There obviously are a diverse number of fine quality display options mentioned here. Thanks for the great contributions and collaboration.
Here's what I'm focusing on now.
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Sheet. Di-Bond. 3 mil brushed silver. Two to three times the cost of white E-Panel. May or may not be worth it on my deathbed, but it is way cooler looking, and it has a meaningful assurance of higher structural qualities (stiffness, fire resistance) than the clones.
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Sub-Frame. Structural aluminum extrusion subframes. I'm leaning toward Lion as what seems like the only purpose-built, plug and play product. Having been down to my local hardware store today to flex by hand all the aluminum dimensional materials they have there, I'm reasonably confident the 15mm Lion panel will approach about the limit of support needed for 4x3' 3mm official Dibond panel. I did find on the internet what looks like stronger but not purpose built structural aluminum extrusions that could also work if the 15 mil Lion version doesn't. I'm checking with the Lion distributor and going to wait to hear their input before deciding whether to use their product or another.
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Adhesive. To be determined. I'm almost certainly going to use one or two of the adhesive products specified by 3A composites for adherence to Dibond. See page 36 here
http://graphicdisplayusa.com/downloads/Dibond%20Fabrication%20Manual_May%202011.pdf. (There is a similar doc you can google for e-panel that on cursory glance may list the same adhesives.) I would love to use tape because of the convenience and near instant cure, but am still very partial to what appears to be longer lasting liquid alternatives. Somewhere I read a suggestion of combining both thin tape and thin liquid adhesive (the tape to hold during a longer 30 day liquid curing process. I'm going to seriously consider that.
Brad