Westinghouse Polisher

[asallwey]

I was given an old (made before 1948) Westinghouse 1/3 hp, 1725 rpm, 5" bench polisher (grinder?). I did some wire replacement and now want to turn it on. But I have a couple of questions.

But what kind of wheel do I have???
It is 1 x 5" and has a slight green cast to it. Plus it glitters with tiny sparkles on the edge and both sides so they are part of the wheel. The wheel probably goes back 30+ years. One flange appears to be sweged or pressed on a tube that slides on the motor shaft, and the flange on the other side is just pressed on so is probably the one that comes off. I've not seen a mounting like this. The flanges are tight so I'm leaving them alone, but there is no label visible.

What oil is recommended for the 2 oil caps?
There is a oil cap over the shaft on each end of the motor. Maybe a light oil like 3-in-1? What about ATF?

FYI the right wheel is a leather one with a label that says it's for polishing.

[Glenn Brooks]

Nice looking grinder. Iam no grinding expert, however green wheels usually indicate a specific type of binder that holds the grit together in such a way that the grinding process produces less heat buildup than multi purpose gray colored wheels. The chief advantage is that the edge of the tool doesn’t burn or get red hot, causng it to loose temper. Often the grit is fine to medium to produce smoother finishes and sharper edges on tools. Think knife blades, high end wood chisels, HSS lathe bits, etc. your leather wheel might have been used to strop knife edges or hone super sharp edges on a master wood workers chisel set. Something along those lines...

The rounded inside edge of the wheel indicates to me either the prior owner didn’t know much about grinding, and never properly dressed the wheel surface to keep it flat, or, alternatively routinely sharpened some kind of specialized tooling that was formed into a half moon, or radius shape - such as an old fashioned hooked sheet rock knife. an unbalanced wheel like the one in your photo won’t allow you to grind straight edges on tooling very well.

Ideally you would want to use medium weight GL -1 rated (non hypoid) machine oil or gear lube in these older motors. Gl-1 oil is straight mineral oil. This was the formulation commonly available in the 1930’s thru late 1950’s and causes no harm to bearings, gear boxes and machined parts that might contain yellow metals or brass/bronze seals. Any oil likely will do on a casual basis. But if you want to preserve the original motor, pick up a quart of Gl-1 rated gear lube at your local auto parts store.

Regards,
Glenn

[asallwey]

Thanks Glen!

The wheel may be almost as old as the motor. I know the last owner hardly used it. It may have been mounted the other way also.

I'll run over to an auto parts store tomorrow to pick up a quart.

I put a new cord on it today so I'm eager to try it out. Then I can figure out what I'll use it for.

Thanks!

[Bill Shields]

That 'green wheel' MAY BE something like industrial SCOTCH BRITE

[asallwey]

Bill, the wheel probably pre-dates scotch brite as it's got to be 30+.

Glen, I started trolling for a GL-1 oil like you mentioned. Not readily available locally, at least in 1 quart or smaller sizes. NAPA has a 5 gallon, and several online sellers have it.

I did fine a correct oil,3-IN-ONE® Motor Oil and it comes in little containers, see below. Turns out I have some sewing machine oil so I topped the 2 cups up, powered it up and immediately shut off and topped up the oil, then ran it, smooth as can be. Not bolted down yet and didn't even walk on my bench.

For anybody interested in oiling electric motors check this out.

https://www.3inone.com/products/motor-oil/
3-IN-ONE® Motor Oil created a special blend of high-grade oils that’s equivalent to SAE 20. The motor oil formulation is ideal for lubricating the moving parts of electrical motors. The site's MSDS also says it is "Highly refined mineral oil (with a ) weight percent of >96".

Another site said: Don’t use automotive motor oil! It’s too “thin” for electric motors. Plus, it contains detergent. If the excess oil seeps onto the motor winding's, it might dissolve the insulation and fry the motor.

And for a lube chart see this: https://inspectapedia.com/electric/Elec ... cation.php

[Harold_V]

The wheel appears to be made of silicon carbide. If it is, it's intended to be used for grinding extremely hard non-ferrous objects. Because silicon carbide is soluble in iron (steel), it is not recommended for use for such an application. If you choose to use it, especially in that capacity, you'll discover the wheel dulls rapidly, and sloughs off even faster. That's how such wheels are intended to function (the sloughing), but the dulling due to dissolution exacerbates the sloughing. So you know, light green wheels are colored as they are so they can be readily distinguished between other silicon carbide wheels, which are typically a shiny black color.

If that's not enough to worry you, do consider that silicon carbide can be troublesome for one's lungs. Unless you will be grinding on carbide, or if you do rock work, the wheel, for all practical purposes, is useless to you. Do yourself a favor and buy one suited to the work you intend to do, and if that is grinding on HSS, please take a look in The Resource Library, where I have posted on grinding wheels. I made recommendations that you can use as a guideline in buying, mounting and using grinding wheels.

If you haven't turned on the motor, don't, not until you've given the wheel a ring test. It, too, is described in my posts on grinding wheels. Even then, don't stand in line with the wheel while it spools up. A fractured grinding wheel is a bomb waiting to blow, and fractures aren't always obvious. A ring test will sort it out for you.

H

[asallwey]

Thanks Harold,
About my green wheel, I'm not itching to use it, but just curious about it. I've seen all kinds of old grey wheels, but not one like this.

I am aware of silicon carbide wheels. You could be right about this one, I believe that my neighbor's father-in-law, besides being a general handy man, also played with stone polishing and rock stuff. I have 1 cheap green wheel (decided not to use a couple of years ago) and I've seen 2 others recently, but this one is a little different, hence my questions about it. Given that it is at least 30 y/o I figure wheels (and their composition) were probably made slightly differently than those today. Given it's speed, perhaps he used this for polishing only and had a regular bench grinder.

I did ring test it and it sounds solid. When I spun it up early this am it was very smooth running. And I do stand to side any time I power up a grinder or buffer, my father taught me that.

I have read your material in The Resource Library, it was good. But it's be some time now so perhaps I go through it again to refind all the things I forgot.

[Mr Ron]

You say you ring tested the wheel! Did you test with the wheel off the motor? It cannot be tested on the motor.

[asallwey]

Yes Mr.Ron

[Harold_V]

Considering the speed of the motor and the wheel diameter, it is being driven well under a common acceptable speed, assuming it adheres to accepted rule of thumb (6,000 sfpm). Still dangerous if it explodes, but much less likely to do so. It would be under driven with a 3,600 rpm motor. I expect the wheel will act even softer than its design hardness. It all depends on the recommended operational speed, which is typically marked on the wheel, either directly or on the blotters.

H