Hand hammer demascus help

RunningManForge

RunningManForge

Joined
Nov 15, 2016
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So I have made demascus before via hand hammer. However right now I've gone through 3 billets that failed to weld.

I'm doing a stack of 3" x 1" of 8 or 9 pieces of 1095, 15n20. I do a clean scotch brite finish and weld the corners. The only difference between these runs that failed and my other runs that worked is that my stock is thicker. Bars of 1/8". I think I was using .095 before. Could this be the problem?

I'm getting it white hot to where the borax is rapidly boiling and my anvil is right next to the forge. I'm putting on borax 3 times before the first weld attempt.

Something else I may be doing wrong Is maybe not hitting it hard enough on the first weld. I'm more or less tapping it. I've heard that's all that's required. I heard a guy welded demascus with a hammer handle. I'm Also increasing power on sequential heats.

Any questions or advice please let me know.

Thanks,
 
I'm not sure I'm the expert, and would wlecome other thoughts, but I think you're overdoing the borax (that may be preventing a good weld). You could also be tapping too lightly (I doubt it, though) but this is hard to determine without being there. The hammer blows of the first hammer heat is really only to get all the parts of each surface mating before setting the weld on the next heat. Having thicker layers will necessitate more force than on a smaller stack, that's for sure. Also, I'm not sure if a scotchbrite finish is clean enough, although I recently read about folks doing successful welds without removing any of the scale, but I haven't tried. Another variable is making sure there's a reducing atmosphere, but if you've been welding before, then you've probably got that right.
 
weo said:
I'm not sure I'm the expert, and would wlecome other thoughts, but I think you're overdoing the borax (that may be preventing a good weld). You could also be tapping too lightly (I doubt it, though) but this is hard to determine without being there. The hammer blows of the first hammer heat is really only to get all the parts of each surface mating before setting the weld on the next heat. Having thicker layers will necessitate more force than on a smaller stack, that's for sure. Also, I'm not sure if a scotchbrite finish is clean enough, although I recently read about folks doing successful welds without removing any of the scale, but I haven't tried. Another variable is making sure there's a reducing atmosphere, but if you've been welding before, then you've probably got that right.
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Thanks you,
Just in case can you run me through how to reduce the atmosphere. I know that you need to run it richer. But I dont know much more then that.
 
If you have a TIG or MIG welder, try welding the full perimeter. Airtight. Then skip the flux. probably could try it with stick, but it may be a bit of a mess.
 
You already know this, but to forge weld you need a "richer" or reducing atmosphere. This means you have excess fuel (or more exact for this discussion, not enough oxygen) in the chamber/forge for the fuel to burn completely, causing it to burn outside the chamber where there is plenty of oxygen, giving you your "dragon's breath ". I'm not sure I'd say you need 6 inches, but I'd never say that's too much.
 
When I weld I bring it to heat and then turn the forge down and let it soak at a lower heat so that I get the whole piece hot but don't burn the steel.

Also I think fluxing multiple times before any welding is a problem. You want to bring it up to a red heat, flux, then bring to welding heat, soak and forge-weld it quickly. Letting it cool 3 times to flux can cause scale or a coating to form on the steel pieces.
 
Flux is not glue. I gently heat and once it’s a dull red I lightly flux. Then heat. Take it up to where you see the flux bubbling between the layers. If you go to hit the flux basically boils off and gets hard and crusty. It that happens then your kinda stuck. I then brush the billet off and reflux . Back into the forge and reheat. But I rotate the billet to get an even heat and get the borax to run through the layers. I heat with the layers in the up/down position. So gravity helps draw the flux into the layers.
 
Bubbling borax is not necessarily the proper indicator that the steel is ready to weld, especially if you are applying a lot of it.
Is your forge capable of getting the steel to sparkle? Sparkling is an indicator that the steel is starting to burn, but also a good indicator as to whether your forge is capable of reaching welding temps.
 
not trying to go off topic, but wondered if anyone has a good resource to read up/watch to learn for a first try at hand forging some Damascus. I've never tried it, and only heat-treated with it and forged some 1084 knives so far. I've got an Atlas with the 30k burner, and only a 4x4" anvil and normal set of hammers. I don't think I am supposed to use borax in the Atlas, think it eats the firebricks.
 
knoxknives said:
not trying to go off topic, but wondered if anyone has a good resource to read up/watch to learn for a first try at hand forging some Damascus. I've never tried it, and only heat-treated with it and forged some 1084 knives so far. I've got an Atlas with the 30k burner, and only a 4x4" anvil and normal set of hammers. I don't think I am supposed to use borax in the Atlas, think it eats the firebricks.
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I'm trying, I'm trying! I filmed/am filming all of the processes with my first damascus but I am a horrible and SLOW editor. ;)
 
Ian Fifelski said:
I'm trying, I'm trying! I filmed/am filming all of the processes with my first damascus but I am a horrible and SLOW editor. ;)
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oh I completely understand that, I'm sure I'm worse in that regards... look forward to seeing the process when done, as am sure others will be too. Thanks!
 
When I first started trying to forge weld I watched a lot of videos, and had a number of failures. I really thought I was doing everything correctly, and I was, but I just could not get things to stick reliably. I really wanted to watch someone do it first hand because I thought it was likely some little thing.

For me it wasn't a little thing. It was a big thing. Color doesn't transfer in video well, and I simply wasn't getting hot enough in that forge.

For about $40 you can get a thermocouple and handheld display that will tell you exactly how hot your forge is. I recommend anyone trying to forge weld who can't see it done first hand just get one, put a small hole in your forge for the probe, get your forge up to what you think is "welding heat" and then stick the probe in and see. If you're going to be leaving it in there you'll want a ceramic sheath, but if you're just checking here and there, it isn't absolutely necessary.

I think most beginners have no clue what temperature they're actually getting in their forges.

I built a hotter forge and using a thermocouple got used to what settings got me to welding temperature and have hardly had a failed weld since.
 
kuraki said:
If you're going to be leaving it in there you'll want a ceramic sheath, but if you're just checking here and there, it isn't absolutely necessary.

I think most beginners have no clue what temperature they're actually getting in their forges.

I built a hotter forge and using a thermocouple got used to what settings got me to welding temperature and have hardly had a failed weld since.
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You can buy a decent ceramic sheathed TC off of ebay for 10 or 15 bucks. I have used several, tested via cone, have never had one that was off.
 
JTknives said:
Flux is not glue. I gently heat and once it’s a dull red I lightly flux. Then heat. Take it up to where you see the flux bubbling between the layers. If you go to hit the flux basically boils off and gets hard and crusty. It that happens then your kinda stuck. I then brush the billet off and reflux . Back into the forge and reheat. But I rotate the billet to get an even heat and get the borax to run through the layers. I heat with the layers in the up/down position. So gravity helps draw the flux into the layers.
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First off thank you, When you say stuck what do you mean. Could you clarify that and the sentence before that. What about soak times. I haven't heard how long you should soak and at what color in a darker shop are we talking so I dont burn or undershoot the temp.
 
JTknives said:
Flux is not glue. I gently heat and once it’s a dull red I lightly flux. Then heat. Take it up to where you see the flux bubbling between the layers. If you go to hit the flux basically boils off and gets hard and crusty. It that happens then your kinda stuck. I then brush the billet off and reflux . Back into the forge and reheat. But I rotate the billet to get an even heat and get the borax to run through the layers. I heat with the layers in the up/down position. So gravity helps draw the flux into the layers.
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Another thing I was wondering is do you put the billet under the burner flame or off to the side? I'm not sure if being directly under the burner will oxidize the billet faster.
 
RunningManForge said:
First off thank you, When you say stuck what do you mean. Could you clarify that and the sentence before that. What about soak times. I haven't heard how long you should soak and at what color in a darker shop are we talking so I dont burn or undershoot the temp.
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Soak time depends on thickness and forge heat output. If the billet I was welding was the better part of an inch thick, I would give it a minute or two after it looks good before I try setting my welds. This is a first heat only thing. I don't worry much about it on subsequent heats as the core cools less quickly than the exterior. Temperature is hard to describe, but bright yellow is the general answer. As mentioned, you are reasonably looking for a temp north of 2100F. There is not 100% visual cue until you are used to your forge. Sparking on the exterior (really the steel is burning rapidly in air) is a decent visual cue, and you can weld at these temps, but it is hotter than you need, and depending on your forge may be nigh on impossible. If you are running coal, sparking is a good judge, in a propane forge, you probably wont get there. Moreover, flux, to some degree, will prevent the sparking by shielding the steel from O2. If you are running a reducing atmosphere, that will also limit the sparking inside the chamber.
 
If you have a flux core, mig, or tig welder you can give yourself a boost by welding all of the seams shut. This locks out air and negates the need for flux. Kerosene or wd40 can be used pre heating to help as well in place of flux (my understanding is that when it burns off it leaves a little carbon jacket blocking out the air, but someone more knowledgeable could probably explain it better). I know there are folks who have success with just tack welding and using kerosene or wd40 (no flux), but I have not personally tried that yet. I’ve succeeded three times and failed once on forge welding with a hand hammer. I fully welded the seams all four times. The three successful times I also sprayed the billet down with wd40 before heating it. I think the bigger difference was time in the heat though. The first time I just watched it until it got to what I figured was the right color and overexcitedly yanked it and started hammering. The two successful times I let the forge get to heat then put the billet in and started a timer. I kept the billet in for 20 minutes then set the weld. Then back in for 10 minutes and another set. Then 10 more minutes and another set. That may be more time than is needed, but I can say it worked the times doing it that way. Two were the classic 1084 and 15n20 (the initial 8 layer weld and the cut and restack) and one was 52100 with aeb-l in a three layer San mai (I had a partial weld failure on this one, but 90% of the 12” length stuck).
 
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