Propane usage? What size tank/s do you use? Fuel level meters?

[12345678910]

Thank you guys for all of the helpful info. Don brought up the idea of efficiency of a propane forge. What are some ways to make a forge more efficient with propane usage. Also would wrapping the propane tank in insulation help with the freezing issue?

Does a forge need a hole(vent) in both front and back, or just front?

You don't want to insulate the tank, exactly the opposite

You need the tank to absorb heat from the surrounding air.

As the propane changes from a liquid to a gas, it absorbs heat
The whole idea of refrigeration is based on that.


In theory you need to add heat to the tank, but that's unsafe

You can't keep the cylinder inside a heated area, it belongs outside
You can't add heat to the cylinder, over heating can cause high pressure to overcome the pressure relief valve and it exhausts all that flammable gas, or the cylinder explodes
hence the need for that cylinder or tank to be outside.


They call that failure a BLEVE
Boiling liquid expanding vapour explosion -
http://en.wikipedia.org/wiki/Boiling_liquid_expanding_vapor_explosion


The solution is a bigger tank as everyone here has mentioned
As the tank gets larger, the temperature difference as it gets used is less due to the mass and large heat capacity

You will see some folks try to put a little bbq tank is a tub of water, which increases the heat capacity but that's a real pita
You will see some folks try to put heating pads and such under tanks, but I think that's too risky
If you can't do one large tank, you can use manifold and connect several together.

 

[NickWheeler]

I know I wrote a reply to this thread... guess the forum software never actually uploaded it.

I was basically just going to echo most of the replies, it's so relative. I can forge a blade in a third of the time it took me when I got started. So that clearly is a big change on fuel consumption.

I was also glad to see Don's post about efficiency. I have two 100# tanks, and they last a really long time. Even if I'm doing a damascus marathon, a tank lasts me several days. When just doing blades (and heating the shop on cold days, LOL) a 100# tank lasts a really long time for me.

I'd like to have a big tank like Karl's, but getting the permit approval around here is a real PITA. Maybe someday...

 

[ron_m80]

Nick, If the forum eats a reply, look for the new feature "restore auto-saved content" in the lower left of the text entry box on the forum. You might have noticed the auto-save function flicker on the screen while you type. If your was long enough to be saved, and you leave the page, or get refreshed away from your post, come back and look for the icon.

Tanks get charged to NO MORE THAN 80% of their Water capacity per DOT regulations. It isn't the required fill amount for the transaction.

 

[Salem Straub]

On an additional note, after Don's remarks about efficiency I focused on my technique a bit.
I found that I hadn't been giving my forge enough credit for maintaining a nice welding heat after initial ramping. So, I had not been turning the mix down enough and was buring more gas than necessary.

I'd get screaming incandescent yellow heats, and be taking the billet out while it was getting hotter. After re-thinking my mix/heat process and turning the burner down after achieving welding heat, I do use less gas. Not as efficient yet perhaps as Nick's or Don's, IDK, but a lot better.

This in a forge that has trouble running BELOW a high orange... kind of a "duh" moment. That, and when adjusted to run a little rich, it seems to actually get good welding heats at a lower total mix? Still playing with that. Anyway, now I can "soak" at welding heat more handily, which can be a very good thing.