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Acid etching project/shield
Posted: Wed Apr 08, 2015 5:17 pm
by MicRidley
Hey peeps,
After seeing some awesome acid etching on this forum I decided I'd like to try my hand at a few things.
My end goal is to have a thin round sheet of metal over a piece of similarly sized wood and a center boss.
I will be using ferric chloride(possibly the radio shack carried brand)
The sheet will be acid etched with Some design as will the boss.
The shield edged with rawhide and laced.
Boss riveted on. (Ordered a stainless from madd Matt and have some mild steel laying around)
My questions regarding acid etching are:
1) What width of wood/gauge of steel do you suggest as a combination?
2) how do I do a whole 26" diameter round shield at once?
3) how do you generally time mild/stainless steel in the formula?
4) any other advice!
Thanks much in advance!
-Batu
Re: Acid etching project/shield
Posted: Wed Apr 08, 2015 5:41 pm
by losthelm
Acid will etch at different speeds depending on temp and concentration.
Mild will etch a lot faster then stainless. so you may want to do them seperatly and do trial pieces.
Ask madmatt for piece of the same sheet so you can experiment a little.
As the acid etches it will form bubbles that won't etch as long as they are on the surface of the steel.
you can dislodge them by taping the etching tray a little or with a brush.
Doing the entire shield face at once means your working with a huge shallow tray of acid.
building a box and line it with plastic seams an option.
It may be easier to work in slices and overlap them a little, or butt the seam and add another layer.
You can likely use two layers of 1/4" ply wood and 18 or 20gauge steel for the shield.
For some reason two layers of 1/4" seam to last longer then 1/2" ply.
If you have a DC power source such as a battery charger it may be worth researching electronic etching.
It takes longer depending on your power supply but your also not dealing with chemicals you have to order.
What are you using for the resist?
How well does the resist come off after your done etching?
Plan a head.
where are you going to work?
how are you going to store the chemicals?
What do you have to neutralize the acid?
What supplies and PPE do you need?
Re: Acid etching project/shield
Posted: Wed Apr 08, 2015 7:18 pm
by Ursus Epicurius
Make sure you know what you are doing with the leftover acid and byproduct before you start working, that crap is nasty.
Re: Acid etching project/shield
Posted: Wed Apr 08, 2015 9:25 pm
by MicRidley
Thanks for the advice guys
And you're right. I need to think of what I'm going to do with it after Ive reused it too many times..it can't sit in bottles forever.
Suggestions?
Aren't there places normally in each town with waste disposal at the dumps ?
Re: Acid etching project/shield
Posted: Wed Apr 08, 2015 11:43 pm
by losthelm
Most municipalities have annual hazardous waste collections for batteries, chemicals, paint, oil and pesticides.
You may find some helpful info on the chemistry involved searching online.
sculpt nouveau, art metal, or ganoskin, likely will have something.
There are also a few instruct able articles on etching that are useful.
Etching copper is an issue, the copper in solution tends to be toxic to marine life in the cellular level.
That's why some pools and fountains use copper ion units instead of chlorine.
Re: Acid etching project/shield
Posted: Fri Apr 10, 2015 11:59 pm
by Malek
I have done some electro-etching. It was on aluminum, but it worked pretty well.
I got a farm/mower battery and a charger for it.
The amperage of the battery is what helps the etching process.
Got about a 0.75mm deep etch after about 20 minutes.

Re: Acid etching project/shield
Posted: Sat Apr 11, 2015 6:18 am
by Kristoffer
My electro etching attempt was successful and I plan to use it on my 16-th century pieces. I prefer the electro-etching over having acids at home since I dont trust my kids.

- done-small.jpg (70.94 KiB) Viewed 176 times
This was some custom ordered fantasy besagues in brass. It was super hard to get a picture because they were so damn shiny.
I vectorized a drawing and used a plotter to cut out vinyl sticker to use as resist. I transferred the sticker to the brass, taped the back side with electric tape and etched the pieces with a modified battery charger and a saturated solution of salt in water. I used 12 volt but you need to do some sample pieces to get the result as you want it. Please remember to work in a well ventilated area because it smells pretty bad.
You can dip it for a while, take it up and inspect it and put it back in. I will not use the vinyl stickers for armour in the future, i just need to find a good resist product that I can use to paint the pieces with.
Re: Acid etching project/shield
Posted: Sat Apr 11, 2015 10:13 am
by Malek
I used el-cheapo 99-cent rattle-can paint for my resist.
Painted the whole thing then used a lightly modified awl to scratch out the design.
Once my shop is up and running again at the new house, I'll experiment a bit more with things like "Frog tape" and such to see how well it works.
Re: Acid etching project/shield
Posted: Sat Apr 11, 2015 10:25 am
by Kristoffer
Is paint like that easy to scrape off and doesn't peel? I tried enamel paint and had big issues.
Re: Acid etching project/shield
Posted: Sat Apr 11, 2015 11:14 am
by losthelm
A lot depends on the paint and surface prep
Sharpie will work some but its not easy to get an even coat.
Removing paint/sharpie is all about the right solvent.
You can darken the etched surface with liver of sulphur and then buffed the raised portion to add contrast.
In theory there are other options depending on the metals used.
Paints, real glass enamels and such.