Today I am going to show you how to make yourself a nice little fire pit that is good for those winter (or summer) nights to roast your marshmallows on. The firepit requires tools that most DIY'ers would have handy in their garage. This build requires NO welding which is a bonus. The basis of the build is an EMPTY disposable helium tank used to fill party balloons that you can buy from K-Mart, Big W and most other big department stores (Walmart for people stateside).
Step 1: First Things First: Safety!
It's all well and good to have a fancy new firepit to put on your back deck or patio to enjoy the afternoon serenity, but there's no point if it costs you a finger or eye to make it! The first and most important thing to consider is safety. You need to take safety precautions and have the appropriate protection kit available as this build has some hazards in it. I will take no responsibility if you injure yourself or damage property - you need to look out for yourself! You will be working with a pressure vessel which can cause injury if you don't take the right steps to prepare the tank. I offer no apologies for harping on about safety throughout the whole process - I definitely don't want anyone getting injured!
Some safety equipment that is a must includes the following items (this list isn't exhaustive):
- Eye protection
- Hearing protection
- Dust mask (I recommend a good quality one that helps filter out paint and fine particles)
- Good quality protective shoes
- Long sleeve shirt and pants (to protect from metal grindings)
Step 2: Prepare Your Helium Tank
A friend of mine had a few of these helium tanks that resemble smaller LPG/propane tanks left over from an engagement party. The disposal instructions said to empty the remaining helium out and throw them in the recycling bin. I hate to throw these sorts of things away, especially when you've paid money to buy them in the first place so I thought turning one into a fire pit might be a good use for the left over tank. You could probably use an LPG/propane tank, but the walls are going to be a bit thicker and they are designed to take extreme pressures making the whole process more a fair bit more hazardous. I'm not going into the LPG tank side of things for this reason, but I do recommend if you are going to try it, that you should absolutely make sure the tank is empty!
The first thing you have to do with the tank is make sure it's empty. The best way to remove the bulk of the helium is by filling up balloons until the tank won't inflate them anymore. The tank is still going to have a little bit of pressure in it. The tank should have instructions on the side of it how to release all the gas and prepare it for recycling. Follow these instructions until you are sure there is no more gas or pressure left in the tank. Remember these things can hold a fair bit of pressure so you won't want to continue any further until you're sure the tank is empty and free from pressure.
Step 3: Tools and Hardware Required
The simple design limits the tools required for this build, but you will need the following:
- High Temperature Paint - something like this will do. The spray can definitely gives a better finish, but the tin is better value for money.
- Permanent Marker
- Mineral Turpentine or Methylated Spirits
- Multigrips or broad headed pliers
- Corded or cordless drill with at least 2x batteries - you will need a range of sizes of drill bits between 5mm and 10mm and a countersink bit
- Sandpaper - you will need at least 5 sheets of coarse sandpaper (40-80 grit) and three or four sheets of 240, 400 and 1000 grit.
- Sanding Machine (Optional - this will speed things up a lot for some sections of sanding the tank, I didn't use one but if you have one lying around it'll help!)
- 4x U-Bolts (I used 25mm ones) with the nuts and the braces
- Spanner to do up the nuts on the U-Bolts
- Dremel (optional - makes things easier when it comes to sanding and rounding edges)
- A file (optional - you'll only need this if you don't have a Dremel with a coarse stone attachment for grinding down the sharp edges)
Step 4: Removing the Valve and Opening the Tank Up
This step shouldn't be taken until you're sure there is no pressure left in the tank. I removed the turnable valve by opening it all the way up to the point it wouldn't turn any further. I then used a pair of multigrips to continue to turn it until the rotating arm broke off (although you should be able to use a set of pliers). I then used the drill with a bit that was just smaller than the diameter of the valve to drill out the remaining plastic in the valve.
The next thing you want to do is trace a line around the tank using your permanent marker just above the curved section on the bottom of the tank. The bottom of these tanks are quite unstable, so I thought the handles of the tank would make a more solid base. Once you've traced your straight line you want to put on your goggles, gloves and other safety equipment on before using the hacksaw to cut along the line until you've cut the bottom of the tank off. You can optionally use a Dremel with a metal cutting saw disk to get through it a bit quicker, but I found the disks wore down incredibly quickly and the hacksaw gave a better finish.
Using the Dremel or your file you want to grind down the sharp edges of both the tank and the bottom section that you cut off (we will use this as the base later on).
Step 5: Drilling the Holes and Attaching the Base
This step is about attaching the bottom section of the tank to the handles using the U-Bolts to make the base of your fire pit. The first step is to drill one hole in each side of the handle (see the picture for the best area to put the holes). Feed the U-Bolts through these holes and place the handles on the base to see where the U-Bolts line up. Mark the location where the U-Bolts should go through the base by tracing around them with a permanent marker. Take the tank off the base and use a drill bit slightly larger than the threads of bolts to drill holes where you've marked. Countersink the holes to remove metal burrs.
Test everything fits together by putting everything together. If the U-Bolts don't fit exactly, use the drill to widen the holes slightly until they do fit. Put on the braces and tighten the nuts up (not too tight). Place the fire pit on a flat surface and see if it sits flat. If it won't try loosening the nuts a bit as this can skew the base. Now you can take everything apart in preparation for sanding and painting.
Step 6: Sanding and Drilling
Now comes the tedious part of the process. You want to sand the external and internal sections of the tank back to bare metal along with the handle section. As you can see from the photos I wasn't able to sand the handles right back - this doesn't matter too much because they won't be subjected to the same heat as the cylinder section. Start with the coarse sand paper to take off the paint and then work your way down to the finer sand papers to get a better finish. You might need to use the Dremel and the coarse stone attachment for the middle section where the welding seam is. The sanding process can take a number of hours but you want to make sure you get all of the paint off the surfaces exposed to the heat as this will prevent peeling when you coat the tank with the high temp paint. I noticed some rust on the inside of the tank around the valve, you can remove this by using a wire brush attachment for the Dremel. It doesn't matter too much if there's a bit of rust left over, after you've had a few fires it will probably get a bit of surface rust inside it anyway.
Once you're satisfied you've sanded it back to a good finish, you can start drilling your holes. These will allow more airflow to the fire. I drilled four rows of equally spaced holes around the tank. Use a piece of string to calculate the circumference of the tank, then divide that number to create an equal number of holes. Mark the holes with a permanent marker and then drill them out. Use your countersink bit to smooth the sharp edges out.
Step 7: Painting
After your happy with the finish on the tank, you want to clean the surface using Mineral Turps or Methylated Spirits. Prep your paint using the instructions on the can or tin. Apply an even coat to all surfaces of the tank including the inside area of it. Leave the tank hanging sitting in a warm area where it won't be exposed to moisture or wind. It's important that during painting the tank it doesn't get exposed to any moisture as this will end up in the paint peeling when you fire it up later on. I know this from experience.. I had to re-sand and repaint the tank after it got a couple of drips on it.
I left the paint to dry for a few days before lightly sanding the tank back and adding a second coat. I did two coats, although you might want to do three to ensure you get a lasting finish.
Step 8: Finished Product!
After you've left your final coat to dry for at least a day, you can go about putting the base and U-Bolts back on. The first fire will properly cure the paint, so start off with just a small fire inside of it and gradually build it up until the tank is roaring. It's important you only fire it up in a well ventilated area as its extremely dangerous to have an open fire inside or in an area that isn't properly ventilated. In addition to this, there will be some odour coming from the tank during it's curing process.
Make sure you practice responsible fire pitting i.e. don't have a fire on a day when there is high heat or high wind or especially when there is a fire ban in place.
Thanks for reading, feel free to comment if you enjoyed the project or if you have any suggestions for improvement. I hope you enjoy your new fire pit and don't forget to vote :-)