For ages, I had been making do with finding a clear spot to weld. Often, the easiest spot was to use the concrete floor. Apart from not being very comfortable, I found that a concrete slab is actually not that level. Normally this is not an issue, but if you are fabricating a tabletop or set of gates, then it can be. I sourced an old solid metal table that had a missing wooden tabletop. I have seen lots of laser-cut fabricating tables and would love to have one, but they are hideously expensive! My option was to construct a slatted metal table using 50mm x 25mm rectangular tube. For strength, I decided to place the rectangular sections with their long edge vertical. Each piece was spaced 25mm. I checked that all the slats were level and square.
The slats make sliding in clamps easy. I have found that squaring up work-pieces then clamping them in place makes a huge difference in the final build quality. As you can see from the photos, you can never have too many clamps!
A couple of lessons for next time. I spent ages using a flap disk to strip all the blue protective paint. Later on Youtube, I discovered that oven cleaner acts like paint stripper and makes paint removal relatively easy. The other lesson is that if I had laid the long edge of the slats flat, I would need far fewer slats and the table would be so heavy. However, I do like to over-engineer things so as it is fitted with some high-quality rollers, it is not too bad to move around.