I'd like to give anouther option if you all don't mind. I see these kinds of posts on here all the time and and cringe when someone says parts are flying what can I do? I understand your a hobbyist and all but sometimes haveing the right tool for the job is the HEALTHY way to go!
Your looking to cut 8 foot of aluminum into some short peices,is there a (proper) machine shop nearby that might be able to cut it for a few bucks? I know if anyone walked in are shop and wanted done what I think your looking at doing,it would be,-sure-(me)-what do I owe you-(you)-a case of beer sounds good-(me).
What I'm sayin is sometimes trying to do something you don't have the tooling or machinery to do can be a very bad thing.
ignore my singature on this post please,thankyou
Just push the button,what's the worst that could happen.