# Big Silver Relay



## Patrick_R (Feb 1, 2012)

Weighing in at 545g. I have 3 of these relays at present time but have access to about 100 lbs more if I get these apart. They have 2 silver contacts which I would guess at 1oz or so. The one in the pics I tried heating with my torch (acetylene) for quite some time, got frustrated and hooked up my mapp gas torch and hoped the extra heat would help, no such luck. The copper wicks away the heat far to fast. I believe that they have been assembled with silver solder.

If anyone has suggestions on how to get them off I would be very thankful. Currently, Heat doesn't seem like an option.

Thanks

Comrade


----------



## Geo (Feb 1, 2012)

the only chemical way i can think of is to cut the copper as close to silver pad as possible and then run through AP. it may take some time bu its sure to remove the copper and leave the silver intact.


----------



## Patrick_R (Feb 1, 2012)

What would you recommend to cut the copper?


----------



## patnor1011 (Feb 1, 2012)

You wont be cutting silver would you?


----------



## Geo (Feb 1, 2012)

hacksaw comes to mind as you only have the few.


----------



## Patrick_R (Feb 1, 2012)

If I get the contract to do 100+ lbs. Hacksaw seems painful


----------



## Geo (Feb 1, 2012)

acety/oxy is plenty of heat. was you heating the pad or the copper? heat the copper behind the pad. place the piece in a vice or stand on its side and the pad will slide right off when the heat gets high enough.WARNING : cadmium may be present in the solder.heating this solder might release cadmium fumes.DO NOT BREATHE THESE FUMES. they are poisonous. do not handle pieces with bare hands until it is washed. wash everything when done and take a shower to remove residue wash clothing separate from household laundry.


----------



## Geo (Feb 1, 2012)

reciprocating saw works well too. try to stay away from the high speed circular saws.


----------



## Barren Realms 007 (Feb 1, 2012)

Take you some bricks and build a small horizontal furnace out of them lined with sheetrock on the sides and bottom. Lay bricks on top so you can move one to access your material. Set your MAPP tourch to blow thru the furnace, once the material starts to heat up you will be able to remove one and finish heating with your oxy/act and remove the contacts.


----------



## Patrick_R (Feb 1, 2012)

I dont have the oxy portion of a torch. Strictly acetylene. But I'll give it a shot with my sawzall. I think I have a couple 14tpi blades kicking around


----------



## patnor1011 (Feb 1, 2012)

how about sharp chisel, that may work faster than hacksaw


----------



## Patrick_R (Feb 1, 2012)

Tried that while it was being heated. Just bent the silver.


----------



## wrecker45 (Feb 1, 2012)

you will never get enough heat without oxy...Jim :mrgreen:


----------



## Barren Realms 007 (Feb 1, 2012)

I use a MAPP tourch for the preheat and then finish heating the pieces up with and act B-tank. The biggest ones I have done weighed about 2 lbs each and were in the shape of a tee with the copper being about 3/4" thick.


----------



## Oz (Feb 2, 2012)

Barren,
Why would you use expensive MAAP gas for a preheat? For the record I do these with oxy/acetylene.


----------



## butcher (Feb 2, 2012)

Use your rose bud tip with acetylene and oxygen torch.
The cutting torch will also work but do not use the cutting oxygen.


----------



## Barren Realms 007 (Feb 2, 2012)

Oz said:


> Barren,
> Why would you use expensive MAAP gas for a preheat? For the record I do these with oxy/acetylene.



Oz, when I did these large ones I didn't have my oxy/act rig with me at the time. My MAPP gas only runs about $7.00 per bottle.


----------



## Patrick_R (Feb 7, 2012)

Hey guys. Thanks for the input. I rebuilt my firebrick furnice and used the btank. They fell right off. 66 grams each. Only took 5-6 mins each. I'll post a pic in a few mins

I'll keep you posted thru the refining process. I'll let you know all know the final weight of the pure silver


----------



## Goldfinger4 (Feb 12, 2012)

And you are not scared of cadmium fumes? Cd evaporates at 767°C.
As long as you don't have to starve if you don't sell silver, I would be careful with my health


----------



## Patrick_R (Feb 12, 2012)

Sadly I am at the point of broke. Lost my job and while looking for a new one I've been scrapping stuff to make some extra cash.

Thankfully I purchased a gas mask some time ago and while removing the silver plates I was out doors with mask on. 

Thank you very much for your concern though. I don't do any refining without it on.

Comrade


----------



## AztekShine (Feb 12, 2012)

From what I hear that's brave! But those contacts look awesome are they .800 Silver?


----------



## Patrick_R (Feb 12, 2012)

No idea yet. As soon as i build a fume hood or spring rolls in I'll let you know. All i know is that they are indeed silver and 60-92% lol. Can't be more vague.

I made the noob mistake on 1 trying to cut it off with a sawzall. I put a bucket under my work bench and hacked away with sawzall (14tpi blade) in one hand and WD40 in the other. Only took 20 mins. Saved all of the trimmings.


----------



## Geo (Feb 12, 2012)

not so noob. ive seen hundreds of pounds cut in this way. i agree it is time consuming but to remove the silver from the copper with chemicals and not spend more than you will make, you have to reduce the copper content in some way.


----------



## Patrick_R (Feb 15, 2012)

I have started to refine these plates. Its a touchy thing because of weather here in the great white north. One observation, White/clear crystals formed on one of the plates. Its about half way dissolved. I gave it a good stir and they broke off fairly easily. I will assume that when I add more acid and distilled water they will dissolve. Anyone have an idea as to what the crystals are? (yes I do know how to use the search bar ) I just want to keep everyone updated as to my progress. One more observation which I am rather excited about, Black... stuff. Floaties. I counted about a dozen. There may be a small quantity of gold in these contacts 

Thanks guys

Comrade


----------



## butcher (Feb 16, 2012)

The white crystals are probably just silver nitrate crystals.
What is the concentration of the acid you are using?


----------



## Patrick_R (Feb 16, 2012)

70% diluted by half or a little more with distilled water. 

Also. I'm working on a way to recover my nitric oxide. I will post pics in about 12 hours. ( please don't put down the crude design. Its all I have to work with)

All criticism is appreciated and will be noted for future improvements.


----------



## Patrick_R (Feb 17, 2012)

My acid fume recovery rig. 

An air pump with 1/8" clear line into a jar (reaction) with a 1/2" into a bottle of distilled water. So far so good. There is a fume hood. Just not in this pic. 

The pressure alone from the gas was working but I didn't want a build up of any sort just in case. 

Edit. I have added a valve about 3 inches from the air pump Kinda looks like the text image below. I close and open it to regulate the BPM (bubbles per minute) based on the pressure and density of the gas. Although the air line is not in the acid at the bottom When I add H2O2 (hydrogen paroxide) 7% to the mix it seems to work longer.


........^
........| 
........X
........|
<--------------->
The X represents the valve.

Well it seems the server wont allow the spaces for my text drawing. Please ignore the ....


----------



## butcher (Feb 19, 2012)

The dilute hydrogen peroxide in the receiver bottle will also help to convert nitrogen dioxide gas and nitrogen dioxide gas back into a weak nitric acid.



Good job I see nothing wrong with your crude design.

Since you diluted your nitric the white crystals may not be silver nitrate, they could be another metal, silver nitrate crystals should dissolve easily.


----------



## Patrick_R (Feb 19, 2012)

I have been running this rig for a couple days now. The water in the jar receiving the gas has turned to a grey color with some dark grey/black powder on the bottom. Any ideas?

And from what research I've done the solder used for these relays contained cadmium. I think its best for me if I only use the recovered acid for relays.


----------



## butcher (Feb 19, 2012)

If all that escapes your reaction vessel is fumes or gases, then the receiver should be a fairly clean acid, although dilute, I am not sure what the black or gray powder is, could your hose be breaking down? Or could it have foamed over?


----------



## Westerngs (Feb 19, 2012)

What I remember from dissolving silver contacts that contained 10% cadmium is that the solution appeared oily afterwards - keep an eye for that.


----------



## Patrick_R (Feb 20, 2012)

No foam over. The hose has become cloudy. Probably breaking down but I'm not worried about that. Its a temp. thing for now. I'll filter the solution before I boil it down. I need to raise enough money to buy some proper glassware. It could be a while.


----------



## Geo (Feb 20, 2012)

Patrick_R said:


> No foam over. The hose has become cloudy. Probably breaking down but I'm not worried about that. Its a temp. thing for now. I'll filter the solution before I boil it down. I need to raise enough money to buy some proper glassware. It could be a while.



tsk,tsk, boil it down? there are two things troubling about that. if your dissolving silver with nitric, theres no need to evaporate the solution down as thats what needs to be done when working with AR to remove excess nitric from solution. and two, the correct term you should have used is "evaporate down" and not boil it down.


----------



## Patrick_R (Feb 20, 2012)

May be a miscommunication. I will boil down the water collecting the fumes, to remove excess water and strengthen the acid.


----------



## Geo (Feb 20, 2012)

Patrick_R said:


> May be a miscommunication. I will boil down the water collecting the fumes, to remove excess water and strengthen the acid.



ahh, i understand. but still, this is evaporating. you are evaporating the water down to concentrate the acid. im not picking on you and you may not have known but you should use the correct terms. believe me when i say, im being alot nicer than Harold would be after his post.


----------



## Patrick_R (Feb 20, 2012)

Yes, Indeed.

I retract my previous statements on boiling. (funny you mention Harold - just read his post about boiling vs evap)

Harold, if you read this, my apologies. Miscommunication on my end.


----------



## Harold_V (Feb 21, 2012)

Patrick_R said:


> Yes, Indeed.
> 
> I retract my previous statements on boiling. (funny you mention Harold - just read his post about boiling vs evap)
> 
> Harold, if you read this, my apologies. Miscommunication on my end.


Not a problem. What's important is that readers understand the significance of not boiling when it is not called for. Boiling is a very useful function, but it can be troublesome, too. It's important that readers gain an understanding of when it is, and is not, appropriate. I simply can't continue to spend my time endlessly trying to have them understand the importance of knowing. 

Looks like you "get it". That's all that is expected, or required. 

Harold


----------



## Smack (Feb 21, 2012)

Simmer people, simmer down your solutions.


----------



## MysticColby (Feb 21, 2012)

if you heat dilute nitric to evaporate, wouldn't the nitric evaporate quicker than the water?


----------



## Patrick_R (Feb 21, 2012)

I am not sure my self. I will be using the same method for capturing the fumes when dissolving silver as I am when evaporating the water from my acid. It will fume, I know that much. I want to capture as much as possible. Only so much will evap. before the water if this is the case. Water will evap. as well concentrating the acid, in turn increasing the boiling point, so less should evap. in theory. I don't think I could have been any more confusing but I hope you understand my understanding of the process.

Comrade


----------



## Geo (Feb 21, 2012)

water boils at 100 degrees C, nitric acid 68% boils at 121 degrees C. the boiling point goes down the more diluted it is, but it will always be above the boiling point of water. as long as you keep the temperature below 100 degrees C you will evaporate water first.


----------



## MysticColby (Feb 22, 2012)

huh, well how about that. I was under the impress you could evaporate dilute / contaminated nitric into a distilling apparatus and collect it in order to condense it. That would only work if it evaporated faster than water. Ah, I think I know: heating nitric will encourage it to break down into nitric oxide gasses. Maybe it doesn't evaporate, but that would certainly make it go away. Though I don't know the rate compared to water...


----------



## butcher (Feb 22, 2012)

If nitric is very dilute mostly water will evaporate off first (some acidic fumes can be involved), the higher you heat it the more acid can escape into these vapors (bursting bubbles carryover acid). 

Evaporation (vaporization) of a liquid can occur way below the boiling point for that liquid, water is more volatile than nitric acid in solution until we reach 68% azeotope of nitric acid.

HNO3
20% HNO3, boiling point 103deg C, 
density 1.115g/cm3 @ 20C, Specific gravity 1.182 @ 32deg, specific gravity @ 59 deg 1.120.

30% HNO3, boiling point 107 deg C, specific [email protected] 20 deg C, specific gravity 1.200 @32deg. specific gravity 1.185 @ 59 deg 

50% HNO3 boiling point 116 deg C, density 1.310g/ml @ 20 deg C

68% HNO3, boiling point 120.5 deg C, 
density 1.42g/ml @ 20C, specific gravity 1.182 @ 32deg, specific gravity @ 59 deg 1.120.

98% HNO3 boiling point 83 deg C (notice the boiling point is lower than the azeotropic 68% nitric acid boiling point is).

--------------------------------------------------
HNO3 content composition % by weight, at boiling temperature (%i n HNO3 liquid), and (%in HNO3 vapor) (by weight), at atmospheric pressure. (Also note: we could get a clue of the acids strength by the boiling points temperature).

Boiling temp. 100 deg C, (0% Hno3 in liquid), and (0% in HNO3 in vapor) (note: this is water)

Boiling temperature 107.8 deg C, (31.8% HNO3 in liquid), and (5.06% HNO3 in vapor) (note: approximate 32%HNO3)

Boiling temperature 111.8 deg C, (42.5% HNO3 in liquid), and (13.4% HNO3 in vapor)

Boiling temperature 117.5 deg C, (57.3% HNO3 in liquid), and (40.0% HNO3 in vapor)

Boiling temperature 125.5 deg C, (68.4% HNO3 in liquid), and (68% HNO3 in vapor)


Note: the boiling temperature of the nitric acid rises (with concentration by weight in liquid), (less water in solution), and (the % nitric acid in fumes also rises), (until we reach azeotope (68%), then the liquid, and the fumes contain same amount of HNO3 acid).


-------------------------------------------


We can only concentrate nitric acid up to the azeotropic point 68% by weight using heating of the solution, (or this method), at this point the fumes and liquid contain the same percentage by weight, if we tried to further concentrate by this method the vapors begin to contain more nitric acid than our liquid would at that boiling temperature (basically we would just boil off our nitric acid into the air)( if distilling we would distill 68% nitric acid into receiver).

There is no reason to boil the nitric acid (at its boiling point {unless distilling}),
We can concentrate the nitric acid in our vessel will without boiling (remove water (evaporate off water) at a temperature below a boil) which is actually better less loss of acid (carryover).



____----------------------------------------------


HCl hydrochloric acid azeotope 20.2% boiling point 108 deg C.

H2SO4 sulfuric acid we can concentrate to 98% (white fumes SO2 gas).


----------



## Findm-Keepm (Feb 23, 2012)

Harold_V said:


> Patrick_R said:
> 
> 
> > Yes, Indeed.
> ...



_There once was a man who used "boil"
His words caused Harold to recoil!
But alas, he was a real kind mate,
corrected the term to "evaporate",
an' thus brought his 'rep no soil._ :mrgreen:


----------



## Oz (Feb 23, 2012)

Findm-Keepm said:


> There once was a man who used "boil"
> His words caused Harold to recoil!
> But alas, he was a real kind mate,
> corrected the term to "evaporate",
> an' thus brought his 'rep no soil.



Too funny!


----------

