Welding Tips and Tricks

New member here. I recently acquired a Hobart Tigwave 250 and the high frequency is being weird. I will push down on the pedal and can here the high frequency trying to light off but the arc will not start unless I scratch it against the steel I’m welding. I have it on the high frequency continuous setting so what am I missing here?

Well, I can tell you what the issue is, how to fix it, might be a bit more tricky, you need to adjust your spark gap, as I cannot find a manual anywhere online, the most info I can find is it was made by thermal arc and this thread.
https://weldtalk.hobartwelders.com/foru ... rt-problem

looking at pictures of the machine, there seems to be a square access port of sorts on the front of the machine that may provide access to the HF spark gaps as it's generally considered routine (every 3-6 months) to check to adjust them, the gap should be 0.008 in, yes you'll need what's called a feeler gauge set, which is basically a set of very thin shims, you can find a set here https://www.amazon.com/Hotop-Blades-Fee ... 374&sr=8-3

The further the gap, the stronger the HF, I believe some people report greater than about 0.010 can nearby interference with radios etc. Given that it's an old machine though unfortunately I doubt its an issue of your spark gap being too small and most likely burnt/corroded points. As mentioned in the thread I linked, as thermal arc does not stock replacements, your best hope is to gently clean the points with some emory cloth or similar

I had two Hobart TIGWave 250s a while back and might be able to help a bit. For one, they don't have a very robust HF compared to many other machines. Also, you should be on HF start, not continuous, for welding steel.

You definitely want to pull the points, clean them, and then set the gap. I use .010" for a gap on that style of machine without any issues and it helps them start a bit easier. As far as cleaning them goes, the general advice is to not use anything abrasive like sand paper or emery cloth....you want something that will clean only, not scratch the metal. The points are tipped with tungsten, so they're actually quite hard. I have an extremely fine wire wheel I use to clean points....gets them clean and can't leave a mark. You could probably just use steel wool or something like a non-woven abrasive like scotchbrite to clean them up as well.

One they're cleaned and the gap set, see what happens, but it still might not have a really robust start. I've even noticed a bit of difference associated with different torch setups...gas lens versus conventional, etc.

One thing to try that always seems to work with the older machines is to tap the tungsten on the work before you step on the pedal. For some reason (people argue why) that seems to be the cure for a weak HF start. I don't know if it's dissipating static, equalizing voltage, or what, but it works.

One side note...if you're running a water-cooled setup and not using either distilled water, or HF friendly coolant, it can cause problems. Normal auto antifreeze can interfere with the HF function in some cases.