Yeah, and that's largely dependent on how much lye you use. The fact is that ALL of the copper compounds as well as the metallic copper itself are all skin, eye and respiratory irritantants I was thinking a "coffee scoop" to about a pint and a half of hot water, a relatively light concentration. I routinely use an entire 1lb cannister at once when cleaning heavy "crust" out of stainless steel tanks, but that wasn't what I was suggesting you do And provided you don't try to re-enact any scenes from the movie "cocktail" with the resulting mixture AND keep some vinegar on hand for neutralizing any spills you won't need a space suit to protect yourself from it. If anyone cares: the Greenish patina on copper is a combination of "copper carbonate" and Copper(II) Hydroxide while the BLACK oxide seen is the result of heating the carbonate to decompose it to "Copper(II) oxide". Heating the copper to high temperature in the flame reduces the "Copper(II) oxide" to copper metal because the oxide combines with the Carbon Monoxide in the flame That's how and why the flame works... I'd be concerned about brazed joints in the flame myself, but you can always use the flame to a lesser degree. I'm not entirely sure of the chemical sequence of Sodium Hydroxide Vs Copper Carbonate and Copper Hydroxide, I just know that when cleaning stainless steel brewing equipment that some copper fittings that were attached became bright and shiny almost on contact with the lye based cleaning solution. I can infer from another known characteristic of Sodium hydroxide (NaOH) that it "steals" the CO2 from the Copper Carbonate. NaOH as well as most other Hydroxides is that they agressively absorb CO2 in the process of converting from the hydroxide to carbonate... I'm sure if someone out there knows more thay will add that information. BTW, if you heat it "Red hot" with a propane torch or over another petrol stove you need not worry (much) about the brazed joints melting. Propane and petrol flames fed with air by convection (not using compressed air) simply don't burn hot enough to melt "yellow" braze joints. They don't actually get hot enough to make "white" (higher silver content) braze joints flow reliably, that usually take fuel gas plus oxygen to accomplish... even if you heat and quench putting a little hydroxide in the water will greatly ease the cleanup afterwards, because heating always leaves a thin oxide layer that can be tedious to polish off.... AD
Hi Jon, thanks on the Epray score, I had to wait for him to answer the "how much for shipping" before I used the Buy it Now, he quoted a fair shipping price and when I saw it was still there I got it. Nice job on your burner, mine looked much the same after cleaning, just the insides weren't so nice. I will rework mine again. On the leaching, the acid gets to the less noble metal, the Zinc, that is why you see the copper color, the surface zinc is gone, and worse, microscopic areas into the alloy that later cause chemical stress cracks. Maybe not so important here with the burners but in thin walled spun or stamped brass founts it can cause cracks. In the heating industry I used to see pin holes in heavy brass valve bodys, I thought they we casting pin holes until I learned that the zinc had migrated out of the brass due to electrolysis or chemical action. Regards, Ed
Another thing that might be helpful is heating the copper or brass piece you are attempting to clean short of the glow point then quenching it in a solution of Zinc Chloride. Or wetting the piece with a ZnCl solution BEFORE heating. Zinc Chloride dissolves most metal oxides, which is why it's a common ingredient in brazing fluxes. After using it I'd recommend boiling the workpiece in water to remove any surplus of ZnCl. AllanD
Umm Arrrr All Balls and stick stuff to me but I belives you's. Heat and dunk works good. U sually do the annular ring first then dunk. Then each side tube. Then a soak in citric for a bit and a good blow out with air hose or garden hose. Wonder how a pressure jet would go?? Gerni thing?? Have had one I did 5 to 6 times. Would work for a while then go off. Close up. week flame etc. then start etc. Clean jet etc etc. Drove me batty. Well more than I and now. Finally with a garden hose instead of a air hose. Luck or maybe thewater / they finally lined up spat it out. Grain of sand which later I think may have been the fluates in the brazing flux and a small sliver of brass and what seemed to have some sort of sting tape or packing in there.. Works Like a new one now. Cheers. Keep up the good thread. Has any one tried just boiling for a few hrs with soap and water? Or wouldn't it clean the insides?? Barra
Lye/Sodium Hydroxide/Caustic Soda - in moderate concentrations is relatively benign. Except for Aluminium.
ok, so now that the burners are cleaned, where do i go for new lower sealing gaskets? can these be purchased from a supplier? can they be made from a somewhat obtainable material? i would like to get a few of them in the next week so i can use the stoves next weekend. any links to suppliers, contact info, or what material to buy would be greatly appreciated.
That Pall stuff sounds interesting. I find Guiness like drinking Asfalt or tar. Newcastle, Killkenney an our own Mack is what counts.
I just buy some dubviiuos looking take away food at a petrol statioin or pie van. Usually does the trick just as well as a vindaloo . Less cooking though. Rather a lemon butter chicken .
The only Take-away food here is hamburgers, chips, Coke and pizza. Its a very small comunity. Only 2300 people here.
Now back to topic you rascals! A few words on the heat-and-quench method of removing hard-baked carbon from the insides of burner tubes (both roarer AND silent). On burners with heavily carbonised internal tubes, I repeat the heat/quench method until no more carbon is deposited in the bottom of the water vessel. This may mean that I repeat the process 10 times or more if necessary. I use a propane gas torch. Don't worry too much about the joints as they have been braised at much higher temperatures. When you heat the burner, look into the bottom opening of the burner and you will see the carbon glowing bright red.
This is the part I wanted to know about right here. Is "red hot" ok, or just the start of the glow as I am thinking. Regards, Ed
Hi Ed I heat the tubes until the carbon within the tubes is red hot. If that means the outside of the tubes are red, then so be it!
Apparently at one time you could take your choked burner to a Primus dealer. He would remove the nipple, connect the burner to a bellows or an air pump, heat the burner with an external flame, and then start pumping air. If the conditions are right, the carbon ignites, like a chimney fire and the combustion gases flow out the nipple hole. When you no longer have a glow from the hole, all the carbon has been consumed and you should have a clean burner. No need to quench or use aggressive chemicals. Be careful not to overheat and melt the braze holding the burner together... that is your only concern. Best Regards, Kerophile
The setup is shown in this SVEA catalogue from c1915. The text is in Swedish, but the drawing tells it all.
Yes, the stove, when working normally heats up the burner to cherry red and the joints don't come apart, so clearly, there's no need to worry about heating them up that far with a blowlamp...
