How do I cut a horseshoeing rasp?

[Grundgedog]

I am new to blacksmithing and have tons of questions, this site has been great for info !! Thanks, everybody !!

I have been picking up large horse rasps whenever I come across one at auctions, flea markets, etc. I would like to use one for a project.

How do I cut it lengthwise? I searched this site for "hot cut" but didn't see what I needed.

I would like the rasp's pattern to still be prominent when I am done.

Kevin

[ThomasPowers]

Laser, waterjet, plasma cutter, O-A, anneal and cut with a hacksaw or large shear, rotozip, or use a handled hot cut with the metal hot from the forge (or even a hand held chisel---making sure the handle is long enough not to cook the holding hand!

Providing information on what you plan to do with it might help narrow down the best method in your case.

Now if you want instructions on how to make a hot cut I'm sure you will ask.

[Dean Christman]

Hey Grundge, there are tons of ways to cut your rasps, it just depends on what's going to be easier for you. If you have a hot cut just heat that bad boy up and start cutting down the lenght of your rasp, or you could hacksaw it is that's an easier route? Angle grinder with a cut off wheel even!

[Dean Christman]

Oh and welcome to the wonderful world of blacksmithing brother :D

[Marksnagel]

Welcome to IFI and your newest passion.

Mark <º))><

[connor bachmann]

if I were you, I'd use an angle grinder to cut half of the way through then lay a side over the edge of your anvil, or a stump (widthwise) and hit it with a hammer (while still full hard). You could also cut all the way through with an angle grinder. Please note that i've never done this before, it's just an idea that i'm pulling out of thin air

[Dave Hammer]

If you want to cut it hot, use a hot cut.

If you want to cut it cold, use a zip-disk in an angle grinder.

[Grundgedog]

Geez, I do have an angle grinder, I will pick up some of those thinner wheels and give it a try.

Okay being a newbie, could you explain the how a hot cut would work for this? I have a cutoff hardie, or do I heat the whole thing up and use a chisel? (Just tryin to learn here guys!)



Thanks for the welcome! I have been wanting to do this forever but just FINALLY put together enough tools to get into Blacksmithing. I was at a sale and a large wooden crate chuck full of tongs were going cheap so I bid like $7 and got the whole thing. That inspired me to buy a 127 lb Lakeside anvil, then got to talking to guys at work and one said he had a forge behind his shop he would give me!!! The rest of my tools were easy to round up. Now I can see I have a THOUSAND things I want to make!!

[pkrankow]

You could use a cold chisel for hot cutting, BUT it is a very wide chisel for hot cutting and will draw the temper making it unsuitable for cold cutting after this.

Alternately you can make a hot chisel out of a piece of coil spring. Normalize and use, no special heat treat needed. You can also use your hot cut hardy, but you will have less control that if you retrain the part and hot chisel.

I would buy some name-brand cutoff wheels and use the grinder.

If you try the snap method above, wrap it in rag. It may shatter instead of breaking along the cut, but it quite likely will break neat. I have had files break from being dropped.

Phil

[ThomasPowers]

Hot Cutting: heat a section of the metal up to an orange heat and lay it on top of your cutting plate/saddle/chunk of steel. Place hot cut on hot steel properly lined up and strike vigorously with your heavy hammer. Walk the hot cut forward and strike again. Continue re-heating the stock as necessary. Once you get a good line all the way down the stock go back to one end and this time try to cut through it---may take several blows---make sure it's glowing! Continue cutting through and walking the blade forward *AND* this is why you want a cutting plate/block/saddle so as you cut through you do not harm the anvil face. (I've used channel iron for cutting saddles or took a strip of 1/4" plate close to the width of my anvil face and hammered one end down to fit in the hardy and then cut on top of that) WEAR HEARING PROTECTORS the use of a cutting plate increases the noise considerably!

I prefer an arched blade hot cut so I can walk it along starting with the end in the old cut mark and then tilt the handle up (or down) to bring the blade onto the uncut section but aligned with the old cut mark.

Note that although the hardie is a "hot cut hardy" (or "cold cut hardy" but the assumption is a hot cut hardy) when the term used is just "hot cut" we generally mean a handled chisel used to cut hot metal from the top where the hardy cuts from below.

Both tools have their places and for beginners it's often handy to be able to see when the cutter has jumped out of the previous cut and will cause problems if you strike it without re-positioning.

There will be some deformation of the rasp pattern having been hot cut. There will also be a sharp edged that should be ground or hot rasped back to prevent cold shuts starting when you hammer on that sharp edge.

[Don A]

I second the thin abrasive wheels in the angle grinder. I've cut a lot of stuff with these and the cuts are generally clean, thin, and no deformation.

However, don't forget your glasses & gloves! With a less-than-steady hand, these thin wheels can bind and make some violent exits. Sometimes the grinder flings the broken disc, sometimes the disc flings the grinder. I've got a nasty looking cut in the toe of one of my boots from a runaway cut-off disc.

The best way to avoid problems is to keep everything well supported, keep a firm grip on your grinder, keep your cuts straight and don't vary the angle of the disc to the metal. Don't rush the tool and avoid binding it.

You can usually find the DeWalt discs in a 6-pack that are not too expensive.

[Dave Hammer]

As mentioned above, buy brand name zip discs if you use them. Cheap ones end up being more expensive anyway (don't last as long) and are more likely to come apart while in use. Personally, I like "Walter" brand abrasives, but I expect most name brands would be OK. It is critical to wear gloves and eye protection while using them also.

It doesn't appear that you are familiar with "hot cuts". The photo below shows how they are generally made. Normally, the handle does NOT have wedges to tighten it to the tool (this tool was this way when I purchased it used). Since this is a "struck" tool, it is better if the handle is not rigid. Usually, the handle extends beyond the top of the tool, and is just snug. Some hot cuts are heavier than the one shown below, but this is the size and shape I prefer (less mass within the tool allows the most energy transfer to cutting). The cutting edge is about an inch and a quarter long. Also, the cutting edge should be (as Thomas noted) slightly rounded so it is easy to "walk" the chisel along the cut...

[Grundgedog]

Thanks guys, I will give the grinder a try, then when I round up the right tools, I will work on doing a hot cut.

[Frosty]

Welcome aboard Grungly one, glad to have ya. If you'll put your general location in your header you might be surprised to find IFI members living close enough to lend you hands on help. It'll also help us old farts so we don't have to try remembering who's in the neighborhood if we want a tasty snack or place to nap.

One thing I didn't see about using a cutoff wheel or "hotsaw" as I knew them, Safety gear was mentioned, do not ignore this warning, what I didn't see is clean the floor and make sure the sparks aren't shooting into a blind spot where flamables may have collected. The sparks WILL start a fire and can travel quite a distance.

Another method for hot cutting I saw Peter Ross use on the Woodwright's Shop was pretty cool but maybe not the thing for preserving the teeth on a hoof rasp. The technique was to take the HOT stock and put it in the post vise with the mark level with the top of the jaws and using a chisel or hot set and shear it with horizontal blows using the jaw top as a guide. This worked really well and a lot faster than I expected when I gave it a try. It was more accurate and worked a lot more easily on thick stock, I worked up to 1/4" testing the method.

Again, welcome aboard, play hard, play safe.

Frosty the Lucky.