AR15 gas tube removal

[cwheel]

Good afternoon,
I'm changing a standard upper to a flat top. No big deal except, after removing the roll pin from the front sight, I find the gas tube is almost welded into the front sight by the thousands of rounds fired. Soaked it in Kroil over night, still stuck. Is there a good way to remove the gas tube without destroying it ?? I've thought of heat from a propane torch, but haven't given that a go yet. Any ideas would be appreciated, thanks,
Chris

[m.chalmers]

They sell a tool for it. Looks like a clamp with a groove. So, spend $18 or make one. Take pliers an wrap them with tape. Grab tube an rotate. Or drill an undersize hole in some cheap pliers, wrap with tape an rotate.

Grab the tube close to the gas block!!!!

Price went up:
http://www.brownells.com/gunsmith-tools-supplies/rifle-tools/wrenches/ar-15-m16-308-ar-gas-tube-wrench-prod25017.aspx?avs%7cMake_3=AR-15

[AggieEE]

Try slight twisting. Not enough to torque tube obviously but get it to rotate in place. Sometimes that roll pin will leave a burr on the tube. Might try heating until the Kroil smokes then dunk in a can of kroil. Get it to suck up into the spaces. Tubes are not that expensive but I understand waste not want not.

[Dutchninja]

+1 for the brownells tube wrench. I've used mine several times, it is worth it.

[cheese1566]

Heat and small twisting motion.

In armorer class some had to use a propane torch to loosen the black crud fouling where it seats in the front sight base. We used a simple small vise grip pliers, but careful not to damage the tube or crush it.

[cwheel]

Thanks to all for the help. I followed the link to the Brownells tool, and made a set of blocks to fit a set of vise grips drilled .178 to fit the tube. More Kroil, a little heat, and it came right out. That baby was glued in place well with carbon. Saved the tube with almost no marks. I've got one more to do, convert from a A1 upper to a flat top, sure this will work for the second one just as well. Thanks again, some good suggestions from this group, as usual.
Chris

[TCLouis]

Thank you cwheel.

I had never really thought about that, but now one day when I am just sitting around scratching and wondering what to do with an hour or so, I will make me one of those and set it aside should I ever have a use for it@!