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This article was first published in 2007.
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If you do any work on your car, having a good
workbench will make life a helluva lot easier. Not only can you work on items at
a comfortable height (nothing gives you back-ache faster than working on the
ground!), but you can also mount machine tools like a grinder and a drill press.
Bolt on a heavy duty vice and you’ll wonder how you did without a bench!
But sourcing a good bench can be damn’ hard so in
most cases it is best to build it from scratch. It will take some time and
effort but it doesn’t need to be expensive – the bench covered here was built
using mostly secondhand materials for under AUD$100 total.
But first up, what do you want in a bench?
Picking the correct bench height is vital. That’s
especially the case if you’re going to be mounting a vice on it. The top of the
vice should be near to the height of your elbow when you’re standing upright
with your arms by your side. That’s because when you place an item in the vice
and file it, you’ll have greatest control if the item is at that height. The
same applies for hack-sawing.
Many benches are too low – in fact, the majority
are too low. Too low a bench will also force you to bend your back more than
necessary.
For specifics: I am 180cm tall and my elbow height
is 112cm. On my current bench, the top of the vice is 110cm from the ground.
That bench is 89cm high, a height I also chose for the new bench shown later in
this story.
A bench should be made as massively heavy as
possible. A well built bench will be heavy as a matter of course (more on
construction in a moment) but having the bench heavy is something to aim for in
itself. Why? A major reason is that when using the vice, you want it to behave
as if it’s part of planet Earth! So say you have a metal bar in the vice and you
want to bend it slightly. If the bench is light-weight, as soon as you pull on
the bar, the bench will skate across the floor. Not good... Of course you can
dyna-bolt a bench to a concrete floor but it simply isn’t the same as having a
massive weight to work against. The same applies when using a grinder or
belt-sander bolted to the bench.
All benches should be built super strong. There
are a few reasons for that.
Firstly – and most simply – you might want to put
something pretty heavy on it! That might be a gearbox or even an engine. Any
well-built bench should tolerate having 300kg or so plonked on top. (Now, do you
see what I mean about how hard it is to find a good bench?!)
Secondly, you don’t want the bench-top to deflect
when you’re hammering something on it. Whether you mount a small anvil on the
bench, you’re using a hammer an item in the vice, or you simply want to
centre-punch something sitting on the bench surface – in all cases, the less the
bench deflects, the better.
Finally (and this is an important point when
you’re thinking about building a bench), a strong and well-built bench will last
you for the rest of your life. Gulp!
I never really thought about the latter until I
reflected on the bench that I built 15 years ago. I made it when I was a teacher
and so had access to the school metal-working facilities. When it came time one
weekend to weld up the frame, the MIG welders were low on gas but I went ahead
anyway – and so the welds weren’t nearly as good as they should have been. At
the time I thought: so what, the welds will work well enough. Now, when that
bench has followed me across four houses and two states, I sometimes wish I’d
waited for the shielding gas cylinders to arrive... It hasn’t broken – but I would
have taken more care in the construction if I’d realised how long I was going to
be working with it! [Incidentally, I paid for use of materials and eqipment in that school workshop...]
A bench can be built in two basic configurations –
island or linear.
An island bench sits in the middle of a
space – it’s accessible from three or even four sides. A bench of this type is
rectangular with about 1:1 (ie square) to 2:1 (ie rectangular) length:width
dimensions. An island bench has some major advantages. You can work with very
wide and/or long items. Alternatively, you can mount things at the corners (eg a
drill press, bench grinder, anvil) and then easily access all of them. However,
an island bench consumes lots of space – so that space needs to be available in
the first place.
A linear bench mounts along a wall. Its
length:width ratio is about 3:1 or 4:1. A linear bench takes up less workshop
space. Where items like a drill press or grinder are mounted on the bench, they
tend to be spaced along it – which leaves less room for working. If building a
linear bench, don’t fall into the trap of making it more weakly (“it can partly
be supported by the wall”) – for all the same reasons as an island bench, it
needs to be super strong.
In my case, already having an island bench, I
chose to make the new one a linear design.
Construction
When you build something - like a piece of
furniture – that’s meant to be pretty strong, you might give the final item a
bit of a push or pull to see how stiff it is. Or say you assemble an Ikea
wardrobe – you might lean on it a bit to see if it seems reasonably strong.
But a work bench is nothin’ like that! Instead, consider how well
that wardrobe would go if you G-clamped a piece of steel to it and then started
bashing the hell out of with a big hammer. Or you put a gearbox on top of it....
Clearly, a work bench needs to be constructed to a completely different
magnitude of strength!
There are a huge number of work bench building
methods, so I’ll deal here only with what I’ve seen work well.
A welded, cross-braced steel frame has the
rigidity and resistance to vibration that are unachievable with a bolted steel
frame or a dowelled-and-bolted wooden frame. However, the top of the workbench
needs to absorb hammer impacts and so must be ‘deader’ than steel – thick timber
or particle board is ideal. And when I say thick, I mean thick!
The top working surface can be stainless steel
sheet or my preference, a thinnish layer of Masonite (Masonite is a high density
pressed wood sheet). The Masonite is easily replaceable after it wears, doesn’t
easily dent and can be kept clean with a wipe-over. It also absorbs spills.
Building a Bench
The incentive to build another bench came when I
went to a local garage sale. On sale were four lengths of 51mm square steel tube
with a hefty 3mm wall thickness. Each had a ‘foot’ welded on it – I think they’d
previously done duty as veranda posts. In addition, there were two 3 metre
lengths of heavy 242 x 46mm timber planks. These perhaps had been used as
rafters or something similar. Total cost for the lot I bargained down to AUD$45.
Now forty-five bucks for some bits of old square tube and some wood can look
rather expensive (my wife certainly thought so!) – but it isn’t. If buying new,
at a typical supplier you’d pay hundreds of dollars for this stuff.
In addition to garage sales, salvage yards often
have plenty of secondhand materials suitable for making benches. One of the
beauties of building a bench is that you can tailor the design to suit the
materials – building-in more braces if the steel and timber are thinner,
etc.
In fact, thinking I’d need some further braces, I
sourced four short lengths of 17mm diameter steel bars normally used for
reinforcing concrete. This steel was bought from a local salvage yard for AUD$5.
I added a few pieces of 5mm thick Masonite at a cost of AUD$8 each and the
construction materials list was complete.
Construction Tools
The bare minimum in tools for building a bench of
this type are a hacksaw and electric drill. However, an arc welder will makes
things much stronger. Now don’t shrug and say: “I knew there was a catch –
where’s the welding gear and the welder around my place?” Arc welders can be
bought extraordinarily cheaply secondhand. As people have moved to inverter
welders and other more exotic designs, the humble transformer-based arc welder
has got cheaper and cheaper. I bought mine – complete with rods, gloves and a
slag hammer – for about fifty bucks... and that’s not unusual. Check eBay (look
under ‘nearest first’), secondhand stores and garage sales.
And you can’t weld? That’s fine. Just practice a
bit first on some scrap. I know that sounds a bit pat, but amateurish welding
that wouldn’t win any prizes in tech school can still be very strong – and much
more rigid than bolting, for example. The key is to make sure that you have
enough penetration – whatever the case, you don’t want a puny bead just sitting
on the surface!
A friction cut-off saw will also make cutting up
the steel much easier, and a table saw will make cutting the timber to size
neater and quicker. But if you don’t have them, don’t panic...
Building My New Bench
The first step was to decide on the bench height
and width. With a strictly finite length of square tube available, the bench
length dimension was simply whatever was left over after cutting the uprights
and width pieces to size! For the framework I used an upright length of 84cm and
a width of 58cm. (Note: the actual height and width of the bench are greater
than these dimensions; the height is increased by the thickness of the top
timber and the width is increased as the timberwork overhangs the frame a
little.) The tube left over allowed a frame length of 172cm.
The framework was in a traditional ‘table’ form –
four pieces of tube welded to form a rectangular frame and then the legs welded
on. Halfway along the top I welded another piece of square tube across the
width.
Such a frame is already pretty strong – primarily
because of the 3mmm wall thickness and reasonably large tube dimensions. But
what if a force is applied end-on to the frame?
As shown in exaggerated form here, the frame will
tend to take the shape of a rhomboid.
A cross-brace, as shown here, will resist this
frame distortion. In one direction of distortion the cross-brace will be in
compression, and in the other direction of distortion, extension. Therefore, if
you’re going to use only the one cross-brace, it needs to be made of material
rigid in compression as well as extension. This was achieved in the case of my
bench by making the cross-brace from the same heavy-wall square tube as the rest
of the frame. I used just the single brace across what will be the back of the
bench.
The same potential distortion can occur if a force
is pushing backwards on the bench. The end view would then change from
this....
...to this.
Another heavy duty cross-brace could have been
used – but I’d run out of the square tube. Instead I used the round concrete
reinforcement rod. However, this rod is not very strong in compression – it’s
much stronger in extension. The rods were used as dual cross-braces - so
whichever the direction of distortion, at least one rod will be in tension.
After welding the frame together, it was painted
with Dulux Quit Rust Epoxy enamel, a paint specifically designed for steel
structures and which bites into the metal very well. It’s expensive (AUD$30 per
litre) but it works so well that I am reluctant to try cheaper alternatives.
Only about a quarter of a tin was needed for two coats.
The heavy timber planks were then cut to size and
glued to the frame. What?! Glued?! Yep. Modern glues are incredibly strong,
cheap and quick and easy to use. I used three cartridges of Bostik Zero Nails to
glue the planks to the frame and the planks to each other. When the bench is in
hard use (eg something is being hammered in a vice), most of the forces acting
on the glue will be sheer forces, something the glue is very well able to
withstand. The glue also acted as a filler where the planks weren’t dead flat.
The alternative of using recessed bolts, washers and nuts would have taken far
longer, cost more and not have been any more effective in use.
After the glue had set overnight, I ran an
electric plane over the surface to true-up the planks (a normal hand plane could
have been used – or you could have used timber that was unwarped!) and then the
Masonite was cut to size and held in place with small brads that were recessed a
little below the surface. The Masonite could have been glued into place but that
would have made it hard to remove and replace – and one of the advantages of
this material is that it can be easily and cheaply replaced after it wears.
On the Bench
This bench was made primarily to support some
tools, rather than act as a dedicated working surface. On the bench were placed
an 8-inch electric grinder, a hydraulic press, a drill press, and a small anvil. Each was bolted into place. The bench is
easily strong enough, rigid enough and heavy enough to support the anvil – as it
would also be fine if a vice later needs to be attached.
Conclusion
A good bench is simply one of the most valuable
tools you can have. So it’s worthwhile spending some time and a bit of money in
putting together a heavy, rigid bench that suits your height and the working
space that you have available.
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Costs
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Square tube and timber |
Garage sale |
$45 |
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Concrete reinforcing bar |
Salvage yard |
$5 |
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Masonite |
Hardware store |
$16 |
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Glue |
Hardware store |
$8 |
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Paint (only used about 1/3rd a tin) |
Hardware store |
$10 |
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Welding rods, grinding disc, etc |
In stock! |
$10 |
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$94 |
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