What are most guys using for interior, 3003 or 5052 alumnium. Also is .040 and .050 most common for this app.

I prefer to use .040 5052. works well when forming and bending. doesn't crack like 6061 but doesn't dent as easy as 3003. cost is pretty even give or take a few dollars per sheet. I have done several cars over the years and its my preference. if you have to weld like a tunnel or something like that I prefer .063 5052. just easier to weld.

Thank you Andy 5602. I am redoing the interior on a new to me Top Sportsman car and I believe all the tin work was .032 and pretty beat up. I have worked with 3003 but I think my last dragster was 5052 and it did seem to hold up better. As far as welding yes Im with you on the .063. I have been using a pulser on the tig and still dont want any less than the .063 on aluminum to weld on. Thank you for your reply as its nice to have other opinions or in this case a back up opinion from someone who has the on hands experience as you have. Thanks again.

3003 works great if you have to do lot of shaping.5052 holds up better but is pan to work in to multiple shape piece.

As for thickness you can use less and bead roll it for some places.Bead will make it lot siffer.More work,cheaper material and less weight. .040 will be 20% lighter than .050 which can be alot if doing whole car.

On FED I used .040 in cpl places I should have gone with .050 and vice a versa. Careful planning pays off,especially if you follow it and don't get in hurry and grab wrong sheet at wrong time.