Duty Cycle of Propane Torch?

While I appreciate the link to an "option" for my weed-torturing sessions, I'm still curious as to why my current torch exhibits the symptoms it does.

Who knows...I might someday have a situation where I need extended run time from my small torch and I'd like to know why it's not up to the task.

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My guess is that if you have a standard non-pressure regulated torch you are inverting the torch to aim it at the weeds and liquid propane is passing through the valve and into the neck of the torch where only gas is intended to go.

Then, when you shut the valve off that liquid propane takes quite a bit of time to turn to gas, creating the "afterburn" you're experiencing.

The same liquid propane where it isn't supposed to be can cause the flaring out effect you describe.

Jeff

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Because your torch probably prefers that the fuel cyclinder be in the "upright" position during extended use. A problem overcome in the unit I pointed out.

My theory also. Try burning it for as long rightside up. Does it work OK?

Could be...

I didn't quite "invert it" but for the most part it was horizontal, so the liquid could certainly have passed into the neck.

Neither of the canisters were full, so that might explain why it took so long to "flame out". I'll bet a full canister would have caused the problem sooner.

I'll play around a bit with the torch upright and see what happens.

Thanks!

Maybe I could use the burner from the Turkey Fryer I picked up for $4 at an Estate Sale a few years ago. Now that would eat some weeds...and use some gas!

Really...I paid $4 for a complete 32 qt Turkey Fryer set.

I find it perfect for the cracks between flagstone. A gas cyclinder lasts for a surprisingly long time, and gas cylinders are cheap. You can also refill them from your gas grill tank for VERY cheap.

For larger areas, I use this:

In the first couple minutes, the orifice and torch body will still be warm. So, you'll get complete vaporization. After a while, the liquid propane turning to vapor will chill the torch head. Which leads to the changes in flame.

A similar operating time upright, would likely not give such problems. Maybe the OP can do an upright torch test, and see if that behaves differently. I'm curious if it does.

Sounds like a partially clogged orifice causing the sloppy flame. When you shut the valve, there is still backpressure in the line, and the flame continues until the backpressure is released.

??? I'm not having any problem.

I just ran the torch upright for over 12 minutes with no change in the flame.

I guess we'll go with the "liquid in the neck" theory.

Thanks guys!

it had to do with being upside down for so long.

Sounds reasonable, to me.

Wrong tool for the job. You need one of these instead:

This one, for a few dollars more, has a built in igniter which is a lot more of an advantage than you might suspect:

And, wait a couple days and it will go on sale. I'd go another five bucks for the self starter torch. I've got a couple self lighting torches that take smaller tanks. Very convenient.