+1 for Kroil
Do you own a strap wrench?

Mouse Milk will work, with a heat gun. You can get it from Aircraft Spruce.

Penetrating oil, vice grips, and a vise got it done. And the receiver threads are in great shape thankfully.

My experience has always been that heat works best when combined with cold after a good soaking with penetrating oil. Start by getting the outer component hot, then quickly apply cold to the inner component using a cold rag or even ice. The general idea is to get the inner part to contract while the the outer component is still expanded.

Trust me on this. Go to Youtube and search "rust removal electrolysis". Yes, you have to get it wet but I've done this a half dozen times and it works.

I knew there would be reasons for paying greater attention during Chemistry Class.

Thanks for sharing.

Just a thought. My Mom bought an old butter churn at a yard sale years ago. Square glass mason-jar type body with the hand-churning gears and handle mounted to a metal screw-on lid. It looks really cool. She wanted to paint blue bonnets onto the wooden paddles inside the clear glass base but the lid was solidly frozen in place. She sent it home with me to try to get off without breaking the glass body. I tried everything I could think of for about three months and was at a loss.

I mentioned it to my neighbor across the road, a 90 year old retired Navy machinist. He said I could bring it over and he'd see if he could get it off without breaking the glass body. A couple days later I brought it over to him. He takes it, puts in between his knees, and TIGHTENED the lid. You could hear an audible "crunch" as the "weld" broke, then he just backed the lid off. He said, well, metal can't just to glass, but it can get siezed to it. Use the threads to break the seize, then it's just a tight lid.

Best of luck with your project.

be sure you do it in a open environment. There is gas thats created .

For sure. Pure oxygen is extremely dangerous no doubt.

Did you notice if the process created an above average load on your battery charger, even at the 2-amp charge rate?

no above average load.

Sounds like you got it off, but was gonna advise to cut a hole perpendicular in the tube and stick a screwdriver in it so you can twist it off.