I am just starting to make damascus. I have hot rolled 1084 from Admiral and some 15N20. I've cut then into six inch pieces, my question is, is it OK to leave the gray scale on the 1084, or must it be ground off. I will clamp, then weld the sides at one end and in the middle, leaving the other end unwelded, if that sounds right.
Bill Foote

Bill,

That should work out just fine. Most of the guys that I know that are making damascus are doing just that. In Eds' video that is what he does and that is what I do also. I would weld both ends on the billet though. If you don't you will take the chance of it spreading and giving you problems. I think that the most important thing to getting good welds is making sure to let the billet soak at welding temp for a sufficent amount of time.

Thanks Bill,
What about the mill scale on the 1084, can I leave it or grind it off?
billfoote

Better safe than sorry. Grind it off. Any advantage you can get in you first attempts are worth the trouble.
I am afraid to weld both ends. I leave one end open to allow for different rates of expansion in the steels. I got that from the Horsulous video. He just wires the stack together for that reason. More than one way to skin a cat I guess.

My method is to stack the billet up, then I run two weld beads across each side. I never grind off the mill scale off the 1080/1084....a good dose of flux takes care of it. Now once the initial welding is done it's a different story. Once the first weld is done, I take it out back of the shop, and grind ALL the weld beads away. After drawing it out, I allow it to cool, then grind both sides of billet clean with a 7" angle grinder. One note of importance when grinding..... make your grind lines run across the billet. This acts just like scarfing, forcing out the flux and gunk that can get between the pieces when you hammer/press the billet together. Once both sides are ground clean, I then divide the billet into as close to equal sections as I can, then cut it up on the chopsaw and re-stack it. On this stack the only welding (arc) I do is on the handle end. Sometimes if you weld both ends, the middle will bulge when heated and create cold shuts that just won't come out. I continue like that until the desired number of layers is reached, and then pattern the steel. After that it's just a matter of forging out the blade.

I clean mill scale off it only takes a swip on a belt grinder it`s very thin - to get it ready and i dont clean it totaly but i scaff it so the flux can get to the metal and it ups the % of a first weld whitch is the most important so i do all i can to insure that. I know it might be over kill but i have found it works -----old school . heats your friend flux is your buddy give it a place to work better .
I stack as many peaces that i can that will fit in the mouth of the forge ,my forges mouth is 3 1/2 " tall that will give me at least 25 count .6--8" long.
I weld both ends and on the sides i weld every 2" apart clamped tight in a vice .and then weld on a handel.
i start with shim stock from Kelly Cupples he will cut any size you want
and its always good steel .
after the first weld and the bar it streached out to a linth that i can cut it at least 4 times . i grind it clean of any scale and restack making it to 100 count depending if i want a two hundered or a 500 count bar will determan the next folding weld .
three welding restacks get me to my count .
i have found that the it takes at least three welding heats to get a sound weld the first its to get it together the seconf will set the weld deeper the third will be even deeper and withstand the streaching of a press or hammer with out taring it open i dont want to do all that work to find a schear or incluson in the final peace
less heat near final sizing is also good for the steel but never in the dull red .
Bowie one week Damascus FREE

Thanks for the info guys, I'm using Kelly's 15N20-clean. I stacked one billet with mill scale removed and one with it left on. They came out the same using plenty of anhydrous borax. I bought Bob Warner's press and it has a small die so I'm taking 2" bites instead of pressing it all at once. I left one end unwelded and it did spread out a little, but I fluxed it and pressed it back together with no problem. I'm gonna have to make new squaring and drawing dies. I'm going to make a flattening die the size of the initial stack and see what happens when it's pressed all at once. When I take 2" bites I know the flux and crap is squeezing out, though.
Thanks for the input, this is fun.
BillFoote

Just to make sure I'm doing this right...After stacking and welding together, I'm getting it up to bright orange, fluxing, putting it back in until the flux flows well, then I use the flat die to make my first weld. I scrape off the scale with a HF carbide scraper and reweld two or three more times just to make sure, using anhydrous each time. Then I use the drawing die to draw it out from 6 to 12". I then use the flattening die to take the waves out from drawing it out, grind off ALL the scale with a 7" angle grinder with a MetalHog disk, cut, stack and repeat. I want tp put twists in, but I'm not sure how to go from a flat billet to a square one.
billfoote

Bill,

Yep you got it right. I think that the easiest way to get a square bar is to make my stack at least twice as high as it is wide. I do this because I and a lot of others believe that it requires at least a fifty percent reduction in thickness to get a good weld. So by going twice as high as the billet is wide I can stop welding and drawing the billet when it is square and still get this fifty percent reduction. To make a twist pattern it is easier to forge the square bar round or octagonal before twisting. this minimizes the chance of tearing the billet.

Bill

Bill,
Thanks, that's what I needed. I'll try stacking 23 layers instead of 11, with 1084 on the outside and drawing out till square. I was using two 6" pieces of solid 1.5" rod for drawing dies, but found I had more control with one round piece on top and a flat die on the bottom. I made a stainless steel "trough" and put it on my kiln shelf to collect the flux and it's been working pretty good at containing the borax.
Billfoote

Since I have just begun making damascus, these things might be common knowledge to the rest of you, but here are some things I found to be helpful:

Fron Don Fogg-my forge sits next to my press, so I welded a steel supoport for a muffin fan to the press that blows across the forge opening, causing the dragon's breath to veer to the side, allowing me to get closer to my work.

The 20% vinegar for scale removal was $20.00 at a feed store, so I did boil four gallons down to one on a propane burner in an enamelware pan as mentioned on another thread, this costs alot less. The 20% vinegar helped greatly with scale removal after a 24 hour soak.

I made a 4" PVC vinegar conainer with a cap on the bottom and a screw on lid on top, like the ferric chloride container, except wider, for big billets.
Those Metal Hog 7" grinding wheels for andgle grinders (as mentioned on another thread) are really the best I've used. Got them at the local welding supply store.

The 3/16 stainless steel pan I welded together has caught all the flux that would normally flow th the bottom of my forge. Although I have several inches of bubble alumina in the bottom, I feel better about collecting the flux before it drains down below the kiln shelf.

I'm looking for a scale that I can put under my 100lb propane conainer so I know when it's getting close to empty.

billfoote

this is one i found http://www.flameking.com/?OVRAW=propain%20gage&OVKEY=gauge%20propane&OVMTC=standard

Thanks Bowie,
Have you tried this one? I noticed it has a type 1 connection, would need an adaptor. Also, I wonder if high flow rates would shut it off, like when I crank the regulator way up for forge welding? I've seen metal scales that the 100# bottle could sit on with a remote weight display, but too pricey. This would be nice if it could be adapted and not restrict high flow rates.
billfoote

1084/15N20 is one of my favorite mixes to play with. Carbon contents very much alike. So no real chance of carbon migration.

Now I grind both steal surfaces clean. But given what I am seeing here, I'll take a chance and skip that step coming up here soon and see what I get. Up till now I have been pretty much of the mind, that I don't want the flux to have to work any harder then need be. That and I try to use as little flux as possible, to save my forge lining.

But that being said, I also used to clean my cable before welding. I don't do that any more. And I don't see where mill scale could be any worse then the junk on the cable I get.

Hmmmmmmm?

Now I don't pre-weld the ends of my billet. I use stainless steal wire. I do this because the stainless will peal right off after the weld (it welds at a much higher temp). And that way I don't get any other alloy messing up my pattern. I know other makers just cut the ends off, but I try not to have the cut the end off. I think this is one of those swear by, swear at things.

I get my 15N20 and 1075/1080 from Admiral and pay to have them cut it all to size so I can get straight to work. I get the 1070 cold-rolled, and I grind off the surfaces on my belt-grinder before binding with 14 ga wire, working a 12" X 1.5" X 1" starting billet of about 12 layers. I find that the cold-rolled material requires less clean-up before welding.

I have found that if I do not grind the surfaces, there is a greater chance of flux bubbles as well as a near certainty of de-carb in between layers, creating a fine silvery line (sometimes with tiny little bubble-shaped voids.) It takes about 15 minutes and makes it way less likely that I'll toss out an entire billet. :)

But that's my process in my smithy...