chemical etching pen?

W

willy m

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Nov 27, 2007
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i just got the enco flyer for may, on page 41 they have a chemical etching pen for 7.49 made by spi. says;" use on heavmetals,stainless,iron,copper,brass,lead,and tin. special acid flows like ink in a felt tip pen. no electrical flux necessary. leaves distinct smudge proof black markings." it doesnt say what type of acid is used. has anybody seen or used this before? could you cover the area in wax and remove the area to be etched. apply acid wait and then rinise with water or baking soda then remove wax? does anyone know if that would work or not? i have no experience with chem. at all!...willy:confused:
 
I have one of those pens and I have experimented with it. The marks I made were not as deep or permanent as electro chemically etched logos usually are. I can't recall exactly how it went but I think I was able to damage the etch just by rubbing it with with my fingers and some 1500 grit sandpaper completely removed it with like 2-3 passes. I was applying the acid multiple times trying to develop the etch as much as I could. If you just draw on the metal, it leaves a yellow mark, with more dabbing it turns brown and then darker gray-brown. The marker is good for writing semi-permanent notes on metal but I don't think it's a good alternative to electro chemically etching.

If you search around the forum here you can find instructions to make a cheap etching device out of a salvaged 9V power converter. There are tricks to avoid purchasing stencils. You can create a stencil/mask by painting some fingernail polish on the blade and then scratching your logo thru the paint, before etching.
 
I have seen some marks with these pens and they are not suitable for marking your logo. The leave you with a really like grayish mark on your steal.
 
If you intend to use wax as a resist you can use "aqua regia" (acid) to etch your blade. Be carfull this stuff will burn a hole through to China. It is made by mixing two acids, I forget which, though someone here will know.

Aussie maker John Jones has been using this method for close to 30 years and produces an excellent mark. It only takes about 30 seconds.

Peter
 
I also have one of those, and like Rob says, the etch is not good.
It's a pen with cold blue in it, and not good blue at that.
It's been gathering dust since about 1984-5...
Electro-chemical is the way to go to get depth to the etch.
 
Willy,

Below is a test I did a while back. I used the etching pen on the left, and an electro-chemical etcher on the right. The acid mark is actually a brownish tinge, not the black they claim. I don't remember how I cleaned it off after using the acid, but I probably just washed it with soap and water. As you can see, the electro-chemical etch is much more uniform. It is also much deeper. After this, I decided that the acid pen is probably only good for marking extra bars of steel that are laying around (and I actually use a paint marker for that).

Two-etches.jpg
 
We use them at work to mark gears.. The ones we have you put your marks, and then wipe it down with neutralyte. Don't look that good but they stay on inside transmissions.
I have never used one for my stuff.
 
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