Rainier

I need thick copper bars, 1/8" thick, for electrical purposes. I've been to the local scrap metal yard & they don't have them in those thickness. I do, however, have a copper pipe with 1/16" thickness. I would like to flatten & forge this pipe to be the bar that I require. I figured I need a flux the inside of the pipe that would weld together. I flatten the pipe slightly to make the inside narrower (noting how soft hot copper actually is). Then I filled the inside with hydrous borax. I heated this to a propane torch until the borax got glassy & added more until I thought I had all the inside covered with glassy anhydrous borax. Then I heated it red hot & quickly hammered the pipe. I expected the borax to shoot out & the copper to weld. But, it didn't do it. Immediately, I had to stop, as with those few hits, I was already making the copper too thin, about 3/32". What am I doing wrong? Maybe I should have added more borax until it was a big goop? Or, maybe I was wrong in thinking I could forge weld copper?