I draped the mold with felt, had 2 finish nails at edges of the centerline that matched holes in the acrylic blank. This held acrylic in place.
The blank was about 2" extra long on ends and I bolted some 2x2 square steel tubes on end to help the drape and keep ends from curling.
Then made an 'oven' out of drywall and 2x2s that was 4"-6" larger each side than the mold.
I quickly learned it has an R value of about 0.5 (!) and couldn't get temps high enough.
The acrylic started drape but not evenly.
Then I insulated outside of box and used two heat guns on either end with a few holes for circulation and viewing.
I used the same blank and reheated
Blank was about 4" long and I bolted some 2x2 square steel tubes on end to help the drape and keep ends from curling.
Heated box using this as a guideline
https://www.usplastic.com/knowledgebase ... entkey=583 Hope this helps. Feel free to ask any questions.
Sorry I am really bad about taking pics while I work.