I PUed a cycle wing back on yesterday and18 hours later it is still soft. The surface is tacky but doesn't stick to my fingers but it ooses underneath. The bead is a bit thick I suppose, bonding a 19mm tube to flat grp but how long should it take to go off?

too dry fully 24hrs but touch dry

In virtually every case, adhesives will go off quicker when they are warmed.

If it's a nuisance that it hasn't set, try warming it a bit.

John

Skins over in a hour usually However depending on how thick the bead was it could take a while. I've seen holes pumped full of PU sealer ( say 25mm thick ) still wet in the middle after a week. It'll be better if you heat it yes.

3 Days for a decent bead of sikaflex to cure throughout....

James

I leave it a week to be sure. But then, I put a lot of it on. Depends on the manufacturer though; Sikaflex takes a good week, while other, more commonly available bath sealants take less time, and harden more (less flexible when cured).

While we're on the topic. Shelf life for PU?
- I presume your good for a month or so with an unopened tube. But once its opened? Days/Weeks/Months?

Failing that, anywhere where you can get half tubes, or little toothpaste-sized tubes of the stuff?

Just thinking for little jobs i have around, blob under the bonnet catches here, blob over a hole in the floor there. etc.


Daniel

Shelf life - you can guarantee that it will go off one day before you really need it urgently.

Has anyone ever managed to get the tubes to last a decent length of time before going off? Ive tried all srts of ways but its like drinking beer - once you crack the seal nothing can stop it

Shame they never sell half tubes. I need a bit to rebond a front wing, will be a terrible waste to buy full tube.