Hand hammer demascus help

Another way to tell if your forge is getting hot enough if you don't want to spend the $ on a thermocouple is to take a piece of mild steel (say 1/4" square) and forge it into a point and bend an inch or so to a 90 degree angle. When you think the billet is hot enough, touch it with the tip of the poker and if it's at a welding heat you can feel the poker point start to stick to the billet.
 
Some thoughts here about forge welding.

In the absence of oxygen, oxides on the surface of the metal are not stable at higher temperatures. Flux does not clean the surface as much as the high temperature. In the presence oxygen and at high temperatures, steel will oxidize very rapidly.

Higher temperatures are not needed to forge weld. Steels will weld to each other as long as they touch at a microscopic level. Higher tempetatures allow steels to be more plastic and thus require less force to make them touch.

To make the layers cohesively bond, a certain amount of overall reduction of the billet is needed. A 50% reduction of a billet with no inclusions will reach a nearly 100% weld between layers.

Any billet can have as little as 1% weld to as much as 99% weld and every amount inbetween. Cleanliness and reduction by forging or rolling make solid welds.

For some reason, lower temperatures require longer soak times to get good welds.

The finer the finish between layers the less reduction is required to get solid welds.

That’s it for now, there’s probably more that I can’t think of right now.

Hoss
 
joedhiggins said:
Soak time depends on thickness and forge heat output. If the billet I was welding was the better part of an inch thick, I would give it a minute or two after it looks good before I try setting my welds. This is a first heat only thing. I don't worry much about it on subsequent heats as the core cools less quickly than the exterior. Temperature is hard to describe, but bright yellow is the general answer. As mentioned, you are reasonably looking for a temp north of 2100F. There is not 100% visual cue until you are used to your forge. Sparking on the exterior (really the steel is burning rapidly in air) is a decent visual cue, and you can weld at these temps, but it is hotter than you need, and depending on your forge may be nigh on impossible. If you are running coal, sparking is a good judge, in a propane forge, you probably wont get there. Moreover, flux, to some degree, will prevent the sparking by shielding the steel from O2. If you are running a reducing atmosphere, that will also limit the sparking inside the chamber.
Click to expand...

I like what Joe had to say about the color of steel for a welding heat, and will add only that I look for what has been called "the color of sizzling butter." That is, the steel won't be oxidizing and throwing large sparks, but will be wet and sizzling like hot butter in a frying pan. Practice and experience will help distinguish this color from that of the molten borax on the steel's surface.

Also, a thermocouple may not be *entirely* essential to tell a welding temperature, as you can check by touching a bare steel 1/8" rod to the billet (please don't use a gas welding rod, its copper coating will spoil the weld); the heated rod will stick to the surface of the billet when it reaches welding temp.
 
Found out the problem!! New jersey steel baron sent me the wrong steel. There was a mix up with there 15n20. Got a new batch and had no problems. Man what a nightmare that was.
 
maybe that is my problem as well. I have had pieces that seem stuck in every test/way and then after a bit of forging, I see layers opening...
 
knoxknives said:
not trying to go off topic, but wondered if anyone has a good resource to read up/watch to learn for a first try at hand forging some Damascus. I've never tried it, and only heat-treated with it and forged some 1084 knives so far. I've got an Atlas with the 30k burner, and only a 4x4" anvil and normal set of hammers. I don't think I am supposed to use borax in the Atlas, think it eats the firebricks.
Click to expand...

I would put down a layer of kitty litter maybe. Let the flux drip on that. Or a sacrificial layer of refractory cement.
 
You must log in or register to reply here.
Back
Top