Haven’t tried FlexSteel, but I did guy a container of Gorilla Glue. GG would not hold.
It is difficult to find stuff that actually measures up to their advertising.
guy = buy
I bought a large container of Gorilla Glue. Used a tiny bit on some project and promptly resealed it.
About two weeks later I needed it for another job and the whole container had turned solid. I phoned their number and the girl said that it was not warranted for that.
Of course I will purchase no more.
Like I said I've never actually used it, but I have used a number of other Gorilla Glue Company products that are simply outstanding and that I highly recommend. Such as Gorilla Tape. Compared to regular duct tape it's probably 4 or 5 times stronger for about double the cost.
The UV glue seems gimmicky, although I've worked in industrial settings with both UV and anaerobic curables in the past. Gorilla Glue is a polyurethane adhesive and I suspect it is a very good one. But you need to know how to use them and where that adhesive is best suited.
As to shelf life, you're the first complaint I've heard on that and I hear from lot's of folks when something seems wrong. One tip I've been using with success with PVC cement is always store the resealed container upsidedown.