Charlie, here's a suggestion that I wish somebody had given me before I built my tent weights. I built our weights using 4" PVC pipe, 4 sections about 3 feet long each with 4 end caps for the bottoms of each pipe (to keep the concrete from flowing out the bottom).
I filled each with concrete and at the top, I had large eye bolts embedded into the concrete with several large washers and bolts at several inches apart. The concrete surrounds the washers that are bolted to the eye bolts, the concrete sets, and now the eye bolts won't be able to pull out of the concrete.
So, I searched Google, got several ideas, put together a parts list, went to Home Depot, got the PVC pipe, had the pipe cut, Concrete, Eye bolts, Washers, Bolts to keep the washers in place, etc. I took everything home then started construction. I got the wheelbarrow out of the shed and started mixing concrete, filled each pipe, stuck the eye bolts in at the top, set them up straight & level then let them harden. They look great & definitely work very well.
Here's a pic of the weights, along with plastic painter sheets I had over our canopy at this outdoor festival, because it rained and poured all day:
https://www.facebook.com/SweetAirSoap/photos/a.606396106092733.1073741826.430439667021712/7699618397...BUT, they're a pain to lug to shows. They're heavy, fairly large and I typically can only carry 1 at a time due to their bulk.
IDEA!! (not mine, I got this from looking at another vendors setup at an outdoor show). This is why I'm always preaching in here to the newbies about taking some time to walk the show if possible, to check out other vendors displays to get ideas for our own displays.
At an outdoor festival, the vendor directly across the street from us took a much easier, much simpler approach. Instead of spending all the time researching, gathering parts and then constructing 4 weights, she simply went to the sporting goods store & bought 4 Hex Dumbbell weights. The hexagon dumbbell's are flat on the bottom, so they won't roll around. They're much much smaller than my weights, AND, they have built in carrying handles to boot. I could carry 2 at one time with those.
So, for all the time, expense and work I did to build those weights, I wish I had just bought 4 - 40lb hex dumbbells instead. Much easier, simpler, cleaner, smaller and easier to carry.