Fred,
I shall have to make another pilgrimage to the 'tute.

The concentric hammer blow pattern on the bottom shows how the base was tuned and leveled by planishing. That action also would have deepened the bowl.

The bowl was not particularly deep.
the 6.5" dia fold formed bowl I made was 2.1" deep.
At 14.625" Karl's bowl is over twice that diameter and only 2.875" deep so most of the shape was from the folding.

My bowl had a single sided flute in each radial pattern, The Nikrasoff bowl has double sided flutes which eat up lots of material. That was partially offset by the stretching the texture blows added to that portion of the radial flutes.
I think we may have more of a folded flamenco dress (added gores) here than a raised piece. The radial "cross peen" tool marks show that stretching has occurred around the circumference,

Gene Olson
Sculptor
Elk River, MN

Gene,
I think the reason for the stretching marks around the cicumference is because the rim is bent downwards. Whenever you raise and put a downward rim you have to stretch the metal. To me the bowl looked raised and then the flutes were added.

warren
http://www.metalrecipes.com

Warren,

Charles and I have been discussing this.
It seems that his definition of fold forming has to do with folding and then unfolding and perhaps refolding to obtain pattern remnants from the unfolded bends as part or all of the pattern, as such this piece probably escapes his definition as the folds were made in the places they were wanted and then never reworked (other than making them crisper/sharper)

Raising is not the major operation in the formation of this shape however. Raising involves pushing the material into itself by making ruffles or tucks and then pounding them back into the sheet, or by working it over a stake so that raised area being struck is driven down and into itself and the surrounding supporting area. The process of raising involves a change in surface area and an increase in thickness, (and sometimes a relocation of that volume to an adjacent area)

My thesis is that the shape is developed by folding or bending, like making an angle bracket, or a box, or a fluted coffee filter.
The entire bowl is one complex set of tucks, one complex set of ruffles, that if you pounded down into a uniform "cone" would give you a raised bowl, but if you step on it and squash it flat, will unfold back to a flat plate with a fold formed pattern on it. (Charles definition of fold formed) instead of a bowl.
That is the reason I did the sample bowl with a similar pattern. I folded the material along the pattern lines to create the shape. That there is further work in Karls bowl, in the textured flutes and the domed up (probably faceted by planishing with a flat hammer over a round stake) areas near the outer edge is obvious, but the making of a flat sheet into a similar bowl can happen without raising. Even turning the outer edge out and down can be done by adjusting the widths in the fold pattern.

There are several ways to go about it.
Marilyn suggested a good one for radial symmetry like this and then there is the way I did it.

I started the folds by tracing them with a hammer and stake moving along the bend line making the bend. kind of like if you took a spoon and clamped it in a vice, laid a piece of foil on it, and then pressed down with a finger just to the side of the tip. It would start a fold at that spot.
If you move the piece over the contact point following a line, you will start a bend in that pattern. It is point deformation.

Marilyn suggested bending a piece of steel strap to match the radial curve and sharpening the edges, then pounding the metal down over the edge of the strap with a soft hammer; after which you would move to the next location and repeat til done. Additional folding work would be required but you would get your geometry and a start all in one go.

G.

Gene Olson, Sculptor
Elk River, MN

I just acquired a small Nekrassoff bowl formed much like the one from the Institute. I agree with you Gene that it was formed by scoring and creasing. On close examination it is obvious how it was made. I must try one of these soon.

Best,
Fred

Here is an image of the Nekrassoff bowl I acquired.

Fred

Fred Zweig
Metalsmith

Warren,

The dish is a bit smaller than 6" dia. 18 gauge. The chased lines are suprisingly crude and the overall effect is quite successful.

Best,
Fred

Fred Zweig
Metalsmith

Fred, Great to know you get to have one for your collection. From the picture you would not know that it is only 4" diameter. Looks bigger but being that small then you realize how it could be made.

www Metalrecipes -- heat and beat to the desired shape, repeat as necessary.
warren

I have just found documentation on how Serge Nekrassoff made this style of bowl in the late 1940s. I need to scan the article and will publish it. The bowl he demonstrates is identical to the bowl attributed to Karl Nikrassoff at the Minneapolis Museum. It would be great to see what mark is on the bowl at the museum. Serge Nekrassoff's script mark has often been mistaken as reading Nikrassoff. I wonder who made the attibution for the Museum.

Fred Zweig
Metalsmith

This article in a 1949 magazine illustrates the steps Serge Nekrassoff used to make the swirling copper bowl.

Fred Zweig
Metalsmith

Thanks Fred for taking the time and energy to share this wonderful article! We really appreciate your efforts on sharing the amazing techniques of repouse.

Enrique,

I am an historian of metalsmithing and metalsmiths as well as a practicing metalsmith. I know the debt I owe to all those who preceeded me and am grateful to them and all the current smiths who are willing to share their knowledge and skills.

Thank you for providing this excellent forum for sharing.

Fred

Fred Zweig
Metalsmith

Thanks for doing the research. Fold forming is still a passion of mine. Brad

I just received an identical bowl featured in the article. and it is remarkable to see how it was made and would love to know the shape of the stake he worked on to create the shapes. I will post image when I can.

Fred

Fred Zweig
Metalsmith