I've installed quite a few of them.I worked for a man that installed hundreds of them starting during the war.What he showed me to do was to make sure the outside of the drum was clean,no rust,paint,slag,smooth,smooth,smooth.Same on the band.If there was a weld seam on the inside of the band,I had to file it down.They were already ground down,but not enough to make him happy.We didn't have gas grilles then,but he did have an old forge that he would fire up if he had enough drums to do.He would use a torch if he had to,but he preferred not to.If the torch was used he would do it,not me.He wanted an even heat around the band.When they were red I would drop them on the drum,when they bottomed out they would clink and instantly cool enough to shrink.Done that way if the drums were OK to start with they seldom needed truing.I like the bands.I really like cast drums,but to go through all the work involved the bands work fine if you have serviceable drums.His bands came in wooden barrels,and the instruction paper in the barrel says not to turn the A drum under .110 thick.Little different than some say today.