Wrought Iron - Artist-blacksmith.pdf - --OBRÓBKA METALU KOWALSTWO SPAWANIE METALOPLASTYKA - aro164

Volume 5

Number

The

Artist-Blacksmith

Quarterly

Blacksmithing is not defined by time period or motif. Blacksmithing is defined by process alone.

Focus:

Repousse'

Tooling:

Bickern

Professional

Smithing:

Fly Press

Tooling

Motif:

Peapod

Architectural

Iron:

Die Making

Focus: Repousse'

T he same tools and processes which formed and

detailed the repousse' leaf in the last issue can be used

to create geometric forms as well.

Ribs, ridges or raised veins are different names for the

same basic, two-sided effect.

Profile & side view of

a basic repousse' stake

used for raised ridges

(veins to lettering)

Lettering or a Celtic pattern can be imparted to sheet metal

with these very simple tools and the raised-ridge motif. The

cross section of a ridge will vary based on metal thickness, tool

size and the distance between the tip of the stake and the

hammer face.

Generally, a narrow cross section will be the outcome

of thinner metal and/or a tighter gap between stake and

hammer. 20 gauge, annealed sheet metal worked over a

1/2" to 3/4" wide stake with a similarly wide repousse'

hammer will show results quickly.

Develop a ridge with a pass along one side of a layout

line or pattern then reverse either sheet or stake and

repeat the layout pass along the opposite side of either

line or pattern. Intersecting lines, such as can be found in

the letter 'H', are made and joined over the same stake.

The rounded corners of the repousse' hammer should

have the same radius as the edge of the hammer face.

This rounded corner will fit up against the

hammer formed side of a previ-

ously developed ridge as the

hammer drives down the metal

along the intersecting line.

Here is where hammer con-

trol, posture (see V5#2) and

short, light repetitious blows

will push the metal down and

blend the corners of the inter-

secting lines.

1 of 3 pages on Repousse'

Use gentle hammer strokes to develop the

actual intersection. Be alert for signs of

work hardening and anneal as needed

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Printed Quarterly Rates: US & Canada $ 28.00 annually, Overseas $40, All payable in U.S. Funds Only

Written, illustrated and edited quarterly by George Dixon . Printed by Precision Graphics, Black Mountain, NC.

Published by NorDix Press - 1229 Bee Tree Lake Rd, Swannanoa, NC 28778

The contents of this publication may not be reproduced without written authorization from NorDix Press.

Metalwork can be very dangerous. Wear Safety Glasses. Be certain to know and follow safe shop practices.

mation included in this publication is intended only for non-powered, hand tool applications.

www.artist-blacksmith.org - george.dixon@mindspring.com

The Artist-Blacksmith Quarterly

1229 Bee Tree Lake Rd, Swannanoa, NC 28778

The Artist-Blacksmith 2

Tooling: Bickern

B ickerns have served many blacksmiths as a

second anvil. The example copied here is Early

American, from the Historic Ironwork Collection .

This bickern was made in an unique manner.

The shank is hammer welded from two pieces,

though the length is only 8" between tenons. The

anvil top is set on the shank with a large mortise

and tenon joint as opposed to being welded. The

tenon face, as set, is 1" x 1 1/2".

The stock size for the original anvil top is 2" x

3" bar stock. The shank is 2" x 2" in section with

a large upset at the bottom and no upset at the

top.

The example selected for this article was most

likely made in a small shop. A long, diagonal

weld still shows in the shank. Materials were

scarce in 17th and early 18th century America,

so welding up two pieces to get an 8" long, 2" x

2" result was of necessity. That the anvil top

was punched and then set on the tenoned shank,

rather than having been welded, suggests that

forge and fuel were adequate for the shank weld

but insufficient for welding the entire anvil top to

the shank.

Today, fuel and metal are not at a premium but

the size and process constraints of the example

make it perfect for the smith in a small shop in

the 21st century

I made the anvil from 4140 tool steel. The

anvil top is of the same size stock as the example,

2" x 3", but about an inch longer (so the tenon

would occupy a smaller percentage of the work

face of the anvil). Rather than buy a different

size bar for the shank, I forged the new shank

down to 2" x 2" from the same stock. Next time

I'd buy smaller stock for the shank, which is cov-

ered in the next issue.

The forging was roughed out with a small

sledge hammer (8 lb) with a helper striking. The

rough forging was then further worked with a

large hand hammer (5 lb) and finished with a

standard forging hammer (2 lb).

The heel was drawn out first. An old pair of

tongs in the shop happened to fit the bar stock,

otherwise, welding a 1" square bar on one end

would give a purchase for smaller tongs. A set-

hammer was struck for the shoulders and later to

forge down a step at the base of the horn. The

heel taper was taken to a 1" square so a comfort-

able pair of tongs could hold the anvil blank. The

12" long anvil blank weighed twenty pounds. It

was drawn out to 18" from tip to tip. The result-

ing face surface is 3" x 6" plus heel and horn.

The shank weighed in at about 30 pounds.

Historic Tool Series

Early American

Bickern

1 of 3 pages on Bickerns

Bickern Project

Materials: 12" of 2" x 3" (top),

16" of 2"x 2" (shank)

4140 (or S7, 1045)

The illustration above shows

the edges preceding the center

of the heel being drawn out

If allowed, the leading edges

will fold into a shut.

To prevent a shut, dub back a

bevel on the edges of the heel so

that the center leads.

Forge a bevel along the sides of the

heel as it is drawn out to counter a

parallelogram from forming

www.Artist-Blacksmith.org 5

Professional Smithing: Flypress Tooling

A ccurate slitting with a flypress driven chisel requires tooling in the

form of a backing plate fixture which can both position and retain the

bar being slit.

The backing plate fixture bolts to the base plate of the flypress. A fly-

press uses one of a pair of heavy cover plates (see V5#2) to support the

tooling and stock. One should be solid, the other should have a large

hole to accommodate drifting. Depending on the operation, the solid or

drilled cover plate is used to position the appropriate backing plate for

slitting or drifting.

1 of 2 pages on the Flypress

A press driven chisel can get stuck in the work piece. When the

wheel of the flypress is turned to retract the chisel the bar can rise

off the backing plate. To both position the stock relative to the chisel

and to strip the stock off of the chisel (retaining it on the backing plate)

a pair of stops with strippers is fabricated and welded to a backing plate

which in turn is bolted to the flypress cover plate.

The stops are made for the specific stock at hand and fastened to the

backing plate. The backing plate is made of 1/4" flat stock. It has tabs

for mounting on its sides. Make one for each thickness of stock which

is regularly slit. Make a set by fabricating two, one with a hole to allow

drifting.

The combination stop and

stripper have a shim sand-

wiched in between them to

provide clearance

There needs to be a slight clearance built into the stops

so placement of the bar stock being slit is easy. The fab-

ricated stop-stripper shown here has a shim of 18 gauge

sheet metal sandwiched between the stop and the stripper.

The easiest approach is to cut two short pieces of the

same stock as the run of bars being slit. Cut the two

stripper pieces from the same stock so they are the length

of the two stop pieces plus their diameter. This extra

length will strip the work piece off of the chisel.

Affix the two stop-stripper assemblies at either end and

on opposite sides of the backing plate. Use a dead

straight piece of bar stock to position the two assemblies

relative to the centerline of the backing plate, clamp and

drill and fasten with rivets or screws or weld.

The Artist-Blacksmith Quarterly

Architectural Iron: Die Making for the Anvil

D ies have been made for use on the anvil for centuries. Dies are

made for production of a piece or an effect. Some dies are made to

produce a blanked form which can then be detailed by hand. An

example would be an animal head which is formed in a die and

then detailed (chased eye, nose and mouth) individually afterwards.

One draw back regarding dies is the amount of power needed to

sink the hob (master form) into the hot die block initially. Related

to this is the additional fact that the master form must displace its

own mass as it is driven into the hot die blank. For every incre-

ment the cold master form is driven down into the hot die block

there is displacement to the sides of the master form. This dis-

placement results in a die which is usually wider than the original

form driven into it.

Invert the master and

sink it into the relieved

hot die block

For a solution to both issues it pays to look back to how the old-

timers used to handle them.

NOTE: This approach is for oil (non-flammable quenching oil)

hardening or air hardening tool steels. It should not be used with

water hardening tool steel.

Prepare a die blank. Shown here are two approaches. One is to

forge a saddle form from the tool steel block, the other is to saw

the die block and forge a separate saddle to be bolted to the die

block later.

The holes will be dis-

torted and filled to

varying degrees

In either case, layout a drill pattern that mirrors the outline of the

intended die master form. In this example a duck head for table leg

finials was the goal. The duck master hob had a footprint of 1" x

3" so three lines of staggered holes were laid out within that

perimeter on the back

of the die block.

The drill size was

5/16" and the depth

was about 5/8" into

the back of a 1 1/2"

thick die block.

1 of 3 pages on Die Making

File the opening

of the die

The spacing should be as even as possible

so that the area between holes is constant.

This will allow the die block to give evenly as

the master form is sunk into it later. Also,

there will be much less spreading of the die

walls due to displacement as the honeycomb

beneath the die master is collapsed.

Forge and refine a master form. Make the master form as sym-

metrical along its centerline as you can. An a-symmetric master

form will travel as it is driven down into the hot die block.

The Artist-Blacksmith Quarterly

Wrought Iron - Artist-blacksmith.pdf

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