What is the right tool for taking out grinder marks?

[Tim Whitten]

My hands are getting tired. I'm looking for suggestions on a power tool that can be used for taking out grinding marks in steel of the sort that knifemakers might use.

More specifically, something that would be good for grit ranges between 80 and 220.

I have a buffing wheel for finishing work so maybe there is some sort of wheel that I can put on that for the earlier stages?

Thanks.

[Kim Whitmyre]

You could make your own:

http://theknifemaker.com/inf/grinder.html

Spend money: http://www.beaumontmetalworks.com/

Spend less money:
http://www.grizzly.com/products/G1015

There's just no shortcut in this process: lots of hand work or a belt grinder.

[Canoez]

Tim,

What are you taking the marks out of? (What shape and size?)

We've used Scotch-Brite wheels of varying grits to clean up parts in our shop with fairly decent results. They mount like a traditional grinding wheel. The problem with them tends to be that you can lose detail pretty easily in a part if you're a bit heavy-handed. The nice part is that they "give" a little, rather than digging into the part right at the get-go like a grinding wheel.

We like them on Brass, Aluminum, Bronze and various steels (mostly stainless), including a variety of air and oil-hardening tool steels.

[Tim Whitten]

A knife belt sander would undoubtedly be the best, but I'm not ready to invest in one of those. I'm trying to take grinding marks out of flat sided knife blanks so maybe the Scotch-Brite wheels would do the job.

Canoez, are the wheels you referred to the sort that have the flaps of abrasive sandwiched between the mesh?

[Canoez]

A knife belt sander would undoubtedly be the best, but I'm not ready to invest in one of those. I'm trying to take grinding marks out of flat sided knife blanks so maybe the Scotch-Brite wheels would do the job.

Canoez, are the wheels you referred to the sort that have the flaps of abrasive sandwiched between the mesh?

Nope, not flaps. Looks like a grinding wheel of dense Scotch-Brite.

http://www1.mscdirect.com/ProductImages/0126149-11.jpg

Here's one source:

http://www1.mscdirect.com/CGI/NNSRIT?PMPXNO=4452557&PMT4NO=35642161

There are a variety of these wheels - check out the 3M website - I'm sure they have specific recommendations of their products for specific applications there.

[John Meachen]

I'd try one of these http://www.rightlines.ltd.uk/products.aspx?lineID=2&groupID=13 and then coarse Scotch-Brite.

[Bruce Hooke]

I've used my belt sander mounted in a stand, with a course grit zircon belt for this sort of work. From there I go to a cloth wheel with silicon carbide grit glued to it using special adhesive designed for the purpose.

[DerekW]

If you can scrounge up an old motor from somewhere then the narrow belt linisher (http://www.leevalley.com/wood/page.aspx?c=2&p=44884&cat=1,43072) frame sold by Lee Valley is good value. Mine sees a lot of use. One of the cheap imported belt sanders could be had for the same price as the linisher, but you'll curse every time you need to change a belt. The Lee Valley item is spring-loaded and changes belts in something less than three seconds.

cheers
Derek

[PeterSibley]

Hmmm ..well being a cheap type , I built one ,using a 1/2hp motor and steel from the scrap pile . Wheels are ply .I had to buy the pillow blocks (3/4") and shafts ...but it still came in at under $80.

It's pretty good too .

[merlinron]

there are also buffing grits abrasive enough to will throw sparks........

if you have a buffing wheel set up, a stitched wheel with one of these compounds will work great. the abrasive is suspended in a latex compound that loads onto the wheel the same as finer compounds. comes in a 2-3 lb. stick in grits to about 240. hold the stick to the wheel, the compound gets hot and sticky and loads the wheel;s edge, then dries harder for use. try searching
" buffing compounds" or "chrome plating supplies". i had some years ago that i got from a chrome shop in milwaukee, but the EPA closed most of them down. one source i know for sure is "Brownell's", the gunsmithing supplier.

one reason belts are so popular is to be able to keep surfaces flat.....something hard to do with a wheel unless it's fairly wide. it's common practice for buffers to build up a wide wheel by stacking a few wheels and "ragging" them with a wheel dresser, just as you would true up the face of a grinding wheel. it works great, but you have to have a fairly powerfull motor to use a wider wheel with a heavier grit of compound.

[Canoeyawl]

I have used a fine wire wheel with polishing compound for aggressive polishing

[Tim Whitten]

My hands and I thank everybody for the great suggestions.