Not really sure about Loctite epoxy and not sure about the parameters of the product (set time ,work time etc) but I will add ,from personal experience ,a good 5 min and 30 min epoxy will benefit you well.Go to a good hobby shop and buy both (smith ,pacer ,etc) as they both have thier uses.Rough up the G-10 with 180 grit as well as the Quantum tube ,wash well with alcohol (99% Isopropanol does well here) and rinse again with same.You need a good bond with G-10 and Quantum tube and sanding & good epoxy does well .5 min will get the fins on but 30 will get the strength done ,as in fillets.
I've been through plenty of the LocTite sets, it works, but it's a lot more expensive in the long run.
You'd be better off just getting the sets that PML has on their web site if you don't have a good hobby shop near by. Worked just fine for my L1 and L2 rockets (both quantum tube endeavour mods).
And, once again like sodmeister said. You really want a nice rough but clean surface for the epoxy to bond to. I managed to slob some drips of epoxy here and there on some non-sanded parts of body tubes, it was fairly easy to just pry off with just my finger nail. I used 80 grit for the centering rings and used a razor blade to make little cross hatches for the fin fillets. Probably over kill but it seems to have worked.
Glad you mentioned the cross hatching technique Scott ,I use it when bonding styrene/plastics as well as G-10 fins ,CRs and Quantum tube parts.I find it helps the parts and adhesive "key" into each other.
I would suggest you measure, by weight, the parts of the epoxy too. A model building club here at school used to just eyeball the 1:1 BSI 5min Epoxy, which would be tacky for days after it was used. I made the guys use the gram scale (which we always had :bangpan to mix a batch precisely, and it set up so well that they were surprised when it did. Hard as a rock after 30 minutes.
Thanks for all the feedback. I ended up using some 30 minute epoxy for the internal gluing (motor mount and attaching fins TTW). I used the Loctite plastic epoxy for the fillets and launch lugs. Here is a photo of what I have been building.