pyrojig Posted February 29, 2012 Posted February 29, 2012 pyrojig is correct on the corrosion happening at the junction of the lead and copper wire. On mine there is some evidence of copper corrosion, It hasn't become a problem yet, I will try a coating of JBweld, never thought of that. Thanks pyrojig. No prob. It is only a temporary cure. Jb weld and epoxy break down slowly in the corrosive cell conditions . It will work though. I spread it ( jb weld) around the base of the electrode ( 1/2" wide or so) to give it structural integrity at the lid of the cell( top and bottom).
Nitrato Posted March 1, 2012 Posted March 1, 2012 Hello, thank you all dudes for replies! @oldmanbeefjerky Thank you for reply.Actually I have a MOT without secondary.. It was designed not to spot welder, but to be part of a high current DC power supply (for chlorates and other electrolysis), like these: I didnt yet finished the power supply since I still need the high power diodes, and also think in use another MOT (also without secondary) between mains and modified MOT to funcion as inductive ballast.. So until now Im still confortably using computer power supplies for experiments. I played with the featured MOT below, making some HV arcs (like pyro, HV hobby is quite rewarding too, but much more dangerous) before my hacksaw dismantled the secondary and then never could give HV again. Yes, like you've said, is quite hard, time consuming and boring to hand saw it..Maybe a electrical rotating diamond blade saw and a pair of safety shield might help or perhaps a good proper chisel and heavy hammer.. Original MOT:http://i242.photobucket.com/albums/ff176/tnitrato/ELETRONICA/DSC05921.jpg Plus hacksaw.. http://i242.photobucket.com/albums/ff176/tnitrato/ELETRONICA/DSC05923.jpg ...and patience.http://i242.photobucket.com/albums/ff176/tnitrato/ELETRONICA/DSC05927.jpg Fine wire was removed:http://i242.photobucket.com/albums/ff176/tnitrato/ELETRONICA%20II/DSC05944.jpg The paper removed exposed the 3 volt filament magnetron wire, that was removed too..http://i242.photobucket.com/albums/ff176/tnitrato/ELETRONICA%20II/DSC05945.jpg So were the magnetic shunts:http://i242.photobucket.com/albums/ff176/tnitrato/ELETRONICA%20II/DSC05946.jpghttp://i242.photobucket.com/albums/ff176/tnitrato/ELETRONICA%20II/DSC05948.jpg A 3 - thick wire stack cable was formed and then 4 turns of it were passed on iron core as new secondaryhttp://i242.photobucket.com/albums/ff176/tnitrato/cloratos/DSC01626.jpghttp://i242.photobucket.com/albums/ff176/tnitrato/cloratos/DSC01624.jpg It was tested, the open AC voltage was little higher than expected, 5V, considering about 1 - 1,1 volt per turn, but its still reasonable..http://i242.photobucket.com/albums/ff176/tnitrato/cloratos/DSC01627.jpghttp://i242.photobucket.com/albums/ff176/tnitrato/cloratos/DSC01628.jpg
Nitrato Posted March 1, 2012 Posted March 1, 2012 (edited) oldmanbeefjerky, my titanium comes from ebay, it was about US$ 30,00 (without shipping). If you want a link for the seller I can PM you if you wish.My Ti rods: http://i242.photobucket.com/albums/ff176/tnitrato/cloratos/DSC01664.jpgDoes anyone knows whats the grade of Ti substrate of laserred MMO electrode? Could be a vanadium-aluminium alloy Ti rod be reliably spot-welded on CP grade Ti? now that i look at it all, Ive got a massive amount of titanium, compared to what i thought i had.Aside from the 3 greenish ones (internally oxidized, these are all in good condition. sorry its a bit pixelated, normally pictures are a little smoother, im still getting used to my new video camera (still better than the old $60 fuji )all of the dark plates except the green ones, were from the self cleaning cell. its all that was in there. they all look alike, and all are in good nic. the light grey mesh is the only cathodes that survived, all the anodes seem to be covered in what looks like ferric rust, varying from cream to brown. could this from minerals in the water? or rust from the anode, meaning it contains iron, and if so how much, or what grade Ti could i expect this from, in your opinions. but just your opinion, i dont ask for a full search into this or anything. Looks like you have a small MMO treasure! Im stocking my electrodes too, the three 10"x6"(IIRC) that arrived couple of days ago: http://i242.photobucket.com/albums/ff176/tnitrato/cloratos/DSC01610.jpg Ive also noticed the rusty spots on my MMO mesh too, I hope that comes from water used.. @hillbillyreefer Thanks for tips, for next uses of the already leaded MMO and no sanding at all, I will put it in a tube and fill with lead, that should make a much more permanent connection though. About steel tube, Ive used sometimes to clean my rusty steel tools with oxalic acid.. The iron oxalate layer is somewhat stable but phosphating should be superior, so I would with WSM advice of H3PO4.. Maybe a aluminium foil wraped in the tube/connection might help to reduce corrosion, as dropplets will have harder time to directly hiting the steel, unless they pass through voids and holes in aluminium paper. @WSM Thanks for input.Yeah, I also dont think lead actually bonds to Ti, but my goal was to isolate the copper in contact with Ti and surrounded by lead, where chlor mists cant get in to mess up. what kind of SS clamping you are refering to? http://www.google.com.br/search?hl=pt-BR&q=stainless+steel+clamping&gs_sm=3&gs_upl=2354l11146l0l11745l24l13l0l9l9l0l1050l4575l0.5.2.4.0.1.0.1l22l0&gs_l=hp.3..0i19.2354l11146l0l11745l24l13l0l9l9l0l1050l4575l0j5j2j4j0j1j0j1l22l0&bav=on.2,or.r_gc.r_pw.r_qf.,cf.osb&biw=1366&bih=552&um=1&ie=UTF-8&tbm=isch&source=og&sa=N&tab=wi&ei=VhBPT8CYE8mUtwfU7YnFDQthese circular ones (for tubes, etc)? Can it make good conection? @pyrojigThank you. I dont have stell cabing, just passed a thick coat of hot glue on exposed copper, yeah thats a big problem if corrodes and contaminates the liquor. I still didnt see signs of corrosion in my cell but I keep watching. Ive used hot melt glue and pvc sealant, but even so Im seeing again the problem of salt creeping. What is the epoxy resin you are refering? Is that the stuff from hardware that comes in a box with two masses (like kids clay) a white and a dark grey one that mixed gives a light grey resin that will get stiff within about two hours? I thought that was more chemically weak than hot glue to chlorate electrolyte. Good if is that resin,, Edited March 1, 2012 by Nitrato
Nitrato Posted March 1, 2012 Posted March 1, 2012 (edited) My cell is about a day producing chlorates..Unfortunately my multimeter (pictured above) died last night, so I cant measure current but guess is anywhere between 3-5 A for a 900mL saturated KCl cell. The cell body is translucent HDPE, Ive passed PTFE tape around the screw to make it more leakproof. A MMO mesh was put through lid and then so 6 Ti rods (3 for each side of MMO) and held by lots of hot glue. http://i242.photobucket.com/albums/ff176/tnitrato/cloratos/DSC01632.jpg The rods are held in place and spaced from MMo with (tight) perforated PET strips, cut from soda bottle. This plastic resists well to chlorate liquor, though is not good to use it at very high pH.http://i242.photobucket.com/albums/ff176/tnitrato/cloratos/DSC01618.jpg Then PVC tube sealant (PVC dissolved in MEK) was put around hot glue in the internal side of lid. A fan was used to speed up drying, then another coat of PVC cement was put, then dried, etc.. A total of 4 PVC coats were put on internal side and one on external side. http://i242.photobucket.com/albums/ff176/tnitrato/cloratos/DSC01614.jpghttp://i242.photobucket.com/albums/ff176/tnitrato/cloratos/DSC01622.jpghttp://i242.photobucket.com/albums/ff176/tnitrato/cloratos/DSC01630.jpg After about 18 hours, the salts started to creep around the hot glue, rising in Ti rods. Damnit! At least the alloyed Ti rods are resisting very well to corrosion and although salts are creeping, the gases didnt seem to leak since the vent tube when put in water gives instant bubbling.. The temperature is quite hot (about the limit of which bare hands support) so I placed the cell inside a water bath. http://i242.photobucket.com/albums/ff176/tnitrato/cloratos/DSC01640.jpg The active area of electrode seems to be fine, both cathodes and of course MMO. The cathodes are with a crust of chlorate on it; but it cleans out very easily, even passing the finger will remove it. http://i242.photobucket.com/albums/ff176/tnitrato/cloratos/DSC01648.jpghttp://i242.photobucket.com/albums/ff176/tnitrato/cloratos/DSC01649.jpg The chlorate is accumulating on the bottom: http://i242.photobucket.com/albums/ff176/tnitrato/cloratos/DSC01671.jpg Im satisfied with the cell although the trial with aditional PVC sealant failed. The copper-lead connection are heavily coated with hot glue, so it will last at least this run.. The real bet for me is if alloyed Ti will cause or not problems. The dann2 (per)chlorate site reports that aluminium alloyed Ti grades are inclined to warp in cells, specially at high temperatures. Ive made a much poorer cell with MMO before, but using Ti foil.. The Ti foil works, but wont last much, maybe a couple of days before it starts to desintegrate, since it will become very brittle, as hydrogen embrittlement takes place. If you dont grab the foil very carefully it will break, like if the foil was made out of magnalium.. http://i242.photobucket.com/albums/ff176/tnitrato/MADSCIENCE%20I/DSC05399.jpghttp://i242.photobucket.com/albums/ff176/tnitrato/MADSCIENCE%20I/DSC05400.jpgNotice the difference in foil, the part directly exposed to electrolyte and the part dont exposed. Results of hydrogen embrittlement:http://i242.photobucket.com/albums/ff176/tnitrato/MADSCIENCE%20I/DSC05463.jpghttp://i242.photobucket.com/albums/ff176/tnitrato/MADSCIENCE%20I/DSC05464.jpg Since the rods of Ti are about 5mm in diameter, I think it wont readily suffer mechanical stress from hydrogen embrittlement, it may take many hours operating... EDIT: sorry for double post, I was unable to put all in one post due to the amount of pics. Edited March 1, 2012 by Nitrato
WSM Posted March 2, 2012 Posted March 2, 2012 (edited) Does anyone knows whats the grade of Ti substrate of laserred MMO electrode? CP titanium under the MMO.Could be a vanadium-aluminium alloy Ti rod be reliably spot-welded on CP grade Ti? Yes, I believe so but CP is a better choice. Ive also noticed the rusty spots on my MMO mesh too, I hope that comes from water used.. The rust colored "smut" (as Swede called it) can be removed by soaking in HCl and rinsing with water afterward. @WSM Thanks for input.Yeah, I also dont think lead actually bonds to Ti, but my goal was to isolate the copper in contact with Ti and surrounded by lead, where chlor mists cant get in to mess up. what kind of SS clamping you are refering to? I was referring to running a stainless steel (300 series) machine screw through the MMO mesh and clamping with two stainless washers and a stainless nut. Where the screw goes through, the mesh can be expanded to accomodate the size of the hardware. It's best to keep the hardware out of the cell liquid (as well as the electrical connection, of course).http://www.google.co...YE8mUtwfU7YnFDQthese circular ones (for tubes, etc)? Can it make good conection? Possibly, but keep it out of the cell liquid.WSM Edited March 2, 2012 by WSM
pyrojig Posted March 2, 2012 Posted March 2, 2012 @ nitrato ...\ I would not suggest the soda bottle plastic as a retainer for the rods.. It will cause a much bigger problem, " a salt bridge" this salt will collecton the support and short out the electrodes killing the PS. Ive watched electrodes get majorly wrecked that way.
oldmanbeefjerky Posted March 2, 2012 Posted March 2, 2012 (edited) nice with the MOT, i gotta try that, or at least find a way to use my welder transformer to spot weld. Dont forget there are alternative methods to attach mmo to titanium sheet, such as using cp titanium rivets, or bolts. im going to try and buy a bunch of titanium bolts from a wholesaler, if i can find ones which are short enough. Odly many i see are for bolting on bike brake pads.chemically pure though is hard to come by. would any other grades be ok? Edited March 2, 2012 by oldmanbeefjerky
WSM Posted March 2, 2012 Posted March 2, 2012 (edited) nice with the MOT, i gotta try that, or at least find a way to use my welder transformer to spot weld. Dont forget there are alternative methods to attach mmo to titanium sheet, such as using cp titanium rivets, or bolts. im going to try and buy a bunch of titanium bolts from a wholesaler, if i can find ones which are short enough. Odly many i see are for bolting on bike brake pads.chemically pure though is hard to come by. would any other grades be ok? I agree, the transformer modification details are nice, and nice to have. CP titanium screws are hard to find (at least I haven't found any yet... that I can afford ), but alloy titanium hardware is available on eBay, though the price is typically high. I avoid using titanium alloys in the cell to prevent introducing metal ion contaminants into the liquor. I believe CP titanium is the best to use in our cells, and I stick to using it exclusively. Sheets of CP titanium 0.040" (~1mm) and thicker work out well if set up right. The bulk of my CP Ti in that range is 0.050" and more in thickness and so far appears to work well in the tests I've conducted (though I have used thinner sheet metal successfully). I think boxing the cathodes around the anode is the most effective technique amateurs can use to maximize the potential output of our anodes and the electrodes should be sized to demand 80% of our power supply's rated output maximum, to ensure minimal stress on our supply (the power supplies will last longer and run cooler if we don't abuse them). Using less than 80% capacity is okay but more than that is not sound electrical practice. Abuse it and lose it !!! WSM Edit: Remember, voltage is like pressure; we need just enough to keep things moving. But amperage is volume of electrons and is the workhorse of our cells which drives the conversion of salt to chlorates and perchlorates. My references above are to rated current output (amperage), not voltage . Edited March 2, 2012 by WSM
Nitrato Posted March 3, 2012 Posted March 3, 2012 (edited) @WSM Thank you. I have a 'feeling' that spot welding alloyed Ti will be fine, though I have some CP items to play also. Although I dont have spot welder, I can ask on mechanical repair shop of university if they can do that for me (hope they do it for free), Ive previously cut my MMO there, but forgot to look at welding section. Ah, about SS screw,washers and nuts its a good idea, but not sure about how you protect it from hungry electron chlor mist, even if cell is sealed.. Since Ag2O is conductive, maybe a full silver coating on SS itens might help (?). Well, from our talking, Im more and more inclined to try the spot welding process, actually is very reliably and turns out to be the simpler process..If I wont be able to spot weld on university then I will be forced to make my own MOT spot welder. About MOT, yeah I know is quite a bit of voltage; I will remove one turn to see (but must acquire a good multimeter) @oldmanbeefjerky Thanks.I can try this 'alternative' method since I have a CP plate too (yeah, CP is hard to come by). @pyrojigThanks for input. But I didnt understand what salt bridge you are refering, by what process..Sorry if Im sounding like a moron. The salt is already dissolved in water and in large amount, turning it conductive, without this our electrolysis process couldnt work. I didnt had any problems with PET strips before; in fact my first bigger cell (NaCl) used PET spacer and did it fine for more than a month withot any problem: http://i242.photobucket.com/albums/ff176/tnitrato/P9060051.jpgThe cathodes are made from nickel (and they are CENTRAL cathodes, sourrounded by anodes which died in the run, I know, its weird, but I was only with these at moment: more treated anodes than cathode material) About epoxi, you are referint to something like this: http://www.lojatudo.com.br/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/d/u/durepoxi_loctite_100fg.jpg (the two composite solids that I speak before)Or maybe this: http://www.concrerio.ind.br/userimages/araldite.jpg (liquid version). Edited March 3, 2012 by Nitrato
WSM Posted March 3, 2012 Posted March 3, 2012 @WSM Thank you. I have a 'feeling' that spot welding alloyed Ti will be fine, though I have some CP items to play also. Although I dont have spot welder, I can ask on mechanical repair shop of university if they can do that for me (hope they do it for free), Ive previously cut my MMO there, but forgot to look at welding section. Ah, about SS screw,washers and nuts its a good idea, but not sure about how you protect it from hungry electron chlor mist, even if cell is sealed.. Since Ag2O is conductive, maybe a full silver coating on SS itens might help (?).Well, from our talking, Im more and more inclined to try the spot welding process, actually is very reliably and turns out to be the simpler process..If I wont be able to spot weld on university then I will be forced to make my own MOT spot welder.About MOT, yeah I know is quite a bit of voltage; I will remove one turn to see (but must acquire a good multimeter) Hi Nitrato, You're welcome. I believe spot welding alloyed titanium will be no different than the CP. I personally want to avoid introducing other metal ions into the corrosive liquor in the cell to keep those metal chlorates from forming and contaminating my end product, so I avoid using alloyed titanium. I use stainless steel hardware to attach my electrical connections to the electrodes outside the cell. The use of silver oxide (or silver) to increase electrical contact is sound, electrically; but really unneccessary for this application. The silver and it's compounds will be corroded by the salt creep and spray as badly or worse than copper, so it's better to stick with only stainless. My first choice in stainless steel hardware is 316 and 304 second. The main trick is to connect the power outside the cell and keep the liquor inside the cell (everything separate). The best method to do this offered so far is to use CP titanium tubing, heated and flattened on one end and spot welded to the electrodes and held in cell-compatible plastic compression fittings (see Swede's blog). When energized, the CP titanium tubing can get devilishly hot. This is minimized by filling the tube with conductive material. I used lead-free solder which is 95% tin (5x as conductive as the Ti) and had no problems. I also used thick walled tubing which allowed me to tap the tube's top end with threads so the stainless hardware screwed right into it for a good, tight electrical connection. I suppose one could just run a heavy copper wire in the tube (well sealed on the electrode end) and connect it to the power supply lead outside the cell. The main point is when running a round tube through the compression fitting, it's sealed in and the salt creep is eliminated near the electrical connections; problem solved . The number of secondary windings in the MOT can be reduced till you get the voltage you want, but don't forget that silicon diodes drop the voltage about 0.6 or 0.7 volts each so a lower AC voltage may not be neccessary. I imagine the DC output will be about 3.6-3.8 volts by the time the AC is rectified, depending on your rectification method (I prefer to use a full-wave bridge plus a Pi filter for my DC circuits). Wait, I was thinking of a cell power supply . If you build a spot welder, don't forget a method of clamping the work to apply pressure. Solid contact is required for a good spot weld. Have fun and let us know how it works out. WSM
WSM Posted March 3, 2012 Posted March 3, 2012 @pyrojigThanks for input. But I didnt understand what salt bridge you are refering, by what process..Sorry if Im sounding like a moron.The salt is already dissolved in water and in large amount, turning it conductive, without this our electrolysis process couldnt work. I didnt had any problems with PET strips before; in fact my first bigger cell (NaCl) used PET spacer and did it fine for more than a month withot any problem: Not to steal pyrojig's thunder, but by salt bridge we mean a salt build up between the anode and cathode which shorts them out electrically and can destroy the power supply. The cell liquid is conductive but offers enough resistance to prevent power supply damage. A salt bridge tends to be too conductive and the power supply sees it as a dead short and can fail as a result !!! It is best to keep the electrodes out of the area of the cell where the crystals collect for this reason. WSM
Nitrato Posted March 3, 2012 Posted March 3, 2012 Hello WSM, thank you for input. Will make another cell (but that will take some time, maybe two-three weeks, since my holidays ends in two days and I have to move to the city where I study). I wasnt aware of this sat bridge problem, maybe this could explain why my cell is so hot, since the electrodes are almost reaching the bottom of the cell where chlorate is depositing. I have to obtain an new multimeter too. About spot welding, what may be the odds of aluminium and vanadium contamination in home grade chlorate? Vanadium is a transition element but is in same column as Nb and Ta that are listed as valve metals and suitable as substrate for (per)chlorate anode making, about aluminium, is in another group, but I dont know if small amounts/traces of its compounds have any catalytic/stability effects on chlorate, but anyway is better to stick with pure product.. About Ti tubes I once had an opportunity to talk with Swede on SMDB and he did let me know of this modification: http://www.amateurpyro.com/forums/blog/2/entry-79-tubular-anodes-updated/ along with other development in his pH controlled cells and bipolar MMO from DeNora corp., also published in his blog, IIRC. Unfortunately I dont have Ti tubing and much less a lathe to drill the leaded tube to make removable connection. At least the problem of Ti tubing may be solvable - the seller where I buy the Ti rods also have some Ti tubes: http://www.ebay.com/sch/Manufacturing-Metalworking-/11804/i.html?_catref=1&_ipg=&_ssn=mettall2000&_trksid=p3911.c0.m1538 but IMHO the rods are somewhat oversized in ID and is somewhat expensive, but affordable (BTW, just a little off-topic, but what happened to Swede? Long time Ive never seen again his brilliant posts. Hope he is ok). The problem of the lathe may be simply skipped if ones dip a heavy wire through tube before filling it with solder, like you've said but in every cell I make Im more and more concerned about permanent copper concection, so a removable and tight connection like in the Swede's blog should be a good thing. I once tried to find these compression fittings but I was uncessfull. Probably I didnt looked hard enough. Regarding MOT, I was thinking in removing one turn of the cable and try a double (alternator) diode configuration or just a complete diode bridge and smooth with a multi-bank of 1000uF 10V or 25V caps (greater voltage rating just in case of any spikes..) and dont forgeting the inductor ballast after mains and in series with MOT.
oldmanbeefjerky Posted March 4, 2012 Posted March 4, 2012 (edited) a shame to hear your electrodes have died. you did actually recitfy the AC right?Also, at 5v, there is a 200A potential from the MOT, and perhaps when you spaced the electrodes so close, that fried it. Salt bridge can be fixed by a cathode in the very bottom of the cell, or some bubbling, to keep the water stirred up Edited March 4, 2012 by oldmanbeefjerky
WSM Posted March 5, 2012 Posted March 5, 2012 Hello WSM, thank you for input. Will make another cell (but that will take some time, maybe two-three weeks, since my holidays ends in two days and I have to move to the city where I study). I wasnt aware of this sat bridge problem, maybe this could explain why my cell is so hot, since the electrodes are almost reaching the bottom of the cell where chlorate is depositing. I have to obtain an new multimeter too.About spot welding, what may be the odds of aluminium and vanadium contamination in home grade chlorate? Vanadium is a transition element but is in same column as Nb and Ta that are listed as valve metals and suitable as substrate for (per)chlorate anode making, about aluminium, is in another group, but I dont know if small amounts/traces of its compounds have any catalytic/stability effects on chlorate, but anyway is better to stick with pure product..About Ti tubes I once had an opportunity to talk with Swede on SMDB and he did let me know of this modification: http://www.amateurpy...anodes-updated/ along with other development in his pH controlled cells and bipolar MMO from DeNora corp., also published in his blog, IIRC. Unfortunately I dont have Ti tubing and much less a lathe to drill the leaded tube to make removable connection. At least the problem of Ti tubing may be solvable - the seller where I buy the Ti rods also have some Ti tubes: http://www.ebay.com/...=p3911.c0.m1538 but IMHO the rods are somewhat oversized in ID and is somewhat expensive, but affordable (BTW, just a little off-topic, but what happened to Swede? Long time Ive never seen again his brilliant posts. Hope he is ok). The problem of the lathe may be simply skipped if ones dip a heavy wire through tube before filling it with solder, like you've said but in every cell I make Im more and more concerned about permanent copper concection, so a removable and tight connection like in the Swede's blog should be a good thing. I once tried to find these compression fittings but I was uncessfull. Probably I didnt looked hard enough.Regarding MOT, I was thinking in removing one turn of the cable and try a double (alternator) diode configuration or just a complete diode bridge and smooth with a multi-bank of 1000uF 10V or 25V caps (greater voltage rating just in case of any spikes..) and dont forgeting the inductor ballast after mains and in series with MOT. Hi Nitrato, I'll try to answer the statements or questions highlighted and underlined above: Heat in the cell is typically due to electrical resistance and inefficiency in the cell, BUT heat is not bad if not too high. Heat does improve the efficiency of the chlorate process. Depending on what materials are in your cell, the heat may not matter. PVC as used for plumbing here in the US is good up to 60oC, but above that starts to soften and deform. CPVC (less common and much more expensive) is usually good up to about 90oC and a better choice if you have access to it. I've done experiments in glass containers and had no problems (maybe because I used distilled or purified water instead of tap water; fluorine in fluoridated tap water can and will quickly kill MMO by attacking the CP titanium substrate). Somewhere in his writings, I think Swede listed some compatible materials for use in cells. I agree with the idea of sticking to "pure product" meaning CP titanium and avoiding alloys. I've had good luck with using CP titanium for my cathodes and electrode leads. I checked the listings and everything I saw in tubing was titanium alloy . That's too bad because they look like a good source otherwise. Swede dropped out of here sometime in the Summer of 2010 for reasons of his own. I had contact with his friend Tentacles who contacted him last year and told me he is okay and pursuing other interests. He has a lot of interests and dropped electrochemistry for the time being, as far as we know... Too bad, we miss his input here. I agree, Swede's disclosure of the compression fittings along with tubular leads solved a major stumbling block to my progress with chlorate cells. His recommendation of Kynar fittings (PVDF polymer) was equally helpful. In the US, PVDF compression fittings are available from US Plastics company and Ozone Solutions company and several other material sellers, or maintenance suppliers. They aren't available from any plumbing sources I've checked so far. It sounds like you have a handle on the power supply assembly part of the project. Let us know how it turns out , and good luck. WSM
WSM Posted March 5, 2012 Posted March 5, 2012 a shame to hear your electrodes have died. you did actually recitfy the AC right?Also, at 5v, there is a 200A potential from the MOT, and perhaps when you spaced the electrodes so close, that fried it.Salt bridge can be fixed by a cathode in the very bottom of the cell, or some bubbling, to keep the water stirred up Did your electrodes die? If so, I must have missed that . Our electrochemistry depends on DC current. AC doesn't do it, so far as I know. I haven't dealt with MOT's so I'm not aware of the spec's on them, but they sound interesting if you're careful. The cathode on the bottom or bubbling air accomplish the same thing; stirring up the cell liquids to eliminate thermal layering or stratification of the heat in the upper areas of the cell. Having a cathode on the bottom of the cell in a batch system means it will be covered with crystals eventually, and I don't think that's a good situation. WSM
WSM Posted March 5, 2012 Posted March 5, 2012 Heat in the cell is typically due to electrical resistance and inefficiency in the cell, BUT heat is not bad if not too high. Heat does improve the efficiency of the chlorate process. Depending on what materials are in your cell, the heat may not matter. PVC as used for plumbing here in the US is good up to 60oC, but above that starts to soften and deform. CPVC (less common and much more expensive) is usually good up to about 90oC and a better choice if you have access to it. I've done experiments in glass containers and had no problems (maybe because I used distilled or purified water instead of tap water; fluorine in fluoridated tap water can and will quickly kill MMO by attacking the CP titanium substrate). Somewhere in his writings, I think Swede listed some compatible materials for use in cells.I agree with the idea of sticking to "pure product" meaning CP titanium and avoiding alloys. I've had good luck with using CP titanium for my cathodes and electrode leads.WSM Speaking of glass containers, I was able to pick up a heavy wall glass tube roughly 8" (200mm) in diameter and 16" (405mm) tall. My thought is to make a demonstation cell that can be seen though, by sandwiching the ends of the tube with clear PVC plate and tying it all together with all-thread rod and nuts with washers, covered with white PVC pipe. I plan on using Viton rubber as gasket material between the glass and PVC to prevent leaks. It ought to be quite a show piece as well as allow me to demonstrate a working cell (somewhat like a science fair project ). I'll try to photograph the tube later and post it here. WSM
pyrojig Posted March 5, 2012 Posted March 5, 2012 Sweeeeeeeeeeeeeeet!\Love to see pics as soon as your able to ...
WSM Posted March 6, 2012 Posted March 6, 2012 Sweeeeeeeeeeeeeeet!\Love to see pics as soon as your able to ... This is the glass tube with the Viton disks I'm planning on cutting the gaskets from. I still need to cut the clear PVC plate and get the all-thread to tie it all together. My plan is to drill and tap holes in the PVC plate for the fittings after I get the basic tank assembled. More later... WSM
WSM Posted March 10, 2012 Posted March 10, 2012 Awesome!!!! That is gonna be a beauty !!! I took a low resolution photo with my cell phone of the glass tube and Viton gaskets with two PVC end plates: The PVC end plates are clear PVC with a blue tint and they measure 1/2" thick by roughly 11" square. I still need to get the 1/2" all-thread rod and nuts with washers. When I do, I'll drill the PVC plates and tie everything together with the all-thread and hardware. I'll cover the all-thread with PVC pipe and the basic form of the tank will be complete. The next step will be to drill and tap ports in the PVC ends to connect various fittings and the electrodes. I'll probably have to rig it with LED lights to illuminate the contents, for that extra little dash of drama (maybe). We'll see... More later... WSM
oldmanbeefjerky Posted March 13, 2012 Posted March 13, 2012 EL Wire might be good for lighting it up, rather than LED, assuming you can some which would fit in there
WSM Posted March 13, 2012 Posted March 13, 2012 EL Wire might be good for lighting it up, rather than LED, assuming you can some which would fit in there I hadn't thought of using electroluminescence because of the low light output. The high voltage AC source for EL lighting doesn't appeal to me either . I was kind of considering drilling short holes in the edge of the PVC end plates to receive LEDs. The idea came to me when using the clear PVC plate for other cells and shining my LED flashlight (torch) to see how it looked. Bright LEDs do a nice job of adding light so the internals of a cell are visible in otherwise dark conditions. Even if I don't care to use them, I'm grateful for the suggestion. All ideas have merit somewhere. They may be ideal in a setting where low light output is desireable. Thanks, OMBJ ! WSM
WSM Posted March 27, 2012 Posted March 27, 2012 I took a low resolution photo with my cell phone of the glass tube and Viton gaskets with two PVC end plates:The PVC end plates are clear PVC with a blue tint and they measure 1/2" thick by roughly 11" square. I still need to get the 1/2" all-thread rod and nuts with washers. When I do, I'll drill the PVC plates and tie everything together with the all-thread and hardware. I'll cover the all-thread with PVC pipe and the basic form of the tank will be complete.The next step will be to drill and tap ports in the PVC ends to connect various fittings and the electrodes. I'll probably have to rig it with LED lights to illuminate the contents, for that extra little dash of drama (maybe). We'll see...More later...WSM I finally got some stainless all-thread rod to tie everything together: Now I need to cut some 1/2" PVC pipe to cover the metal all-thread (and protect the glass from being damaged by it) and plan the plumbing of the cell !!! This is going to be an interesting thing to look at (and explain to visitors who view it ). More later... WSM
pyrojig Posted March 28, 2012 Posted March 28, 2012 Need a lamp shade? Might add a nice decor , could even get some double takes...
WSM Posted March 28, 2012 Posted March 28, 2012 Need a lamp shade? Might add a nice decor , could even get some double takes... Actually, when it's all hooked up with the plumbing and wiring, it'll look more like a movie prop from a mad scientist's lab (muwahahaha!!!) . WSM
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