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Bill Schmalhofer

First WIP : Rock Hammer

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Posted (edited)

Doing my first WIP. It’s not a knife, but hopefully you will enjoy it all the same. First, thanks to those who suggested metal combinations for this project. Second, a bit of background. My brother-in-law is a geologist and an avid fossil hunter. I got to thinking that he might think a Damascus rock hammer would be a pretty cool Christmas present; thus was born the idea. Based on the previous mentioned suggestions, as well as the design idea I had, the initial stack of steel.

 

 

1.jpg

The order is:

15N20 (0.12)

8670 (0.084)

80CrV2 (0.032)

8670 (0.084)

15N20 (0.064)

8670 (0.084)

15N20 (0.064)

8670 (0.084)

80CrV2 (0.032)

Repeat twice more

80CrV2 (0.032)

8670 (0.084)

15N20 (0.12)

for a total of 23 layers.

 

The idea was to have a majority of the steel the ultra-tough 8670 (which would hopefully etch gray), then an almost as tough shiny highlight layer of 15N20, and a final thin dark contrast layer of 80CrV2. The numbers in ( ) are the initial thickness of the given layers. I made the outer layers of 15N20 thicker to protect the billet during weld up and to account for scale loss. The initial width was 1.5 inches.

 

Initial heating of billet.

2.jpg

 

Billet welded and drawn to 1.25 inches square. Was using my thermocouple to check the temperature of my new and improved forge (Thanks Geoff for your pinned topic on blown forges!). Got to 2500F and was still going up! Was actually seeing the outer most layer appear to start to bubble. And I know it was the metal because I fluxless weld…

3.jpg

 

Billet rounded to 1.125 and ready for twisting.

I unfortunately didn’t get any pictures of the twisting. Twisting a 1.125 inch diameter bar was a real pain. It took 6 heats to get 2 full twists as I stopped well before cooling below bright red. During this I learned a few things that I will incorporate into the next time I do this. The main thing I learned was that, on this bar, I forged down a tip on one end of it to make it a bit smaller to “get a better grip on it for twisting”. What I learned (as people who have done this more than me probably already surmised), is you want to keep the billet as close to even as possible. The smaller tip twisted much faster than the rest of the bar and I eventually twisted it off. A complete waste of material…

4.jpg

 

Round twisted bar drawn out to 1 x 7/8 and ready for punching.

5.jpg

 

Eye hand punched with plug. I was surprised how fast and easy this was.

6.jpg

 

The homemade punch. Just a ¾ round of H13 ground down to the shape I wanted. No heat treat. Worked an absolute dream. Still going to have to make a punch for use on my press though…

7.jpg

 

Eye drifted and hammer rough forged to shape.

8.jpg

 

Rough ground to 120 grit, ready for heat treat.

10.jpg9.jpg

 

Had to do the obligate “quick and dirty” dunk in the etch tank. The pictures don’t show it very well, but the theory for the stack up worked exactly as I had hoped – Gray body with bright and dark banding.

12.jpg11.jpg

 

The issue and things I have learned.

First obvious issue is the eye. It deformed a bit during punching, and I was never able to get it really worked back out. Second (and this will probably help with the first issue) is I shouldn’t have forged it quite so close to final size before punching. After the forging to shape and grinding, it is a bit smaller in dimension than I was shooting for. Third (as already mentioned), twist full size.

Dimensions are:

Weight: 12 ounces

Head width: 5/8 inches (was shooting for 3/4)

Head height: 3/4 inches (was shooting for 7/8)

Total length: 8.5 inches

Planning on heat treating this weekend and putting a handle on it. Also planning to make a second, larger one for my brother-in-law. My wife (who also loves collecting fossils - has to be genetic...), has already claimed this “perfect for me” sized hammer. Will post final pictures as soon as I get them.

2.jpg

3.jpg

Edited by Bill Schmalhofer
Addition and subtraction
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Nice!  Thanks for sharing.  Can't wait to see the finished pieces.

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Well, that worked out!  :D  

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I was able to heat treat yesterday: 

Heat to 1600 - cool to black

heat to 1550 - cool to black

heat to 1500 - cool to black

Heat to 1550, soak 3 minutes, quench in high temp vacuum pump mineral oil at 120F. 

Tempered 2 x 2 hours at 425.

 

I am wondering if I actually should temper it higher? Suggestions welcome.

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I have (mostly) finished the hammer. I say mostly because as I was taking these pictures, I noticed I have a bit of clean up to do on the bevels on the face, as well as one more coat of tung oil.

 

Final pictures:

IMG_1905.jpgIMG_1907.jpgIMG_1908.jpgIMG_1909.jpgIMG_1910.jpgIMG_1911.jpg

IMG_1906.jpg

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Nice  !!

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That came out nice!  

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How did I miss this? Way cool Bill. How are you going to keep that a secret until December? :P

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Thanks all for the nice comments.

1 hour ago, Joshua States said:

How are you going to keep that a secret until December? :P

He lives in Calgary, I live in Indiana. :D

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10 minutes ago, Bill Schmalhofer said:

He lives in Calgary, I live in Indiana. :D

That wouldn't keep it from eating at me to have something so cool for someone and not share it with them.  Something that awesome I would need to get it in the intended recipients hands sooner rather than later.  

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2 minutes ago, Jerrod Miller said:

That wouldn't keep it from eating at me to have something so cool for someone and not share it with them.  Something that awesome I would need to get it in the intended recipients hands sooner rather than later.  

Oh it’s eating at me alright. I wanted send it to him early, but his sister says I have to wait.:lol: 

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50 minutes ago, Bill Schmalhofer said:

Oh it’s eating at me alright. I wanted send it to him early, but his sister says I have to wait.:lol: 

Send it to her and make her hold onto it until December......

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2 minutes ago, Joshua States said:

Send it to her and make her hold onto it until December......

Pre-wrapped and labeled "Do NOT open until Christmas".  I see no reason this is not a valid plan.  It would at least get it out of your hands.  Out of sight, out of mind.  ;)

 

Did you by chance break some rocks with it yet?  If so, how did the face hold up to being marred?  

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17 hours ago, Joshua States said:

Send it to her and make her hold onto it until December......

You missed the joke. My brother-in-law's sister is my wife, so technically she already is holding on to it until Christmas.:lol:

 

17 hours ago, Jerrod Miller said:

Pre-wrapped and labeled "Do NOT open until Christmas".  I see no reason this is not a valid plan.  It would at least get it out of your hands.  Out of sight, out of mind.  ;)

 

Did you by chance break some rocks with it yet?  If so, how did the face hold up to being marred?  

Actually I'm in no hurry to send it out. I like looking at it. Just got done taking some 50X micrographs of it on my wife's dissecting scope. The etching looks like canyons that close up - can actually see shadows and under-cutting.

 

Usually he comes in to visit for Christmas and my wife wants to see live the expression on his face when he opens it. I'm just hoping COVID allows this to happen. We have a plan "B" to "open presents by ZOOM" if COVID doesn't cooperate, but it won't be the same.

 

I tried the chisel end on some mudstone (where fish fossils are usually found - pretty soft) and the face on some slate before I etched it (had it just pressure fit on the handle) Nothing on the chisel end and less marring on the face than what happens to the commercial rock hammer I have. I should have more faith in my work but I didn't have the guts to try it on anything harder.

 

I'm making a second one for my wife and we'll get to put that one through the torture test.

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4 hours ago, Bill Schmalhofer said:

You missed the joke. My brother-in-law's sister is my wife, 

Ah yes. The corporate office got involved. Well, that's company policy then. Can't change it. :)

  • Haha 1

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