mousey Posted September 4, 2018 Report Share Posted September 4, 2018 Just bought a smallish Olympic (2331G ) gas kiln for reduction work, specifically lusters, celadon, and shino. As I only have access to propane, thats what I ordered, but I'm reading that on top of the implicit difficulty bringing a gas kiln into reduction in general, propane is particularly problematic. Can anyone give me any hints on how best to get a suitably reduced atmosphere for these sorts of endeavors using propane, or warn me now if I'm just chasing an impossible dream? Link to comment Share on other sites More sharing options...
neilestrick Posted September 4, 2018 Report Share Posted September 4, 2018 I have never heard of propane being more difficult to reduce than natural gas. The difficulty will be in getting your little round gas kiln to reduce evenly and fire evenly. As high fire reduction gas kilns go, they are not well designed. Do some searching here on the forum and you'll find all sorts of discussions about how to make your kiln work. Link to comment Share on other sites More sharing options...
mousey Posted September 4, 2018 Author Report Share Posted September 4, 2018 Much obliged, will do. I read that propane was simply harder to starve of oxygen, in so many words, because apparently its a lot more efficient than natural gas, but per your advice I'll trust the advice of people who have walked this path more than a random article any day. Link to comment Share on other sites More sharing options...
High Bridge Pottery Posted September 5, 2018 Report Share Posted September 5, 2018 In my head it seems easier to get enough oxygen for methane CH4 than propane C3H8 but that is just my armchair logic not very scientific. Just assuming shorter chain carbon molecules would be easier to get complete combustion. I haven't noticed any difference in reduction when firing with propane or methane. EDIT I did a little googling and it seems to be right. Propane needs more than double the oxygen for complete combustion. "The second difference is in the oxygen to gas ratio required for proper combustion. LPG requires an oxygen to gas ratio of approximately 25 to 1. Natural gas requires a ratio of around 10 to 1. To achieve this difference, LPG is typically provided in a smaller quantity but at a higher pressure, drawing more oxygen with it into the combustion process." Link to comment Share on other sites More sharing options...
nancylee Posted September 5, 2018 Report Share Posted September 5, 2018 How do those small raku kilns play into this? The ones where you bring the cover down from above and it comes over the base? Link to comment Share on other sites More sharing options...
neilestrick Posted September 5, 2018 Report Share Posted September 5, 2018 4 hours ago, nancylee said: How do those small raku kilns play into this? The ones where you bring the cover down from above and it comes over the base? Raku kilns are fired in oxidation, so no worries about reduction issues. They also don't go very hot, so evenness issues don't really come into play either. The propane vs natural gas issue, while different on paper, doesn't come into play in practice. Link to comment Share on other sites More sharing options...
nancylee Posted September 6, 2018 Report Share Posted September 6, 2018 20 hours ago, neilestrick said: Raku kilns are fired in oxidation, so no worries about reduction issues. They also don't go very hot, so evenness issues don't really come into play either. The propane vs natural gas issue, while different on paper, doesn't come into play in practice. Oh, thanks. I always thought that when we fired in the raku kiln with the propane in class it was reduction. Duh. It’s just a different source of heat. Thanks! Link to comment Share on other sites More sharing options...
Benzine Posted September 6, 2018 Report Share Posted September 6, 2018 14 minutes ago, nancylee said: Oh, thanks. I always thought that when we fired in the raku kiln with the propane in class it was reduction. Duh. It’s just a different source of heat. Thanks! Rakuware is fired in oxidation, but then taken out and put in reduction bins, to create the familiar effects. At least that is the way it is done in "American Raku". Link to comment Share on other sites More sharing options...
JohnnyK Posted September 6, 2018 Report Share Posted September 6, 2018 13 minutes ago, nancylee said: Oh, thanks. I always thought that when we fired in the raku kiln with the propane in class it was reduction. Duh. It’s just a different source of heat. Thanks! With Raku the reduction happens in the post-kiln processes, i.e., the bucket with the combustibles... johnnyK Link to comment Share on other sites More sharing options...
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