Hello gentlemen, I picked this Disston rasp for $1 at my local flea market. 1Can anyone tell me if this is machine or hand stitched? The teeth look pretty uniform, but it is stamped Disston USA on the tang; no and sons. I know they stopped making these in the 1930s.

Also, do you think a brass brush would damage the teeth?

Thank you.

Not an expert on these but I agree with you on the symmetrical patterns.

9 minutes ago, lew said:

Not an expert on these but I agree with you on the symmetrical patterns.

Thanks. Yes, pretty sure it is a machine stitch. Doesn't matter. The rasp I have is made of chinesium. This is a far superior tool regardless. I think a brash wire brush in my drill will clean it up without damage to the teeth. They should be hardened to  a great enough degree that the brass won't effect them.

Got yard work right now, but maybe this evening or sometime next week.

Thanks, Lew!

Well, I found this on "tools for working wood", I remember reading before but wasn't sure where I had found it. Anyway:

 

According to Michel Auriou, the maker of Auriou hand-cut rasps, the best way to clean a rasp is using an all natural bristle brush. He says that metal brushes of any kind, brass or steel, will eventually dull the rasp and shorten its life.

 

This might be unique to hand stitched rasps (Auriou) or not, but it might worth thinking about. That said, it might be a good idea to get the rust off with a brass brush and then change methods.

Edited August 30, 2025Aug 30 by Fred W. Hargis Jr

Although I have never tried it I've heard that an overnight bath in vinegar will take the ruse off and add to the sharpness at the same tine.  Check on YouTube for videos.

 

 

I've done that sharpening a couple times, first with vinegar and next with nitric acid.  I did the nitric more to get the ferric nitrate solution that results - great for staining maple.

I forget the time I left them in, but with nitric it was short.  I did some tests with old chainsaw files before putting anything good in there!

 

That Disston looks machine stitched to me.  I would clean the rust off with some mild acid like vinegar and a plastic or hair scrub brush.  Rinse thoroughly and neutralize with some baking soda.

Edited August 30, 2025Aug 30 by JWD

I think the brass wheel worked just fine. It is slightly duller at the tip on the round side, but it was that way when I bought it it the flat side nor The rest of the teeth are any less sharp than they were. It's nice and sharp and burns through white ash. So I call that win win.

Edited August 30, 2025Aug 30 by Handfoolery

Dan, thanks. I tried the vinegar with an old Nicholson cabinetmaker's  rasp and did not get any results at all, but I think that rasp was too far gone in the first place. I'm way happy with the results I got with this one. It might in fact be a bit too aggressive; I'm pretty certain I'm going to need to be very cautious when first introducing it to wood.

I have always heard Apple Cider Vinegar. If you leave metal in it too long it will etch badly.

I have sent some rasps and files to Boggs.  They do a great job for just a few dollars plus return shipping.  If it's not salvageable, they will either return or trash, at your choice.  https://boggstool.com/  

Edited August 31, 2025Aug 31 by kmealy