Introduction: Design Coffee Table
I'm a DIY-er with too many ideas. Some of these ideas I do make, most of them I don't. It depends mostly on time and money whether or not I bring certain ideas to life. This was an idea started with the fact me and my girlfriend want to life together after our internship abroad. We already made a list with stuff we still need at that point of living together, one of them being a coffee table. Of course I wanted to make one myself, but as a student I didn't want to spend any money. I also had lots of other cool projects which wouldn't cost me anything. A week later someone offered me almost 5.5 meters of square tubing. That same day I started the design.
This instructable will explain all steps for creating the same coffee table I did. In order to create an as simple as possible instructable I devided the entire build in 6 parts. This devision make not all steps chronologic placed but results in the best instructable in my opinion. Below I briefly explain the 6 parts before going into full detail in the following steps. Enjoy the build en your new coffee table.
Part 1: Design
The first part, the design all depends on your design skills and the materials you want to work with. Take your time to make a good design, because when your design is already not a big succes there is a good possibility the results will be even worse.
Part 2: Frame
The frame will take a lot of time. Many time consuming steps need to be done. First you need to cut the frame. The welding is done in two main steps, first attaching is al together (spot welding), secondly you need to weld the rest. During the welding make sure your frame doesn't deform. After the welding everything needs to be grinded/sanded, followed by smoothing everything with putty. The last step is the painting in the desired color.
Part 3: Wooden top
The wooden top is one of the easiest parts of the build. Take an old top, remove the old varnish, cut is to the proper size and finale revarnish/paint it to the desired color.
Part 4: Redesign
During the build you can already see some sort of a result. Sometimes a good addition is devised during the build, this was the case for this coffee table. Especially for friends I designed it in Google Sketchup so I could show them what is would be like. Normally I wouldn't do the redesign part in Google Sketchup due to the fact that I already saw it in real life so I know it looks good.
Part 5: Shelf
The shelf is made from rest materials from the old top. We gluid them together, cut the result into 3 pieces, then gluid it another time. The results was cut to the right size and planed before the revarnishing/painting.
Part 6: Assembly
Now all parts were present, the table could be assembled. Holes for the screws were drilled in the frame. The frame was attached to the top. The shelf got its final destination and caps were attached to the bottom in order to prevent the table from scratching.
Step 1: Materials
- square tube, steel, 30 x 30 x 2 mm
- primer(putty, 2 component)
Top and shelf:
- old coffee table
- glue (only when there is not enough wood for the shelf. In this case it has to be made from pieces from the old cutted top)
- caps (to fill the holes for the screws)
- caps (in order to prevent your steel frame to touch the floor, this way the floor won't be damaged)
- Miter saw for steel
- MIG welder
- Welding table
- angle grinder
- grinding disk
- sanding disk
- putty knifes
- sanding paper
Top and shelf:
- paint scraper
- circular saw
- table saw
- thickness planer (in case you are not able to use one, an electric plane will also work. It only cost more time)
- cordless drill
Step 2: Part 1: Design
With the received square steel tube I immediately had a vision, a steel frame with a wooden top. And with creating as a hobby I wanted something challenging and something no one else will have.
I designed the table using google sketchup. It took me about half an hour to learn the basics, just by watching the youtube videos provided by google.
I wanted to make something challenging, 4 equal legs like this would do the trick. My girlfriend didn't like it enough, not even after two hours of trying to let her like it.
I knew my girlfriend wanted a shelf, so I tried to adjust the first design. I didn't like this as much as the first design.
After the failure of the first design she was thinking of something antisymmetric. This was my first creation.
She liked design 3, I didn't because it wasn't the antisymmetric she wanted, is was point symmetric. I adjusted the design to design 4. This however looked strange.
With the first designs already failed, I tried a new approach, two frames instead of one. We both agreed with this design. It was a pitty I didn't have enough material.
Design 6 and 7:
Design 6 and 7 were created to compensate for the material, design 7 won. The small frame is in this design 1/3 the size of the big frame, where it was 1/2 in design 5.
Google Sketchup files:
I don't have all design files anymore, only from the 7th design.
Step 3: Part 2: Cutting
As I told in the materials section, the cutting of the steel tube gave me almost much trouble. With a few calculations I managed to get all the desired pieces out of the material I had. Remember to measure all pieces in between to be sure you're doing it right. Also don't make mistakes in cutting the angles in the correct direction because two 'likewise' pieces are eachothers mirror image. When setting the correct angle on your miter saw, small deviations can be corrected during the welding.
Most measurements can be seen in the pictures. For the rest you should use the Sketchup-file.
Step 4: Part 2: Welding
For the complete welding I added a 2 mm space in between the tubesections during the spotwelding. I did this simply by placing a piece of steel, 2 mm thick, in between the tubesections. By having these pieces of steel long enough, they are easy to remove. In order to create exact 90 degree angles I used a welding table with a right angle. With clamps I kept the sections in this angle during the spotwelding.
While doing the complete welding it is important to constantly measure your frame so you know which weld to weld in order to keep your frame straight. I succeeded with this for the small frame. With the large frame I forgot to measure in between so I took very stupid mistakes. In the middle of the frame it came 1 cm short. A car jack provided me the strenght to bend the frame outwards. By over-bending the frame it elastically deformed back to the desired distance.
- I didn't used the 2 mm spaces during the calculations of the tubelengths, so my frame became a little bigger. This was no problem for me.
- Don't ask me how I decide which one to weld, I did it on my intuition. Maybe it was pure luck.
Step 5: Part 2: Grinding/Sanding
Grinding, not much to tell about. Use the grinding disk for the begin and end with the sanding disk. The inside corners I only did with the grinding disk. The sanding I did by hand which took a lot of time. As you can see, small strokes are not welded correctly, these we will restore in the next step.
Step 6: Part 2: Priming/Sanding
I'm not the best in priming as you can see in the pictures. This has two reasons, my putty was to old and I made to many of the two-component material at once, which made it dry much to fast. The result, the putty works but a lot of sanding was required. In the previous step I removed the top layer of the metal by sanding on the places I wanted to prime. This is neccessary to make the putty stick to the metal.
The picture indicate how much sanding is required for the best looks. Less sanding can result in a little 'bump' on the frame which you can see after painting the frame, depending on your paint.
Step 7: Part 2: Painting
Before painting the frame it needs to be cleaned. The top layer of the metal, a layer protecting it from rust called mill scale, needs to be removed. This can simply be done with a little piece of sanding paper. Afterwards I painted the frame with a white primer, this primer sticks to the metal and let you use many different kind of paint which don't stick to the metal itself.
The actual painting of the frame I did at the end of the build, that's why in all pictures the frame is white. Painting a frame is again a simple task, just follow the instruction on your can. I used a roller instead off a normal brush to avoid the creation of ugly lines in the paint. I also painted the caps, which go in the screw holes, the same color as the frame.
If you are able to powdercoat your frame I suggest you do that. Much better results.
Step 8: Part 3: Remove Old Varnish
A small step in the entire process. Scrape all the paint from the table.
Step 9: Part 3: Cutting
Before the table was cut to the right size I disassembled the table so the top was lose. The rest of the table was used as a workbench for the cutting.
At this moment I had no clue I was going to make a shelf, so I had no intentions to take into account that the pieces I cut off were wide enough. It is definitely worth making your table 1 cm less wide so a shelf can be made.
Luckely me and my dad first cut off the sides and afterwards the ends of the table. So the pieces turned out to be long enough and just wide enough. We used a circular saw with rail in order to get it al straight.
When we put the top on the frame we saw the two pictures. Too crowdy, so we turned the small frame 180 degrees. Still not the desired look from the design. Time for some redesign.
Step 10: Part 4: Redesign
During the previous step my dad and I placed a piece of 3 cm thick plywood in the frame because it was something which fitted the small frame so trying is never wrong. We immediately knew this was needed for the completion of the table. I redesigned it in Sketchup, the result can be seen in the picture.
Google Sketchup file:
Again I added the sketchup-file.
Step 11: Part 5: Gluing
Gluing is devided in two steps for this instructable. Before en after the cutting. First the two pieces which were cut off of the old table top are glued together. Make sure you tighten them good together while drying. You need to remove the excess glue as fast as possible in order to prevent the glue from soaking your wood and by that colouring the wood.
The second step is after the long piece is cut into three. Again tighten them good together. However, this time we also need to level it by thighten it, in my case, to the work surface. In order to prevent it from sticking to the workbench I used a simple newspaper. The allignment of the three pieces depends on the previous cuts. My allignment can be seen in the first picture of step 13.
Both steps can be seen in the pictures.
Step 12: Part 5: Cutting
The long glued part needed to be cut into three pieces. I had plenty of length for the desired width of the shelf, so I cutted the piece in different length as can be seen in the picture. This difference in length results in the removal of the rounded edge.
As can be seen in the second picture we tried to straighten the pieces on the table saw. This didn't succes because the saw was dull, we decided not to cut them before gluing. Instead of this we just roughly sanded the wood before gluing.
After the planing we cutted the shelf to the desired length the same way as with the top, simply with a circular saw with a guide rail.
Step 13: Part 5: Planing
I used a thickness planer to get my shelf to the desired thickness. Make sure you don't remove too much wood in one go. Just do more steps. In case you don't have a thickness planer, just use an electric planer which will work almost as good only takes longer.
After the planing and cutting I sanded the shelf. Because my thickness planer was a little dull and not in the best shape due to its age, some small burn spots were created. Sand your shelf untill you can't see them anymore, when you don't you will regret it.
Step 14: Part 5: Placing the Shelf
We worked out the ideas with a thick piece of scrapwood. In the frame we drilled three holes, 2 in the small frame and 1 in the big, which we threaded and a headless bolt was inserted. By trial and error the correct length of the bolts and the placement of the holes in the wood were specified. The pictures explain the idea how to insert the shelf in the frame. The pictures contain no top, but it is also possible to insert the shelf with the top attached.
- When drilling holes in steel always start small, I normally start between 2 and 4 mm.
- When increasing the size of your drill, don't increase it to fast, again I normally increase between 4 and 6 mm.
- Use a cooling liquid when drilling a hole.
Step 15: Part 5: Varnish Both Shelf and Top
I don't like painting, but with the end result in my mind I must say I liked it this time. Three layers of varnish were used to get the desired result.
Didn't ad pictures because there was nothing to be seen on it.
Step 16: Part 6: Full Assembly
Most steps of part 6 are done before the painting of both the frame and the wood in order to prevent damage to the paint job.
In the small frame three holes were drilled to attach it to the top. The large frame got 4 holes. In order to cover the holes with a cap and in order to get the screw through the hole, the holes on the inside of the frame were drilled bigger, at the size of the caps. Again, remember to start with a small hole and encrease your drill size with small steps. With the holes in the frame we alligned the frame to the top. We pre-drilled the screwholes due to our relative thick screws.
At this stage of the build, after the last holes were drilled, the table was painted and assembled.
I'm not sure the color of both the top, shelf and the frame are the desired colors. This will depend on the colors of the rest of the furniture, which we do not have yet.
All left to say is enjoy your new coffee table or keep enjoying my instructables because i'm sure more will come in the future.