I checked to see how far I had gotten with the welding of the shelf supports, as I wasn't sure if I had just spot welded them in place or had finished welding them. I had actually finished welding them and I had welded them without notching the back or leaving a gap next to the diagonal. The reason being (as I said earlier) that you cannot notice that they are not perfectly square and it isn't critical.
Some pics:
Top joint showing the top rail notched to join the vertical upright and the lap joint of the diagonal upright to the vertical upright. You can see my 'uphill' welding isn't flash. I should have just spot welded it like the notched joint. I climbed on the frame and welded the top from above, which is why you can see the penetration. I figured that I wasn't going to try and balance it on its pointy end to weld that up from the inside!
Here is the bottom right-hand rear corner showing the bottom rail notched to join to the vertical upright and the butt joint of the side rail. These joints are just spot welded in this photo and once the rack was complete, I have since gone round and welded these up properly. Its not a good picture - sorry.
Here is the side rail from the picture above notched to join the front rail. Again, this joint was spot welded (from the other side) when the rack was on its back and has since been finish welded. You can see the bottom of the diagonal upright in the top left-hand corner.
Here is one of the rear shelf horizontal rails, which has been notched to join the vertical upright. The shelf support / divider is simply clamped to the underside of the horizontal rail and welded in place.
Here is a view from the rear side of one of the horizontal rails. Gaps like this are good when welding parts inside a frame and will fill nicely when finished.
Back on the welding bench so that some of the joins can be finished. Remember, you don't have to weld up every seam. As long as you have a good weld between two pieces, it will not fall apart. I look at my own access when welding. The easier the position to get the torch into the more likely it is that I am going to run a bead there! If I were making this for a client. I would ensure as many of the welds were hidden as possible, such as those joining the shelf supports / dividers to the front shelf horizontal rails. I would weld them on the inside of the shelf section.
This was actually how it started out, with the vertical uprights clamped to the welding bench and then the top and bottom rails welded in. The side and front rails went on next and then it was stood upright.
It works!
I still have a bottom rail to cut and drop in for the bottom shelf. It probably doesn't need it but I think once the wood goes in it will finish it off nicely. All it needs than is a coat of paint.