Over the years I have found many uses for old and discarded propane and air tanks for my projects. My flying pig post is one such example and I will have another post in the near future demonstrating a few other projects using old tanks. Before anyone attempts to complete a propane tank project there are a few tips and safety strategies that I will discuss to help make your project safer and more than likely easier.
First and foremost, NEVER, and I stress, NEVER cut into an old propane tank without taking the necessary precautions to ensure your own safety.
Step 1: Make sure that all of the propane in the tank has been used. This is accomplished when the propane tank is empty and no longer contains an adequate amount of gas to fuel whatever it was connected to, such as a burner, heater, or torch. I have heard of people simply opening the valve to release the propane from the tank, but this does not sound very safe or environmentally friendly to me.
Step 2: The valve (shown in the picture above) will need to be removed from the tank once it has been emptied in order to remove the small remaining amount of propane from the tank. Being a round tank, it is often difficult to remove the valve due to the tendency of the tank wanting to roll around. To combat this I ratchet strap the tank in between two trees or posts to secure it in place and allow for easier removal of the valve.
Step 3: Some projects may require the guard ring around the valve (pictured above) to remain on the tank, but I always remove the guard because it allows for better access to get a pipe wrench on the valve to remove it. I do not ever cut the guard off with anything that will cause a spark, as the tank still has propane under pressure in it and I do not want anything to even have a chance to ignite. Bolt cutters work well in removing these guards and will not cause any type of spark.
Step 4: Now that the tank is secure and the ring has been cut out of the way, I use a pipe wrench and pipe extension to unscrew the valve from the tank. It is a good idea to start with the pipe extension because the valves are usually brass or aluminum and can be broken if too much force is applied to just the wrench, making the valve more difficult to remove. The added length from the pipe gives good leverage and requires less force to remove the valve from the tank.
Step 5: Once the valve has been loosened I finish unscrewing it by hand and what I have left is a tank that looks something like this.
Step 6: Once the valve is removed there will be an obvious presence of propane noted by the strong odor, that is normal. Propane is heavier than air and will not be completely evacuated without this step. To ensure that the tank is completely free of all propane I insert a hose into the tank and run water into it until only water, no bubbles, are exiting the tank from the opening at the top. I usually drain the tank then repeat this step at least once more to ensure that there is no propane gas left in the tank.
Once I have completed step 6, I personally feel confident that my tank is safe to cut, grind, and weld on without any additional fire hazards outside of those that always exist with the cutting, grinding, and welding of metals. I say this because I have completed many welding projects involving propane tanks and have yet to blow anything or one up in the process. If anyone has strong reservations about using propane tanks in their projects, air tanks come in many similar shapes and sizes to propane tanks and can be disassembled using the steps above minus the sixth step. Thank you for reading and if you have any questions please let me know. If you enjoyed this article or found it informative please like, comment, and follow my site. Thank You!
I am not suggesting that anyone cut into a propane tank or attempt to complete a project using a propane tank, I am just demonstrating the method that I use when employing a propane tank in some of my many projects. Tool-school.com and its authors are not liable or responsible for any injury or death involving propane tank projects. If you do use a propane tank for a project and want to follow the steps in this post to clean it, make sure that you complete all of these steps outside of any building in an open, very well ventilated area.