Converting NG Forge to portable propane forge.

[Jim Erickson]

I built a natural gas forge that runs off of the residential supply line that was ran to my garage.  I used an old hair dryer for the blower, and I was able to forge weld and it performed everything I wanted it to do.

But I am moving out of my house, and I wanted to bring my forge to work, and maybe use it there after hours.

My question is can I use a 20lb propane tank as my fuel source, and still use the blower?  I dont want to build another burner, just the same set up as before.  Would I need a regulator that goes down to the 4-8psi range that was the same as my natural gas?  Would an old grill regulator work for this purpose?

Thanks guys.

[Michael Cochran]

I'd imagine you'll need to change the jet before anything else can be done.

[swedefiddle]

Good Morning,

Everything will be the same except go to a smaller jet. If the Propane bottle freezes up, put it in a pail of water to act as a heat-sink OR connect two bottles in PARRALEL. The draw off each bottle will be half of one bottle, so you won't get the same temperature differential.

Neil

[Charles R. Stevens]

You do indead need to use a BQ regulator and a smaller jet, as a unregulated propain bottle wile provide way to much presure and the BQ regulator provides the same presure as your houce natural gas. Of the to my head I dont know the ratio between the required jets (if you are using one) but it is near 50% the area to get the same BTU's. You will most likely have to adjust the air and all to get it burning nutral again.  

Edited July 11, 2015 by Charles R. Stevens

[Frosty]

There's another concern, propane is a much more chemically reactive. Your regulators, valves, hoses, etc. must be propane rated or they'll degrade eventually. By eventually that's MUCH faster than they would under normal use.

A gun/blown burner can use most any flammable gas if you adjust the fuel air ratio. Depending on the burner type it may be as simple as changing the jets or a more thorough conversion. In some case home builds usually, simply changing the gas pressure will do it.

I'm not making predictions for your burner but in general conversion isn't difficult. Just change out anything that contains rubber for safety's sake.

Locally a 0-30psi propane regulator runs $25.00 +tax a gauge runs in the $10 - $15 range, depending on where you look. The real wallet bite is the hose.

Frosty The Lucky.

[Jim Erickson]

I dont have a jet in the burner, just a 3/4 Tee with the gas coming in one side and the air from the blower in the other.  I would just fiddle with the blower speed and the ball valve on the gas side.  I could adjust how hot it was that way.

My thoughts are just barely turning the gas on until i get a flame similar to the natural gas.

 

[Charles R. Stevens]

Something like that, lol. Carful you dont melt her down to slag.

[Frosty]

That'll work fine Jim. You'll find you have better control if you put a regulator on but it's not necessary. Propane and air don't mix as well as NG and air. You'll get a more even flame if it has longer to mix. Putting the T with the gas injector between the air supply hose and the iron so the air fuel has to go around the 90 will really help mixing.

The best propane gun burner I know of injects the propane into the blower's impeller and provides a very nice complete burn.

I can't recommend you inject the propane in the hose or blower because I don't think it's propane rated. In fact I highly discommend injecting propane in front of the steel pipe. It's better safe than sorry when messing with potentially explosive stuff.

On that thought it occurred to me we don't know where your forge is. I can see the roll up doors in the picture but you said you're moving yes? You MUST have good ventilation a gas forge consume a LOT of oxy and produces lots of carbon monoxide CO. Excellent ventilation is okay but not too much. I don't do much forging in winter as I don't like opening the shop to the cold and like breathing CO even less.

Frosty The Lucky.