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Pottery/Raku Kiln Propane Gas Pressure Problem


I have been firing my raku kiln and just recently my burner seemed to run out of pressure. After refilling both tanks and trying to resume, I continued to have the same problem. My system consist of 2 30 lb propane tanks twinned together. Thinking that I had a regulator failure, I removed the regulator and tried to run again. The same problem occurred. I have checked everything from the burner orifice back to the propane tank connectors. No obstructions, everything is open and clear. I next opened the tanks and there was nothing, hardly any gas. I use a MR750 ward raku burner with high pressure regulator and hose. I used this system before and never had this problem till now. I am stumped, please help. Thank you.

ANSWER: Dear Angela,

    Thank you for your recent question. It sounds to me like you have a leak in a hose or at a connection. Pressure problems often are caused when there is a leak, and not as likely due to regulator problems. My suggestion to you is to not use the burner until you have the hoses pressure checked. You can take the tanks, regulator, hoses and burner to your propane supplier and they will do a pressure check for you. This is the same check that is often done when you have propane filled at home. I would not use the system until checked because propane is difficult to recognize when it is leaking. It also settles low to the ground and can cause an explosion when a burner is ignited. So please have the system pressure checked before resuming your firing.

    The reason I say to take all of the system to be checked is because the tanks may have a leak around the handle, the regulator could be leaking, the hoses may have a pin hole in them or the burner may have a pin hole in the hose. I don't know how your tanks are piggybacked together so, having them both checked is the best solution.

    I hope this helps you. If you have further questions, please feel free to contact me at any time. Always at your service. Much luck to you.

Ms. Ti Phillips
Earth Stoke 'N Fire Pottery Studio and Artist Retreat

---------- FOLLOW-UP ----------

Thank you for your very quick response. I took my rig to our propane supplier and he tested everything. Nothing seemed to be wrong with the hoses or tanks. He took the burner and attached it straight to a new tank, with a new hose and we still had the same problem. He said the only thing that could be wrong is the burner and he couldn't think of what could be wrong with that as the orifice is not blocked and the gate valve opens and closes with no problem. I spoke with the tech expert at Axner's Pottery supply and he never heard of this problem. I'm going to replace the orifice, it's a $3 part, I figure I can't go wrong. We'll see what happens. Have you ever heard of a burner failing? Thanks again,

Dear Angela,

    Thank you for your follow-up question. I really don't think this would be the orifice or the burner. When you are firing your kiln, do the tanks begin to gather condensation and frost on the outside of the tanks? Especially since the temperature outside has been cooling off? If this is the case, then you are going to have to increase the size of the tanks to 30 lbs each. Let me explain.
    The use of propane is very much dependent on the outside temperature. The colder the temperature, the less pressure you get from the tank. This is true for all size tanks. And as propane is used from the tank, the pressure begins to drop because of the changes in temperature from the amount of space in the propane tank without propane any longer. However, the larger the tank, the more time you have for the maximum pressure. In most cases, when you see condensation and frost building on the outside of the tank, the level where the condensation and frost stops is the top level of the propane inside the tank.

    A regulator regulates pressure, but only to decrease the amount of pressure expelling from the tank. It does not increase depleting pressure. The temperature outside will dramatically affect the time you have for maximum pressure too. This is why you are loosing pressure.

    So, the solution is to increase the size of your tanks to increase the time you have for maximum pressure. You can try to wrap the tanks with a kiln blanket to see if you can extend the time of maximum pressure, or set the tanks into a hole in the ground. Do not cover the tanks with dirt, only pack it around the tanks. This might help you increase the time of maximum pressure. However, DO NOT heat the tanks in any way. This is a safety issue. Otherwise, you will have to increase the size of your tanks, until summer, when the heat will keep the tanks from building condensation and frost.

    I hope this helps you. If you have further questions, please feel free to contact me at any time. I am always at your service.

Ms. Ti Phillips
Earth Stoke 'N Fire Pottery Studio and Artist Retreat


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Ti Phillips


Will answer any questions on hand building, wheel, glaze, firing. Speciality questions to include those in glaze calculation and development, firing techniques. Please do not send questions on identifying pottery. Although I would love to add this to my question topics, I have a retreat to run as well as the studio and volunteering on AllExperts, and therefore do not have the available time to research indentification and marks. Thank you for understanding.


Experience includes 30 years in pottery design and education. Have taught online and studio classes worldwide for the last 20 years. Own a pottery retreat specializing in firing techniques. Have 12 years solid experience in glaze calculation and formulation as well as problem solving in glaze chemistry. I am the first potter in the United States to have developed a complete package of pottery equipment blueprints for a studio. The blueprints include wheels, kilns, studio furniture, wedgeboards, raku kilns, slab rollers, ball mills and studio tools.

Alliance of Pottery Artists Worldwide Association

Ceramic Industry - PPP Wyndstryder Press - Pottery Journal

University of Sciences and Art's of Oklahoma, studied under Professor Jaymes Dudding.

Awards and Honors
Potter of the year with APAWA, various awards for showmanship and design.

Past/Present Clients
Available upon request.

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