[AK_LAMNA]

I bought a stubby collet and #5 9/20 cup for welding aluminum with my CK TL26 torch. I like the ergonomics of the setup, but the overall length from the front of the cup to the rear of the back cap is shorter than it was with the standard 17/26 cup. Now I cannot fit a full length tungsten without excessive stickout. I have been breaking the tungstens to make them fit, but I would prefer to find a longer back cap to accommodate the full length of a fresh tungsten. Any thoughts?

[cj737]

Don't break your tungstens- it creates splinters down their length. Grind them in half.

I take full lengths, grind in half, sharpen all 4 ends, then go to town. Keeps fresh tips at the ready.

[Spartan]

^^^^ What he said^^^^

Also, your "long" back cap may really only be a 3/4 back cap. Try getting a true full sized one at the link below. I use the stubby consumables on my 17/18/26 sized torches and have never had an issue getting a full-length tungsten to fit when using a back cap that is actually full-sized. I really only use a full length tungsten when welding thick AL, though, and usually cut them in half to grind 4 points as cj mentioned for most materials.

https://furickcup.com/product/full-leng ... k-57y02pk/

[Oscar]

^^^^ What he said^^^^

Also, your "long" back cap may really only be a 3/4 back cap. Try getting a true full sized one at the link below. I use the stubby consumables on my 17/18/26 sized torches and have never had an issue getting a full-length tungsten to fit when using a back cap that is actually full-sized. I really only use a full length tungsten when welding thick AL, though, and usually cut them in half to grind 4 points as cj mentioned for most materials.

https://furickcup.com/product/full-leng ... k-57y02pk/

What is the OAL of a full-length vs a 3/4 cap? I ask because I can attest to what he is saying about not being able to use a "full length" backcap with a brand new tungsten when the front end has been shortened.

[Spartan]

^^^^ What he said^^^^

Also, your "long" back cap may really only be a 3/4 back cap. Try getting a true full sized one at the link below. I use the stubby consumables on my 17/18/26 sized torches and have never had an issue getting a full-length tungsten to fit when using a back cap that is actually full-sized. I really only use a full length tungsten when welding thick AL, though, and usually cut them in half to grind 4 points as cj mentioned for most materials.

https://furickcup.com/product/full-leng ... k-57y02pk/

What is the OAL of a full-length vs a 3/4 cap? I ask because I can attest to what he is saying about not being able to use a "full length" backcap with a brand new tungsten when the front end has been shortened.

I'll have to get those measurements when I'm back at the shop tomorrow, but If I recall, a true full-sized back cap is darn near close to 6.5-7" just on its own. I've found that most back caps that are sold with kits, or come with machines, torches, etc., are actually 3/4 back caps.

[Spartan]

The dreaded 3/4 back cap often masquerading as a full-sized cap can be seen here. About an inch or so shorter than a full, and far too common.

Screenshot_2020-08-31 TIG Back Cap Kit 41V33 41V35 41V24 41V24L Fit DB PTA SR WP 9 20 25 TIG Welding Torch 4pcs - - Amazon [...].png (264.37 KiB) Viewed 1303 times

[Oscar]

Very useful, thanks. I never knew that.

[AK_LAMNA]

Thank you for the tips.

It may well be that I am better off cutting the tungstens in half as you say, and that will be fine. I just had a notion (perhaps misguided) that by keeping my tungstens whole, I would waste less. How short would you say you can grind a tungsten and still use it?

Also, since I am fairly new at this, can you elaborate on the best technique for using the grinder to cut a tungsten in half? I am not sure if I am doing it the best way. So far, I have just used the corner of the grinding wheel and spun the tungsten slowly until I cut through.

I think that the back cap I have now is a 57Y02. It measures about 4 3/4" in length. I made the mistake of buying an "extra long" 41V24L cap. It measures about 5 3/4" in length. It would be long enough to accommodate the full length of a tungsten with my stubby collet and little #5, but the thread size is different. I did not realize that the back cap thread size for 9/20 torches is smaller than the back cap thread size for 17/26 torches. If there were an "extra long" back cap for 17/26 torches it would accomplish my original goal.

[Spartan]

How short would you say you can grind a tungsten and still use it?

Completely depends on the size of the torch and the consumables. So long as the collet can grab onto the tungsten with a solid connection, you can use it. I use tungstens that are only an inch or so long sometimes in my 20-size torches.

Also, since I am fairly new at this, can you elaborate on the best technique for using the grinder to cut a tungsten in half?

Just hold the tungsten with a pair of pliers or in a vise (gently but firmly if using a vise) and slice it with a cutoff wheel on an angle grinder.

[AK_LAMNA]

That’s great. Thank you Spartan.

I will run some tungstens down until the collect can’t hold them anymore.

I was using the bench grinder to cut the tungstens in half. I will try it the way you suggest with the cutoff wheel in the angle grinder.

[cj737]

Better yet, hold the tungsten against the edge of a bench grinder wheel and let the wheel grind it in half. Takes just a few seconds. Plus you’ll be right there to sharpen the tips.

[AK_LAMNA]

Thanks cj737.

I started out cutting tungstens on the edge of the bench grinder wheel. It does seem to erode the edge and round it off fairly quickly. Is that normal, or do I have an especially soft grinding wheel?

[BugHunter]

Here are pictures of two of my torch heads for my weldcraft torch. Both of these are sporting a brand new never ground tungsten. You can see why they put two different caps out there, they are for different torch heads.

[cj737]

Thanks cj737.

I started out cutting tungstens on the edge of the bench grinder wheel. It does seem to erode the edge and round it off fairly quickly. Is that normal, or do I have an especially soft grinding wheel?

Possibly, but that shouldn’t be a real problem as you’ll end up grinding a point on it anyway.

[AK_LAMNA]

Thanks cj737. I will spend some time testing out cutting techniques, both with the bench grinder and the angle grinder.

Thanks BugHunter. I think I see the reasoning for the longer back cap on the little water cooled torches and somewhat shorter back cap on the bigger air cooled torches. They expect you to run a smaller cup on the smaller torch and a bigger cup on the bigger torch. I was just following the trend of running a smaller cup on the bigger torch. It makes sense to me for the improved ergonomics and modified grip.

In the attached photo you can see an uncut tungsten in my torch. Behind it is the longer 41V24L back cap that doesn't work with my torch because of the thread incompatibility. I was hoping to find a back cap at that longer length that fits a 17/26 torch.

AK1-2.jpg (77.57 KiB) Viewed 1211 times

[Oscar]

So then does one really exist? The one Spartan linked was for the wrong torch then?

[AK_LAMNA]

The one he linked to is a 57Y02. That’s the one on my torch in the photo. The thread fits fine but it’s not long enough to accommodate the full length tungsten with that stubby setup. The longer one in the photo is the 41V24L that is made for a 9/20 torch and the thread does not fit a 17/26 torch.

[BillE.Dee]

I have 4 back caps for my 17, 18 and 26 torches. The button cap, the half cap, the 3/4 cap and the long cap. Also dependent on the cap size is which cup or cup assembly you are using.
for my 9 and 20 torches I have a button cap and a long cap (at this time) and do believe that here is a half cap for these. And as above in the 17, 18, 26 torch, the cup assembly will be effective on the back cap size.
That's what Ive found, anyway.

[Oscar]

So who has the actual part # for the 17/18/26 full-length backcap?

[BugHunter]

Thanks BugHunter. I think I see the reasoning for the longer back cap on the little water cooled torches and somewhat shorter back cap on the bigger air cooled torches. They expect you to run a smaller cup on the smaller torch and a bigger cup on the bigger torch. I was just following the trend of running a smaller cup on the bigger torch. It makes sense to me for the improved ergonomics and modified grip.

It has nothing to do with air-cooled vs. Water cooled. The two pictures I showed you are both water cooled heads for the flex head water cooled torch I have. I won't say I don't own an air-cooled torch because I think there is one on the Shelf but I have never used an air-cooled torch in my life. The difference is the amperage capacity of the torch heads and that is what determines the length of the head thus the length of the back cap.