The reality of steel prep for damascus

D

deker

Joined
Nov 14, 2005
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So I just spent my morning work time prepping steel for billets and during all of that grinding, grinding, and grinding, I had some time to think. When I think it's usually dangerous, but this time all I came out of it with was questions.

I know that the 1084 I got from Aldo needs to be ground to get the mill scale off. That's just sensible. My question though is about steels in other forms. For example, the 15n20 I get from Kelly Cupples. It's clean, but I grind it anyways. am I just wasting my time there? If I were to get steel that's pickled and oiled, would I need to grind the surface of that? If not, could I just pickle my 1084 and save a BUNCH of time?

I had hoped to get 4 billets worth of steel ready this morning since I'll have access to a decent welder over the weekend and figured it would be smart to get a bunch of stuff welded up and ready. I only made it through 2. I'm just looking for ways to speed this process up without taking any chances on quality. If the answer is "grind everything" that's fine too, I'll keep doing it, but I just have to wonde sometimes if there isn't an easier way...

-d
 
If the surface has any discoloration to it I personally would still prep it. If the surface is nice, silver and shiney, then I would wipe it clean with a good solvent and stack 'em up:thumbup: .
 
To pickle steel is to remove scale by putting it in acid usually hydrochloric.
 
Kevin R. Cashen said:
If the surface has any discoloration to it I personally would still prep it. If the surface is nice, silver and shiney, then I would wipe it clean with a good solvent and stack 'em up:thumbup: .
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That will save me a bit of time, hooray!

Now, onto my pickling question....Can I save grinding time on my 1084 by pickling? The mill scale on the stuff from Aldo is very thin, but still needs to come off.

-d
 
I keep searching for a better way too, unfortunately I havent found it. I grind mill scale but not the 15n20 I get from Kelly. I'm w/ Kevin I just clean it w/ a solvent and then stack.

Shawn
 
I've gotten all of my 1084 and 15N20 from Kelly also. I try to do things when I prep the steels to be stacked up. To get down to good metal with no scale or rust and to crown the pieces slightly. With the edges of the pieces in the stack thinner than the center of the pieces, it creates room for the flux to get in and protect the steel from any oxidation, and at the same time gives it room to be squirted out instead of trapped by the weld. This is the way I was taught to prepare the stack up and it works, so I do it.

If I'm stacking the pieces alternating between 1084 and 15N20, then I only worry about the 1084 being beveled. I still do a light sanding of the 15N20, but don't worry about profiling it too much.

If I'm putting two pieces of 15N20 in sequence in the stack up, then I'll worry aboiut profiling it to create that room for the flux to get in and out.

Ickie
 
In a steel mill pickling is done with hot hydrochloric acid .You would have to deal with fumes from a health situation ,in a separate building [tends to rust things ] and disposal of used acid. Mechanical removal is better.
 
mete said:
In a steel mill pickling is done with hot hydrochloric acid .You would have to deal with fumes from a health situation ,in a separate building [tends to rust things ] and disposal of used acid. Mechanical removal is better.
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Ok, there's enough reason to drop the idea. I was figuring on maybe cold muriatic or something...that sounds like too much trouble....

-d
 
mete said:
In a steel mill pickling is done with hot hydrochloric acid .You would have to deal with fumes from a health situation ,in a separate building [tends to rust things ] and disposal of used acid. Mechanical removal is better.
Click to expand...

Okay. This is bringing up some very sour memories. I used to work in the Timken Steel mills as a millwright and for about 3 years I was in central maintenance at the Gambrinus Steel Mill. About 300 feet from our shop areas was the pickle house. I used to have to go down there and fix the plumbing, weld the plastic tubs, lubricate the bearings, etc. etc. etc. What a nasty place! Most of the guys that worked there day in and day out didn't have many teeth left. They had special face masks to wear, but they wouldn't wear them in the summer because it would get so stinking hot.

Pickling is not something that a knifemaker really should do in their garage or shop! The fumes are just horrible both from an olfactory and from a health standpoint.

I'm still shivering from the memories.

Ickie
 
If the steel is HR and has the hard crust or has been forged and has flux residue on it, I'll often "Pickle" it--i.e. put it in a pvc tube of hydrochloric to eat it off, then I grind. Otherwise you kill your belts on the scale.

I keep those little acid tanks outside, well away from anything that can rust.
 
Scott, you bring back memories !! We always stopped at the Gambrinus Inn for a coffee break on our way from Harrison Ave to the Gambrinus Mill .Gambrinus is the patron saint of beer and the Inn at night was a tavern !! Iron City beer -brewed with mill water !!
 
Why are you grinding all the scale off in the first place?:confused: Try this - assemble a billet without grinding off the scale. Heat till the billet is red, remove and flux using anhydrous. Heat to 2300-2400 F. then just weld the thing.:eek: I make up billets that are 31 to 32 layers of 1/8 X 1 x 6. Materials are 1080 & 15N20 and they weld up great without any defects. I am assuming you are not doing this by hand but rather a press or power hammer. You are working too hard, there is no reason to grind the scale off, the flux will handle that.
 
mete said:
Scott, you bring back memories !! We always stopped at the Gambrinus Inn for a coffee break on our way from Harrison Ave to the Gambrinus Mill .Gambrinus is the patron saint of beer and the Inn at night was a tavern !! Iron City beer -brewed with mill water !!
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I had a hunting buddy that I worked with at Timken. The Gam Inn was halfway between us. We'd meet there, have breakfast really early in the morning and then leave one car there while we went out deer hunting all day. We brought quite a few deer back to that parking lot and drew a crowd each and every time we did.

Did you ever have a beer at Ida's? It was a couple of blocks west of Harrison Avenue. Back behind the parking lots. The home of the quart beer. You had to buy beer by the quarts there, because they didn't have anything smaller.

I used to drink Strohs back then. Yeeeeuuuuckkkk....youth....

Ickie
 
I was grinding all of the scale off of my 1084 until I went to a hammer-in about 6 years ago and watched several mastersmiths welding up billets with the mill scale still on.

I haven't ground it off since, and have never had any problems.

Not to be rude, but why in the world would you be grinding the precision surface ground 15N20 that Kelly sells??!?!?! :confused:

BTW- I'm just backing up my good friend Bill's post above :D
 
NickWheeler said:
I was grinding all of the scale off of my 1084 until I went to a hammer-in about 6 years ago and watched several mastersmiths welding up billets with the mill scale still on.

I haven't ground it off since, and have never had any problems.
Click to expand...

I'll try one and see how it works for me...

Not to be rude, but why in the world would you be grinding the precision surface ground 15N20 that Kelly sells??!?!?! :confused:
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Ounce of prevention = pound of cure? Really, I was told that surface prep was important, and watching other folks locally struggle at times with scale and slag inclusions has made me really anal retentive about prep and using a minimum of flux. So far it's worked very well. I've only ever had one billet go south on me and it wasn't COMPLETELY bad, just ends that wouldn't stick on the final weld of a composite piece. I cut the ends off and used the rest.

Sometimes you just gotta take a poll and see what the cool kids are doing though I guess :)

-d
 
I tried not grinding HR scale from 1084 some time ago. It is true that most of the time there is absolutely no problem.
HOWEVER, I did notice a small increase in inclusions popping up from time to time. (from essentially zero to one every now and then).
At the time I was doing some Viking swords. There is a Lot of welded surface in one of these and NOTHING is worse than exposing an inclusion as your sanding a 30 inch fuller (Which is when it usually pops up--then it's too late to go back to the forge and fix.) You litterally could loose hundreds of hours.
When the stakes are high, and it's my income at stake, I spend a few extra minutes and make sure those surfaces are clean, especially when there's going to be some difficult welding technique ahead.

Having said that, I agree that the mill scale doesn't usually seem to pose a problem, but doing without has become sort of a "best practice" to me.


I usually just get things CR, and it has no scale. Just clean/degrease it really well and off you go.
 
i agree with the non scale grinders -- i have done it both ways cant tell a diffrence-- but never prep the 15n20 out ot the box in the billet. it dont hurt to grind the scale off if you have the time!! do whatever you are comfortable with. bb
 
Aside from the scale issue, on whether to grind it off or not, what about grinding a crown into the pieces? I've been told that it is very beneficial by quite a few bladesmiths. I've been told that it gives the flux a place to squeeze out of the billet, instead of getting trapped inside. Is it necessary, or is it a waste of time?

Ickie
 
I've never done it.
It seems to me the tightest joints are the best.
The wider the gap, the more likely you'll get contaminants into it (burnt flux, refractory bits, not to mention scale formation on the cracks, exposed to forge atmosphere)
Seems like it would increase the likelihood of trouble to me ... But like you say, there are guys doing it so (???)
 
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