Gas forge or oxy/acet?

[Danjmath]

Going to make some coin mokume today. I have done it successfully in my gas forge before, but I was wondering if it would be worth the cost of using my O/A torch and making it in a vice instead?

I have talked to people who do it both ways, but does anyone have advice on which is better (and if using the torch is enough better to offset the cost).

 

[teenylittlemetalguy]

in my opinion heat is heat, so I would go for cheaper. I also like to make larger billets and a torch would be less favorable. 

Even though not as cool you generally can get better product using a kiln with temp controls. 

[ThomasPowers]

Lets see you want: control, evenness of heat and controlled atmosphere.  Seems like a well built and tuned propane forge would be better in all three of those.

[Danjmath]

Thanks. Most of videos I watched on making mokume used torches, probably because they were mostly jewelers and don't own forges. 

[ThomasPowers]

A very good point. Folks tend to use what they are familiar with and already have to hand.

[teenylittlemetalguy]

Danjmath, no matter the heat source with coins there are things you can do to improve your chances and the quality of the results. 

The mantra of CLEAN material is very important. Even though it is possible to use uncleaned pocket change it is an advantage to clean it. It gives you a similar starting point every time so you can focus on what else you need to adjust to do it better next time. 

Scale that will interfere in a weld on most non ferrous materials is a REALLY thin layer, often it is hard to see. Don't be fooled, sand immediately before cleaning and welding for most consistent results. Scale needs air to form so the forge needs to be running just a little rich to slow it from forming. This also means leave it in the forge till ready to weld, no taking it out just for a look. 

Coins are lumpy, which makes little gaps for hot gases from a forge or torch to get in and make scale, undoing all your hard work of sanding and cleaning. often the only welds actually being made are the high spots where the coins touch, it is difficult if not impossible to simply hammer past that remaining thin line of scale and make a solid billet.  This has got to be the number one issue smiths face with coins and most won't have the insight to see the root issue because it is not as critical when welding steel.  Aquick couple blows from a flat faced hammer on a cold coin can really be an advantage when welding later. 

Good luck to you!