Yes I know I can hunt down a farrier and find used ones. Yes I know you can find them on FaceBook and pay shipping. Neither of these is efficient.

Plus I can buy an 18" hoof rasp on Amazon for around $15 with free shipping. (Yes, probably Chinese made. Don't care.)

My question is what would be a good way to dull a hoof rasp so that it is useable when forging?

I can think of a number of ways, some draconian, some labor intensive, etc.

I'd like to how you would go about dulling a hoof rasp to suit your forging needs.

Take this with a grain of salt, because I've never had one from new myself, and I'm not trying to be a smart alec, but couldn't you just start using it from new? If you know the teeth are a little sharper you could adjust accordingly.

Alternatively, I imagine filing on cooled forge scale will dull it pretty quickly. Or you could get a piece of old leaf or coil spring, grind a rounded edge on it then quench and temper it and then start filing it with the rasp.

I'm just spit-balling here, I hope something of this is helpful!

Cheers,

Jono.

I did consider that and it might work. My thought is they're so sharp to start with they'd do a lot of gouging on hot steel before they wore to whatever is an appropriate 'dullness'. I think a sharp rasp would also be pretty difficult to push against steel.

Ultimately I have no idea. Your thought is as valid as any other.

If you are buying new, why not just buy a cheaper coarse file. Maybe just me but there isn't much in forging I find myself needing a rasp for that a coarse file wouldn't handle. Yeah the teeth on the file side of the rasp would bite a bit much but a coarse file would do the job. 

If you are set on dulling a new rasp i would probably "lightly" grind over it with an angle grinder with a stone or abrasive disk then test it and repeat till it was to my liking. 

Thanks Daswulf.

Amazon has an 18" for $15. I didn't notice coarse grades for hoof rasps. I thought they were all the same. Duh!

Used ones on FB are more plus shipping so expense isn't really an issue.

Maybe I can do it like we used to do blue jeans and drag it down a gravel road a ways. :-)

take the temper out----throw it in the heat, soften it up  then put a grinder to it.....

As I read this, I'm wondering what you want to do with the hoof rasp.  Will it be a tool and used for hot rasping or are you going to forge it into something?  While I've never done any hot rasping I would think a hoof rasp would get dull quick enough from use - the hot steel will draw the temper from the teeth and they will get softer and wear faster - at least that is my guess.  If you're going to make something with it, get it it hot and hammer it.

hot rasp

my unsolicited 2 cents------also on my list-----using large rasp (ive got a few)  for large cutters/bowies-------most ive seen leave a little or a lot of "tooth pattern" on the spine of the blade 

Meant a coarse metal file. I don't know much about hoof rasps to say if there are different coarseness. 

Lets clarify, do you intend to hot rasp metal you are forging on to clean up edges and smooth surfaces, or do you intend to forge it into something. 

I gathered that you want to use it to hot rasp your work.

Anyway, you could just get one and give it a shot. The toothy side will be too aggressive but the file side will dull a bit in use. It will be bitey at first. 

most ive seen end up as blades--------reason the teeth have to be dealt with-------each one can be the start of a crack in the finished blade

The coarse side of a hoof rasp is not designed for filing metal -- it's designed for rasping hooves. If you want to use it on metal, use the other side.

The subject of this thread IS "how to dull a hoof rasp." Drifting off into how to use them is good and often interesting but not the actual question.

Dulling files of any kind is EZ. PZ. If you're dulling quantities tumble them in a gravel media. If you're dulling one, file gravel for a manual method or sand blast the teeth. Wearing good PPE use a cup brush on an angle grinder and brush it in a box of sand. Draw the file across cold steel backwards to roll the teeth then sideways to snap the rolled edges off. Heat it to orange and give it a puff of just oxy from a torch. Turn the oxy off and pass a fuel gas only flame across the HOT file to reduce the scale to good steel. Or brush the scale off after it's cooled down.

Buying files in bulk anywhere risks useless, el-cheap'O case hardened junk.

I asked a farrier friend for A dull file to play with and he unloaded a bucket of them from his truck. I like them for hot rasping but I'm not a bladesmith guy so only ever made one pattern weld type billet. Maybe I'll forge something from  it someday, who knows.

Frosty The Lucky.

Heating to orange and letting it cool will ruin the heat treatment, and the first time you file anything with it afterwards will take care of the dulling just fine!

The point of dulling the rasp is to reduce the probability of inclusions in billets. drawing the hardness and just rolling the teeth almost guarantees inclusions, doesn't it?

Not leaving any rolled teeth is why I suggested doing it to a hard file then snapping the rolls off with sideways strokes. 

Thinking about it again, taking it to the belt grinder or heck a disk grinder would dull it in seconds. It might lose the "pointy tooth" pattern though. 

Frosty The Lucky.

I always use the 2X72 belt grinder with a 60 grit belt. Makes short work of the teeth.

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