[TheForge] Copper inlay in steel

Mon Jun 3 21:38:00 2002

Ok, here is the text part of an essay I wrote a while back, hope it helps in
spite of the drawings being absent.

Jim Jordan

Inlay techniques for metal work.

Here is a simplified discussion of the process of inlay for metalwork. While
not complete it should give the beginner an idea of where to start.

There are a number of different techniques used for the various kinds of
inlay; some of the major ones are;

1) Simple, flush line inlay.
2) Raised line inlay.
3) Flush plate and Raised plate or 3D inlay.
4) Multiple wire filled inlay, flush or raised.

I will try to give a brief description of the procedures in this paper. As
with any art or skill, the best way to learn this process is to experiment
and try it yourself.

Learning to inlay in metal is an inexpensive technique that can increase the
quality of you artwork considerably. The tools needed to do inlay can be
home made, or purchased, either way you can acquire a good outfit for less
than a night at the movies and dinner.

Basically, you will need a small hammer, a light ball peen will work fine,
or you can use an engravers hammer if you have one available.

Next you will need some way to hold and manipulate the work piece.
Traditionally an engravers ball is the tool of choice. They are fairly
expensive though, and for a beginner it isn't really needed. A pitch bowl
works well or a bench vise will do in a pinch..

Inlay of course can be done using the most precious of metals. Gold and
silver are wonderful to work with but are very expensive. But even these
metals are used in fairly small quantities even on a complicated piece of
work.

Nevertheless, at first you will probably make a few mistakes, so the cost of
precious metals could be prohibitive to use as a learning tool.  I would
suggest the use of alternatives for the beginner. These alternatives can be
found at welding supply houses, hardware stores and home improvement
outlets.

All that is required of an inlay material for practice is that it be cheap,
reasonably soft, malleable and easily available.

As an inexpensive alternative to silver you can use aluminum welding rod, it
is available in various diameters, and is sold by the pound. For a few
dollars you can buy enough for years of practice. The same goes for brass
brazing rod, it is cheap, easily available and can be had in various sizes.
Solid copper wire is a good inlay material, though you will have to remove
any insulation or enamel if it is so coated. You may want to anneal the
material if it is stiff or work hardened.

For practice inlaying in steel, you can also use soft iron wire to give you
a nice contrast with tool steel if the finished product is later etched.
This could work very effectively on Damascus steel.

?
Simple flush line inlay as shown above.
Raised line inlay is similar but the metal is left to extend above the
surface planes.

First the design is drawn, transferred or otherwise placed on the work
piece. For practice any type of metal will work, but brass is fairly easy to
use. Cold rolled steel, bronze or just about any metal can be used as long
as it is harder than the inlay itself. Later this can be changed but at
first it will be easier to have a harder base and a soft inlay.

After the design is transferred to the work, the design lines are cut into
the work as in the illustration at (1).
Then the grooves are undercut to give a mechanical hold for the inlay. (2)
The grooves should be slightly deeper than the diameter of the wire, (3) and
the groove should be just a tad bit narrower than the width of the needed
inlay as the undercut will tend to open up slightly when the wire is swaged
in place. (4)
The wire should just fit in the groove or even be a little tight. If the
wire is a little too big it can be flattened a little to help it fit.

Remember to undercut the ends of your groove to hold the wire in place there
also. Since the wire will lengthen as well as widen as it is swaged in
place, the wire should be about 10% shorter than the groove. This is where
experience comes in, it can be difficult to judge how much the wire will
lengthen, so it is a good idea to go ahead and leave it slightly long and
cut off the excess when you get to the ends.

So, here we are with our groove undercut, the wire to a reasonable length,
what next?

It has been my experience that the first hammer blow is critical. If the
first hit doesn't lock the middle of the wire in place it will be hard to
keep the inlay from bowing and peeling itself out of the groove. Placing the
wire in the groove, (3) I take a punch with a rounded tip and give it a good
firm thump to set the center of the wire in place. The next blows can be
lighter and alternate side to side of the center, each blow forcing more of
the wire into place and swaging it into the undercuts. Try to keep the blows
even and overlapping each other. Do not hammer it completely into the
grooves, we want to simply set the wire into the groove at this time.

As you reach the ends of the groove you will probably find that the wire is
now too long. I usually cut the inlay to size when I am about 1/4" to 1/8"
from the end, this gives me room to tweak the wire into the grooves since as
the wire is hammered the loose ends will curl up out of the groove and need
to be pushed back into place.

With the inlay ends pushed into the groove and the inlay set in the majority
of the work go ahead and firmly hit your punch to set the ends. Now we can
go back over the entire length of the inlay with a flatter faced punch (4)
to fill the groove and flatten the inlay to slightly above the surface. We
will leave a small amount sticking up above the finished surface for filing
and finish work.

Plate or insert inlay

By carving a depression in the surface of the part, shaped to the outline of
the inlay, and undercutting the edges you can create an inlay larger and
wider than with the line inlay technique. In addition creating a roughened
surface in the depression will help to fix and retain the plate inlay
securely.

 A piece of inlay material is cut to the outline of the depression.
Depending on the design the plate can be slightly thicker than the
depression to make a flush inlay, or it can be considerably thicker to give
the inlay depth and allow the artist to carve a three dimensional surface
inlay standing above the surface of the work. Giving the artist the choice
of either doing a flush plate or three dimensional inlay.

This inlay insert is placed in the depression and hammered into place. The
roughened bottom surface and the undercut edges create a grip to permanently
hold the inlay in the work as the insert expands from the hammer blows into
the undercut edges and the rough surface of the work grabs the insert.

This technique works best when there is a reasonable difference in hardness
between the base metal and the inlay, with the base being harder than the
inlay. If there isn't enough difference, the softer roughened points of the
surface will not bite into the inlay and hold it tight in the depression.

The idea is that the rough surface has it's own undercuts that will cut into
the inlay. These hooked undercuts will then slightly deform from hammering
to fold down and hook into the inlay forming a permanent mechanical bond
with the softer material.

Hope this helps.
Jim

Copyright 2001 JKJordan

----- Original Message -----
From: Marc <[email protected]>
To: <[email protected]>
Sent: Sunday, June 02, 2002 9:51 PM
Subject: [TheForge] Copper inlay in steel

> I had an idea to gouge a piece of steel (1/8" to 1/4") with a plasma
cutter
> and either hammer in or melt in some copper wire. I tried it really quick
> today and it doesn't look like it is going to be easy.
> Has anyone tried it or heard of doing it?
> The melting process just produced blobs of copper. Is there some kind of
> prep after the gouging to clean or flux the grove?
> I also found it difficult to get a uniform grove. So I think that is why I
> had problems with the hammering approach. Maybe going over it with some
type
> of gouge or rotary tool might even it out.
> Does anyone have any ideas.
> Thanks in advance
> Marc V. Davis III
> Marc of the Hammer
> Allen Park, Mi.
> [email protected]
>
>
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