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Damascus woes... feedback requested


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I tried my hand at damascus this weekend. 4 layers of 15N20 and 3 of 1084 approximately 1.25” x 3.5”. The 1084 is 3/32” thickness, the 15N20 is ~.080”. I did my surface prep with a 40-grit ceramic belt and tacked everything together on the corners and sides with my stick welder. Brought up to dull red, dusted with borax for flux, and brought up to temp and went through the steps; fast, light blows from the center outward, re-fluxed, brought back up to temp, another set of light and fast blows, and a final flux/bring to temp before I started drawing it out to either cut & stack or just forge a blade from. 
 

This evening I cleaned it up on the grinder around the edges and noticed partial delaminations on a couple layers. I took a chisel to them and this was the result... hopefully one of you guys can give me feedback on what I may have done wrong. B0D13EEC-DC8A-45D4-85B9-2BA61B230AFB.jpeg

 

I feel like maybe I just missed the smooth section in the middle, and at the handle which didn’t allow it to weld up properly... 

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Hey man Could have been anything. I think there is a consensus that grinding lengthwise is better than across. And your hammer blows should be progressively a little harder for about 3 or so passes (or until you feel good about it lol.. What did you use to guage temp? 

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The best way to grind it is probably a great topic of discussion, sitting in the shop and sharing a few beers.

 

I'm thinking you didnt quite get it hot enough, at least not all the way through the billet.  If you've never accidentally sparked your steel before, and you're judging by color, I'd recommend taking a small scrap piece and heating it up until it throws sparks.  That's actually too far, but at least itll give you an idea of the color range that you're shooting for.  Another indicator is watching the flux.  Once is flows and starts a very rigorous boil, it's a good indicator that you're up to temp.

 

Good luck to you.  It can be a pain to figure out by yourself, but once you do it's pretty straightforward (until it isn't! :D).

Edited by Alex Middleton
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17 minutes ago, Alex Middleton said:

If you've never accidentally sparked your steel before, and you're judging by color, I'd recommend taking a small scrap piece and heating it up until it throws sparks.  That's actually too far, but at least itll give you an idea of the color range that you're shooting for.  Another indicator is watching the flux.  Once is flows and starts a very rigorous boil, it's a good indicator that you're up to temp.

 

This is the kind of quality information that I joined the forums for! I'm still not at the point of doing Damascus since I'm not really set up for it, but I love learning about it. Maybe one of these days I'll get there and not have too many headaches when I first try.

 

I love seeing these little tips. Keep it up!

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IMNSHO-

 

Grinding the pieces across is much better than lengthwise, especially when you use flux. Flux will get in between the layers and you need to jettison it out when you hit it. The distance across is shorter than along the length, so the flux has less distance to travel and is less likely to get trapped.

 

2 hours ago, Eric Morgan said:

surface prep with a 40-grit ceramic belt

Far too coarse. You are asking for trouble by creating large grooves to trap flux. If the truth be told, I rarely grind my initial billets anymore other than cleaning any grease or marker off with acetone. Rusty pieces will get 100 grit sanding. With fresh clean steel, I just layer it up, tack weld the ends, dunk it in diesel fuel and hit the forge.

 

58 minutes ago, Alex Middleton said:

Another indicator is watching the flux.  Once is flows and starts a very rigorous boil, it's a good indicator that you're up to temp.

 

This is the best info on forge welding by eye that anyone can give you. I sprinkle a little flux on the flat of my billet and look for the boil. It's sort of a mystic ritual now.

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This may sound like it is going against the prevailing wisdom but I swear it is the truth. 

you don't need flux and you don't need to do any surface prep, for the last 5-6 years i have not used any flux for any Damascus work I have done, this is the method I use. 

For initial stack I just cut bars to length and weld the corners to hold everything in place on longer stacks I  will run a bead down the middle. I don't prep any thing unless it has white paint (that can stop a weld flat). I weld in a gas forge running hot,  the temp isn't super important hotter is better up to a point. you do want a fairly reducing atmosphere, that is a dragons breath out of the forge. If the forge isn't reducing you will get a excessive amount of scale and a lot of decarb on the outside of the bar. The weld will be unaffected.   

My best practices for a weld. 1st layers must be fit tightly. 2nd soak time at temp is key 2-10 min 3rd temp and amount of scale dictate length of soak time. 4th set the weld in one go, if it is to long repeat soak and fit requirements. 

Restacks I will grind for fit but even on mosaics I don't sweat getting every last bit of scale off. 

I have been teaching this method with hand hammers for the last two or three years, in that time I have not had any student that followed best practices get a bad weld. 

MP

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11 hours ago, Matthew Parkinson said:

This may sound like it is going against the prevailing wisdom but I swear it is the truth. 

you don't need flux and you don't need to do any surface prep...

 

I'll clean of any crusty stuff or red rust, but otherwise do as you do.  My current pattern weld stock is about 100lbs of 1084 and 15N20 pieces I bought already cut to 6" lengths.  I just pull them out of their respective buckets, stack them up, and head to the forge.  (Thanks Gary!)


I get them hot enough to use the press to squish out any gaps.  Then it is back to the forge to get it as hot as I can before welding.  On a good day I can get my forge up to 2200-2300F.  No flux, no mess, no drama.

 

I'm obsessive about grinding off scale when restacking, but I don't have nearly the time at the forge you do.  It would be nice if that paranoia would fade over time :)

 

Edited by Brian Dougherty
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Hey guys, thanks for all the advice in this thread! This site is truly a treasure chest of knowledge and experience. 

 

I'm hanging these pieces in my shop on the wall to remind me that failure isn't the end, its just part of the learning and growing process. Can't wait to get back in there and make a successful billet

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I too do not use flux. I sand them much finer than others do apparently though. I go to at least 400 grit. I clean and stack, then fusion weld it either in stitches, or sometimes all the way around until it's solid with no gaps. If I weld all the way around, I don't use anything on it. If I stitch it, I spray it down good with WD-40. Then into the forge. I heat until the entire billet is one solid bright orange color[if the center still has some darkness too it, it's not hot enough], then give it another 10 minutes from there, and set the welds. Haven't had a bad weld yet in over 60 Damascus blades. I prefer to do a lot of layers at once so I don't have to re-stack much. You loose a lot of steel everytime you re-stack. So far, the highest layer count I started with is 48, made from 5 different steels, the thickest being .100", but most were in the 1/16" range. No inclusions or delaminations.

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I forgot to mention that when I looked at your photos, my first thought was that it didn't get hot enough.  I think those smooth sections you see were the only spots that welded.  The rest still shows your 40-grit lines which makes me think they didn't get "squished" at all.

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On 3/22/2021 at 7:18 PM, Matthew Parkinson said:

This may sound like it is going against the prevailing wisdom but I swear it is the truth. 

It's difficult to go against the prevailing wisdom when there is more than one way to skin a cat.

:D

 

Flux or no flux, grind or no grind, if it works, it works. Hancock never sanded his initial billets or did much except flatten his stacks. He said the scale will get reabsorbed into the steel or flush out.

 

Good list of steps for best practices Matt.

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On 3/22/2021 at 7:18 PM, Matthew Parkinson said:

This may sound like it is going against the prevailing wisdom but I swear it is the truth....you don't need to do any surface prep..

The more billets I make, the more I believe this.  

I still grind the mill scale off the 1080 and the rust and pitting off my 15N20 flat stock (lumbermill bandsaw blades) using an old 36 grit belt before tacking the corners, but am gradually moving towards acting like this is an unnecessary step.  But I still like the confidence this step  give me during the welding.

 

Here's more documentation about surface prep being unimportant: 

 

 

 

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I take the mill scale off mild steel, and heavy loose rust off wrought, but that's about it.  I don't tack, I wire.  Since I work mainly in coal, I do use flux.  Makes the clinkers easier to pull out. ;)

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Working in Coal I would use flux as well. Especially for odd shaped welds like hawk eyes. 

its is the consistent soak time at temp that is key to breaking down the scale, I don't know that i could do that in a coal forge with out burning up the work flux would shorten that soak time. in fact to long a soak when using flux and the flux will get full of crud and cause issues. 

MP

21 hours ago, Alan Longmire said:

I take the mill scale off mild steel, and heavy loose rust off wrought, but that's about it.  I don't tack, I wire.  Since I work mainly in coal, I do use flux.  Makes the clinkers easier to pull out. ;)

 

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On 3/25/2021 at 8:35 AM, Matthew Parkinson said:

demo video I did  6-7 years ago for NESM 

 

Yeah, I remember that video.  This is the one that finally pushed me over to the fluxless side.  Thanks for re-posting.

Edited by billyO
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I'm with Alex on this. I think your heat is too low.

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  • 2 weeks later...

I would vote too cold, not enough soak time at heat, or a combination of the two. (oxidising atmosphere in the forge as a distant 3rd in the why did it not weld conundrum). Forging pressure is a consideration, but Ive dropped billets before on the way out of the forge, when everything else has been good, and they are welded when ive picked them up!

 

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