Aluminum diamond plate flooring, for a fishing boat (jakeru's #10)

[jakeru]

how wide is the bead on the diamond plate?looks good . and how thick is the diamond plate.

I'm going to say based on the pictures, that the bead width was probably around 1/4"-5/16".

Great job as usual!
Diamond plate is typically either 3003 aluminum, or 6061. Not ALWAYS the case, but usually tool boxes, or decorative are 3000 series, and structural items are 6000. The 3000 series is very formable. The 6000 is still formable, but not nearly as much as the 3000.

I don't think the diamond plate was all 6061, because I didn't notice any hot cracking tendencies (which I usually notice when welding 6061 to 6061.)

Also I had to hammer one bent corner down before welding it, and subjectively, it didn't seem as strong as 6061-T6 would have been to me (although it was no "softie" either.)

More than one local metal suppliers do sell the thin-gage diamond plate aluminum in 5053, and I've worked with it (smooth sheet though, not diamond plate) in the past, and certainly wouldn't rule out that possibility. The 5xxx series seem pretty popular for marine applications.

There is also the possibily that the two different thicknesses of the diamond plate I welded were dis-similar. (Since they were different thicknesses, and only one kind had adhesive residue on its back side, it was obvious they each had varying "previous lives".)

Is there a convenient way to test presence of various aluminum alloying ingredients you are aware of?

I don't know if it would be very practical to use in the field, but I've noticed or at least suspected that different aluminum filler rods may burn different colors when overheated. 5356 in particular seems to (maybe) "burn" green, perhaps from the magnesium content.