I've never been happy with what's available for the general public out there for a backyard fire pit. They are either too expensive, or don't suit the needs for what I was wanting. My goal was to have something I could sit around with family and friends, enjoy the nice ambiance of a flame, and be able to have food and drink around the pit. Secondly I wanted something that was easy to build or put together. Unfortunately, finding something that meets all of these requirements is pretty hard to come by (especially the price).
A quick trip to a couple of local box stores and I came up with this idea. I built several of these years ago, and you may have seen this instructable on a couple of other websites. I have since divorced, moved, and therefore needed to build me another one (she got the old one). In doing so I thought I would document it for you to glean from my mistakes and triumphs and allow you to modify or do what you want with this project.
This table will be using Propane Gas, and as such there are inherent risks. Be careful, don't do stupid things (something I'm well known for) and follow any and all safety instructions on the devices you use.
For those of you who have a bit of backyard metal working abilities this should be a fairly straight forward project for you to accomplish. Simple welding, metal bending, cutting and brazing should do the trick.
This is my first instructable on this website, so I'll see what I can do to make it as easy to follow along as I can...
Step 1: Purchase the Needed Items
- Tape Measure, ruler, or other measuring device
- Saw Horses or other support
- Metal cutting tools
- grinder, cutoff tool, Dremel, Jig Saw, Sawzall, or good old hand tools
- Grinder, Sander, Scrub Wheels or other tool to remove paint and clean up metal
- Oxy/Acetylene Welder, Map Gas Torch, Propane Torch or other tool to join copper pipe
- Gas Welder, MIG Welder, TIG Welder, other form of getting metal to stick to one another
- Safety Glasses, Good Gloves, Ear Protection
- Black Paint
I shopped around at the local hardware stores and discovered what I needed to make this little fire pit table.
Lowe's has a good garden table to use and the base is a great place to store the propane tank.
Garden Treasures Davenport Black Round Patio Dining Table - $98
Lowe's also has a good little fire pit to put in the center of the table.
Garden Treasures 29.5-in W Black High Temperature Painted Steel Wood-Burning Fire Pit - $59
Home Depot has a nice little fire pit to use in the center of the table, and is the one I used as it's $20.00 cheaper. Since the stores are almost always right next to one another it was just a simple jaunt from one to the other.
Lawrence 29 in. Round Wrought Iron Fire Pit - $39
Both fire bowls are pretty much the same, so I went with the Home Depot fire bowl and the $20.00 savings! Another note on the bowl, I don't think there is any reason one can't use stainless steel kitchen bowls, and I may try this out next. Cheaper, more variety of sizes, thereby giving you more room on the table to put "MORE FOOD and DRINK!"
You just have to contain the flame in an area with something that won't melt. Whatever steel bowl you do use will dictate how precise you have to be when cutting out the center of the table. The lip size of the bowl will be all that is supporting it, so the wider the lip on the bowl, the less precise you have to be in cutting out the center of the table.
Step 2: Start With the Table Top
I used a couple of saw horses to place the table on top of as it's a comfortable working height for me (somewhat), and easy to set up and take down. They are also easy to spread apart, or bring together based on what you are doing and the amount of support needed for the task (explained later).
Start by removing the plastic center cap out of the table and toss it... The cap is no longer needed for this project but use of the center umbrella hole will help in keeping the cut out, true and precise.
Set the table on top of the saw horses, right side up, and get the tools you'll need for this part. I used a Dremel to score the top of the expanded metal where I needed to cut out the center of the table. You can also use the Dremel to cut through the metal, but you'll go through those little discs way too fast. I put a small grinding bit on the end of the Dremel and used it to score the paint away at the end of the radius I measured for the bowl insert.
Step 3: Measure and Score the Circle to Cut Out
I used an adjustable clamp to make the measuring of the radius of the circle easier, and here is how I used it.
Once I measured the fire bowl, I learned I needed to have a radius close to 11 3/4 inches. I set my clamp to that distance, placed the non-handled end end in the umbrella support hole on the table, and began to go in a circular motion around the table. I used the Dremel to score or scrub the paint away where I needed to cut through the table. This was mostly done by "eye" as I would place the clamp end over a piece of metal to be cut, looked where I needed to score, moved the clamp, and scored the location with the Dremel. Leaving the clamp in place will chew up the clamping surface while scoring the table with a Dremel, so just a quick peek, move, and score worked well for me.
You can use anything to mark the location of the radius around the table. I just didn't have anything that worked well on the black painted metal. I tried using a razor blade but it was a very thin score line and hard to see. I tried using my daughters colored pens, but against the black paint they were close to invisible. So, I ground the paint away with a Dremel. Whatever works for you.
Step 4: Time to Cut the Table
Time to start cutting. You can use a number of tools to accomplish this, whatever you happen to have at your disposal. I used an angle grinder with a cutting disc to get through the expanded metal and support bars. A jig saw or sawzall with a metal blade will work. As stated before a Dremel would work, but could take quite a few discs to get through all of that metal! A plasma cutter would be awesome and make "quick" work of the metal! Whatever you may have to cut out the hole should work... You can even go old school and use hand tools!
Align your cutting blade on the score marks and just start cutting. I didn't cut all the way through the support bars from the top as I just wanted to cut through the expanded metal and enough support angle iron to know where to cut from the other side. Once the expanded metal is cut out, just flip the table over and start on the bottom section.
Step 5: Cut Away the Angle Iron Supports
Once the table is flipped over so you are looking at the bottom side, make sure the saw horses are in close enough that the cutout and the table are both supported on the saw horses. As you cut away the angle iron supports this well help in preventing it from bending your table as the center will want to start to hang down.
Once the center is cut away completely, just lift it out and you just ruined a perfectly good $100.00 table! ;-)
Step 6: Check for Fit
I flipped the table back over, spread the saw horses apart a bit to allow the bowl to sit in the hole to check for fit. Then removed both, and pushed the saw horses back together and placed the bowl on the saw horses. I then placed the table over the bowl to check how close I was for the measurement.
All looks good!
Step 7: Cut Out the Umbrella Support
The bottom support ring for the table has an umbrella support mount (what the table was originally designed for). I removed this so I could put the propane tank in here, as it just seemed like a good place to store it. Keeps it out of the way, no need to get a longer hose to feed the pit, and keeps it neat and tidy.
This table has 8 cuts that need to be made. Take it slow, cut close to, but not on top of the frame. You can grind back the stubs that are left without damaging the outer ring. Once the support bars are cut away, just remove the umbrella support.
Now time to bend and weld a piece of flat stock to give the table back it's support that was removed from the center of the table.
Step 8: Remember Safety
One of the things that "most" of us realize is when we are in danger. Apparently I missed those genes...
I was cutting away at the table and noticed my finger was getting quite warm. I thought, "I have gloves on, no big deal," and kept on cutting. My finger kept getting hotter and hotter and soon enough I checked what the problem was (at my disgust having to stop my progress). I soon learned I had burned through the leather, and started burning the tip of my finger with "all those sparks of hot metal!" I also noticed my finger was still burning as the glove was on fire. Needless to say I switched hand positions, and continued.
On another note, make sure you wear the "appropriate" eye safety! I used a pair of safety glasses that fit closely to my face and I "thought" were adequate protection... Ummm, nope! As I work, I tend to sweat (it was 90+ degrees outside too), and as such the glasses slowly moved down my nose. A hot piece of metal bounced off of my forehead, onto the back of the safety glasses (next to my eye) and in turn, bounced into my eye.
Again, I didn't think much of it and continued to work, and soon enough figured out I had a pretty good owie! The hot metal spark landed on the eye and burned into the cornea of my eyeball. Sorry for the graphic photo, just letting you know what can happen with inadequate safety equipment and would rather it be done at my expense and not yours. The photo shows a before shot of the eye with metal in it and after the doc cleaned it out. No worries, the cornea replaces itself every two days, so I'm good to go!
Step 9: Insert the Flat Bar Support
Start by turning the table upside down on the saw horses. I noted the spot welds on the table were pretty inconsistent and some of the angle iron supports were quite flimsy. I threw a few extra spot welds on the angle iron to expanded metal to keep the supports from moving around here.
Pre bend the flat bar into a "circular shape" to prep it for putting inside the cutout. To find out the length of flat bar that you'll need just use basic geometry, C = πD (circumference = pi * diameter) or technically C = πR2 (circumference = pi * radius * 2) same result. So, if the diameter of the hole is 24" across you can solve for the length of flat bar needed by doing this calculation. 24" X 3.1415 = 75.4". So, I needed a piece of flat bar at least 76 inches long.
I went to the local metal yard and searched and searched and searched, but they did not have any flat bar stock thin enough for what I needed. So, I found some sheared pieces that were uneven, but were thin enough to fit my needs. Since it was all I could find that worked, I went ahead and brought it home to use. You can see in the images the difference in widths at each end, 1/2" over the length of the metal.
Step 10: Clean Your Metal
I used a flapper disc to clean the metal of surface rust (very common in a metal scrap yard as it sits outdoors) which is inevitable in the Willamette Valley of Oregon. The flapper disc makes very quick work of this in just a few minutes and it's bright and shiny.
Once the metal is cleaned up enough you can start bending it into a circle. I started by just getting it to sit inside the outer lip of the table, and continued to work it until it was about half of the diameter of the table. Takes just a few minutes, and the nice thing about metal is you can pound it back out with a hammer or something else. Just slowly work your away around the length of the flat bar and put small, light, slight bends in it to get it to start circling in on itself.
Once you have a pretty good circle in place, you can start to clamp it to the table in the hole previously cut out. I used a couple of large Quick Clamps for this as they are easy to use, have plenty of room to work with, and easy to connect and disconnect.
Step 11: Start to Tack Weld It in Place
Once you have close enough circle to start tacking it inside the cutout, use a quick clamp so the beginning of the flat bar is in the middle of two angle iron supports. Use a clamp to hold it tight to the immediately close angle iron and then a attach a second quick clamp in between the the first angle iron support and the second one. This allows you to pull the flat bar in tight to the cutout and the next angle iron support. If you just clamp on the end pieces of the angle iron supports you won't get the space in between up tight to the expanded metal and the flat bar support won't be very round.
Throw a tack weld on the first angle iron support beam and the flat bar to lock the steel flat bar in place. From here, I just put the clamps in between the angle iron support bars so as to pull the metal in tight to the circumference of the cutout, as well as hold it up tight to the angle iron supports. This also saves the clamping fingers of your Quick Clamp from melting as it tends to get VERY HOT (molten metal vs. plastic and plastic will "always lose"). Make sure you line up the flat bar with the top of the table at the expanded metal (which is currently on the bottom). When you flip the table back "right-side-up" the flat bar will be flat around the top of the cutout. Sometimes a little persuasion is a good thing with metal and a small sledge hammer does the trick.
Continue to work your way around the circumference clamping in between the angle iron supports of the table top (or bottom as you are looking at it) and tack welding the flat bar to the angle iron. One you have the tack welds around the circumference of the cutout you'll come to a point where you have to overlap the beginning and ending of the flat bar inside the circumference of the cutout.
Step 12: Cut and Weld Together the Flat Bar Ends
I used a metal C-Clamp at this point as there is going to be some heat buildup here in cutting and welding the two ends together. I aligned the two pieces (you can really see the difference in widths at both ends here) so that the top of the table was flush and the wider side is on the bottom (top to you as your are looking at the bottom of the table). I clamped the two ends together with the overlap and used my cutoff wheel and cut between both pieces of metal so there was only about 1/16 of a gap between them making a nice flush zone to weld up. UNFORTUNATELY, I got in a hurry and forgot to take some photo's of this stage.
Again, I used the C-Clamp to bring the two pieces together and tightened it down a but but not too tight as you'll use the persuasive tool to align the two ends together before welding (on the top side of the table, but bottom as you are looking at it). Once you are happy with the alignment, throw a tack weld between the two end pieces also known as a butt joint. I did a quick tack on both sides of the butt joint and then removed the C-Clamp.
After removing the C-Clamp, I threw a thick weld on both sides of the butt joint, and then continued around the table doing a good stitch on both sides of the Angle Iron and the Flat Bar securing it nice and tight to the structure. This is not to hold the flat bar in place (at least not the primary reason) but add a substantial amount of support back to the table since we cut out the center weakening the structure substantially. With this flat bar welded in place, we've now added back plenty of support for the table to hold not only the bowl and piping, but sand, rock, or other media you want to add for ambiance.
Once all of the Angle Iron supports were securely welded to the flat bar, I went around the table again adding a quick weld between the flat bar and the expanded metal table top to be sure it's tight, strong, and secure. Then I ground down the weld on the inside of the flat bar at the butt joint just to be sure it doesn't rub against the bowl if it's a tight fit (probably wasn't necessary but I like to grind and weld and do way more than is necessary!).
Step 13: Check for Fit.
Flip the table back over on the supports so it's right-side-up and place the bowl in the center of the table. Check it for fit and see how much play is present. Mine was right on the money, but others I've built were a little too loose for my comfort and I've added some gussets to tighten it up a bit.
Now, you can stop here and call it a success if you are going to use Charcoal, Wood, or some other source of fuel that doesn't require high BTU gaseous substances. I prefer the cleanliness of Propane or Natural gas, but there is nothing like the smell of burning wood to add to the ambiance of the event.
If you call it good at this point, just attach the legs, and the base for support and your are in business. If you wanna go on with making a propane or natural gas fed fire pit then we'll continue...
Step 14: Building the Burner
I came up with a pretty simple design to produce more than enough flame depending on how much gas you use to set the amount of flame you want. I purchased a short length of 1/2" copper pipe, 10 pack of 1/2" copper T's, a 10 pack of 1/2" copper 90 degree elbows, a fitting to go from the 1/2" pipe to a brass FP to FIP fitting which will attach the propane hose from the tank.
Start off by cutting several 1" lengths of copper pipe to use to fit the burner together as you want it. I went with a simple 4 outlet burner which provided more than enough flame for the table (too much in fact on high!). I began with a T and put a 1" length of 1/2" pipe into the center of the T and attached the 1/2" slip to the FP fitting. From the two ends I added another 1" length of pipe to two more T's. On the two open ends of the T I put a 90 degree elbow, and then from there added another 90 degree elbow on top of these so the flame on all 4 corner points back into the center. I tried another design where the 90 degree elbows were all offset to the right (or left) to create a bit of swirl/fill and it worked just fine as well.
Step 15: Stuffing a Baffle Into the Copper
In my initial testing I found that the propane tank/diaphragm sounded like a jet engine when I turned it on, and especially when I ramped it up a bit. So, I tried a few different baffle systems to see if I could quiet it down a bit for a more enjoyable time around the fire. I have three videos below that will give you an idea as to the amount of sound that comes out of this device.
Unbaffled is way too loud and I wouldn't recommend it. Sand it great and completely silences the burner, but it "burps" the sand out of the burner. Without additional surrounding sand to help fill it back in tends to fail. Along with the sand being used as a baffle, with my design the sand will end up going all the way down the hose and probably be way too messy when changing out the tank. I ended up packing the pipe and fittings with large steel wool. Now, when I say "packed," I mean "PACKED!" I shoved steel wool in these things until no more would go in, and the fittings were coming apart. I wanted to get as much steel wool inside the piping to break up as much of the sound as possible.
Step 16: Brazing the Copper Together
Here I brazed the pipe and fittings together with some brass/bronze filler rod as the solder's melting point is way too low to work with this device. On a side note, I am by no means a master welder and especially not a master at brazing, so be kind to my work here. I mainly wanted to make sure the propane wasn't leaking through the joints.
This design has the top 90 degree elbows pointing in to the center, but offset to give a slight swirl and filling affect. I didn't notice much difference between this design or the 90 degree elbows pointing at one another. Whatever your design is, you'll want to make sure all of the joints are sealed with a filler that will take the heat. Copper is a great conductor of heat/cold so it spreads throughout the burner immediately and heats up quickly.
Step 17: Attach the Burner to the Bowl
Once the burner is complete, get a stepper drill at a local store (Harbor Freight is cheap) and drill a hole in the center of the bowl. I don't recall the diameter of the hole is, but just progress through the stepper drill and test fit your fittings as you go. Once the hole is the "right" size, place a large washer on both sides of the bowl, insert the burner into the hole, and screw the brass fitting on the bottom of the bowl.
Slip the bowl into the table and attach the propane hose to the bottom fitting of the burner/bowl assembly (assuming you put the table together already). Give it a test fire, and see if it's what you wanted. I've attached a couple of photo's here of the different flame heights based on where you set the gas output.
Fill the bowl with your favorite filler such as pea gravel, sand, marbles, water or whatever works for you. Propane in this environment burns dirty and leaves a black soot over whatever you have in the bowl with it. You can either completely cover the burner holes with it, but it will blacken the media, or leave just the tops out to lessen the amount of soot accumulated.
Total cost depends on what you have on hand and what you have to purchase. The table and bowl runs about $140 to $160 depending on where you obtain your items. Miscellaneous pipe and fittings run about $15. The flat bar at a local steel yard is around $0.50 a pound.
I hope you enjoy this as much as I enjoy it. It's a lot of fun to hang out around and entertain with family and friends!
Now I'm working on an off road wheel chair for a paraplegic friend of mine... I'll try and document that as I go for the next instructable.