Any tips on masking a 72 dart grill for paint?

No, not white glue. Its usually green and is sprayed on to help keep fiberglass parts from sticking to the mold. But yeah I bet you elmers glue would work as a mask.
I ordered some pva and will give it a shot. I will post back and let you know if it worked.
PVA PARTALL by REXCO MOLD RELEASE #10 PARTING FILM pint 16oz FREE SHIPPING 710928968725 | eBay
No, no. Use this "Vallejo Liquid Mask":
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Places carrying airbrush supplies will have it, or something similar.