shiftingmetal20h janetb
Aren’t you supposed to forge all castings before rolling?
scavengerqr18h
I’ve been told that but never had confirmation from experience. Aren’t you doing the same thing either way. You’re compressing the molecules and realigning crystal structure.
Rolling compresses just the surfaces. With forging, you can get the compression to go deeper into the ingot. Ideally, it should be be compressed all the way through.
I usually don’t forge yellow gold or palladium white gold before rolling, but I do forge nickel white gold. A master goldsmith I knew would have his workers forge platinum for ages before rolling…
I remember Leonid Surpin discussing this issue. Here are excerpts from two of his posts on the subject. There is more about this on Orchid .
What's the purpose of "forging" with the hammer before rolling?
Right after casting, metal grains much larger than they should be. Forging breaks it down into fragments, which upon annealing re-crystallize into smaller, compact grains. This is one of the principal differences between handmade and cast jewellery. Metal prepared that way is much stronger and retain polish longer, if fabrication proceeds with direction of the grain in mind.
In my DVD “Eternity Ring” this principal observed very stringently. It allows creating of the structure, which look very flimsy, but actually much stronger that it’s casting counterparts.
Forging step can be avoided if one has industrial mills. First pass should be 1/3 of ingot thickness, followed by multiple small passes rotating ingot 45 degrees each pass, until only half of the original thickness remains. After first annealing, rolling should resume in normal fashion. Not as good as hand forging, but acceptable. This is only possible with very large mechanical mill.
To give general answer is enough to say that it depends on type and design of jewellery. If it is a thick square with the hole drilled in a corner to wear it as a pendent, than absolutely anything will be satisfactory. But if it is a ring to be worn every day and the ring incorporates delicate structures; a goldsmith simply must give it the best chance of survival from daily abuse, by taking every opportunity to strengthen it. Pre-forging is a very important tool in goldsmith repertoire. Non pre-forged alloys are defective from the point of view that they are not as good as they can be. Wether or not it will show as a defect in finished product would depends on the product and its application.
I decided that I could get good use from this adjustable ingot, but when I attempted (4 tries) to purchase your ingot through the link you supplied, for some reason the site and my PayPal do not seem to like to communicate.
The Purchasebutton takes me to my PP, but then there is not info on the purchase that I requested. When I go back, it starts all over.