tig torches

By cccasey (**)

Date 03-05-2003 04:55

If you're using a Weldcraft WP17 or something interchangable then the thread is 3/8-32.
Curt

By paulatsnowdrift Date 03-05-2003 05:05

Thanks Kurt; Do you have any ideas why this happens. Or any tips on keeping it from happening.

By cccasey (**)

Date 03-06-2003 21:24

The threads are so fine that you have more of a chance of cross threading if you frequently remove the back cap. I was having my students break down the entire torch after each class to teach them the torch components but within two weeks they ruined 5 torches from cross threading. I had to special order a 3/8-32 tap to salvage some of the torches so needless to say they don't remove the back cap unless it's absolutely necessary.
Can't imagine what your aluminum bits may come from.
Curt

By paulatsnowdrift Date 03-08-2003 19:29

Thanks again CURT I appreciate your time on this, It makes perfect sence that I am simply cross threading, it is odd that i don't notice it harder to thread on but it is obvious when i un-thread it.Some one in the Metal Boat Society forum suggested that a small bit of silicone grease could help.What do you think? Paul.

By brande

Date 03-09-2003 04:34

Don't know for sure, but I have experienced the same type thing on tig torches using gas lenses. Lots of aluminum buildup on gas lens screen.

I have found, that when starting, if enough current is not used on starting, the arc tends to be very erratic. This erratic arc can volitize some aluminum, with it's low melting point.
Keep in mind, too, that an erratic arc can be traced down to worn consumables (collet and/ or collet body).

As an experiment, you might try a new collet / collet body. In addition to this, make sure you are using enough current to "light off" the tungsten. Nail it (current wise) when starting and back off to the current level required. If you can't make a puddle in aluminum in 4 seconds or less, you are too cold.

Be sure, too that you are not using too large a tungsten. A too large tungsten will amplify this problem. Low current/tungsten diameter ratios can always cause hard starting and the problems you mention. Also, a cold tungsten does not start as well as a hot one does. A quick heat-up on a clean piece of copper or stainless might help.

There are a number of size/amperage charts available on the net from various mfg. If you come up empty handed, email directly and I can forward a chart.

Anyway-keep us posted. Hope this helps a little.

brande

By ScottV

Date 03-09-2003 16:37

I have pretty much have to agree with Brande on everything he said.Because I have did my own test with my ac/dc inverter,and it all was true.One other point on starting,some torches are harder starting then others even if they are exactly the same type,and brand.even changing out all the parts between the two.