Introduction: Industrial Conduit-Shelving

About: BongoDrummer is co-founder of Flowering Elbow. He loves to learn about, share, invent, and make things, particularly from waste materials. Check out his youtube channel:
So we have a blank wall at the FloweringElbow workshop we have been making, which needs some shelving and power outlets. As we are all about the upcycling jazz, we obviously want to make something with reclaimed materials. In this project we make a set of shelves who's frame also acts as a protective conduit for mains wiring. 

What are our requirements here?  

1. Make some massively strong shelving that can hold exceptionally heavy workshop related jazz.
2. On the same wall, rout a new ring circuit providing three normal (for the UK) 13A 240V sockets and 3 high power 32A 240V plug sockets. 
3. Use up some of the scrap metal piping and reclaimed timber we have knocking about.
4. Improve welding and metal fabrication skills. 

Step 1: Planning


It is at about this point that we should have a warning about electricity and its general badass nature. We use electricity to weld together this project which itself is used to protect electric cables which carry currents that can kill. Pretty much any of the tools and processes involved can badly injure you, and many of them can kill. We'll try and highlight some particular safety concerns as we go along, but don't expect a recitation of the exhaustive warnings in, for example, your welders manual ("do not microwave oven this product" and other common warnings will be absent!).
If you don't know exactly what your doing, mains electricity can kill you. If in doubt ask and get knowledgeable help!  

Materials and Tools

If you set about making something similar to this, the materials and tools available to you will be different to what we had to hand. We, for example, used old pressure pipe for this project, because it is what we had (it was dug out of our friend Dave's back garden). Being round it required different and more complicated fabrication techniques than say square stock (which would be our preference for a project like this).

Here are a few general things you will need if you want to make something like this:

1. Lengths of hollow metal. Needs to be sturdy enough (adequate wall thickness) and large enough to accommodate you cable - work out cable sizing first, and remember that sections of conduit may be carrying two cables even if you are not wiring up a ring main (pulling/feeding cable through conduit in which they only just fit can be frustrating and it can also damage the cable's insulation!).

2. Something to cut metal. We use our cool power hacksaw, but a metal mitre saw or an angle grinder with a guide would do the job well. A plain old hacksaw or careful freehand angle grinding is possible in a pinch. Wear eye protection, even if hand hacksawing. 

3. Something to cut holes in the tubing. We used a drill with a hole saw, and various standard metal drill bits. If using round stock like we were a fine toothed hole saw is way better than a regular one, which will be catch-tastic.  

4. A de-burring tool. Exceptionally important for the holes which cable is routed through. We tried using a 'proper' de-burring tool, a variety of hand files and a rotary tool like a dremal.

5. A welder, and all associated safety kit. Though I feel compelled to mention it would be possible to do a project like this with heavy duty pipe threading kit and fittings. But that would usually usually involve buying tools and new angle and t-pieces, and it wouldn't be as fun and wouldn't be an much of an upcycling project ;)

6. Something to clean up the areas to be welded will almost always be needed on reclaimed scrap metal. Before welding anything you need clean and bright bare metal. We usually use a 115 or 125mm angle grinder with flap disk - works a treat. Acetone is also useful to remove oily residue before welding. Remember eye and ear protection!

7. Workholding kit - magnetic angle clamps designed for welding are especially useful.    

8. A spirit level or plumb line or techy laser - whatever you have for getting things straight. 

9. Electricians tools. If you don't know exactly what they are, get trained help (hmmm, that feels patronising and unhelpful. Sorry about that, I just don't want to be responsible for teaching you mains wiring safety).

Step 2: Measuring

Measuring is always a good starting point, if in doubt measure and sketch - works for most things. The inner skin of the wall we wanted to 'shelfize' was made of 4 full sheets of mdf (reclaimed stuff, of course). As the sheets were old, they shrunk quite a bit as they dried in the workshop, leaving little gaps which we then sealed. We figured that it would be kinda nice to cover over the sealed joins in the mdf with the vertical conduit run. We also wanted the sockets at a certain high - quite low so that trailing wires would be less obtrusive, but high enough to make access easy. We also knew we wanted the bottom shelf to be a certain height so that the thicknesser, being one of the tallest machines in the shop, could roll underneath, partially out the way.

The wall to which you mount something like this is quite important. Luckily as we had insulated and clad the wall not that long ago we knew the exact location of the timber studs, and just how solid they were. The position of your fixing points is definitely worth considering in advance so you can plan out the dimensions (and feasibility) of the project . Because we wanted super strength, we also extended the vertical all the way to the floor and gave them little legs. Not only did this make the structure much stronger, it also made assembly a lot easier, the whole thing was free standing even before bolting it to the wall.

Ok, enough waffle - most of the fabbing info and tips will be given on the notes in the photos ...

Step 3: Making the Top Run

To make the long horizontal run across the top we had to join two pieces of tube end-to-end. A method of welding two pipes to make one long can be seen in the pics: we used two other pipes to form a straight 'cradle' of sorts to ensure the join didn't go wonky. As with most all the joints we made tack welds first to hold the pieces together firmly, then stitch welded them together (making welds of about 3/4 to 1" long, then moving to another section). Doing it that way helps prevent heat warpage of the material. 

A note on welding reclaimed pipes like these: the ones we had, although a tad rusty in places were galvanised originally, this layer of zink needs to be completely removed form the weld zone (think at least 1" around where you plan to make the weld) - It gives off toxic fumes if melted. 

After that we made some mounts from scraps of angle iron and welded them on. We could then stop resting it precariously on the ladder, and more importantly we would have a reference plane, so we knew which way was down (without this the pipe rotating could confuse us). 

Once we had our cross piece test fitted to the wall, we needed a small outward deviating bit on the end (no, I'm not sure what else to call it), to bring the pipe to the entry point of the consumer uni. That was just a case of cutting off a little piece of pipe at an angle. 

That done, we marked off the points at which we would need to join the vertical sections, and the holes we would need to make to thread the cable through

Step 4: Joining on Vertical Sections

The vertical sections join to the horizontal top piece. BEFORE doing any welding drill all the holes you need - it's much easier to use the pillar drill than do it with the hand drill (though hand drilling is quite possible). More importantly YOU NEED TO DE-BURR all the holes very well and round off the edges. If you don't do this you will damage the cable's insulation when you try pull it through. 

Remember that we also need access holes at all the junctions - so we can push cables in the right directions. For example, where each vertical joins the horizontal top piece we need a hole above and below: the cable goes through the hole below, the one above is used for access, to push the cable in the right direction. 

Once all the holes are complete and we have ground the joint area to bare metal and we have messed about with positioning and are happy, we can tack weld it. Our approach was to make a few small tacks in situ, just enough to hold it firmly in place, then take the whole assembly outside and lay it down flat for proper welding. At very least it would need to be moved away from the wall anyway so you can access the other side (and so the workshop will not burn down).  

Step 5: Mid Mounts, Feet & Socket Joints's

Lets start with the mid mounts (aka 'ears') used to fix the vertical runs to the wall: we used the scrap pieces left from the hole saw (you did save them right?) for this - they have a convenient hole ready made in the middle for our fixing screw. Two carefully welded together make an excellent strong fixing ear. 

The feet are fairly self explanatory, see the notes on the pics. They also yield some off cuts that can also be used as ears!  

The socket joints, are just bits that branch off the vertical runs and go to the different sockets. The angles were cut, the saddles made.. see the pics for details. 

Step 6: Shelf Brackets

So the conduit runs are mostly done. It's time to cut and add the shelf brackets.

The picture notes tell the story, but a few points of note.  Once they are tacked into correct position we continue to stitch weld them on until they have a continuous bead all round. One benefit of welding like this say 3/4" at a time, is that you can use higher voltage and feed setting of the welder = better penetration = stronger joint (usually). 

As a very happy accident we had a little bit of another pipe size and it fit inside the first - this allowed up to have extend the shelves as needed... 

Step 7: Wiring Up

Before starting on the wood for the shelves it is time to pull and push the wire through the conduit. As the wire we were using was pretty buff, it was possible to push it quite easily. The whole process of feeding through cables is much easier with two people.

As for wiring it all up at the sockets and consumer unit, that's beyond the scope of this instructable as qualified help is quite likely to be required. Whoever does the wiring, remember that the conduit structure will need to be connected to ground with a sufficiently sized conductor, and metal clad sockets, like we use, will also all be grounded.  

One IMPORTANT POINT is that you cannot do any welding on the project once you put cable into it - that should be fairly obvious, but just in case.
Also make sure the screws holding on the cover plates don't extend through into the conduit (they need to be short). Just think protect the insulation at all costs... 

Step 8: Shelf Wood

Ok so at this point we were lucky, as our local chapel was replacing its nice (but admittedly rotten in places) wooden picket fence with a not so nice plastic version. Anyhow they offered us the wood, which was great. A bit of sorting, cutting, de-nailing and planing later, and we were ready to laminate up some shelves... The benefits of laminated shelves - like most things made of laminated wood, is that a defect in one piece need not be to much of a concern as there are two or more others pieces glued to the side of it to give it strength at that point - knotty 'defect' ridden wood becomes quite useful.

Step 9: Organized Use

Ha! As 'timber-projecting throughput' occurred the shelves got messy...

But they are very useful and there is never any real worries about them not being able to take the weight, which is nice! The part time extensions are really useful for storing boards and bits that are in process... We just need to be quite strict about only using them for in-process items and putting them away straight after (they stick out into the shop too much to leave in).

The plug sockets are nicely distributed and work well. We are pleased. Thanks for reading. Now lets have a tidy up... 
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