As a note from the mobile world where back side repairs aren't done,. On a crack like that, you could just get it really hot and smear it onto itself so you are using the same material. Or, melt mesh, I use grease splatter screen then do your repair. Good job on drilling out the end of the crack too. You can also drill holes around the crack to get your filler keyed in more spots. That will help.
I did just a front side repair on a 10in crack with just epoxy a couple months ago and had to redo it this week. I will get out my welder from now on. These type of repairs are a lot more tricky then people think. That is why bodyshops prefer buying new ones.
I had someone tell me to ditch the ADPRO and get a torch instead and flame the plastic to increase adhesion. They said that the promoter was causing a weak link. If you ask 10 people the same question you often will get 12 different answers. Read more...
329 days ago
. On a crack like that, you could just get it really hot and smear it onto itself so you are using the same material. Or, melt mesh, I use grease splatter screen then do your repair. Good job on drilling out the end of the crack too. You can also drill holes around the crack to get your filler keyed in more spots. That will help. 
