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Up Topic Welding Industry / General Welding Discussion / Tungsten sharpeners
- - By alan domagala (**) Date 01-16-2011 02:17
Anybody use those electric handheld tungsten sharpeners? Im thinking on buying one but I want to make sure they're not pieces of junk.
Parent - - By HillbillyWelder (**) Date 01-16-2011 14:58
Try the Pirhana II from Diamond Grind, I think they are about 1200 to 1500.
Parent - By gndchuck (**) Date 01-17-2011 00:33
I've used the Pirhana II's, they are really good and fast.
Parent - By cmays (***) Date 01-16-2011 15:01 Edited 01-16-2011 15:24
I have a couple of the sharpie models. Purchased them from arc-zone.com . They work very well and they are less expensive than the 1200 dollar diamondgrinds, like 300 dollar range. I have them both in my fabshop and the sharpie works just as well as the others. Make sure you order a few extra diamond wheels with them. They last for a long time its just nice to not have to wait when you need one. Arc-zone has a couple other sharpness too. We buy most of our sharpners and purging equipment from them.
Parent - By Jenn (***) Date 01-22-2011 18:57
I have one of the handheld models at work, and quite frankly - I never use it. We have 2" wide open belt grinder that makes for a WAY longer and nice point. Our belt grinder is also dedicated to just the welders, so no worries about "contamination". I mostly use the handheld one for cutting my tungstens in half (I use a short cap, due to tight work room). Its really fabulous for that, but not needed if you don't do that much.

Its worth the coin if you can spare it, and find a need for it frequently.

Regards,

Jenn
- - By ccbrown (*) Date 01-17-2011 02:11
I have also used the sharpie type, perfect for the field but you can't get that nice long sharp point that a bench grinder gives. Still beats a grinder straped to a chain vise though.
Parent - - By joe pirie (***) Date 01-17-2011 02:18
try using a bench grinder with the tungsten inserted into a cordless drill 
alot cheaper than a tungsten sharpener  and works way better than spinning by hand  joe
Parent - - By cmays (***) Date 01-17-2011 15:30
That really does work the best. Just make sure you dedicate that grinding wheel to nothing but sharpening tungsten to prevent contamination.
Parent - - By DaveBoyer (*****) Date 01-18-2011 04:36
Do You suggest an aluminum oxide wheel or a silicon carbide [green] wheel?

Where I was an apprentice, I used a diamond wheel that We used for carbide lathe tool bits.

I have used a silicon carbide wheel here in My shop. I am not sure I want to sharpen electrodes on a diamond wheel I paid for.
Parent - - By Lawrence (*****) Date 01-18-2011 05:34 Edited 01-18-2011 05:38
I don't think it really matters for most work Dave.

Tungsten, being the hardest metal in the periodic table, is not going to be easily contaminated. 

Most of the X-ray quality welds made in my career had tungstens that were sharpened by a 2" belt sander with aluminum oxide 80 grit.. The finish on the tips was best when the belts were almost worn smooth..  A manual tig operator will not be able to tell the difference between a diamond sharpened electrode and a grinding wheel or a belt sander..  

If operations include aluminum than it's best to stay clear of any type of wheel.. diamond or otherwise..  Loading a diamond wheel will smear it up and reduce it's lifespan by... well alot..   loading a grinding wheel with aluminum is downright dangerous.

Diamond wheels are useful when adaptive feed back of arc voltage  is used to control the Z axis of a semi-auto or orbital tig.. A change in included angle will cause a variance of voltage which will in turn change the standoff distance between the tip and the work..

Not bashing diamond wheels... They work great... But also suggesting that they are not a necessity, except in a very few specialty situations.

Edit:  We bought a little hand held job that had a 1" diamond wheel inside..  Worked great.. Lasted about a semester per side on the diamond wheel, and thats with beginners who don't know how to use the thing... I'll post the brand name of the tungsten grinder when I get back to work as I don't remember off hand who makes it... I ran under $200      Fit's in a tool box or even a tool belt, runds on 110.   Very good tool.   With 40 Tig students going at a time here it's important to have several sharpening options or the line is very long for the first few weeks eh?
Parent - By Stringer (***) Date 01-21-2011 02:16
Gotta chime in and agree with Lawrence. But one other thing, I don't know if I've seen it mentioned, but frequency of cleaning also plays a part. I use a standard bench grinder, well, an older, heavier one (better than a DeWalt) and spin my tungsten by fingers and eye and have for 35 years, 40 hours a week or more. If I'm literally working on rocket parts I'll go sharpen on the darex mill head sharpener. Otherwise, I'll use a fast method because I work fast and I sharpen often. I think the $1200 dollar sharpeners are nice, but they are too slow for me. I've talked with a tungsten engineer about dust and radioactivity and he said the weight of the dust will tend to send it to and keep it on the floor. A respirator is never a bad idea around a weld shop, in my opinion, and I buy good ones and use them often, but not when I'm grinding tungsten (almost exclusively sylvania 2%). Maybe I should.
Parent - By DaveBoyer (*****) Date 01-21-2011 03:40
I wasn't really concerned about contamination, but being a pretty hard material, it doesn't grind easily, or let Me say it takes it's fair share of the wheel.

The 100 grit 100 concentration resin bonded diamond wheel cut it pretty fast with a fairly good finish, but that was probably a $100 wheel.

We were not welding aluminum in that shop, but here in My home shop I do at times. I use a 100 grit silicon carbide [green] wheel that I use for carbide lathe tools.
This gives a half decent finish, and by moving it across the wheel as I grind, I don't put a groove in the wheel.
- - By Platinumbased (**) Date 01-18-2011 23:15 Edited 01-18-2011 23:20
I've used the Piranha 2 Tungsten grinder.  They WILL pay for themselves on large jobs with multiple welders if you have tool room or designated person to prep both new and used tungsten.  Note that inhaling radioactive thorium dust is very bad for your health.  Radioactive heavy metals in the lungs can't be good for you.  FWIW.

The Radioactivity Problem
The Thorium used in 2% thoriated tungsten is a radioactive element and therefore can be dangerous to the health of those exposed to it and to the environment. It is an alpha emitter, however when it is inside a tungsten electrode rod, it is enclosed in a tungsten matrix and so there is little radiation emitted externally. The main risk to the welder occurs in the ingestion of the material. This occurs primarily during the inhalation of dust caused during grinding of tips for welding, but also to a lesser extent during breathing of any fumes released during welding.

The American Welding Society, in their A5.12 "Specification for Tungsten and Tungsten-Alloy Electrodes for Arc Welding and Cutting" states the following on this issue: "Thorium is radioactive and may present hazards by external and internal exposure. If alternatives are technically feasible, they should be used." They confirm that the primary concern in using this material is in ingesting dust produced while grinding points on electrodes. They go on to say:

...during the grinding of electrode tips there is generation of radioactive dust, with the risk of internal exposure. Consequentially, it is necessary to use local exhaust ventilation to control the dust at the source, complemented if necessary by respiratory protective equipment.
Parent - - By Lawrence (*****) Date 01-18-2011 23:53
While all of what Platinum said is 100% factual;

There is not a single case recorded anyplace, of thorium radiation related illness of welders using thorium alloyed electrodes. 

The tungsten dust itself is also toxic, so the precautions for thorium should be taken for any electrode in my opinion.

I buy alternatives  (Lanthanum and Cerium)  but have absolutly no fear of thoriated electrodes either.

BTW  This is the brand of portable sharpener I mentioned before... Around the  $200 mark.. Pretty tough and the folks selling it are from South Carolina.. Not sure if they make em there but I think they might.
http://www.techsouthinc.com/grinders/pp.html
Parent - - By Platinumbased (**) Date 01-19-2011 00:19 Edited 01-19-2011 00:22
Lawrence:  In my trade (Boilermakers) they blame all lung cancer on Asbestos. At least that's what all the lawyers pounding us with TV ads and direct mailings say.  Who knows what causes the lung cancer??  I sure don't.  All I know is that I've grown weary of hearing that "this won't harm you" from job foreman, stewards etc. when the label on the product says it is a known carcinogen.  I'm also sick and tired of going to funerals for men as young as 44 and as old as 61 who are all dying from cancer.

If you are grinding thoriated tungsten, wear a respirator.  Many of the younger guys on the job are doing this these days.....and they are getting called a PUSSY by the older guys who stand there with a smoke hanging out of their mouths sucking in all the radioactive dust.  Sad to see such ignorance condoned by my union.
Parent - - By Tommyjoking (****) Date 01-19-2011 00:40
I have to agree with Law on grinding options.  It really does not matter, they only time you will find a difference if you use a very low # abrasive...deeper lines in the tungsten have bad effects on the arc.  BTW if I contaminate my tungsten with aluminum I just snap it off in a vice and regrind.

I am not 100% but I think they have requirements for water wheels sharpening tungsten in Europe because of the "danger" of thorium etc.  That's nice for the manufacturer of those grinders but WAY WAY overkill imho.  A brand new small drill chuck and a bench grinder or belt sander makes a good sharpening device....but just rolling it in my fingers works fine for me....I guess I am just cheap.
Parent - By rlitman (***) Date 01-19-2011 18:01 Edited 01-19-2011 18:03
I just use my belt sander or bench grinder, but I was warned that snapping off a tungsten causes tiny fractures that run the length of the tungsten behind the point that you snapped off, which causes more issues than a rough grind.  I try to grind most of the way around and through before I snap off what's left at the tip and grind one more pass.

I too have had luck grinding by just rolling in my fingers.  I've got about 30 tungstens in the size I use most, and wait until I've only got 4 or 5 clean ones before I start to grind them all.  I start on one, and when it's too hot to handle, I just put it down and go on to the next.  After 2 or maybe 3 passes through the group, I'm done.

Oh, and just to be clear, I don't own any thoriated tungstens.  Just lanthanated, and a dozen or so zirconated in the larger diameters for aluminum.
That, and I wear a P100 respirator whenever I'm grinding anything (or sanding wood for that matter).
Parent - By Lawrence (*****) Date 01-19-2011 01:39
My opinion is what it is.

My advice, has been consistant for over a decade, and is to treat "all" tungsten electrodes with the same precautions one would with thorium.  As I said.. All tungsten dust is toxic.  Every MSDS agrees.

The only published links to thorium radioactivity problems and resulting illness I've ever seen is with the folks who mine it.

So if you are advising the youngsters to be extra careful thats a very good thing to do.
Parent - - By Blaster (***) Date 01-19-2011 00:32
Lawrence - Do you know if there has ever been a study <conducted> to see if there is any correlation between heavy thorium tungsten use and health issues?

If a radioactive particulate accumulated in the body, would it show in the form of various common cancers of the lungs, organs, and/or other areas of the body?  If so, I doubt anyone would check to see if the cause could be proven to have been related specificly to thorium inhalation.  I don't know, maybe tumors related to radioactivity are unique?
Parent - - By Lawrence (*****) Date 01-19-2011 01:53
http://www.iem-inc.com/prmade9.html

http://www.epa.gov/rpdweb00/radionuclides/thorium.html

The only relationship I've ever found is this"

"Workers who had high exposures to cigarette smoke, radon gas, and thorium had cancers of the lung, pancreas, and blood. People who had large amounts of thorium injected into their blood for special x-ray tests had more than the usual number of liver tumors, cancers of the blood, such as leukemia, and tumors of the bone, kidney, spleen, and pancreas."

I think the key is "high exposures"   and the average welder is not getting that.
Parent - - By rlitman (***) Date 01-19-2011 17:58
"Exposure" is a tricky thing to pin down, and the technical term is "dose".

For one thing, there are many kinds of "radiation".  Gamma radiation can penetrate right through you.  Beta can't get as deep, but is more ionizing (and so is more likely to DNA damage).  Thorium is an alpha emitter.  Alpha radiation is the MOST ionizing form of radiation, but an alpha particle is so large, that outside of the body, it would be blocked by just a few feet of air, or at the worst, simply by your dead layer of skin.
The problem, is that an alpha emitter within the body puts it into a place that it WILL cause damage.  Now, will that damage lead to cancer?  That's a question I'm not prepared to answer.

For another, dose is time and concentration dependent.
Asbestos is dangerous in the lungs, because it stays there, without ever being bioabsorbed.
Iodine 131 has a relatively low level of radioactivity, but ingest even the smallest of doses of it, and the body will concentrate it into the thyroid, greatly increasing the chances of thyroid cancer.
When ingested, Thorium is most likely to pass directly through your body, but your lungs do not posses an anus.  Either you cough it up, or more likely, it gets bioabsorbed.  This is a double edged sword, because while it isn't allowed to linger in the lungs as long (which would increase the dose), it tends to end up being deposited into the skeleton (which is probably why thorium is known to cause blood cancers).
Parent - - By joe pirie (***) Date 01-19-2011 19:56
While working at San Onofre years ago a welder exited the plant
and had several pieces of tungsten in his pocket. It set off the radiation
alarms and Health Physics took the welder away for examination
Certain types of tungsten are radioactive
Parent - By rlitman (***) Date 01-19-2011 21:23
It is the thorium in the tungsten that is radioactive.  I'm surprised that it set off an alarm, but the sensors at nuclear plants are of the highest sensitivity (for numerous reasons).
Several years ago, my father had a thallium stress test.  The following day, he went to drop off some junk at the town dump, and set off the alarms as he drove past the gate, still sitting in the car.  That took some explaining.   :)

Dumps and metal recyclers have been on the lookout for radioactive materials since this awful incident:
http://en.wikipedia.org/wiki/Goi%C3%A2nia_accident
Up Topic Welding Industry / General Welding Discussion / Tungsten sharpeners

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