Sometimes You Need a Good Stiff Belt

August 27th, 2016

I Really Needed One More Tool

I did it. I bought a 2×72 belt grinder.

I’ve been wanting one of these things forever, but they’re not cheap, and building one for yourself is a pain and costs nearly as much as buying one. I figured I could live without it. Then I started making knives, and I realized using a small 1×42 grinder was going to make me miserable in the long run.

Actually, it makes me miserable even in the short run.

Truthfully, I am not quite as gung ho about knife-making as I was a week or two ago, but I kept getting the nagging feeling that I needed to do this. I felt like God wanted me to do it for some reason or other, so I gave in. Now that it’s on the way, I hope I use it.

A lot of Christians are involved with knives and guns, not to mention all types of machining and woodworking. Strange. I guess the zombie predictions are coming true; the heathens are busy playing video games, protesting, and fornicating, so they’re not as likely as we are to have shops full of much-needed tools and weapons when everything goes sour. They will probably be visiting us in groups eventually.

A 2×72 grinder is a remarkable thing. If you work metal, there will be many, many times when you’ll need to remove metal from parts in a hurry, and depending on the job, you may need an angle grinder, a mill, a lathe, a band saw, a drill press, a plasma cutter or cutting torch, or a big belt grinder. They’re not interchangeable.

Now that I think about it, I didn’t mention shears. In the metalworking world, “shear” doesn’t just mean scissors. It can mean a heavy machine you operate by jumping on a treadle, to make long cuts in big pieces of sheet metal.

I’ll post a video of someone showing off a belt grinder. If you’re a man, and you have struggled with wimpy tools, you will instantly want one of these things. Spend two days trying to cut a part down with files and a bench grinder, and you may be willing to trade a leg for a belt grinder.

Here’s something really nice about belt grinders: they’re not limited to steel and iron. You’re probably thinking, “Neither is my bench grinder. I grind aluminum on it all the time.” Well, here is bad news: you’re risking a big accident. Non-ferrous metals can accumulate on a bench grinder wheel and melt into it. Then the next time the wheel gets hot, they can expand and make the wheel explode. When that happens, the best possible outcome is that the wheel will be destroyed and you’ll have to take time off to replace it. The worst outcome is that bits of it can penetrate your face. That has actually happened to people.

Another wonderful thing about belt grinders: you can change grits very quickly. It takes about ten seconds. You can go from 24 grit to a cork belt with polishing compound without removing screws or turning nuts. That’s very nice.

There are a lot of grinders available. I decided to try an Oregon Blade Maker. Some guy, presumably in Oregon, started making grinder bodies from heavy steel plate. He welds them together and puts wheels on them. People who use them like them a lot, and the design seems a lot smarter than the stuff the competition puts out. Also, they’re pretty. They come with nice powder-coating.

Best part: not expensive. When you put “well made” and “not expensive” together, you have my attention.

You can drop three grand on a factory grinder. I don’t see where the money goes. It’s not a complicated machine. You make a box with a cavity that holds an arm that holds the contact wheel or platen, and you stick a few wheels on it, plus a tensioned arm that allows you to put slack in the belt in order to remove it. Simple. It’s not a vertical machining center.

People talk about how grinders have to have mass and so forth. I suppose they must know something, but it seems to me they must be exaggerating. You don’t put an engine block on a grinder rest. The grinder doesn’t have to resist tons of force. It’s not like a mill, which has to weigh over a ton in order to get anything done. I started to make a belt grinder from plywood once, and I’m sure it would have worked fine. I am confident that a welded box made from heavy plate will work just fine, and it should be easier to move around than a giant industrial machine.

Let me see if I can find a Youtube of a wooden belt grinder, just to be a troll. I’ll bet I can.

I found one. This guy went a little nuts; he even made wooden wheels. But the grinder works.

He probably died horribly later. Like the old joke about the guy who backed into a sander says, “a horrible end, but a beautiful finish.”

I was all worked up about making a stand for the grinder. Then I realized I already had one. I have a Northern Tool foam cart I use to hold my bench grinder and 1×42 grinder. I am thinking I’ll remove the bench grinder and put it on a Harbor Freight stand. Then I can put both belt grinders on the cart. That will be convenient.

I learned a few things about belts. Most people like 3M and Norton belts. Basic belts come in aluminum oxide and zirconia. Belts made with zirconia cost a little more, but they supposedly last twice as long, so I assume they’re worth it. I rooted around looking for belts I could buy with credit card points, and I found Red Label Abrasives. You can get them at Sears.com. I have never used one, but I saw a lot of glowing reviews, so I took a chance.

Aluminum oxide is harder than zirconium dioxide (zirconia), but zirconia is tougher. Don’t ask me to explain it, but it supposedly makes a better belt.

While we’re on the subject of economics *rationalization cough cough*, big grinding belts are cheaper than little ones. A 2 x 72 belt contains 144 square inches of grit. A 1 x 42 has 42 square inches. That means a 2 x 72 belt gives you 3.43 times as much grit, for a lot less than 3.43 times the money. Big belts and big motors save time and money, apart from the initial expense.

I wish I could use the plasma cutter for knife work, but I’m a little worried about having problems with the steel, as a result of having nearby metal vaporized at 6 million degrees. It might work, though. I suppose what you do before heat-treating steel isn’t that important.

That would be hilarious. Draw a couple of lines on the metal…ZZZZZHHHHTT…ZZZZHHHHTTTT…clang…done.

I will keep the world informed of my progress, if any. I hope this gives you reason to carry on.

2 Responses to “Sometimes You Need a Good Stiff Belt”

  1. lauraw Says:

    Fun fact about bench grinders: lots of people use the side of the grinding wheel for quick little deburring tasks and whatnot (I’ve done it countless times before I learned better), but any little pressure applied to the side of the wheel can also make it asplode into little shrapnel bits, because it wasn’t designed for that. So don’t do that.

    Another fun fact about bench grinders, II: what do you get when you mix steel dust left in a bench grinder, with aluminum dust left in a bench grinder, plus a spark the next time you grind?

    Thermite, kids! Thermite. That’s not just a few pieces of rock in your face. That’s ‘oopsie my hands instantly melted off in a sudden white flash.’ And yes that has happened to people.

    I used to work in a metal shop. The plasmarc cutter and the grinding belt were my two favorite tools!

    Told hubby recently that when we have some extra cash for toys, one of the first things I’m getting is a little welding machine and a set of torches and tanks.

  2. Steve H. Says:

    That fact about using the side of a grinding wheel is one of the most annoying things about bench grinders. Using the side of a wheel is a great convenience, so it’s a bummer not to be able to do it.

    The thermite thing is news to me. Thanks for the info. I read that the brightness of a thermite explosion can damage your eyes instantly, so that’s another nice thing to look forward to.