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Old 10-16-2008, 08:30 AM
paul66 paul66 is offline
Steel
 
Join Date: May 2008
Location: Australia Vic Horsham
Posts: 73
Default Re: Pauls Tutorial:Making a Punch

Hello, Back to finish this project

I would like in advance to apologize for some of the out of focus pictures, I dont know if it was the scale of the subject me or the camera, but I had great difficultly even achieving these pictures, I think in future I should work on subjects MUCH bigger.

I set up the nail in my engravers ball to work on under my microscope, on full power it takes up just under 1/3 the view and the work area is even smaller, but this is still a HUGE improvement than my first effort under a hand loop.



ATTEMPT 1
Now this is where I supposedly dazzle everyone, but on my first attempt I engraved my boarder too close to my guide line and stuffed it up. However a few file strokes and back in the gravergraph and 2 minutes later I could have another attempt.

ATTEMPT 2

OK this is the one.
First I want to engrave the outline or boarder for my stamp, but this time I cut well away from the guide line, In fact because of the scale of the stamp, the smallest slip or bulge of metal may mean starting over so I plan to engrave all my lines away from the guide lines and as I achieve the depth I want I will slowly reduce the thickness of the walls I am engraving.



I next realized I did not have a graver small enough for the engraving, Using a Lindsays template I ground a very small knife graver that had a very small flat heal ground on the bottom, This was used for the whole engraving.



After the outline, all the background was cut away in small stages, slowly adding depth because if a big cut was attempted you ran the risk or distorting the metal around your cut. Also Don't cutaway and leave the "lines" too thin or they will be too fragile and may break off, Eventually you want them to taper from a fine short point down to a broad base down to the background, but this is not achieved just yet.



After the depth was achieved I wanted to level the background evenly, I made a small fine punch by spinning an old broken drill bit up over a file to get a long fine taper with the smallest flat on the end, this was just hand pushed over the background to flatten it evenly



To achieve the tapered "lines" you could engrave the taper but one slip would mean starting over, Instead I used a polished carbide starlight bur in my drill handpiece. This burnished and polished the metal to a taper and by doing both sides you achieved your point .



Next I removed the remainder sides of the punch



Next job is to reharden the metal and then temper it so it is not too brittle. My experience with this is only at an amateur level but this is quite adequate for using this punch on soft metals gold or silver, If it were to be used on steel you would need a much more accurate method to heat treat and temper the tool like a thermostat controlled furnace, or send the tool away for heat treatment.

To make the tool hard again its a simple matter to heat the tip again under the torch till its red, then immediately dip it while red into a cup of water. Now the punch is hard again but brittle, it needs to be tempered for any practical use.



To temper the punch it needs to be reheated again but to a lower heat, to gauge this temperature you will need to observe the metals color as you heat it up.
First clean all the discoloration from the end of the nail with emery paper, this will make it easier to see the color changes on the metal.



This next bit is better performed with the lights turned off so you can better observe the color changes on the metal. Start to heat the meal, but not at the tip, a bit further down, I wave the torch back and forth across the metal slowly, when there is a fine "straw" color where you are heating you lift the flame up towards the tool tip drawing that color along the meal, as soon as it has reached the tip, again quench the metal into water, it should be hard but tempered.
To test lightly rub a file over near the tip, it still should have that glassy feel, if it wants to file you have gone too far with the tempering, but its no loss as you just reharden it again and try again. It took me a second go to get it right.



Now test it



IT WORKS !!!

I would recommend a bit of experimenting on another nail the color changes metal goes through when you heat it, under low lights its easy to observe. Also the way you move this color along a piece of metal is useful to practice. If the metal just seems to go red, try heating it slower, and make sure the metal is clean to begin with when tempering. A little bit of practice will help you when it comes to the real thing. Also remember to test the tempering with a file, but dont file your work by mistake

Yours Paul