Welding Tips and Tricks

Hi,

I am looking to put a brushed finish on a lot of stainless. Of course the scratch marks must all go in a straight line. I was watching a video with a guy who was using a Dynabrade surface conditioning tool with a sanding drum that inflates:

https://www17.dynabrade.com/view-product.php?mn=DYS1

I have seen the Metabo one also. Those are both really expensive. I have also seen people do it with a belt sander. which seems like a good option because they are so cheap. The guy in the video looked like he knew what he was doing. So, I assume there is a benefit to using a surface conditioning tool over a belt sander.

So, mainly my question is will the 120 grit drums for the Harbor Freight one work for this:

https://www.harborfreight.com/9-amp-sur ... 58079.html

Or do i need one of these:

https://www.jegs.com/i/JEGS/555/95717/1 ... RA1XyZZf-Y

This is the only thing i can find to use sanding belts on a surface conditioning tool.

120 grit is very coarse for stainless surface conditioning. I have one of those drum sanders specifically for doing stainless counters. And I have about 6 different grits.

The tool you linked from HF is the correct type. The drum from Jegs is not needed if you buy the sanding drums (colored) from HF.

If you want to save a lot of money, and this is not going to be a regular requirement, you can use large, square ScothBrite pads. They come in Brown, Green, Red, Blue and Grey (coarse to fine). Clean the surface, start with the Red pad, long strokes from end-to-end. Wipe down the surface after each pass to remove any grit. Step up to next pad after wiping the whole surface. Stope when you get the finish you wish.

Stainless is very soft and scratches hella easy. So be very conscientious handling and working it.

Are you saying the scotch brite pads will create a brushed finish, and last longer than the colored sanding drums? Or will the finish with them be a different finish than brushed?

Also, for it to not rust, do i need to pickle any spots that have been grinded or only the welded spots?

The pads are pretty similar to the woven/non-woven drums. Difference is with pads, you don’t buy a machine.

You should not create any rust areas by gently surface finishing. Only welding without a purge creates the oxidation. You can use a paste called Solar Flux when covering a flat weld in the backside is not viable. Then passivate for optimum results.

my understanding is some grades will rust from cutting, but most won't. especially the common ones.
your not going to cause rust by finishing work, unless you use pads which have been used on steel.
tho it easy to run acid over cuts etc if you wanted to.

there is a bit of a difference between pickling and passivation, often mixed up. i tend to forget which is which. pickling is whats done after welding to remove heat tint/oxides and exposed iron. passivation is to improve the natural chromium oxide layer that forms on the surface which what makes it stainless. (a bit like what anodizing is to aluminum).

Ok, thank you.