Etching

Bee's wax will make a decent resist. Paint it on or dip the blade into it while it is fluid, them scratch the design into the wax. I don't remember which acid I used so many years ago, but it may have been nitric

Resist: Bees wax or the tarry stuff used to paint cut surfaces where tree limbs once attached.

Etchant: Ferric Chloride

These things are sold at electronic supply houses for making printed circuit boards.

In the 1970s in Baltimore I used the wax plus ferric chloride approach to etch a friend's name into his knives - he worked as a cook, and wanted his knives to stay his.

A year later, he was going to work on his motorcycle and was stopped by a traffic cop, who found the knife roll and charged him with carrying a deadly weapon.

The Judge took one look at this 10" chef's knife with BARTLETT etched into the blade with 1" high letters, said that this was clearly a tradesman's tool, and dismissed the case.

Joe Gwinn

Then Bee's wax it is . Thanks I will pick some up tomorrow . Ken Cutt

Thanks . I don't know of any electronic supply places any where near me but I will start checking tomorrow . Would there be much difference between this and hydrochloric acid ? Ken Cutt

Radio Shack

One can get such chemicals by mail order, from Allied or Newark.

Local stores are unlikely, unless you live in a major urban area.

Ask local electronics nuts where the stores are.

Ferric chloride is not volatile (won't evaporate), is easier to control and is safer, and for those reasons is a standard etchant for steel.

Joe Gwinn

How does it bite, compared to nitric? Does it undercut? Do you have to etch in multiple bites?

-- Ed Huntress

Joseph Gwinn fired this volley in news: snipped-for-privacy@comcast.dca.giganews.com:

Y'know, I've used ferric chloride to etch zinc, aluminum, and copper. But I never thought to use it on any iron-based alloy.

I'm a bit confused about this. Is the ferric chloride actually etching the iron, or just leaching other metals out of the alloy?

The reason I ask is, ferric chloride is chlorine and iron in its most stable dimer state of Fe2Cl6. It can dissociate/reassociate bidirectionally in aqueous solution to/from FeCl3, which is also stable.

So... my read is that it cannot actually etch iron. It can "stain" or "reveal" features in iron by leaching out other metals, thus leaving a distinct marking on the metal -- but not actually removing any significant mass of the "etched" area.

When I think "etched", I think of fairly deep removal of the surface metal -- i.e. "dissolved". My best bet is that your friend's blades felt essentially the same across the "etched" areas as in all other areas of the blade.

Yes? No?

LLoyd

Ken - maybe search this group or google for electrical or electrolytic etching. I have not done it at home but recall reading about it (probably here!) - if I recall correctly you can use an auto battery charger and the etchant was quite a bit safer than ferric chloride or acid.

I used a system years ago for marking tools & prototypes that used some sort of waxed paper which was marked in a typewriter (remember those?). A mesh or something was used to clamp the paper to the workpiece. The paper was flooded with electrolyte and the mesh & workpiece hooked up to a power supply.

"Lloyd E. Sponenburgh" fired this volley in news:Xns999D6338FBD7Clloydspmindspringcom@216.168.3.70:

Hmmmm.... maybe I "oops'd" a little. Running the redox again, FeCl3 could dissolve some iron to yeild FeCl2, but it would be darned slow... maybe hours in the solution, unless heated nearly to boiling, and with lotsa agitation.

Was this the case? (I try to learn somethin' new ever day. Usually it's the "wrong" stuff that ends up surprising me.)

LLoyd

Good for you to help your nephew.

Get him the book "Step-by-Step Knifemaking: You Can Do It!" by David Boye. It was published in 1977, and is still available in paperback at Amazon.com

for $14.93.

He dedicates an entire chapter to etching, with plentiful drawings to explain the process. I don't know how good these are in the the paperback version, I have the hard cover.

As a resist he uses a mixture of equal parts by weight of beeswax and asphaltum. He explains how to mix them properly, and how to apply to resist properly to the blades to be etched.

For acid he uses Aqua Regia

This is an acid mixture that I as a goldsmith am very familiar with, since it is the only acid that will dissolve gold.

I want to strongly caution you, that using Aqua Regia (as well as any other acid used to etch steel) is risky and possibly very dangerous if not used carefully and properly. Mixing acids is extremely dangerous if not done properly. Especially when mixing with water to dilute the acid.

Do not let an 11 year old do this without supervision. I am not suggesting that you would, just want to make sure.

Yep. I've etched stainless with FeCl3, it took half an hour to go 5 mils. Turned a sheet of shim stock into custom-size washers that way.

Marking, though, doesn't need much penetration. I've also (accidentally) got a little oxalic acid (used for bleaching wood) on a stainless knife, and it left quite a mark, frosting the surface (which started polished).

Which is best, I wonder: polish the blade, then etch to make a frosty mark, or etch, blue the blade, and polish to make a contrasty mark?

No more Radio Shacks here , now the Source . I will check them out . Thanks Ken Cutt

My nephew does not live near me and is here as a holiday until school starts . The etched design was an after thought or I could have done my homework ahead of time . So for this project it is going to have to be the stuff I can get my hands on the fastest . Thanks Ken Cutt

I like the idea of using paper to hold the acid in contact . Thanks Ken Cutt

Hi Abrasha good to see your name attached to a post here again , seems like its been a while . At 11 he is still young enough to not mind a high level of supervision . No doubt that will change as he gets older . Being as his first attempt turned out so well the level of expectation is very high for the second attempt . So it is pushing me into new learning experiences , always good . I picked up the bees wax today and hopefully some acid tomorrow , should have the blank ready to etch by Sunday . Thanks Ken Cutt

I've never used Nitric Acid for etching, so I cannot offer a comparison.

I've etched carbon steel (1095) and high-carbon stainless steel (like

440C) with wax resist and a cotton swab soaked with concentrated ferric chloride solution at room temperature, sweeping over the area to be etched manually. I don't recall how deep it went, but it was not superficial. I recall it taking ten or twenty minutes total, but I was talking as I did it, so I wasn't keeping score.

Joe Gwinn

Thanks. If anyone has compared it with nitric acid, I'd really like to know.

-- Ed Huntress

Ferric chloride is not chlorine and iron.

Ferric chloride can be reduced to divalent iron chloride.

Ferric chloride is not stable in the presence of a strong enough reducing agent. Iron metal is a strong enough reducing agent so the reaction takes place and the iron dissolves.

The net reaction is 2Fe+3 + Fe(metal) ---> 2Fe+2 (the chloride does not change valence)

Your read is incorrect.

Ferric chloride can indeed dissolve metallic iron. The amount dissolve depends on the quantity of trivalent iron available.