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Treating Gouging Rods

Ioxoi - 24-9-2007 at 12:20

Hi everyone,

I'm planning on eventually making a rather large (4 gallon) chlorate cell using NaCl, with dichromate additive, steel cathodes, treated gouging rod anodes, magnetic stirring, crude pH control, and a 5vDC 40A power supply or two, assuming everything doesn't blow up first.

But it won't be up and running for a while. First I need help on treating the rods, of which I have 60. They're 3/8" x 12" and cost 30 cents each on eBay.

I have been told that linseed oil soaking helps make rods last longer. Frogfot said that treating gouging rods with 15% linseed oil / 85% mineral spirit under vacuum, then curing, is the best way. He also said that some people use the same mix but without vacuum, but that it doesn't work as well.

Does anyone know the best way to treat rods with linseed oil (or linseed oil/solvent mix)?

[Edited on 24-9-2007 by Ioxoi]

Xenoid - 24-9-2007 at 13:21

I hope you have tried chlorate cells out on a SMALLER scale first!!!

I treat my gouging rods with about 10 - 15% by volume boiled linseed oil in "AQUELLUX S".

"Aquellux S" is a cement and concrete water proofing material (paint and spray on type) comprising silane and siloxane mixed with white spirits. It has amazing penetrating properties. When the rods are dropped in the solution they actually fizz as the air is forced out. I then pump them down under a light vacuum (old refrigerator compressor). The "vacuum" chamber is just some PVC drain pipe with end caps. But leaving them for a few days without vacuum should be OK.

I've always thought that the linseed oil procedure was a bit "old fashioned" and that there should be better modern materials available, hence the silane/siloxane. It seems like a good topic for the amateur. Battery carbons appear to have a waxy substance impregnating them. I did a few experiments dissolving various waxes in various solvents but never carried it any further.

Regards, Xenoid

Ioxoi - 24-9-2007 at 14:02

Thanks for the tip, but unfortunately I don't live in New Zealand. Oh well.

And yes, I was planning on building a MUCH smaller 'pilot cell' first! That way I can figure out the big problems, like wire-to-graphite connections, chlorine corrosion, current draw... the list goes on.

I'll be building my little pilot cell soon, as soon as I can get my mom to order the power supply and the other items.

[Edited on 24-9-2007 by Ioxoi]

Xenoid - 24-9-2007 at 15:49

I believe "Aquellux S" is available all over the world, even upstate New York!

In any event, I just mentioned that as an example, check out concrete and cement treatments in hardware stores, etc. There should be something similar. These silicone based treatments aren't pore filling they just line the pores. You need the addition of a thicker substance like the linseed oil to actually fill up the pores.

I think I've mentioned it at least twice in other threads, to get a good connection to a gouging rod, leave about 2-3 cm of the copper on the end of the rod that you are going to make the electrical connection. You can then solder your wires onto the copper, or make small stainless steel clips to clamp onto the copper.

Watch out for corrosion, that's your biggest enemy. Salt, water and chlorine combine to make a big mess. In addition make sure you have an ammeter in your circuit, if you don't know how much current is flowing through your cell, you don't know where you are. As corrosion sets in your current will drop.

Good luck, your problems are just starting...

Regards, Xenoid

Aqua_Fortis_100% - 10-1-2008 at 14:46

Hi

Several persons here and out have said that is good to treat gouging rods with brownish linseed oil and "mineral spirits"..

I was under the wrong impression that this "Mineral spirits" would be some sort of denatured alcohol and the like... And because of this I never was able of mix properly the linseed oil and ethanol (I've used this).. Some days ago I tried to mix linseed oil and a paint solvent called "hammerite" which contains a lot of aromatic hydrocarbons..And they are totally miscible!!!

My gouging rods are still left on this mix (about 6 days) and I will remove that and let dry..

Should I let dry at room temperature or should I put on anything warm/hot ? (Xenoid, you said in another thread that I let your anodes one week in a warm place.. what is this 'warm place' you use? Additionally Tim said that is good to after this treatment to bake the anodes at aprox. 150*C for some hours.)

Can I treat "somewhat" used anodes?

[Edited on 10-1-2008 by Aqua_Fortis_100%]

Xenoid - 10-1-2008 at 18:07

@ Aqua_Fortis_100%

Sounds like you finally have a viable treatment. Hexane camping stove fuel or turpentine are other solvents for boiled lindseed oil. I just allowed my rods to dry in our hot water cylinder cupboard (40 oC. may be) as I wasn't in any particular hurry, but you could dry them in an oven (a bit smelly). You live in Brazil, just put them out in the hot sun! I haven't ever really heated my rods, but I guess you could try 100 oC. or 150 oC. in the oven as 12AX7 suggests.

I wouldn't try to treat "used" anodes as they will already have been saturated with brine and will contain salt, once dried, I think this would render the linseed oil treatment useless.

garage chemist - 10-1-2008 at 18:35

Dont forget to keep the current density low enough and the solution cool (40°C).
Those precautions prolong the life of the anodes far more than treatment.

Also, add dichromate to the solution. It will really pay off to synthesize some before you start your chlorate cell.

Xenoid - 10-1-2008 at 23:10

Actually, I think the main benefit of treating gouging rods (or graphite for that matter) is that it slows down the penetration of salt, chlorine and hypochlorite up the rod. These play havoc with the electrical connections, no matter what type or design! The treatment will also help hold the graphite grains together to a lesser extent!

garage chemist - 11-1-2008 at 11:59

You're right, that's a good point.

Letting a chlorate cell get too hot is probably the main cause for short life of graphite anodes, along with too high current density.
Yes, higher temperature means somewhat higher efficiency because the favorable disproportionation of hypochlorite (vs. the oxidation of hypochlorite at the anode, which consumes more electrons) takes place to a larger extent, but current efficiency is not really that important to us.
Anode lifetime, on the other hand, is more important.

Maybe someone experimenting with chlorate cells could try to make a cell specifically built for maximum lifetime of the graphite anode (per amount of chlorate produced, of course).
Low current density, electrolyte cooling, dichromate addition, linseed oil treated anodes.

Xenoid - 11-1-2008 at 12:33

Quote:

Originally posted by garage chemist
Maybe someone experimenting with chlorate cells could try to make a cell specifically built for maximum lifetime of the graphite anode (per amount of chlorate produced, of course).
Low current density, electrolyte cooling, dichromate addition, linseed oil treated anodes.

Well personally, I am moving away from gouging rods, to oxide coated Ti ...

But as I mentioned earlier in this thread, linseed oil seems a "bit old fashioned". Battery carbons are impregnated with some sort of wax. Candle wax or bees wax dissolved in various organic solvents are a possibility (but still old fashioned). Silicone based cement/concrete treatments are a possibility (I have used this). Another idea, I haven't tried is polyurethane based varnish/coatings. This could be diluted, and would penetrate well, especially under vacuum. It would have good pore filling and bonding characteristics, and "sets" very hard!

Rosco Bodine - 11-1-2008 at 13:15

It would seem like the anomalous iron nitrate / metastannic acid hydrosol would be a natural candidate
for soaking a gouging rod and baking out for two or three
coats , and then maybe following that with a manganese
nitrate dip and bake .

Aqua_Fortis_100% - 11-1-2008 at 13:59

@Xenoid,
Very good idea you suggested.. I will put these treated anodes in the sun.. But unfortunatelly the time here right now is very weird.. At this season , constantly are raining here.. Can I safely let the anodes on the roof even with raining?
Just to remember: What the time you let your anodes ? one or two weeks?

If treating used anodes are useless , are there some thing to do to improve it?
I will use it as cathodes, because I don't have like much of spiraled iron wires ..Is very hard to control the cathode-anode distance, even with a plastic base to fix or the like..And I couldn't find the proper SS plates ..

But this corrosion of connections is really a bitc* .. In my early mini cell , the connections were destroyed very quickly! It not delay one day to copper wire turns green at surface..

But and if I will solder also these connections? Will lead from solder resists to contact brine at graphite surface?

@garage chemist
Yeah, until yesterday I haven't ANY chromium compound.. But today I finally found a chemical Supplier and buyed 1Kg of sodium dichromate (the minimal amount they sold) and 1 L of technical 98% sulfuric acid .. I'm very, very happy

Unfortunatelly , here is quite hard to found a decent pottery supplier which sold these marvellous pigments like Cr2O3 , ZnO, BaCO3 , etc All are 'synthetic' type poor pigments ...

So I can't make K chromate/dichromate without Cr2O3..

@Rosco Bodine, are you proposing a potential (per)chlorate anode ?

Seems very interesting

[Edited on 11-1-2008 by Aqua_Fortis_100%]

Al Foil

MadHatter - 11-1-2008 at 14:45

Peel off all the copper on the gouging rod. Wrap some aluminum foil around the
end and clamp with a clothespin(preferably plastic variety). Make sure enough foil
extends away from the rod to connect your power source. When the brine attacks
the Al foil just redo it. Setup right this will keep the brine from attacking power
supply connectors.

Xenoid - 11-1-2008 at 14:53

@ Aqua_Fortis_100%

You are just trying to "harden up" the linseed oil, a few hours in an oven, or a few days in the hot sun should do it.

Even soldered connections will start to corrode, but are the best option. Some of my wires, 30 - 40 cm long, coming from the cells, are sometimes corroded for their full length and can't be reused.

For a cathode you don't need SS, if you don't have anything better, just use a steel can! Cut off the ends, and cut it to a suitable shape for your cell. IT WILL NEED PROTECTING IN THE REGION ABOVE THE ELECTROLYTE. You can use some heatshrink tubing or electrical tape and hot glue, etc.

Actually, I have never used dichromate in a chlorate cell, you certainly don't need it if you are using SS cathode/s as plenty of Cr seems to go into solution anyway! It's just an extra contaminant that needs removing when cleaning up your chlorate!

Aqua_Fortis_100% - 11-1-2008 at 17:27

@Xenoid,
in Wouter's page he said that removing the dichromate needs only of some BaCl2 solution to precipitate yellowish (?) Ba chromate until the white ppt forms (Ba chlorate)..
Really I need of this procedure to remove chromate from sodium chlorate, or just one or two recrystalisations would suffice? This will help in reclycling the electrolyte, because I will dont need to add more dichromate . Can this residual (di)chromate be harmfull in chlorate stability or any particular pyro mix made with it?

( just as side note , at least right now I wont use this chlorate in perchlorate making because of PbO2 anode which I'm still learning methods before really try to make it)

Today ocurred me an idea..
Can I replace solder by just a quick dip of the connections in semi-molten lead ?
If yes this would be great since I will speed up greatly the anode connections making , save electrical energy and 'heavy duty' soldering irons , and can maybe even be more smooth..and of course much more cheap , because lead is much more cheaper than Sn-Pb based solder..

Some hours ago I removed the anodes from linseed/hammerite mix and put in the roof.. I hope dont rain today/tomorrow..

Is somewhat hard to me to find a long length and small diameter SS can with fits well in my cell , because I choose my body cell in such way to be able to use the max. possible graphite anode (more cm^2 per less anodes), and unfortunatelly it is only 17-18 cm diameter.

@MadHatter,
Interesting idea about al foil.. But how long it stands to brine attack? Because it is a very reactive metal if one compares with copper which is destroied very quickly..

But really may pay to try, since corroded wires are a real "pain in the ass" to replace

@Rosco Bodine,
I forgot to mention, but if you really are talking about a (Per)chlorate anode , it will really works for perchlorates?
Dann2 and several others have said which gouging rods are pratically useless to perchlorate anode making..

[Edited on 11-1-2008 by Aqua_Fortis_100%]

[Edited on 11-1-2008 by Aqua_Fortis_100%]

Xenoid - 11-1-2008 at 18:09

Quote:

Originally posted by Aqua_Fortis_100%
Today ocurred me an idea..
Can I replace solder by just a quick dip of the connections in semi-molten lead ?
If yes this would be great since I will speed up greatly the anode connections making , save electrical energy and 'heavy duty' soldering irons , and can maybe even be more smooth..and of course much more cheap , because lead is much more cheaper than Sn-Pb based solder..

Is somewhat hard to me to find a long length and small diameter SS can with fits well in my cell , because I choose my body cell in such way to be able to use the max. possible graphite anode (more cm^2 per less anodes), and unfortunatelly it is only 17-18 cm diameter.

WTF..! Just SOLDER the connections on to the remaining copper plate.

I didn't say SS can ... :mad:

I said steel can! You are not going to tell me that you don't have steel cans in a variety of sizes in Brazil...! You can use just about anything for a cathode. The main reason for putting dichromate in the mix is to protect a steel cathode. Stainless steel doesn't really need it!

Have you actually read Dann2's web pages!

http://www.geocities.com/CapeCanaveral/Campus/5361/chlorate/...

Rosco Bodine - 11-1-2008 at 19:53

All I am proposing is there are probably better things than linseed oil for toughening a gouging rod . How tough
and how long it would last , well who knows unless they try it . But yeah , it would probably make perchlorate
for awhile .....5 hours , 5 days , who knows .

Aqua_Fortis_100% - 12-1-2008 at 06:54

Quote:

Originally posted by Aqua_Fortis_100%
Is somewhat hard to me to find a long length and small diameter SS can with fits well in my cell , because I choose my body cell in such way to be able to use the max. possible graphite anode (more cm^2 per less anodes), and unfortunatelly it is only 17-18 cm diameter.

Oh , Sorry.. I give the wrong info.. My cell body is only 7,5 cm diameter but 30 cm in length..

Quote:

Originally posted by Xenoid

WTF..! Just SOLDER the connections on to the remaining copper plate.

I didn't say SS can ... :mad:

Xenoid, really there is no OTC steel can with this small (less than 7.5cm) diameter and too long here..At least in supermarkets and at hardware..I'm not living in a BIG commercial center where "all" is possible to find and purchase..And I'm not going to get trouble in trying to find such can..Well , at least now.. As you and others suggested I will experiment with others materials to see what is best to my cell, and I will try first with graphite..If this will not be so good I will try to find such can or another suitable steel can..

( But maybe a galvanized iron/steel pipe does the job..Only stripping off the deposited zinc with HCl and washing..)

Yeah, I know that the dichromate functions only to protect the cathode with a layer of hydrated chromium oxide and helps in avoiding formed chlorate reducing back again there (just like a 'membrane' around the cathode) and thus improving the efficience of the cell and saving energy.

But my doubt wasn't this.. My doubt was if removal of dichromate/chromate with BaCl2 is really necessary before getting the chlorate, this is, if traces of (di)chromates in homemade chlorate would be harmful to stability of such chlorate and any particular composition made with it.. If no , I can simple boil off half of the water , remove the crop of NaClO3 and reclyce the electrolyte.

Thanks.

Rosco,
Will these chemicals you mentioned (or more specifically the oxides which these chemicals will give) if some flake off the anode and fall into electrolyte sensibilize the formed chlorate to any extent (even if pratically insoluble)?
Thanks.

Rosco Bodine - 12-1-2008 at 08:07

What will happen with this I don't know , but it just looks very promising as pure experimentation which hasn't been described anywhere before . There has been only the cryptic mention of "nitrates" in connection with the tin oxide precursor , sprinkled about in several of the patent references , without any elaboration . And those references just seem to sit there for me like little flashing beacons on the page

It's because the precursor is
so heavily loaded with the desired material as a precursor
that is so nearly , so closely "almost there" to being the
developed DTO , just needing a bit of heat to drive off the water and then sinter the collapsing lattice . Ummm , ummm , ummm , uuuumh , uuuuuump is what would be
the comment if it was a girl walking by with everything
properly swaying

Looks good anyway

Some more details are in the tin nitrate thread
http://www.sciencemadness.org/talk/viewthread.php?tid=8347&a...

[Edited on 12-1-2008 by Rosco Bodine]

Attachment: MSE06.pdf (373kB)
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Rosco Bodine - 12-1-2008 at 08:34

This also looks good because of the non-critical
non-demanding preparation of precursor materials . The 8%
Fe doped SnO2 could be derived from OTC materials
pretty easily via several different methods .

I really think that the mixed valency polymer scheme
of the Pytlewski patent US3890429 could be useful as
an initial treatment on graphite , since the polymer
has such profound effect as a wetting agent . One of those
mixed valency polymers , could be very useful as a sort
of sticking agent for the initial coating , and perhaps between coats ,
to help everything sinter smoothly at
the layer transitions . That polymer isn't heat treated
by itself but simply dipped and shaken off and dried to
leave its film which provides the wetting effect for subsequent coatings .

[Edited on 12-1-2008 by Rosco Bodine]

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Rosco Bodine - 20-10-2008 at 10:32

Here is an interesting Russian method for treating graphite to inrease its useful operatiung current density
and to greatly decrease its erosion rate. Several sealant combination schemes are compared, and several catalytic additives are also compared for performance in a 100A test cell.

US4472257 Cobalt Spinel treated Graphite Chlorate Anode

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