Got Ferric?

Can't touch that! They do not sell to individuals. You must have a business license.

Funny how stuff like that can shut down a good supply really quick.

Doc
 
Time to start an LLC, Doc? I did. It was the best thing I did for my taxes. No sales tax and no income tax in NH, but the Feds and State property taxes will give you a good whuppin. I had to do something. Well worth the money to license your trade name.
 
0.025% w/v sounds a little low to me, as if it's a titration reagent as opposed to an etching solution. If I remember correctly, the stuff for PCB is 30% or more.
 
Good point Mike.....I missed that.

I have no need to incorporate at this point, and have enough electronics supply houses here to keep me in Ferric for the next thousand years. It kinda helps that I live in an electronics mecca.

Doc
 
fitzo said:
0.025% w/v sounds a little low to me, as if it's a titration reagent as opposed to an etching solution. If I remember correctly, the stuff for PCB is 30% or more.
Click to expand...

But we dilute the stuff anyway. I ordered two liters. Should be fine. Dammit, Mike, now you got me worried...
 
Okay then, Fitzo! Check THIS out and see if you think this is worth getting:

Crystal Ferric

I'm thinking I get this and mix it with distilled water to the solution strength I want. Anyone ever try this? I've discovered my pot full of ferric is flat as a cowpie in the rainy season. I need more!
 
You might want to have some test scrap laying around when you start diluting that. You may end up with it so strong it eats anything that comes in contact with it......lol.

Doc
 
I cancelled the order from Lab Safety and bought this:

Ferric

I bought 5 jars of it. That should make five pints of copper-etching strength.
 
That's a much better choice, Jeff. I sincerely think the other stuff is way too weak. I went and found the MSDS for PCB Etchant earlier and it said the concentration was 32-45%.

I also just checked the price for reagent grade ferric chloride crystals at VWR Scientific, and they wanted $95/250grams of the high-purity stuff, so the $12/100g is a fairly good price provided HAZMAT fee doesn't apply.
 
Now that final stuff is an excellent price!!

You'll also find it'll make up a helleva lot more than a pint of the concentration we need for blades. Some folks dilute it 1:5 with distilled water, so that is down in the 6-8% range.

Good find, Jeff!
 
fitzo said:
Now that final stuff is an excellent price!!

You'll also find it'll make up a helleva lot more than 4 pints of the concentration we need for blades. Some folks dilute it 1:5 with distilled water, so that is down in the 6-8% range.

Good find, Jeff!
Click to expand...

Well I was diluting the Archer stuff 50/50 with tap water. It worked well, but it did take a while. This new batch is going to be better. Hey I also found some great patina recipes on that second site I listed...
 
Jeff, if you have hard water or softened water it will immediately neutralize a lot of the acidity of the ferric chloride, causing premature depletion. I'd strongly recommend distilled water. I purposely tried diluting some in hard Lake Michigan water, once. It killed it. Lesser concentrations will also result in a greater degree of etching difference between the two steels. I simply thought 0.025% may take a few too many years. ;)
 
The ferric chloride will get "used up" over time. Each ferric chloride molecule will pull only so many copper or iron attoms off the item being etched. Old etchant will take a lot longer than fresh etchant. I also used to get crud deposited on my circuit boards when using old etchant.

Ferric chloride will dissolve many substances. My high-school electronics teacher put some in an aluminum baking tray and left the room. When he came back a half hour later, the room was full of smoke, there was no evidence of the pan and there was etchant all over the table and floor. We got a good laugh out of that one.

The etch rate will increase at higher temperatures. I have seen circuit boards etched really fast by putting the etching tank on a hot plate and boiling it. When doing this, it seemed that the edges where the piece was masked off was more ragged than when etching more slowly.

When etching large pieces, it may help to aggitate the etchant. Otherwise, some parts may etch faster than others. An aquarium pump bubling air at the bottom will do.

To get consistent results, keep it clean, use reasonably fresh etchant and the same temperature each time. That is what the circuit board manufacturers do.

Oh yes, only store it in tighly sealed glass or plastic containers. A metal top on a glass jar may get eaten by the fumes over time. I seem to remember that the crystaline form of ferric chloride will absorb water from the air around it. This makes it form into a hard cake in the bottom of the container. It also never seemed to work as well for me when this was allowed to happen.

Hope this helps.

Phil
 
pso said:
The ferric chloride will get "used up" over time. Each ferric chloride molecule will pull only so many copper or iron attoms off the item being etched. Old etchant will take a lot longer than fresh etchant. I also used to get crud deposited on my circuit boards when using old etchant.

Ferric chloride will dissolve many substances. My high-school electronics teacher put some in an aluminum baking tray and left the room. When he came back a half hour later, the room was full of smoke, there was no evidence of the pan and there was etchant all over the table and floor. We got a good laugh out of that one.

The etch rate will increase at higher temperatures. I have seen circuit boards etched really fast by putting the etching tank on a hot plate and boiling it. When doing this, it seemed that the edges where the piece was masked off was more ragged than when etching more slowly.

When etching large pieces, it may help to aggitate the etchant. Otherwise, some parts may etch faster than others. An aquarium pump bubling air at the bottom will do.

To get consistent results, keep it clean, use reasonably fresh etchant and the same temperature each time. That is what the circuit board manufacturers do.

Oh yes, only store it in tighly sealed glass or plastic containers. A metal top on a glass jar may get eaten by the fumes over time. I seem to remember that the crystaline form of ferric chloride will absorb water from the air around it. This makes it form into a hard cake in the bottom of the container. It also never seemed to work as well for me when this was allowed to happen.

Hope this helps.

Phil
Click to expand...

Thanks, Phil. This is really great advice. I've kept my ferric in a 4" pvc pipe until now. One end capped, and the other left unglued. This worked well for a long time but I am ready to try something new now.
 
"Oh yes, only store it in tighly sealed glass or plastic containers."


I got about 200 of these surplus valves from a place that went out of buisness. I came up with a use for them after storing them in my garage for a year. When the valves are closed it forms a water tight seal.

I cut the PVC tube long and when the valves get to nasty to use any more i cut off the old valve and glue on a new one. they work great. I have one with etchant and one with water and baking soda to nutralize the etchant.

please see pics for more details.

they also make great blast gates for my air filter system

Thanks
Michael
 
adammichael said:
"Oh yes, only store it in tighly sealed glass or plastic containers."


I got about 200 of these surplus valves from a place that went out of buisness. I came up with a use for them after storing them in my garage for a year. When the valves are closed it forms a water tight seal.

I cut the PVC tube long and when the valves get to nasty to use any more i cut off the old valve and glue on a new one. they work great. I have one with etchant and one with water and baking soda to nutralize the etchant.

please see pics for more details.

they also make great blast gates for my air filter system

Thanks
Michael
Click to expand...

Golly, I have to admit that's a sweet little setup, Michael! I have a 4" pvc pipe construction adhesive-glued to a chunk of plywood to keep it from tipping. That looks like a dandy setup, though! I may have to try something like that. Did you make the stand, or was that mamma's plant stand in a former life? :eek:
 
That was a rummage sale find, that and almost everything else in my shop.
Thank God for GoodWill Stores and rummage sales.

If you are interested in a couple of those valves let me know, ill send you 2 of them.

Michael
 
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