[HennieL]

Hi Everyone, being a brand new TIG welder with zero TIG experience, this is my first technical post after introducing myself.

Being new, I regularly dip the tungsten, or touch it with the filler rod (believe me, I really try not to ). Anyway, I noticed that there appears to be some residue on the tungsten some distance away from the tip after a dip or touch. I stop welding when a dip occurs, and I re-grind the tip, but the residue that I'm talking about is located further back from the ground tip, and I cannot clean this up when grinding the tip normally.

Question: would residue on the tungsten further away from the tip have any detrimental effect on my welds?

If yes, then how do I remove this residue - do I grind the rod thinner further back from the tip in order to clean away the residue, do I sand the rod with some water paper, or do I do something else (what...).

[cj737]

Yes, it will effect the arc, but it can also interferes with the tungsten sliding into the collet holder. Best to grind the tungsten in half above the "wart" then regrind a fresh tip from there.

If you're really careful, you can touch these warts to the side of your grinding wheel (I use a silicon carbide wheel in my bench grinder) to whittle it down and avoid grinding into the tungsten diameter. Then, you can polish the tungsten (end-to-end) with some fine grit and continue using it. If you're just practicing currently, save yourself some $ and just "repair it" while you learn. If the work is to a code specification, cut it off and re-grind.

[HennieL]

Thanks for the info - much appreciated

If you're really careful, you can touch these warts to the side of your grinding wheel (I use a silicon carbide wheel in my bench grinder) to whittle it down and avoid grinding into the tungsten diameter. Then, you can polish the tungsten (end-to-end) with some fine grit and continue using it.

I'm a part-time knife maker, and use a 2m belt grinder for many of my grinding - this works a lot faster than a bench grinder, but can also grind/polish much finer than any bench grinder if I just change belts and slow down the speed. It won't be a problem for me to just clean the warts off with (say) an 80 or 100 grit ceramic belt, and then polish it all the way down to 600 grit or even 800 grit, if required.(I could take it all the way down to 2500 grit by hand, but suspect that there would not be any benefit to this)

Questions:
1. Should I grind the rod longitudinally as done when grinding the point (and why)?
2. How smooth should it be polished - would (say) 400 grit be sufficient? Would polishing it smoother have any advantage?

Whilst on the subject of grinding & polishing: I currently grind my tungsten points with a clean (i.e.new) 80 grit ceramic belt. Would there be any advantage to smoothing the point with a finer grit belt (again, I could polish all the way down to 800 grit if there would be an improvement to the arc)?

[cj737]

Always grind longitudinally. 2500 grit is pointless. I use a Red ScotchBrite pad to buff mine when arc quality matters.

Always grind your tungstens in half to reduce their length. Don’t cut them, don’t saw them, don’t snap them. Use the edge of a grinderto grind them in half, then grind lengthwise to put a point back on.

[HennieL]

Thanks for your reply.

Always grind longitudinally.

Why would that matter on the shaft of the rod? I can understand that longitudinal scratches (i.e. grind marks) on the tip will have a smaller influence on the arc formation than transverse scratches, but cannot think of any reason why the direction of the scratches on the shaft would affect the arc?

Not trying to be difficult here, I genuinely would like to know/learn

[cj737]

Well, the arc travels the length of the rod... will you notice much difference? Probably not, but best practice is to always and only grind along the length.

Those who weld professionally the most exotic and specific materials, have extreme regimens for tungsten prep and care.That is an aspect of how they achieve such excellent results. I always do what I can to improve my chances of a better outcome. Sort of like the carpentry adage: frame for finish.

[HennieL]

OK - that makes sense, will probably not notice any big difference, but it certainly won't do any harm to polish lengthwise.

Those who weld professionally the most exotic and specific materials, have extreme regimens for tungsten prep and care.

Care to elaborate - I'm always interested in such things

[Poland308]

I can say there should be a limit to your concerns. If the contamination doesn’t interfere with getting the tungsten in the torch.( I grind points on both ends and flip mine over). Then grinding a normal point is fine. Unless your doing high end pharmaceutical grade or high grade food contact welds. Or if it’s contamination from a different base metal, IE changing from SS to carbon. Then I grind it all off.

[bap_]

If you have a smaller piece you don't mind experimenting with, try "slipping" off the side of the grinding stone/wheel and scuffing the side of the tungsten. Just the smallest amount of wear will be noticeable.

At low amps you'll notice the arc will sort of flare off that scuff. Probably due to reduced cross sectional area, similar to how the tip has a smaller cross sectional area compared to the rest of the tungsten body.

[HennieL]

I can say there should be a limit to your concerns.

Agreed - I'm more "concerned" from an academic/interest point of view (i.e. learning the theory), rather than being concerned regarding the actual weld... my welding quality is still way below the point where things like minute contaminants in the metal would cause me to lose sleep

If you have a smaller piece you don't mind experimenting with, try "slipping" off the side of the grinding stone/wheel and scuffing the side of the tungsten. Just the smallest amount of wear will be noticeable.

I can understand the theory regarding the scratch direction, as electrical current flows on the outer surface of any conductor. Any sharp point or nick in/on the side of the conductor (tungsten) (or semi-circular scratches caused by grinding on the side of the wheel) would thus create a "point load", thus easing the start of a secondary arc (much like lightning jumping to/from any high point such as a church bell tower or high tree...). I do have the luxury of being able to use a belt grinder, and can thus easily grind longitudinally either on the contact wheel, or on a flat platten, and thus do not need to grind on the side of a disk grinding wheel. My earlier question regarding the degree of "polishing" that is normally done on the tungsten shaft (i.e. grinding to a 400/600/800 ... 2500 grit finish was to establish to what extent the scratch depth (i.e. grit size) would affect the performance of the tungsten and weld.

I love to experiment, bap_, and once I'm a little more proficient with the actual welding process I will certainly do as you've suggested

[pgk]

Check out Aarons tungsten sharpening method for SS. https://www.youtube.com/watch?time_cont ... rSX9FWlpi0
I tried it and couldn't see much of a difference with my Tig abilities, I'm sure Aaron can..

[LtBadd]

Check out Aarons tungsten sharpening method for SS. https://www.youtube.com/watch?time_cont ... rSX9FWlpi0
I tried it and couldn't see much of a difference with my Tig abilities, I'm sure Aaron can..

Well, I know I don't have 2 of those belt sanders, and where are the cries of the contaminated belt and what looked like a scotchbrite belt loaded with aluminum

One thing for sure, there are plenty of ways to sharpen tungsten, for $ and $$$$

[HennieL]

One thing for sure, there are plenty of ways to sharpen tungsten, for $ and $$$$

Yes, I believe you are correct.

I already have a belt grinder that I use to make knives, and I also have a small bench grinder that I only use with a wire-wheel brush to remove dirt from steel (the belt grinder is much more efficient at removing metal, and much faster and controllable than the bench grinder). For me, there is thus only the difference in cost between the grinding belts (cheap) vs. buying separate grinding wheels for aluminum, stainless steel, mild steel, and (one day soon...) titanium, and having to constantly change the wheels as required (changing the belts only take about 5 seconds).

I will gladly change to the bench grinder if there is a good reason for doing so, but so far nobody has convinced me of such reasons

[pgk]

Check out Aarons tungsten sharpening method for SS. https://www.youtube.com/watch?time_cont ... rSX9FWlpi0
I tried it and couldn't see much of a difference with my Tig abilities, I'm sure Aaron can..

Well, I know I don't have 2 of those belt sanders, and where are the cries of the contaminated belt and what looked like a scotchbrite belt loaded with aluminum

One thing for sure, there are plenty of ways to sharpen tungsten, for $ and $$$$

LOL I know! That's what I was thinking when I saw him using a belt sander that has probably seen a lot of aluminum use, but it doesn't appear to hamper his welding abilities??

[pgk]

Check out Aarons tungsten sharpening method for SS. https://www.youtube.com/watch?time_cont ... rSX9FWlpi0
I tried it and couldn't see much of a difference with my Tig abilities, I'm sure Aaron can..

Well, I know I don't have 2 of those belt sanders, and where are the cries of the contaminated belt and what looked like a scotchbrite belt loaded with aluminum

One thing for sure, there are plenty of ways to sharpen tungsten, for $ and $$$$

LOL I know! That's what I was thinking when I saw him using a belt sander that has probably seen a lot of aluminum use, but it doesn't appear to hamper his welding abilities??

[cj737]

Check out Aarons tungsten sharpening method for SS. https://www.youtube.com/watch?time_cont ... rSX9FWlpi0
I tried it and couldn't see much of a difference with my Tig abilities, I'm sure Aaron can..

Well, I know I don't have 2 of those belt sanders, and where are the cries of the contaminated belt and what looked like a scotchbrite belt loaded with aluminum

One thing for sure, there are plenty of ways to sharpen tungsten, for $ and $$$$

LOL I know! That's what I was thinking when I saw him using a belt sander that has probably seen a lot of aluminum use, but it doesn't appear to hamper his welding abilities??

He mostly welds aluminum, so I doubt he’s concerned about cross contamination.

[LtBadd]

LOL I know! That's what I was thinking when I saw him using a belt sander that has probably seen a lot of aluminum use, but it doesn't appear to hamper his welding abilities??

I can't prove this, but as hard as tungsten is, I wonder if it's even possible to contaminate with aluminum particles under normal sharpening procedure.

Maybe if the tungsten was red hot as it was pressed against a belt or wheel loaded with...and other metal?