Introduction: Industrial Scrap Coffee Table
This is a coffee table I made from some old oak beams and a piece of industrial scrap metal.
This was a fun project and I learned a lot along the way. I've tried to cover the entire build process in this Instructable, so hopefully this will be helpful if you're interested in doing something similar.
Thanks for taking a look!
Step 1: Wood: Before & After
The wood for the table top came from a pair of old weathered oak beams.
I bought them from a used building supply store (ReStore), and I have no idea how they were used previously.
It's entirely possible they were soaked in carcinogenic chemicals; however, for what it's worth, the classic lick-test did not reveal any particularly non-oaky flavors.
Here is a separate Instructable showing how I milled these into usable boards: How to Flatten Boards With Just a Planer
Step 2: Metal: Before & After
The base for the table was made from this 1/4" steel plate that (according to the attached label) was part of a "Forney Testing Machine." In its former life it held two large dial gauges, and from what I can find was likely part of an industrial concrete compression testing machine.
I found it in a pile of junk at the same place I bought the oak beams. I thought it was cool and had a lot of character so I couldn't pass it up!
Step 3: Thoughts
The metal plate had some great patina, and weathered old wood always has a lot of character.
I wanted to showcase these features, so I tried to not over-transform the core materials.
I feel like I struck the right balance and I'm quite pleased with the finished piece.
Step 4: Start Cutting
I started by extracting four (mostly) symmetrical pieces from the plate.
This left a straight piece that would later become the cross piece between the two sets of legs.
The long cuts were made using a jigsaw with a metal cutting blade, and an angle grinder with a cut-off disc was used to remove a pair of brackets that were welded to the underside.
The label was carefully pried off before cutting up the metal; I figured it would be a neat feature to re-affix later on.
Step 5: Think About It
I moved the four pieces around and around toying with different ideas until inspiration struck.
Step 6: Cut Some More
This little bandsaw has been a fantastic tool to have in my shop. But to make it completely useful I had to first build a stand for it which I outlined in this other Instructable: Portable Bandsaw Metal Stand
Step 7: Weld
The leg pieces were welded at the top.
The original finish was ground off about 3/4" back from the edges to be welded, and ground down at 45 degree angles to create a trough for the weld bead. This was done on both the front and back of these pieces.
The intention was to let the weld bead fill up the trough to minimize the amount of grinding required to make a clean, smooth surface between the newly-welded pieces.
The basics of my welding setup:
- Hobart 140 mig welder
- Antra auto-darkening welding helmet
- Tillman welding jacket
- basic welding gloves
- Argon/Oxygen mix gas tank
- Homemade Welding Cart
- Channellock welder's pliers
For cutting and grinding metal, I have:
- a few Makita angle grinders
- Dewalt portable bandsaw
Step 8: Clean Up Welds
The welds were ground smooth using an angle grinder.
Step 9: Prepare Cross Brace
The cross brace was made by trimming both ends to a 12 degree angle.
The leg pieces were marked where this brace was to be welded.
Step 10: Weld Cross Brace
The cross brace was welded in place, first with tack welds on both sides followed by full bead welds.
New to welding and metalworking? I'm relatively new to it and my welds are far from perfect. But it's a lot of fun and definitely something I recommend learning.
Some excellent reading for more info:
Audrey's Welding Class
Randy's Metalworking Class
Step 11: Make Tabs
I used some of the scrap bits that were cut from the metal plate earlier to make some tabs.
These will be welded in place and the wooden top panel will be fastened to the base through these.
Holes were drilled using a drill press, vise, clamp, and cutting oil. Then the pieces were ground down to bare metal (in order to be welded), and then cut into individual pieces.
Step 12: Weld Tabs to Base
The tabs were then welded to the base.
Note that the outer tabs have a slot rather than just a hole. This way if the table top were to expand or contract over time or during season changes, there is a little wiggle room to allow for movement.
There should not be much movement at the center of the panel so the middle tabs just have holes, although they are oversized which will allow for a little movement if needed.
To complete the base, I ground off the sharp edges along all of the areas with fresh cuts. The original edges were already rounded over for the most part. I went over all edges lightly by hand with 100 grit sandpaper, to ensure that any snaggy bits or sharpness were completely gone.
Step 13: Make Wooden Panel
Step 14: Fill Cracks
This step is a bit longer, as this was somewhat of an experimental process.
And it was incredibly tedious, but I really like the results.
The wood I used to was full of cracks and knots, and I wanted to fill them all with black epoxy. But in the end the epoxy was used to fill and darken all of the porous oak grain as well, which makes for a neat contrast.
I purchased some bartop epoxy at my local Home Depot. I went to the paint counter with the epoxy in hand along with a plastic mixing container (sold there), and asked if I could have about a half-ounce of black tint squirted in the container to use with the epoxy.
They said "sure" and put the cup under their paint machine for a few seconds worth of tint. I wasn't sure if they would oblige me, or if the tint would even work with the epoxy . . but in both instances I had positive result.
This epoxy is a slow-set epoxy and has some very specific instructions. I followed the instructions precisely and mixed a small (but equal) amount of each part. Midway through the 12-minute (yes) stirring process, I added 2 drops of the black tint which proved to be sufficient.
I masked off the edges of the wood panel and poured the epoxy into the cracks and knots, and then just squeegied the entire surface with the black epoxy getting it into all of the wood grain and imperfections in the wood.
This was allowed to cure for a couple of days, and then I sanded the surface with an orbital sander with 80 grit paper to remove excess epoxy.
More epoxy was added to completely fill various imperfections in the topside of the panel, allowed to cure, and then sanded smooth.
Then I repeated this process a few more times, to give the edges and underside of the panel the same treatment.
However, on the underside it's possible (cough.. likely) that I skimped on the effort and wasn't as thorough as I should have been. This might have been the cause of some problems I encountered later on . . .
Step 15: Flatten, Sand and Route
This project was spread out over a few weeks time, and at some point the panel began to cup upward.
Perhaps this was from not applying an equal amount of epoxy to seal the cracks and voids on the underside, or perhaps it was due to a change of seasons as the weather warmed up where I live. Maybe it was both.
Regardless, the panel became unusable in the cupped state it was in.
It's not shown here, but in a later step you'll see that I cut a series of grooves along the bottom side using a circular saw. This was done to allow the panel to flex a little more once it was attached to the metal base.
After cutting the grooves, I soaked the panel in water and put heavy weights all over the topside edges of the panel and let it sit for a few days like that. This actually removed most of the cupping.
With the panel dry and mostly flat again, the entire thing was progressively sanded up to 220 grit using an orbital sander and all edges were routed with an 1/8" round-over bit.
Step 16: Apply Finish
The panel was coated entirely with boiled linseed oil, allowed to let it soak in sufficiently, and then wiped clean and allowed to cure for a few days.
Once the oil was completely dry, the panel was sanded very lightly by hand with 220 grit sandpaper.
It was then sprayed with several coats of semi-gloss lacquer.
The oil penetrates the wood and makes the grain stand out, and I like the slight sheen and feel of the lacquer finish.
Step 17: Fasten Top to Bottom
The top is attached to the base with pan-head screws.
Note the de-stressing grooves on the underside that were mentioned earlier.
Step 18: Add Details
The original name plate was reapplied using contact cement.
Tiny holes were drilled at the corners and brad nail heads were superglued and pounded in place. These are mostly for looks.
Step 19: Touch Up
After I moved the table into my house, I noticed how unsightly the shiny ground-down welded areas were.
I got out the acrylic craft paints and very carefully added some layers of camouflage.
This was done with a base layer to match the general color of the gray metal areas, and then various layers of browns were stippled on to recreate the look of the rusty sections. The brown colors were used to do this to the shiny cut edges of the metal legs as well.
This is all on the underside of the table, and because the base is so varied and full of blemishes anyway it goes completely unnoticed now. And that was the point.
Step 20: Done
Thanks for checking this out!
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