Introduction: Propane Tank Bench

Picture of Propane Tank Bench

This bench is made from a scrap propane tank.

Step 1: The Raw Material

Picture of The Raw Material

This idea originated with a junk 575 gallon propane tank on my property, which my wife told me I had to get rid of or "do something with." A lot of energy had been used to form the 5/16" thick steel into this curvaceous shape and it seemed a shame to just cut it up and recycle it as scrap. We needed some outdoor seating so I began to consider possible ways to carefully dissect the tank and reassemble the parts into a bench. My goal was to not have to reshape or reform the metal in any way, just carefully cut out the parts and weld them back together.

Step 2: Design Parameters

Picture of Design Parameters

These are my initial two sketches. As I considered exactly where I would make my cuts my thinking was as follows:

  1. There is only one straight edge in the tank's shape, along the cylindrical portion, so that would have to serve as the seat and backrest.
  2. Standard height for seats is 17-18" and standard seat depth is 19-21", based on my field research of measuring lots of park benches.
  3. The bench needed to be balanced properly since the backrest would make it back heavy.

With the above functional elements factored in I began to consider the design's aesthetics. I wanted to add additional curvature so there were no straight lines in the whole design except for along the seat and backrest. I also wanted to keep it simple and not dissect the tank any further than necessary.

Step 3: Marking the Tank Ends

Picture of Marking the Tank Ends

The 575 gallon tanks have a 37" diameter, large enough to support the basic seat and backrest dimensions mentioned previously, so I decided to cut them out first and then fit the seat and backrest between them.

Step 4: Preparing the Tank for Cutting

Picture of Preparing the Tank for Cutting

Just to be clear, I am NOT recommending, suggesting or implying in any way that you should cut up a propane tank. It is very dangerous and could kill you if it explodes.

Our scrap tank had been sitting for decades outdoors with some of the fittings missing, so I was relatively confident there was no more gas inside. Just to be sure I filled it 80% full of water.

Step 5: Cutting the Ends

Picture of Cutting the Ends

I tried to keep as steady a hand as possible.

Step 6: Measuring the Seat

Picture of Measuring the Seat

I placed the two ends on my work table and clamped them in place. I marked the seat height at 17". I rolled 1" bar stock and made a curved steel frame that matched the curve in the tank. This allowed me to make a template of the joint between the curved seat and spherical end. I marked out the shape of the seat on the cylindrical portion of the tank and cut it out.

Step 7: Attaching the Seat

Picture of Attaching the Seat

I welded in the seat and feet, which I also made from the cylindrical portion of the tank. I drilled 3/4" holes in the feet before attaching them.

Step 8: Measuring and Cutting Backrest

Picture of Measuring and Cutting Backrest

I used the same jig I had made for capturing the seat joint to make the template for the backrest. I eyed what I thought would be a good position to allow the backrest to provide lumbar support realizing that I still needed to determine the exact position. I marked the remaining tank material and made my cuts.

Step 9: Fitting the Backrest

Picture of Fitting the Backrest

The backrest was so heavy that I had to use my tractor to help position it onto adjustable stands. Then began several weeks of trial and error to determine the exact position for the backrest. Numerous friends and family sat in the seat and patiently waited as I made adjustments (unfortunately I do not have photos).

After much experimentation an ideal relative position of curved seat to curved backrest was determined which provides good lumbar support for a wide range of body sizes. As it turns out, the combination of curved seat and curved backrest allows smaller bodies to slip slightly further back and down into the funnel like shape at the rear of the seat and receive good lumbar support. I believe this arrangement provides an ergonomic advancement over traditional benches with flat seats.

With the backrest position finally established I welded it in place.

Step 10: Trimming the Backrest

Picture of Trimming the Backrest

I used a piece of plastic EMT to mark a gentle curve for the top edge of the backrest before trimming it off. I ground down the welds and other sharp edges.

Step 11: Assembled in the Raw

Picture of Assembled in the Raw

Here's what the bench looked like before I sent it off for powder coat. I decided to leave the original lift hooks in place as a way to reference the source material, in case it wasn't obvious enough.

Step 12: Completed Bench

Picture of Completed Bench

I had it powder colored in it's original color. I also affixed a new decal and mounted the original manufacturer's ID plate, showing the tank was made in 1972.

This bench is sculptural, comfortable, durable and extremely eco-friendly, containing 99% post-consumer reused content. I was so thrilled with the design that I applied for a patent and 9 months later it was granted! I've taken the next step and applied for a utility patent to protect my concept and process.

Step 13: Epilogue

Picture of Epilogue

The first bench wetted my appetite.

As I searched for more junk tanks I learned that locally sourced scrap tanks are an abundant and sustainable "raw" material due to strict regulations limiting their service life.

I have continued to create new seat designs. See attached PDF or visit my website:


MishkaJk (author)2017-06-20

Okay that's awesome and I love that you left the handles on because it gives people somewhere to tie their dog leashes! Awesome!

Duplo for Daddies (author)2017-05-18

Wow! That is an amazing job, with a beautiful result. Like others have mentioned, it could fit into any museum or gallery. I hope to learn welding at some point. Keep up the good work, and thanks for sharing.

Shop27vt (author)2016-08-07

Great use of scrap!

toastdore (author)2016-04-24

nice :)

kart15 (author)2016-04-05

great work.

buck2217 (author)2016-03-02

Awesome, glad you won the grand prize (although IMHO the first prize choice was better than the grand prize - instructables sometimes baffle me with their choices!)

andrea biffi (author)2016-03-02

I LOVE it!

buck2217 (author)2016-02-26

That is beautiful. Brilliant idea

sunslayer (author)2016-02-26

You have a very creative mind for cutting, assembling and making this from the propane tank. I wish I had the same vision as yours.

Good job, awesome work.

jeanniel1 (author)2016-02-07

Really great welding and plasma cutting. So smooth. Obviously a pro. Love your line of chairs, chaise loungers, and planters!

Mihsin (author)2016-02-06

This is a unique creation should be dedicated to an art gallery or a park. You're an excellent metal fabricator. If you can go back to edit this 'Ible, Pls. underline: Fill the tank with minimum 80% water. A friend experimented a 20 ft flight and slam on the next wall because he didn't fill the barrel, he was cutting, with water.

Best regards

gdomantic (author)2016-02-04

Hank Hill would've been proud! But on serious note, this is beautiful!

snotbucket (author)2016-02-03

That is AWESOME! When I first viewed the bench I saw a modern design with a classic automobile vibe, and would never have guessed its been recycled. You, Sir, have incredible vision.

phillipnolan (author)2016-02-03

Outstanding repurposing. Well done.

Tool Using Animal (author)2016-02-03

That is one of the most beautiful things I have ever seen.

tetrahemicon (author)2016-02-03

Very cool, nice work and it looks comfortable.

Swiss artist and
mathematician Paul Schatz wrote a book in German that I can no longer
find reference to. It's title translated to A Quest of Art Based on the Strength of Perception.

I think you've got it Colin

Peter van der Hoeven (author)2016-02-02

Way cool! Nicely done. Great idea.

workoutbuddy78 (author)2016-02-02

Great work, great eye :-)

Do you have any ieas for a 5 gallon propane tank?

calistoar (author)2016-02-02

What a nice piece of metallurgy!! I think if you create a business to sell these units, this should be called "The think tank" . Congratulations!!. A big hug from Patagonia, Argentina. ps: you have my vote!

alanjamesblair (author)2016-02-02

This is so super-spiffy looking! I'm sure you could sell these for a bundle and what a creative way to reuse this material!

Naugas (author)2016-02-02

You got the shape and lines just right, it looks really good. Nice work!

Scottie62 (author)2016-02-02

fantastic, i love it. amazing

Toga_Dan (author)2016-02-02

very cool. I like the signage which shows it's origin.

desertsniper (author)2016-02-02

Hank Hill approved!

"we sale propane and propane accessories"

VonMoto (author)2016-02-02

You have my vote !

Greetings from Portugal

patdoherty (author)2016-02-02

Great execution!

schabanow (author)2016-02-02

Amaizing, absolutely incredible. Design of high art. Thank you for the Music!

r3t2 (author)2016-02-02

brilliant. In one of the pictures, I thought you also had a capsule bed.

ClareBS (author)2016-02-02

Beautiful, I bet your wife is happy now.

Heath A.B (author)2016-02-02

Love it, Great concept and execution!

Stryderx (author)2016-01-31

pretty cool work but wouldnt be more useful (and expensive) as a tank?

Cream of Deer (author)Stryderx2016-01-31

It probably could still work as a tank for holding stuff. However, it is illegal to store pressurized materials in a tank that has exceeded its service lifetime (such as this one, obviously) and therefore it cannot be used as a pressure tank.

ah, but. The larger propane tanks don't have a service lifespan as do the 'portable' tanks because of the thickness and type of metal used to construct them. My 500 gallon tank was fabricated in 1956. If, due to inspection concerns by the filling company, it is unsatisfactory they won't fill them. Extensive rust and pitting, dents, corroded valves etc are the criteria used to determine end of life status. Several of the local companies ship their returned tanks to a place in CA where they are inspected, revalved, cleaned, painted and put back into service.. Should you desire to purchase your own tank from a local propane facility you could end up with an older refurbished tank!

Dakotamouse (author)2016-02-02

Gorgeous! I could never make this but I really appreciate the artistry!

fdc313 (author)2016-02-02

amazing vision

WyldStyl3 (author)2016-02-02

Wow! This is fan-freaking-tastic! Awesome work.

alehnhar (author)2016-02-02

That's amazing! Great job!!!

KOJohnson (author)2016-02-02

Yes, this one is really superb. Very clever perception on your part, and very beautifully achieved.

Ancient Android (author)2016-02-02

WoW !

Philippe Starck would love to get his hands on this work.

Well designed, Beautifully executed. Work of ART this is.

Thinkenstein (author)2016-02-02

I love it! It looks aeronautic, and a lot lighter than it must be.

DarylM11 (author)2016-02-02

Truly impressive! Thanks for sharing!

MadJimFlynt (author)2016-02-02

This would be perfect for the Arkansas River Bridge project in Tulsa.

pocodot (author)2016-02-02

After many years in the propane industry I thought I had seen it all, but I have never seen anyone do this before. :o) Beautiful! Good thing you left the hooks on it, you will definitely need your tractor to move this one around. LOL

bnaivar (author)2016-02-02

Well done sir!

jproffer (author)2016-02-02

very well done and beautiful! you have my vote.

David Catriel (author)2016-02-02

Wow. Incredible idea and beautifully done!

Skywalkar (author)2016-02-02

Gorgeous result; awesome job finding the most visually appealing way of cutting and reassembling those pieces!

This is great! Keep it up!

About This Instructable




Bio: Raised in an ecologically conscious household the importance of conserving our planet’s resources was instilled in me from an early age, although my parents ... More »
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