etching - confused newbie

[Rivkin]

Dear All !

I've read megazillions of pages on etching, and now I'm really confused:

Background: I want to etch a blade, about 17 inches long, potentially mechanical damascus. The blade is from a museum (still had a catalogue number "dotted" on it), where it was cleaned very well - the surface is non-shiny gray.

Things that I can't seem to find out:

a. Should I dunk it into the acid, or should I use swab and put the acid on it ?
First things seems complex - I don't have plastic bottles 17 inches high.

b. Should I let it sit for an hour, or should I let it sit for a minute, wash with soda or Windex, grind with paper, and repeat the whole process until reaching the desirable result ? Should I use sharpening stones (I would like to sharpen it a bit) after or during the etching ?

c. Some recipes categorically recommend FeCl, some go for vinegar, in between we have mixtures of cider, juices and coca-cola. Should I start with vinegar ?

d. Can I use my sink or pro-chemistry lab (have one available) do better ?

e. Should I preheat the blade couple degrees (don't want to go to high T), or it really won't make such a difference ?

Please help a dumb newbie !

Sincerely yours,

K.Rivkin

[Andrew]

Others here have done this much more than I, and will have better advice. However, my personal advice is to go slow. Start with weaker acids (FeCl is strong stuff). Try wiping on warm citrus fruit juices to see if you get the effect you're looking for. Keep a bottle of base nearby (baking powder dissolved in water works well) to neutralize the acid when the desired etch is obtained.

Soaking for long periods of time can be problematic. (Don't ask. )


Incidently, Rivkin, what kind of blade is it?

[tom hyle]

If you do any sharpening it's best to do it before the etch for a more even surface appearance and a possibly microserrated edge, or after the etch for a smooth, polished edge that will hold and will cut smoothly. I prefer an acid bath for a naked blade, if you can suspend it in there, preferably vertically, without the flats resting against anything that might leave a mark (what was that..."don't ask"....?). If you go with a wiped on etch, the trick is to keep the whole surface constantly and consistently wetted, and to not create a false grain affect with your wiping motion. Acid is tricky, and old alloys vary tremendously. Watch that stuff closely 'til you know it well, then you'll know to watch it closely ;D

[Rivkin]

Thanx a lot, the blade is this one:
http://www.vikingsword.com/vb/showthread.php?t=152

I think I'll try 1:4 vinegar or lemon juice first.

[Jens Nordlunde]

Have a look here http://www.vikingsword.com/vb/showthread.php?t=157
it seems as if Spunjer has tried alum, and that it works slowly.
I know that some build a bath of plexiglass for the etching, so the blade can hang freely, and you should at the same time be able to keep an eye on how the etching is going.
I fully agree with Andrew and Tom, don't rush it, if you don't suceed the first time, clean the blade and start all over again.
Good luck
Jens

[Yannis]

Etching long blades is really a problem, specially if you cant unmount the hilt.

(For "newbies": Do NOT touch a hilt from organic material with acid!)

For knifes i use a big jar were i can bleach all the blade and feel safe about the hilt. This way a solution 1/3 of vinegar for few hours gave me exelent results. Maybe a different solution or time could do something better. I dont know.

I prefer vinegar for 2 main reasons:
1. It is cheap and easy to find
2. In my country we produce a lot and it is "traditional" to use vinegar for thousand of actions, among them to clean things (my wife use it for cleaning the carpets )

A friend sugest that for a long blade we have to make a "bath" from adhesive tape like this: [_] where [ and ] are the sides of the tape and _ is the blade. I have not tried it yet but it looks ok and I will do it.