First Propane Burner test

[Melchior]

Hello, I built an propane burner today, and fired it up. I used a 3/4 pipe, drilled a couple of 10 mm air holes, a 0.8 mm MIG tip and forged a flair with a unscientific angle (thought it looked good).
This is the first test where I change the pressure and limit the amount of air with my hand.

What do you think?

It seems to me like it is not burning with the best fuel/air ratio. Seems to need more air, but I do not know.

/E

[macbruce]

Looking good. I'd like to see some stills of the whole burner....... :)

[Melchior]

The burner seems to perform well with high pressure gas flow. The flame does not loose grip on the nozzle (?).

Here are some stills:

[macbruce]

B) Looks like a winner! Eliminating the T pipe fitting at the top has It's advantages........

[timgunn1962]

Looks pretty good to me. I think there's a fair chance it'll be OK for forging temperatures as it is, and may manage to hold stable at HT temperatures once it's in a forge and has an air restrictor sleeve on it.

What are you intending to use it for?

If you are going to be trying for welding temperatures, You might be better off with a 0.6mm MIG tip to lean off the air:fuel ratio, as you suggest.

If you can get an even smaller jet, preferably 2 or 3 of them, and a cheap set of drills in .05mm increments, you can tune it to near-perfection. I think we ended up with a 0.65mm drilled jet on Greenbeast's burner over on British Blades. That was a 3/4" pipe burner, albeit with a different mixer arrangement to yours. For the jets, we just used M6 brass screws, through-drilled to 0.55mm (because it was too small and I had lots of drills that size) in a lathe. Then it was a case of open out the hole by hand with a drill held in a pin-chuck until things got worse. Then just open out another one to the best size tried.

I think the hole in the original 0.6mm Mig tip was about 0.73mm, and was too big.

If I was to do it again, I might try hammering a .6mm MIG tip down onto .6mm MIG wire first.

[timgunn1962]

Just realized I posted on IFI, not a knife forum. I think you'll need to go a fair bit leaner/hotter for welding mild steel or wrought iron.

[Melchior]

Thanks for the comments.

I do not think I follow properly, 2 or 3 of smaller jets? Pic?

Hm, I do think you are right when it comes to the mix. I need to put in a smaller MIG tip. I will try to change it next time and try it out. I may be a good thing to buy some jewelers drills for the hole.

I am going to use the burner for a small forge for knife making. I already have a big one that is used for big welding (using a blower). So the purpose is a smaller forge that does consume to much gas. I do not know yet if I want to use it for welding. I do not know if I want the tear and ware from the borax. But I may change my mind. I will post some pics on the finished forge.

/E

[timgunn1962]

The 2 or 3 is for the tuning: fit one, try it, drill it out, try it again, see if it's better or worse Keep going 'til you've gone too far, then go back to the best size. It's easy drilling them out, but harder to put it back in, so you'll need a second undersized jet to open up to the right size. It's always good to have a spare in case you break a drill in one.

For the tuning, you want the air fully open and the gas pressure at maximum. The temperature to aim for will be just a tad hotter than you feel you'll ever want to go. You can adjust the temperature down on temperature (edit; that should read air restriction) and pressure, so that way you get the maximum usable range.

I've no pictures of Greenbeast's burner, I'm afraid. I sorted the bits and left him to do the hard work. The first iteration was with an M6-threaded MIG tip, so the easiest way to get smaller jets with what I had available was to use M6 brass setscrews and drill them in the lathe.

If you don't have a lathe, you can do it in a drill press as long as you don't adjust the table: Locate a piece of scrap material and clamp it to the table. Drill it 5mm and tap it to M6 using the tap in the chuck. Screw your jet-to-be into the tapped hole and drill it. If you are testing somewhere nearby, you can drill to size. Greenbeast was 200 miles away, so I drilled undersize for him to open out by hand. I'm assuming you are somewhere metric from the reference to a 0.6mm mig tip. You'll need to use appropriate drill and tap sizes if you're not on M6 MIG tips.

[Melchior]

I am in Metric (Sweden), not as cool as Lancashire! :)

I am using M6 MIG tips and I can easily weld it shut an drill it again. So I will check what I can muster in form of small drills.

And thank you for the info on how to adjust and test the burner.

/E