Ive heard some people say you can get away with 3/4 inch. But 1 inch is a much safer bet.
I see got some decently sized plates on the way.
I ended up doing the plate quench vise setup, and i really like it. The only thing i would change, is eventually ill buy a quick release vise for it, instead of the normal woodworking vise i use. Dont get me wrong, it works fine, and im able to still get knives into it quickly. But with a quick release i could have it wide open and quickly drop it down to make it even easier.
Instead i check how far i need it open to fit the knife in without issue before putting the blade in the oven. Either way, i like having the vise for it a lot.
I lost most of my notes when I came out of teaching (moved from where I taught back into the plant) drafting in '89 but I did check some of the notes on AL that I still have and here is some information which may or may not help: For what it is worth, Aluminum is described as: anything under 1/4 inch thick is considered as sheet, anything over 1/4 thick is plate. This is usually good to know when you are talking to someone who is familiar with AL.
If you go to the Boeing surplus store (assuming there still is one) you might be able to get some plate in:
• 6061-T4 (solution treated then naturally aged to a substantially stable condition),
• 6061-T451 may be available; it is something I never designed to. 6061-T451 is solution heat treated and stress relieved by stretching. The temper is equivalent to T4 temper.
• 6061-T6 (is solution treated then artificially aged.
• You don't want material in the -0 condition as it has been annealed (softened for forming) and must be either age hardened (-T4) or solution treated to another temper. You would need to know how long it has been sitting in that form and as a clue to where it is in the aging process.
• For most materials, the -W (quenched) and -T4 tempers artificially age to -T6.
• 6061-T6 plate that has been rolled and stress relieved by stretching is designated as -T651.
• As I remember, 6061 can be welded, and will polish up quite easily and as far as AL is concerned. The major components of the 6061 alloy is magnesium and silicon and the alloy is pretty corrosion resistant.
• You might even find some 7075 (zinc is the major alloy component here) there too which is (was?) used structurally in aircraft.
• At far as the thicknesses you are talking about: the minimum bend radius is going to be over 1.25, more like 1.50 or more depending on the temper. As a general rule: the higher the temper number and the thicker the material is, the larger the minimum bend radius.
• There is some 5000 series AL (magnesium is the major component of the alloy) which may be available and it is supposed to be corrosion resistant. I have not dealt much with this alloy of AL so I can’t help here. There may not be weld ability here either (I could only find that in castings it wasn’t weld able). It is something I am not fully sure of as I think I only had to use of it once, maybe 40+ years ago. I am not sure if we purchased it in plate either.
Lee