I've been looking for a way to contribute something since everyone has been so helpful. I'm NOT expert at this, but perhaps I can help by passing along advice I was given and which *seems* to help me when forge welding.
Here's the advice I was given:
• Cheat to get things together. Tack welding has been mentioned, but I've wired things together (about the time the wire
burns off you're good to go). When making a carving or bbq fork I bend a loop in the end of the stock, forge weld it to itself,
and then cut through the end of the loop and form the two tines. The idea being to have only one piece to manage whenever possible.
•Heat it slowly. You want it hot all the way through, not just on the surface and it's easier to avoid burning it.
• Learn to judge the heat it is hard to look at once it gets really hot, some people say it "disappears" against the fire, I watch for it get shiny or greasy looking but it can weld colder than that. I've been told a piece of wire can be used as a probe to see if the metal is "sticky" I've not tried this.
• Try welding colder than you think is necessary. Burning metal doesn't weld well, a good solid connection can weld as low as room temperature in certain odd corner cases. (I'm a little skeptical but I've seen a guy jump weld pieces on a branding iron when the iron appeared to be just orange... ymmv)
• Avoid the "tire tread" scoring. Instead make the scarf smooth and slightly convex. The hammer blow will force oxidation, flux, dirt, etc. out the sides of the weld and avoid inclusions.
• If you can, weld right in the fire. Align or connect the pieces, bring them to heat, use a long "spoon" to flux, then clamp them together with tongs, preferably tongs with the jaws bent to a 90 degree angle.
Now, maybe someone can comment on how in the world you get the edges of the weld cleaned up. I've had much more trouble with that than the actual weld, but maybe that's another thread...
I sure hope this helps and isn't obvious redundancy.