Smaller torch tip

Ignoramus32003 fired this volley in news: snipped-for-privacy@giganews.com:

Yep, Small tip, small kerf. Depth corresponds to width.

I have a small Victor hobby torch I bought decades ago for use on angle- irons, and the like under 3/8" thick. Lots less messy and more conservative of gas than the big torch, but not a lot slower, so long as the material isn't too thick.

Lloyd

Which size tip do you use for welding?

I bought a used Victor tote with a J28 torch and #2 tip, which makes more flame than I want to weld thermocouple wires. I have a #000 tip on order because it's the only size that doesn't exceed the withdrawal rate rule for an MC tank, if that really matters. (?)

My other intended use for it is filling in gaps and pits from MIG welding car sheet metal.

-jsw

Plasma....

For economy some people also use LPG for cutting or brazing.

Propane is too slow to heat up metal, a lot of time wasted.

i

, made of thin metal. I want to

Can you use your hydraulic press instead?

Dan

These are benches, and stuff like that, too big for a press.

I actually could compact them with several steel counterweights on a big forklift (about 4 tons). But in the final analysis, it is easier to do with torch.

i

The first place I saw it used was at a "junk yard" cutting up scrap cars :-)

To me, propane works too slowly to heat stuff up.

I tried a #2 torch tip and it works nicely and uses less gas.

I torched a bunch of stuff today, it was very pleasant, not a lot of phone calls interrupting me, like during the week.

i

I would contest that last statement. The main reason people try propane once and then go back to acetylene is that they make the mistake of setting their flame as if it was acetylene. A Propane flame is completely different. With acetylene you want a sharp blue-green flame. With LP gasses you want a very LOUD pale blue flame. If you set a propane flame correctly it will cut faster and deeper than acetylene.

If you just want to scrap it out, use a larger tip and put the torch at a very low angle to the metal. You will be amazed how fast it will cut that way, but it doesn't work well for accurate cutting.

So, Ernie, this is really intriguiing, since propane is 10 times cheaper.

And I do have both a O/A torch set as well as a propane torch.

Are you saying that I should have more fuel gas in a propane torch for preheat?

What exactly should I do differently? I would love to use propane instead of acetylene. It lasts longer and is a lot cheaper.

Thanks

i

This applies to all LP fuels: Propane, Propylene, Flamal, Chemtane, MAPP, Natural gas etc. Make sure you have a LP tip that matches your gas. LP tips are usually 2 pieces. An inner brass mixer and an outer copper shield. This makes it very easy to clean them. Each LP fuel has a slightly different chemistry so the the inner brass mixer will either be flush with the copper or recessed to varying degrees. This doesn't mean that it won't work with other gasses, it just won't work it's best.

Never set your fuel above 5 psi for cutting, no matter how heavy a cut. Your oxygen with obviously vary by the thickness of your steel.

Start by cracking the fuel and oxygen valves just a tiny bit. Place the tip of the torch against a piece of steel at a 45 degree angle, and ignite it with your sparker. You should have a tiny flame. Now bring up your fuel and oxygen in stages until your fuel is maxed out and the inner cones have pulled back into a LOUD little ring of pale blue flames. An important thing about LP fuels is that the greatest heat is not at the tip of the inner cones, like acetylene, but rather 3/4" to 1-1/2" from the tip. This is why they cut better on heavy plate steel and why Propane and Natural gas are the predominant gasses used for all CNC cutting tables. To start your cut float the tip 3/4" to 1" from the steel.

Another wonderful quality of LP fuel cuts is that the dross on the bottom of the cut is much more brittle so it chips off easier.

One boss would stand over you and make you turn the oxygen pressure to

70psi, no matter how clean, accurate and fast your cut. At 70psi, was both less accurate AND slower - finding slower was a surprise - and slag was needlessly sprayed around the place. Mysteries of it all sometimes... LOL