Hey Jerry , I,m in the same boat as you except my milling machine is already built. My column is a 2x3x 1/8 hollow tube. This I plan to fill with a grout/cement. I used to work construction along time ago and we did this job of removing the grout off theses steel column feet(HUGE) anyway I remember swinging a sledge hammer(big one) to break up the grout and it just bounced off the grout, you could not chisel this stuff, it was as if it melded with the steel column and turned to steel. We ended up grinding it off. I never knew what its actual name was but thats the stuff I,m hunting down to fill my column. What do I think its impact on performance will be by filling it? I figured a 3-5% increase in performance of the mill as far as rigidness goes and every % counts in my book. Heres a link to my never ending project
http://www.cnczone.com/forums/showth...2&page=5&pp=15
CNCzone.com-The Ultimate Machinist Community - My Manual small mill project