Getting a welding table flat

admin

I made an investment in some welding tables, I couldn't find any for sale so I made my own. I made two bases out of 3" x 1/4" square tubing, 35" high, 54" square top. with 3 cross members spaced equally. I ordered 2 5'x5'x5/8" plates for the tops and they weren't flat by anyone's standard. The plates seemed to make a bowl shape if you can picture that so I placed them on the table, with the bowl in the middle so I could bolt down the outside and flatten the table. They were both off by about 1/4" on the ends (gap between the top and the table). So I got my mag drill, drilled some 9/16" holes, countersinked the top, and used flat head socket cap screws, grade 8 nuts and hardened washers underneath. Well it pulled the top down, and the table stayed flat, but what I can't understand is the table is still making a bowl type shape. When I put a 4' straight edge across the top, it looks to be about 3/32" gap in the middle, Like I said, the table base was not pulled out from being flat when I bolted the top down, but the top didn't go all they way to being flat, It's not that there are some low spots/high spots, but the top is still making that bowl shape. I've tightened down the top as much as I can, but it still doesn't seem to help. Anyone have some advice? I spent about $750 on each table and would hate to think I spent the money for a table that's not even flat. I do A LOT of tables, and table legs so it's pretty important to be a little more flat than it is, but I don't need blanchard ground precision.John 3:16(2) Miller Pheonix 456(2) Millermertic 252Dynasty 210DXHobart 210MVPDoringer D350 SA Cold SawScotchman 350LT Cold SawWebb 10x50 MillWebb 15x40 LatheGeka Bendicrop Ironworker
Reply:Have you tried a shim(s) under the center at the cross member or a threaded adjustment(s) there? 5/8" mild steel plate is not that stiff. Laid on something flat you could likely lift one corner more than a 1/2" without lifting any of the other 3 corners just under its own weight.---Meltedmetal
Reply:Its not what ya want to hear at this stage in your build brother, but if ya would have started with 1" plate, had it Blanchard ground, then built the base on that, your table would be flat. One inch plate can be found on Craig's list fairly cheap, and depending on where you live, having a 5'x5' x1" plate Blanchard ground would be approx. $100, depending on how flat the plate was to start with, and how flat you needed it to be. The guy that did my table quoted me $180 (if i remember right) for both sides and when it was all said and done, he did it for free. GarLincoln Electric, Power MIG 256Hypertherm Powermax 45 Miller Dynasty 280DXSmith O/A torchGenesis of a welding table