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Grinding wheels for tungsten

Posted: Sun Jan 26, 2014 9:38 pm
by Ultralow787
Hey folks, just thought I would share something with you. I was looking for a better alternative for grinding tungsten on a pedestal grinder. The silicon carbide wheels just wear out too fast and become dangerous once they get a groove worn in them. I recalled a friend at Lincoln Electric had mentioned that they were using diamond impregnated wheels on their pedestal grinders, but he did not have the particulars at hand. I contacted him again and he gave me the exact specs. They got theirs from McMaster-Carr. I looked them up and found that they did indeed have 6" diameter versions available, but the center bore was 1 1/4" dia. Our grinder has a 1/2" bore. After calling them, they said they had the bushings to reduce down to 1/2". However, once we got them, the bushings were wrong. I was able to use part of their bushing plus a bronze bushing to get from 7/8" down to 1/2".

I put them on and cannot believe how nice they work. Lincoln uses 100 grit, but I got one 100 grit and one 180 grit for our set up. We use a small cordless drill to spin the tungsten and just touch it ever so lightly to the stones and they do a fantastic job. The down side is that they list for $113.00 each, but were actually $180.00 each by the time I got them in hand here in Canada. We buy through our Industrial Supplier locally that is able to bring stuff in through McMaster-Carr in the US.
I start with a fresh tungsten on the 100 grit to get it roughly down to shape, then finish up on the 180 grit. I don't see any wear at all and they appear to be able to last a good long time. Lincoln was getting a year out of theirs in their welding school with a lot more use than ours should ever see.

I am now working on a dust collector system to hook up to the rear of each wheel as we use thoriated tungsten.
I can't find anything for our Dewalt Pedestal grinder available, so we will custom make our own.
Hope this helps. If interested, I can put up a link to the page at McMaster- Carr.

Re: Grinding wheels for tungsten

Posted: Sun Jan 26, 2014 10:26 pm
by RichardH
Ultralow787 wrote:Hey folks, just thought I would share something with you. I was looking for a better alternative for grinding tungsten on a pedestal grinder.
I just got one of these; now waiting on a welder to test the results. Some info here:
http://forum.weldingtipsandtricks.com/v ... 207#p23453

I found those reducer bushings ridiculously hard to source. I'm surprised McMaster-Carr (or virtually every other abrasives source) doesn't offer them for this purpose. Even eBay failed. Clearly this is an uncommon need. I found one source, but paid dearly in minimum order and shipping fees.

I left the stock aluminum oxide (fine) on the grinder to rough shape fresh ends, then got the 320-grit diamond wheel to put a clean finish on it. I know AlOx isn't recommended, but I'm hoping this will give the diamond wheel even longer life and speed the process, and any contamination added to the tip will be ground off by the diamond wheel.

Cheers,
Richard

Re: Grinding wheels for tungsten

Posted: Sun Jan 26, 2014 11:00 pm
by Ultralow787
Man Richard! Talk about me trying to re-invent the wheel! lol
The info in your post and the video is the exact ones I bought. You order the 8725A81 wheel and just specify the grit.
I think the same person that showed it to Mr. Tig is the fellow that told me about it.
Glad to see others were impressed as well.

Re: Grinding wheels for tungsten

Posted: Mon Jan 27, 2014 1:20 am
by RichardH
Ultralow787 wrote:Man Richard! Talk about me trying to re-invent the wheel! lol
The info in your post and the video is the exact ones I bought. You order the 8725A81 wheel and just specify the grit.
They say great minds think alike. :D Do note the problems seen by the fellow in the other thread - if the drill spins too fast, he was getting diagonal striations that affected his arc.

My current challenge is finding a cheap grinder with a light that doesn't have a wobbly spindle. I grabbed a Ryobi at Home Depot for $45, and while I like the magnifier in the viewing shield I didn't fare well on the wobble. If Round 2 isn't any better, I'll try my luck at Harbor Freight (which I expect to be cheaper, but maybe no better).

I haven't come up with any good ideas for grinding angles - either adding a rest or just marking a guide somehow. A tube-style guide would work great, except it'll wear the wheel in just one spot. Got any ideas, or just going to freehand it? Got a solution for cutting off contaminated tips?

Cheers,
Richard

Re: Grinding wheels for tungsten

Posted: Thu Jan 30, 2014 1:12 am
by SteveJ
To clip off a bad tungsten tip I just clamp it up in the vise with the bad part sticking out of the vise jaws.... Use pliers to grip the bad end sticking out of the vise jaws... Then just a tipping motion, with the pliers will snap off the end flush with the vise jaws!! Right or wrong it works for me every time .... I have done it to "E3" , Thoriaded , Ceriated and Lanthanenated (sorry about the spelling).... Make sure and wear some safety glasses! I have had some very small chips fly off at times! Hope this helps! .... also I submitted a "POST" for a diamond grinding wheel from "Harbor freight" that I adapted to a 5/8 arbor.... for a cost of $10.00 and a little time!! It works great.... you need to use the side of the wheel... See this POST


" Video for newbs & maybe some not so newb " ...... Steve

Re: Grinding wheels for tungsten

Posted: Sun Feb 02, 2014 10:44 pm
by Ultralow787
Richard,
We just have a DeWalt pedestal grinder. I am trying to come up with a light to rig up over the unit. I don't know why there are not more accessory items available for these units. I would also like to adapt something to catch dust at the rear of each wheel.
To snap them off, I just grind a groove around the diameter of the tungsten using the edge of the wheel. They snap off easier then.

Re: Grinding wheels for tungsten

Posted: Sun Feb 02, 2014 11:42 pm
by RichardH
Ultralow787 wrote:Richard,
We just have a DeWalt pedestal grinder. I am trying to come up with a light to rig up over the unit. I don't know why there are not more accessory items available for these units. I would also like to adapt something to catch dust at the rear of each wheel.
To snap them off, I just grind a groove around the diameter of the tungsten using the edge of the wheel. They snap off easier then.
So, I tried a couple other bench grinders in-store and they weren't any better on the side-to-side wobble. I messed with it a bunch and eventually figured out that the stabilizers are just too thin to be effective at holding square to the spindle. Combined with having the wrong reducer in the wheel, it was easy to get out of true.

With enough fiddling I got it running true and ended up keeping the Ryobi with the light. I just got the reducers exchanged for the right ones (I'd ordered the wrong SKU), which may also help a lot.

I'll probably end up adding a vacuum port to the shroud, though a lot of the dust gets thrown forward of the grinder because I'm grinding fairly high on the wheel (tip up). I have an idea that I'll share in a future post (requires some creativity).

Cheers,
Richard