Preserving etching patterns

Date 12-07-2007 14:58

For carbon steel I use Nitric acid and then immediately rinse and quickly use compressed air to dry and then coat it with a quick shot of clear poly.

...but I'm not familiar enough with etching the different grades of Stainless to help, but there are others here who know the magic potions you request.

By jwright650 (*****)

Date 12-07-2007 15:05

Quick search of the forum resulted in this.....red down the page, post by G.S. Crisi spells it out for you.

http://aws.org/cgi-bin/mwf/topic_show.pl?pid=27575;hl=etching%20solution%20for%20stainless%20steel#pid27575

By hogan

Date 12-07-2007 15:24

i believe that you can also etch ss while hot, by brushing with fat.

By rlitman (***)

Date 12-07-2007 18:51

From a different perspective:
I've used ferric chloride (available in small quantities at radio shack, as a circuit board etchant), to bring out the differences in damascus steel. I've used it on both home made/forged damascus (layered from old band saw blades and shipping crate straps), and on sweedish "damasteel" stainless (georgous, but WAY expensive). I know damasteel makes an austenitic grade as well, but don't know how easy that is to etch.

Just polish first, and then mask the areas you want to etch. I've had luck masking with a sharpie magic marker, but sometimes the marker doesn't give a thick enough coating so you should go over it a few times. Shellac (with a tint added to see where it is), is basically the same thing. Nail polish, would work too. Anything that would give some level of "stick" to the polished stainless. You don't need a permanent coating. It just has to stay around long enough to survive the etch. Etching takes a minimum of 20 minutes. You'll start seeing results sooner, but you want a complete and even finish. It may take an hour or so, depending on your preferences, the alloy, and age/strength of the etchant.

-- Robert

By DaveBoyer (*****)

Date 12-08-2007 05:10

One of the guys on Forgemagic.com made a pattern welded pizza cutter, but I havn't heard of a pattern welded tatoo gun before.

By Plasma-Brain (**)

Date 12-08-2007 19:02

Robert, Im trying to get the effect over the entire peice, so im not sure id need to mask it, however that is a good idea and it might be fun to try...
You mentioned that you make your own damascus with bandsaw blades, ive heard of damascus steels before but i was under the impression they were a "lost art" and that the patterns that modern damascus blades were just laser etches. If im wrong, please correct me because ive had a strong intrest in damascus blades but never any information about them, especily how they are made.

Dave, a pattern welded pizza cutter? I just woke up a few min ago so im still a little fuzzy but im afraid youve lost me...
with the tattoo gun i was just wondering about how to marco-etch (i think) to bring out the crystal structure for asthetic value. I was going to weld patterns on it first (or just run a tig puddle without filler rod) and probibly use my plasma cutter to gouge patterns in it ( i have a gouge tip for it).

For an idea of the size and shape,
Id probibly be using 2 to 3 inch solid Stainless bar stock with holes drilled through it. Id then weld/ gouge any patterns id want into it, then polish and etch any surface that needed/wanted it. after that id seal it with a nice durable UV stabilized poly coat.

gots to go for now,
- Clif

By DaveBoyer (*****)

Date 12-09-2007 04:49

Pattern welded steel is made of layers of different materials chosen for their differing colors when etched, This is not a lost art, there are bladesmiths and blacksmiths all over the world doing it every day. The layers are forge welded together, then twisted, sawn & re stacked etc.& re-welded to develope the patterns. There might be some fake "damascus" blades that are laser etched. The pizza cutter comment has to do with a blacksmith I know who made a pizza cutter from pattern welded steel, just for the visual effect.

By Plasma-Brain (**)

Date 12-09-2007 19:37

Ahhh, ok i see now.

Along those lines... any idea what would happen if i was to go get a pound of a CP titanium tig rod and put a few dabs on the surface of a stainless peice?
I wanted to do the same thing with some nickle rod and or any other kind of metal I could get my hands on, then grind and etch it.

Theres an article in this months Welding journal in the research part that has some cool micrographs of Ni/Cu welds thats inspiring me to try diffrent mixes of metals...

-Clif

By DaveBoyer (*****)

Date 12-10-2007 03:43

I guess any weld that will stick to the parent metal is worth a try, but for all that really neet grain to be easily seen You might need a microscope. There are outfits that sell pattern welded blanks, check the blade forums. Those guys could probably make You some material that suits Your needs better than a blade blank. Another process for You to check into is Mokum Gane, but I might not have speeld that right.

By Plasma-Brain (**)

Date 12-10-2007 13:47

Mokume-gane, just looked it up on wiki and yeah thats a really cool effect. Might be a little more expensive than I was thinking for the start... what with the gold and silver involved, but thats something ill keep in mind for later when i have some more money on hand.

Something else I was thinking of, using metal powders for spraying operations.
Mix and match the powders then zapem with the tig, only problem is that I dont know where to get the powders.

Any ideas?
-Clif

By rlitman (***)

Date 12-10-2007 20:23

Mokume-gane (in metal), is frequently done with copper and nickel. Relatively inexpensive.
Yes, my use of the word "damascus" was technically incorrect. The procedure used in making "damascus" steel is indeed lost, however forge welded layered steel is well understood.
Pattern welded steel is frequently called damascus, whereas when softer metals are used, its called mokume-gane (mokume itself is often done with colored clays).

Katana blades are properly made from steel that is many layered (of one alloy however), by the process of fold, forge weld, repeat. When done with one alloy, the layers are a little hard to discern with the naked eye, but probably because of the surface local decarburization in the forge, they are visible.
You can forge weld together two or more different alloys in layers, with a resulting increase in contrast, which can be brought out even more by etching.
The cool part, is manipulating the metal in ways that alter the pattern of the layers in three dimensions. One of the simplest patterns is the twist.
I took 7 layers of box straps (clean metal), spaced between 8 layers of carbon steel bandsaw blades, forge welded them together into a relatively square cross section, then twisted along its length, then forged out into a blade. Stock removal and forging alter the pattern into really neat shapes.
A neat scaly effect comes from forging steel cable into a blade.
Its very much like how the colors get into candy canes (or those peppermint candy rounds). At the New York Custom Knife show, I've even seen mosaic patterns such as animals or the american flag, worked into the side of a blade (these guys are -way- beyond my abilities).
The damasteel that I mentioned is made by a Swedish company which produces their own alloys from powdered metal, vacuum sintered into billets, and they then forge in the pattern themselves. A bar of billet blank for your a tatoo gun would probably run $50 or so, depending on your supplier.

Of course, there are blade makers out there, who choose the cheap way out, and just etch that pattern onto the metal . . .

BTW, if all of what you're doing is in stainless, I wouldn't put a poly coat on it. I'm not sure how well poly will stand up to an autoclave (for sterilization), but stainless (if you choose something austenitic) will be fine on its own.

As for powdered metal sprays. I always thought that field was dominated by eutectic castolin. If you -need- a certain alloy, they can be a lifesaver, but for playing around, their prices can be outrageous. OTOH, I've seen some random lots of their powders on eBay for a song. Using TIG to fuse them. Interesting, never thought of that one.

By Plasma-Brain (**)

Date 12-12-2007 13:33

Neat ideas, most defently, but it brings up a few questions.

I guess the first would be if you can hot work stainless the same way you can carbon steels, or what special conciderations one would have to take in order to do so.
also, if you dont mind sharing, how are you heating the steels your working with? do you have a forge set up or do you use a rosebud on an ox/act torch?

Thanks for the replys
-Clif

By rlitman (***)

Date 12-12-2007 15:38

I made my last blade blank on someone else's coal forge. Yeah, a forge of any kind is easiest.
A rosebud should work for small pieces, but if you're using a torch, a gasaver is almost a necessity, or you'll spend most of your time adjusting the flame.
You could make a rudimentary forge with some firebricks (or kaowool), and a torch.
I actually use a welding/brazing tip with oxy/acetylene a lot, for more localized heating, but with the gasaver, its real easy to just pick up the torch, heat, put the torch down, and work.

Any hot work with pattern welded steel needs to be very careful (stainless or not). The forge welds in any steel produced in a non-inert process are weaker than the base metal, and can open up (vacuum welded stainless is better about this), and the forge welds also can create internal stress risers leading to cracks in odd places. Its kind of like working with wood with a grain, in that you want the grain to go with the piece, and not against it (especially at a high stress area, like a tang).

As for stainless:
My work with damasteel has been stock removal, and I've never attempted to hot work stainless (other than TIG, or plasma cutting, if you consider that hot work).
It should be malleable enough to be worked a bit though.
I know that any hot work on stainless needs to be finished with some amount of stock removal and/or treatment, to preserve the metal's corrosion resistance.

By DaveBoyer (*****)

Date 12-13-2007 05:21

Clif: Look at http://ronriel.abna.org/design1.shtml for a great website on propane forge and burner design. My gasser uses a slightly different burner than the ones He shows, I built Mine with what I had laying arround My shop. I have only welded in a coal fire, but it can be done with a gasser if You build it properly.

By Plasma-Brain (**)

Date 12-13-2007 15:25

Dave, the link isnt working right, it brings up the "page cant be found" error.

Ive been looking into trying to get a hand cranked air blower and using a coal fire for a forge. A local "old timer" metal artist showed me his shop one day and he had a small forge with a little squirrle cage blower on a hand crank and holy poop did it move air. 3 good cranks and it would bring the fire up to temp with very little effort.
And I kind of like the idea of muscle power over electricity or propane just so I wouldent have to worry about the cost of either.
Not knockin on other methods... im just a poor college student so having a way to make money without having to spend as much is what im after :).

Robert, what exactly is a gassaver? is that something that adjusts the flame automaticly?
Also, with the stainless, would a pickeling or passivating (cant spell) paste/gel be used to restore the corrosion resistacne after heating and working?

thanks again,
Clif

By rlitman (***)

Date 12-13-2007 20:20

Yeah, hand cranked is nice. The cranking motion is actually kind of theraputic, and it gives the best control for coal (not to mention that it saves coal when you step away).
I've seen riveters forges with hand cranks, but they're kind of expensive. I guess demand is high. My forge is natural gas, and runs of the feed for my barbeque.
If you choose coal, I just hope you've got some distance to your neighbors. The sulfur emitted on startup is afwul. I live in suburbia, so coal is out of the question at home.

As for a gassaver. Well, with reference to oxy-acetylene (there is a completely different device of the same name used for TIG), its a hook that you hang your torch on, where the weight of the torch on the hook closes a pair of valves, cutting off the gas flow. Most also come with a pilot light, so you can just pick up the torch and wave it past the pilot light, to get right back to the same size and mix flame you had. I've done a number of ornamental copper projects (rain chains, ornamental electric fence to go around a koi pond, etc.), where there's lots of time positioning pieces, and a few seconds to make the next brazed joint, where this -really- saves time.

Yes, passivating is exactly what's done to restore the corrosion resistance of stainless after hot work (even welding). BUT, it can only help so much.
Deep grooves, voids, or roughness, are great initiation sites for corrosion. When heated in a non-inert environment, you will also get a thick nasty crust [technical term :) ] which needs to be removed mechanically. I've heard that solar flux can help reduce this (seen it used for knife heat treatment, to limit this scale). I've also seen stainless foil used to cover parts (good for heat treatment, but useless for hot working). Chemical or electrical treatments will only go so far, and cannot really remove fire scale.
Personally, when I've finished grinding and polishing, I give a very vigorous brushing with a stainless brush, and then thoroughly rub the part down with Bar Keeper's Friend. The oxalic acid in it, helps to passivate the metal, but its is a whole lot less toxic/caustic/dangerous than standard pickling chemicals.

By DaveBoyer (*****)

Date 12-14-2007 04:13

Coal is fine IF You can get good soft coal. That is not a problem where I live. Hand cranked blowers are not too hard to find in Pensylvania, but I don't know about where You are. Real charcoal works well and isn't as smokey if that is an issue. An advantage of a hand cranked blower is that You tend to burn up less work, because You are right there cranking. Any small blower, hand or electric will work to some degree. My coal forge is fabricated from 1/4" plate steel and angle iron, You could build one pretty cheap. I might have gotten the link wrong, You can find it on anvilfire.com under "Navigate Anvilfire"in the links section.

By Plasma-Brain (**)

Date 12-14-2007 13:51

Yeah you guys are right, charcoal is what id be using when i get it set up, i forgot the "char" when i posted.

Im up in New York by Albany and I havent been able to find anything other than a hand cranked grinder.
Its a neat old tool and im looking to see if i can just find a blower with a pulley mount so i can rig it up to the grinder shaft.

Those gas savers sound cool but I dont use my torch enough to warrant getting one at the moment, but ill keep it in mind because im sure ill have a need for it some day.
For cleaning the "thick nasty crust", a stainless wire wheel on a 5" grinder and a dremel w/wire wheel for hard to reach places and cravases, then hit it with the surface treatment? Also where can i find this Bar Keeper's Friend that you speak of?

thanks again
Clif

By rlitman (***)

Date 12-14-2007 21:19

Stainless wire wheel for removing fire scale. Might work, might not be aggressive enough. No harm in trying though. You could always use a flap disc on stubborn areas.
Yes, real charcoal does work, and burns quite cleanly, but it also burns quickly. You'll be refilling your forge about four times as often as coal, although some time is saved in heating/converting the coal into coke. That, and charcoal doesn't work so great in a coal forge. It really needs something a bit deeper, so since most of the old forges I've seen (and the infamous diy "brake drum" forge) were designed for coal, you might want to just build something. Other than the tuyere, a well built forge should last your lifetime.

As for BKF. Its on the shelf with comet and ajax at your supermarket. It uses oxalic acid instead of bleach (found in comet et al), so does a great job on rust.
Have you ever noticed pieces of flatware that come out of the dishwasher with rust spots. Those spots on the stainless have gone active, and simply rubbing the rust off doesn't help, because the next time you put them in the dishwasher the rust spots come back. The oxalic acid in BKF can gently passivate those spots, and stop them from returning (just trying to take an example from real life here). Just be sure to rub it in with something non-metallic (scotch-brite, scrubby sponge, rag, etc). Rubbing stainless with steel wool (or bronze wool, or even stainless scouring pads), can re-activate the metal.
REAL passivation done industrially usually uses Nitric Acid, but that's probably not the best thing for you to use.

By DaveBoyer (*****)

Date 12-15-2007 05:44

rlitman mentioned that the charcoal firepot needs to be deeper, 6"+ deep should work OK. Fabricated forges and firepots work fine, and when You burn it up You just rebuild it, You are a welder. To find a blower, or any other used smithing equipment You need to go to a "Hammer In". There are always guys selling stuff out of the back of the truck, this is called "Tailgating". Go to the "Virtual Hammer In" section at the Anvilfire.com website and ask about any events near You, and any equipment You want to purchase.

By Plasma-Brain (**)

Date 12-16-2007 14:16

Well, as for a deeper forgre for charcoal, me and my buddy just finished building a grill that were pretty sure will end up doubling as a forge.
Its a peice of 1/4" pipe, about 16 or so inches deep that we welded 4 1/2" legs too.
For the moment its just a grill, but once i get my hands on a blower were hooking it up and putting it to work makin parts instead of steaks :)

thanks for the replies

-Clif

By DaveBoyer (*****)

Date 12-17-2007 05:07

Clif: Find some pictures of forge firepots on the web. This is what You want to build. Generally a firepot is about 10-12" square [or round] at the top and about 4-5" square [or round] at the bottom, 4-5" deep for coal or 6"+ for charcoal or coke. The air usually comes in from the bottom on American designs. It can come in past a clinker breaker or through slots or holes. Small slots or holes clog up easily, a single 1"-1 1/4" hole will work, a modification of this theme is a 3/4" long pipe sticking up to keep the air hole above the junk in the bottom of the fire. You work in the upper third or quarter of the fire, Your work is covered by the burning fuel, not laying on top of it. By staying high in the fire You keep oxidation to a minimum as the oxygen is used up that high in the fire. The tapered walls of the firebox helps in fire maintainance, which is an ongoing chore.

By Superflux (****)

Date 12-20-2007 03:28

Hair dryer with a light dimmer switch makes an xlnt coal forge blower. "The Pattern Welded Blade" by Jim Hrisoulas will get any questions answered about beginning Damascus. And yes those cheap pieces of feces are laser etched. IMHO Damascus is a beautiful medium for blades, however, modern metallurgy has improved on cutlery steel. ATS34 is the ultimate if properly heat treated.