Rasping hot metal

[Joe C B]

Hello all, What's the deal with filing or rasping red hot steel? I have heard of this and seen a quick video clip.
Does this technique require a special file? Seems like it would ruin a normal file? I have a couple of pretty good Blacksmithing reference books and neither mentions the subject.
Joe B

[chyancarrek]

Do you know any farriers? Get a few of their old hoof rasps - they work great for hot-rasping.
Drill a hole in a golf ball and stick it on the tang for a grip.

[Tim McCoy]

Ditto - 'nuff said.
Tim

[Mainely,Bob]

Why a golf ball as opposed to a wood handle with an insert that threads onto the tang?

[pete46]

Why a golf ball as opposed to a wood handle with an insert that threads onto the tang?

The golf ball fits in the palm of your hand better.

[bigfootnampa]

Joe; I was taught to hot file at 400 to 700 degrees. Note that this is WELL below red hot. Even so these temps are enough to make steel significantly softer. In most cases this type of filing is done to quickly rough out bevel angles and smooth tapers/shapes. It is the primary way that I sharpen my hardies and chisels (though I will often touch up the edges on the belt sander). Though these temps are well below red hot or critical temps they are hot enough to draw tempers so coarser toothed files and rasps (mostly larger ones as the teeth are coarser in the larger sizes and the mass is helpful too) are used and the work is done quickly with the files in contact for as short a time as possible. Obviously tools that require heat treatment must be hardened and tempered AFTER the hot filing is finished.

[Joe C B]

Thanks guys, that helps. I'll try hot filing, I do have a couple of old 14" course files.

Joe B

[Mainely,Bob]

So you drill the ball and glue it on the tang?

For a regular rasp or file better control comes from a proper handle,this being rough work that control may not be critical.Having a secure handle does 2 things,it protects you from injury by the pointed tang and provides a secure grip.I`ve seen pics of the golf ball but always used a wood handle that mechanically attached or was glued on for both grip and safety/security.
Unless you folks who use the golf ball approach know of a different way to securely attach them I`d go with an adhesive in the drilled hole to keep it on .
Just trying to keep people from getting hurt.

[MattBower]

You don't need adhesive. Drill the hole a little undersized (straight through the center of the ball, and out the other side) and drive that sucker on there with a mallet. It's not going anywhere anytime soon. I find them pretty decent handles, and far better than the bare tangs that I was mostly using before I got hold of a bunch of old golf balls. (Not a good idea, I know. I'm just telling it like it was, not recommending others follow my bad example.)

Hot filing does tend to draw the temper of the file or rasp, but then it doesn't need to be as hard when the steel you're working is hot and soft. Still, you don't use your good files for this. You set aside some worn-out rasps or coarse files just for hot filing.

[ThomasPowers]

There is a use progression: Horses => working handles and other "traditional woodwork" => Hot Rasping => stock for forging rasptlesnakes, kindling hatchets, etc.

Of course a rasp can go up or down the progression at need...

[edge9001]

when hot rasping, I know farriers hoof rasps are good. what about a simple wood rasp. when working with heated metal would a wood rasp do? I ask since the only rasp I can find is a wood rasp at the local HD.

[eric sprado]

When I was shoeing(for 25 years) I'd go through a rasp in a couple of days in Summer when hoofs were hard. They lasted a long time for next uses-clinching,hot rasping. Point being there must be LOTS of shoers in your area with LOTS of used rasps. If you can't find any I'll send you some if you pay for flat rate shipping box. I'll see if they fit in flat rate box.

[edge9001]

When I was shoeing(for 25 years) I'd go through a rasp in a couple of days in Summer when hoofs were hard. They lasted a long time for next uses-clinching,hot rasping. Point being there must be LOTS of shoers in your area with LOTS of used rasps. If you can't find any I'll send you some if you pay for flat rate shipping box. I'll see if they fit in flat rate box.

I'm interested.

[edge9001]

When I was shoeing(for 25 years) I'd go through a rasp in a couple of days in Summer when hoofs were hard. They lasted a long time for next uses-clinching,hot rasping. Point being there must be LOTS of shoers in your area with LOTS of used rasps. If you can't find any I'll send you some if you pay for flat rate shipping box. I'll see if they fit in flat rate box.

EricI would
Did the rasps fit in a the flat rate box? how much is shipping? I have only one shoer I've been able to locate so far nd he is not responding to my calls or emails.

[Frank Turley]

The hot farrier's progression of rasp use may be something like this. The new rasp levels the horses hoof, plantar surface. Then, the same rasp becomes a finishing tool for dressing off (touching up) the clinches and "polishing" the hoof below the clinches with the file side of the rasp. When it becomes too dull for finishing, it becomes a hot rasp.