the pipe i believe is coated in scotchcoat or something like that. If you go to home depot or lowes and look at the gas piping you will find that 3/4 inch piping is way too small. However if you look at the 3/4 brownish coated pipes its substantially thicker and fit pretty darn snug in the yakima towers. You can have them cut to size in store for free and you can use 1 inch furniture plugs on the ends. I believe a ten footer cost me 27$ cut to 54" which is about perfect.