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Grinding tungsten tip from a newbie

Posted: Sun Aug 13, 2017 6:32 am
by Futterama
Hi,

I have had my TIG welder for a good month now and I wanted something simple and inexpensive to grind my tungsten electrodes. So I came up with this.
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Its a piece of polycarbonate plate with a center hole for a carriage bolt, a turned aluminium piece with threads for the bolt and normal 180 grit sandpaper for a sanding disc for handheld drilling machines.

The idea came from the local hardware store where I got the sandpaper and the black sanding disc attachment. I mounted this is my drill press but I could not see what I was grinding because the sanding face was down. So I made this for facing the sanding side up.
I know the sandpaper does not hold up fantastically, but it's cheap and I don't have access to diamond wheels here.
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I use my cordless drill to chuck up the tungsten while sanding it, just as they do in all those videos I have seen.

I had some trouble with my arc, so I took a closer look at the sanded tip of the tungsten using an USB microscope, and it appears that I was running the cordless drill way too fast (actually I just gave it full speed in high gear = 1600rpm). The 125mm/5" sanding disc was running about 1200rpm. And this caused twisted sanding marks. I was not able to see this with the naked eye, those tungstens are 1.6mm 1/16".
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In those videos showing the chucked tungsten in the cordless drill, they never tell you how fast they are going, and it's not possible to see it either.

So I tried to the lowest speed in high gear on the cordless drill and upped the sanding disc speed to 1500rpm, and look at that, much better!
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So basically my tip today is run the cordless drill slow on your finishing tungsten grinding pass.

As I'm a newbie, I still wonder about a few things.

Those sanding discs are dedicated to only grind tungsten. And I have labeled them on the back for which color band tungsten they go with. But can the normal type sandpaper contaminate the tungsten? Do I need to wipe down the tungsten after grinding as the sandpaper generates some dust? They never clean the tungsten in the videos, but does that mean it's not needed?

Re: Grinding tungsten tip from a newbie

Posted: Sun Aug 13, 2017 7:30 am
by Mike
Thanks for sharing.

Re: Grinding tungsten tip from a newbie

Posted: Sun Aug 13, 2017 8:18 am
by clavius
Not at all a bad idea. I like how you tracked down the wandering arc issue using a microscope to examine your tungsten and sorted out the issue. Those little USB microscopes are super handy for lots of things for the short money they cost.

I'm no expert, but I would not think the disks you are using would contaminate the tungsten any more than any other grinding wheel, though wiping it off sure could not harm anything.

As for being able to get diamond wheels, some like these are inexpensive and available in grits down to 120. You could mount them in the same manner as the disks you show here. They are designed for lapidary work but I've used them for everything but that and they work just fine. I presume they could be shipped to where you live:

http://www.ebay.com/itm/4-Grit-120-3000 ... 0005.m1851

Thanks for posting!

Re: Grinding tungsten tip from a newbie

Posted: Sun Aug 13, 2017 8:30 am
by Futterama
clavius, thanks for the link, those discs could probably replace my current sanding paper solution as those are around $1.30 each and rather quickly wear out.

I see those diamond coated discs are also available in 5" so they would fit my current setup with minor changes (they are 16mm arbor hole where I have 8mm now, but that is quickly fixed on the lathe).

Now, what grit would be best, 180 is actually a bit high for the final finish to my liking but that was the only option besides grit 60 in the hardware store.

Re: Grinding tungsten tip from a newbie

Posted: Sun Aug 13, 2017 8:51 am
by Futterama
While looking at ebay for these diamond coated discs, I see more 4" and 6" sizes than 5". Perhaps I could layer a 4" on top of a 6" with a 6" backing plate and then have a course grit on the 6" for crude grinding like a new tungsten or one I got dipped in the puddle, and then a finer grit on the 4" for a finishing pass :)

Re: Grinding tungsten tip from a newbie

Posted: Sun Aug 13, 2017 9:28 am
by AndersK
Good idea.

I bought small diamond wheels at Harald Nyborg.
Also bought a cordless Dremel type grinder and an attachment to grind saw chains. Turned it into a tungsten grinder.
Clas Ohlson and Jula sell the discs too but I'm not sure if they have any stores in Denmark.

Re: Grinding tungsten tip from a newbie

Posted: Fri Sep 01, 2017 2:36 pm
by Futterama
Quick question!

All the tungsten grinding videos tell you to dedicate a grinding wheel for tungstens to avoid contamination.

But will different kind of tungstens be able to contaminate each other? Can I use the same grinding wheel for both lanthanated, ceriated, thoriated ect. without worrying about them contaminating each other?

Re: Grinding tungsten tip from a newbie

Posted: Fri Sep 01, 2017 3:02 pm
by noddybrian
Should be fine between tungsten types - maybe if your really " Sheldon " doing code work on titanium you'd keep one separate - biggest culprit is when you get a big dob of metal jump onto the tungsten or you dip it - that metal will stick to a grinding disc - I keep one normal stone wheel on my grinder to take off the rough stuff & a fine diamond on the other side for finishing - this is on a mini 3" bench grinder - I keep it on a moveable arm on the side of my weld cart - it was designed to hold a large monitor screen in a hospital - I scored it from their skip !

Re: Grinding tungsten tip from a newbie

Posted: Sat Sep 02, 2017 5:03 am
by Futterama
Thanks!

Re: Grinding tungsten tip from a newbie

Posted: Mon Sep 04, 2017 4:15 pm
by Oscar
Futterama wrote:Quick question!

All the generalized tungsten grinding videos tell you to dedicate a grinding wheel for tungstens to avoid contamination.

But will different kind of tungstens be able to contaminate each other? Can I use the same grinding wheel for both lanthanated, ceriated, thoriated ect. without worrying about them contaminating each other?
Fixed it for you. :lol:

I've seen my fair share of videos that recommend that very thing. And then they go right to TIG welding on a crusty old car-frame covered in dirt, rust, and grease, LOL. Truth is, it won't matter if you're doing home projects and you're at least being careful to not grind things like aluminum and copper, or anything greasy/oily on your grinding wheel. Now if you're doing code work where parts get X-ray'd and what not, then you might not want to risk it.

Re: Grinding tungsten tip from a newbie

Posted: Mon Sep 04, 2017 4:55 pm
by Poland308
Done x ray work! I'm with Oscar. It's relative. But not required for every job.

Re: Grinding tungsten tip from a newbie

Posted: Tue Sep 05, 2017 2:42 am
by Futterama
Thanks, I have had some arc start issues which I thought were from tungsten issues, but it turns out not to be related to the grinding process. So I have been overly careful with the grinding even though I'm a hobbyist.

I will use the same "wheel" for all my tungstens, and I will have course grit for the big stuff and a finer grit for finishing. At the moment I'm using plain sanding paper, which is cheap to replace and when replacing it, I'm sure to get a new clean sanding surface, free of material from previous tungsten dipping mistakes :lol:

Re: Grinding tungsten tip from a newbie

Posted: Tue Sep 05, 2017 8:11 am
by Graveyard
I broke down and bought an entry level tungsten grinder. It's a Tech South brand, non adjustable. It was about $230 I believe, after grinding tungsten on a wheel for years and having to walk back and forth from the welding table to the grinder this thing is the cats ass. I hang it right on he table and if I touch or gum up the tip I can just reach down and sharpen it. Had it for almost a year and I wouldn't go back. If your a hobbyist it's probably not really worth it but if you're welding every day or even several times a week I recommend spending the money. I was apprehensive for a long time but now that I have one I don't regret it for a second. I like all the ideas you guys have, budget sharpening at its best!!

Re: Grinding tungsten tip from a newbie

Posted: Tue Sep 05, 2017 2:27 pm
by Gavin Melville
This is a diamond wheel, well actually CBN. The diamonds are on the back for a few mm as well. The wheel is so smooth that you can touch it with no skin lost. The alignment turned out to be perfect, no shims or eccentric washers. I use the 45 deg face against the rest to get the basic shape (yes I know), and then clean up using the front or back flat. Despite the very fine diamond grit the grinder is able to remove enormous amounts of Tungsten.

The wheel came from here, which isn't going to help anyone, but the type will be available.

http://tradetools.co.nz/products/2020250 is the spare part. It's actually for a drill sharpener, and 200 grit.

http://www.gsc-tw.com/products_03.php?id=7 Is the machine that uses that disk.

The Makita grinder had a slightly bent other end shaft, so it's now not there. It's sharpened thousands of Tungstens, still going well.

Re: Grinding tungsten tip from a newbie

Posted: Tue Sep 05, 2017 2:49 pm
by LtBadd
Graveyard wrote:I broke down and bought an entry level tungsten grinder. It's a Tech South brand, non adjustable. It was about $230 I believe, after grinding tungsten on a wheel for years and having to walk back and forth from the welding table to the grinder this thing is the cats ass. I hang it right on he table and if I touch or gum up the tip I can just reach down and sharpen it. Had it for almost a year and I wouldn't go back. If your a hobbyist it's probably not really worth it but if you're welding every day or even several times a week I recommend spending the money. I was apprehensive for a long time but now that I have one I don't regret it for a second. I like all the ideas you guys have, budget sharpening at its best!!
Thanks for the review, have you had to replace the wheel yet?

Re: Grinding tungsten tip from a newbie

Posted: Tue Sep 05, 2017 4:32 pm
by Futterama
Since this thread is still going, I have another question.

I received some CK Worldwide 0.5mm/0.020" 1.5% lanthanated tungstens today. They are all matte and almost black, not silver and shiny as the CK 1.0mm/0.040" 2% lanthanated tungstens I already had. The CK 0.5mm/0.020" thoriated tungstens I got by mistake, are somewhere in between, not silver, not all black but mostly matte grey.

Is this OK for brand new tungstens? I mean, will they act contaminated?

I'm thinking the supplier may have had those is stock for a long time, maybe those small tungstens are just not sold very often, and due to long storage, the tungstens have oxidixed?

The picture shows the 3 mentioned tungstens, to the left/top the black 1.5% lanthanated, middle is the thoriated and the bigger on the right/bottom is the 2% lanthanated.

Re: Grinding tungsten tip from a newbie

Posted: Tue Sep 05, 2017 6:00 pm
by LtBadd
Futterama wrote:Since this thread is still going, I have another question.

I received some CK Worldwide 0.5mm/0.020" 1.5% lanthanated tungstens today. They are all matte and almost black, not silver and shiny as the CK 1.0mm/0.040" 2% lanthanated tungstens I already had. The CK 0.5mm/0.020" thoriated tungstens I got by mistake, are somewhere in between, not silver, not all black but mostly matte grey.

Is this OK for brand new tungstens? I mean, will they act contaminated?

I'm thinking the supplier may have had those is stock for a long time, maybe those small tungstens are just not sold very often, and due to long storage, the tungstens have oxidixed?

The picture shows the 3 mentioned tungstens, to the left/top the black 1.5% lanthanated, middle is the thoriated and the bigger on the right/bottom is the 2% lanthanated.
I've used a lot of .040" but never seen this, or have I heard of tungsten oxidizing (not that this means it doesn't)

Why are you choosing 1.5% Lan over 2% thoriated? If you're going use use lan tungsten all reviews I've seen recommend the 2% lan over the 1.5% lan. I do use 2% lan myself, but in the past always 2% thoriated for DC welding

Re: Grinding tungsten tip from a newbie

Posted: Wed Sep 06, 2017 3:16 am
by Futterama
LtBadd wrote:I've used a lot of .040" but never seen this, or have I heard of tungsten oxidizing (not that this means it doesn't)
My .040" are looking fine and shiny, it's the .020" that is looking very different.
LtBadd wrote:Why are you choosing 1.5% Lan over 2% thoriated? If you're going use use lan tungsten all reviews I've seen recommend the 2% lan over the 1.5% lan. I do use 2% lan myself, but in the past always 2% thoriated for DC welding
I would rather just use 2% lan all around, as Jody recommends. But my supplier did not have 2% lan available in 0.5mm/0.020". If they should get it for me, I would have to buy 100pcs and wait for 3 weeks. At other sources, I would have to pay an absurd amount for shipping. So I went with 1.5% lan as my supplier had that in stock, thinking I would try it out as I'm still so new to this that I can't say 2% lan would be any better for my application.
The 2% thoriated was shipped to me instead of the ordered 1.5% lan as a mistake, they corrected the mistake but the received 1.5% lan are black, which puzzles me.

Re: Grinding tungsten tip from a newbie

Posted: Wed Sep 06, 2017 11:53 am
by Graveyard
LtBadd wrote:
Graveyard wrote:I broke down and bought an entry level tungsten grinder. It's a Tech South brand, non adjustable. It was about $230 I believe, after grinding tungsten on a wheel for years and having to walk back and forth from the welding table to the grinder this thing is the cats ass. I hang it right on he table and if I touch or gum up the tip I can just reach down and sharpen it. Had it for almost a year and I wouldn't go back. If your a hobbyist it's probably not really worth it but if you're welding every day or even several times a week I recommend spending the money. I was apprehensive for a long time but now that I have one I don't regret it for a second. I like all the ideas you guys have, budget sharpening at its best!!
Thanks for the review, have you had to replace the wheel yet?


No sir, still using the same wheel and I'm told that when one side wears out you can flip it. Not sure if there is any truth to that but I'm going to try when the time comesz

Re: Grinding tungsten tip from a newbie

Posted: Wed Sep 06, 2017 6:40 pm
by LtBadd
Graveyard wrote:
LtBadd wrote:Thanks for the review, have you had to replace the wheel yet?


No sir, still using the same wheel and I'm told that when one side wears out you can flip it. Not sure if there is any truth to that but I'm going to try when the time comesz
What diameter tungsten do you typically use? I use mostly 3/32 and 1/16"

Re: Grinding tungsten tip from a newbie

Posted: Wed Sep 06, 2017 7:31 pm
by Poland308
I use 1/8 and 3/32 99% of the time. I've only recently begun to experiment with smaller sizes.

Re: Grinding tungsten tip from a newbie

Posted: Thu Sep 07, 2017 9:21 pm
by Graveyard
LtBadd wrote:
Graveyard wrote:
LtBadd wrote:Thanks for the review, have you had to replace the wheel yet?


No sir, still using the same wheel and I'm told that when one side wears out you can flip it. Not sure if there is any truth to that but I'm going to try when the time comesz
What diameter tungsten do you typically use? I use mostly 3/32 and 1/16"

I use 3/32 (red) 99% of the time.

Re: Grinding tungsten tip from a newbie

Posted: Mon Sep 11, 2017 6:58 am
by Futterama
So I've been in contact with CK and this is their response to the discolored tungstens:
I looked at our stock of T0207GL and there is some discoloration on the electrodes. I did some digging and it is actually an oxide layer. The surface oxide layer can be more aggressive in hot humid weather. I think you guys have been experiencing that this year. If you take a clean emery cloth and run it up and down the electrode, it will clean it up and be back to shiny silver. The small diameter, .020” (.5mm), would be more susceptible to having a more visible oxide layer than a bigger diameter. I am sure that even the first striking of an arc would burn it off. I don’t see this as being anything to worry about but just to cross your t’s and dot your I’s put an emery cloth on it and remover the oxide layer before you weld.

Re: Grinding tungsten tip from a newbie

Posted: Mon Sep 11, 2017 10:17 am
by AndersK
....hot humid weather. I think you guys have been experiencing that this year.
:lol: Coldest summer in a hundred years in Scandinavia this year it was.

Re: Grinding tungsten tip from a newbie

Posted: Mon Sep 11, 2017 2:48 pm
by Futterama
I just received my diamond grinding discs from ebay today:

http://www.ebay.com/itm/6-Grit-60-to-30 ... 2749.l2649

http://www.ebay.com/itm/4-80-3000-Diamo ... 2749.l2649

These work fantastic, much better than sandpaper!

Now, I learned that sandpaper is not the best for metal grinding, so I got some emery cloth to try out too, and I'll compare to the diamond discs.

The diamond discs are 120 grit and 320 grit. After grinding using the 320 grit, the tungstens look like on the photos. The first photo is a 2mm - 5/64" tungsten, and the second photo is a 0.5mm - .020" tungsten.

Do they look like they should or do I need to get a finer grit diamond disc for the final grind?
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