I did this test years ago and what was strange is all the epoxys I let soak in Alcohol stayed good but JB weld in running engine or AB epoxy would not make 4 passes in w2 pushrod Area on alky and heads had JB weld in the for 100 plus passes on race gas.

Somthing with heat and evaporation in running engine is hard on epoxy.

Try air plane "dope" for wing covering alky nitro Resistant helps buy some time.