SQLGuy

So far, not that impressed with PC7. Even after curing for about 15 hours, it's still pretty soft/rubbery.

In the past I've had very good luck with the Loctite Plastic Bonder Epoxy. That stuff can be drilled and sanded... it was even good enough to drill and tap to hold machine screws. I used it to restore the broken pieces of my tweeter grilles, then turned the cured epoxy in a mini-lathe to match with the old surface.

Anyway, I was hoping for a more paste-like version of this in the PC7... maybe I got a bad batch. For what I'm doing with the wing, though, it may be a useful "feature", as it should allow final alignment of the bolts even after a few hours of curing.

SQLGuy

OK. A closer read of the instructions says that cure times of 24 hours are normal at 50F. My garage is more like 60F, so overnight not being fully cured may be normal. I'm going to bring the wing inside for the next phase of curing...

SQLGuy

Bringing it inside, into 72F ambient, didn't make things cure noticeably faster. That said, even though the cure times are much longer than the packaging would indicate, the PC-7 does seem to be pretty good stuff.

In the end, my process was to keep more like the original mounts, rather than cutting further and adding a bar. I first filled in the cavities with PC-7. Let that cure for about a day. Drilled the holes back to more-or-less original dimensions with a 3/4" Forstner bit. Then mounted stainless bolts (M6x1.0) and non-stainless fender washers (couldn't find stainless ones, and these will be sealed in epoxy anyway) in the PC-7.

After curing for... I'm going to say 6 hours or so... the PC-7 was still pretty soft and tacky. I had tried aligning the bolts by supporting the wing actually in place on the hatch, but that didn't work at all... the PC-7 stuck to the painter's tape I had put on the mounting areas on the hatch, and it seemed impossible to get all four bolts anywhere near straight at once. Instead, I took a couple of scrap pieces of 1x3 oak, marked them against the hatch holes, and drilled them to match the holes (17/64). I put paper strips, with holes punched through, over the bottom of the wing to keep the oak from sticking (much), and put the oak pieces over the bolts to keep them upright and aligned while the PC-7 cured. I tapped them flat with a hammer, and also used a bolt to push the bolts all the way down into their recesses.

After curing another day and a half, or so, the PC-7 was pretty hard. I separated the oak from the wing with a spackleing knife, and tried the install on the hatch. It was a bit of a snug fit for the front pair of bolts, but workable (and they were straight). I applied a small amount of black RTV around the bolt holes to help seal the area when I put the wing in to bolt it down. I used new lock nuts... probably would have anyway, but, in this case, I had to, since I could not locally find M6x1.25 as was previously in there (not in stainless, and not at all).

The finish on the wing is still terrible, but at least it's now firmly attached to the car.

Thanks for the help.

Livio928

I also made some blocks that helped keep the spacing of the bolts straight and in line with where the holes were on the hatch. I used some wax paper between the block and the epoxy so that it would let loose, and even if it did stick, it wouldn't create a problem. Remember to use the gasket that should go between the spoiler and the finish of the hatch. I think Roger sells them or any of the Big 4. Looks like you figured it out and all is good. The finish/respray is another matter that should probably be left to professionals. Any decent body shop should be able to tackle that.