robk

Figured I'd chime in here with a bit of legalese as the bit about

not a firearm by US law, as it doesnt take a premade ammo

seemed incorrect to me. So I looked it up:

The term "firearm" means (A) any weapon (including a starter gun) which will or is designed to or may readily be converted to expel a projectile by the action of an explosive; ( the frame or receiver of any such weapon; © any firearm muffler or firearm silencer; or (D) any destructive device. Such term does not include an antique firearm.

18 U.S.C. sec. 921(a)(3).

Yup...unless it's an antique, it's a firearm. That's why I protect my shop with sharp forged objects :)

My understanding of the issue with welding with propane is the rate of flame propagation. This is the measure of the velocity of the flame front through the gas.

Acetylene burns at 5900* F with oxygen at a rate of 25 feet/sec. Propane burns at 5650* F with oxygen at a rate of 12 feet/sec.

While the temperature of the combustion reaction for both gasses is similar (within a few hundred degrees) propane burns at approximately half the speed. Thus less heat is put into the metal being worked on.

It should be noted that the gas velocity at the tip must not be less than the rate of flame propagation in order to avoid flashback.

Those are usually handling holes used to maneuver the anvil (with long bars or a clamp on a gantry) while hot during the manufacturing process.

Wife came home from work the other day and handed me a copy of "The Complete Bladesmith" by Jim Hrisoulas. She said she saw it and thought I might like it.:D

From Wikipedia:

Propane undergoes combustion reactions in a similar fashion to other alkanes. In the presence of excess oxygen, propane burns to form water and carbon dioxide.

C3H8 + 5O2 → 3CO2 + 4H2O + heat

When not enough oxygen is present for complete combustion, propane burns to form water and carbon monoxide.

2C3H8 + 7O2 → 6CO + 8H2O + heat

Non-life-supporting gasses are a byproduct of ALL combustion save a few special cases (like oxygen generating candles used in the space agency)

I weighed in on it as well. Thanks, Peyton.

That is exactly what I meant. Sorry for the confusion.

On lathes and ships....I've heard tale that when a ship is under way that machining was a no-go. Something about the way you could see the tailstock move when sighting along an open center...perhaps some other old hand could be more specific.