pattern. In most cases, you are sanding the entire length of the piece to get the grits to line up properly. If you're trying to match via small hand strokes, you may get close but there will still be imperfections in the finish.

To sand straight enough, you would have to rig up a jig (like a parallel rail on a table saw) to control the direction. You're in for some tough work.

Mcguire is right; this is a hell of a thing to try and fix.

 

[mcguire]

tripleZ
Good information. I didn't mean mill polishing was done with only one grit size. J&L used to use four successive belts of progressively finer grit, a fairly common practice. Your scotchbrite aging process sounds like a good way to make the process more uniform, which is a major problem with mill finishes. The end of the coil doesn't ever look like the beginning!
What kind of refrigerator could I see this finish on?

Michael McGuire

http://stainlesssteelforengineers.blogspot.com/

 

[mikeo56]

Thanks Guys

I appreciate the information. I used 220 to remove the scrathes, then 320, then 400, all by hand. The original finish did look as if was not made by long brushing method but more like the short grain line. The lines also, seemed to criss-cross, creating diamond shapes.

Mike

 

[tripleZ]

Mcguire:

The high end stuff primarily...SubZero or Wolf SS brush finishes will give you an idea of what I'm talking about. Most of my experience is with the smaller, more complex shape components.