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Sikaflex
Bumble - 20/7/10 at 02:30 PM

How do you all stop the Sikaflex or similar from drying up after opening and blocking the nozzle?? Bl**dy annoys me every time. I've tried various methods none of which are ever very successful. Is there some trick I'm missing??
Cheers,
Matt

BenB - 20/7/10 at 02:33 PM

Just an idea but it's solvent based so wouldn't keeping it in the fridge / freezer work.

balidey - 20/7/10 at 02:34 PM

Get extra nozzles. Make sure you leave the nozzle full so its that bit that dries up, not the tube. Then just use a new nozzle. They are meant to be dispossable. As far as I know there is no good way of saving a nozzle. And we use a couple of hundred tubes a week at work.

sucksqueezebangblow - 20/7/10 at 03:58 PM

As far as I am aware, once it is opened it is going to go hard whatever you do. It lasts a couple of days before going off in the tube. I try to plan ahead and have enough jobs ready to use most of a tube at once. Or just resign myself to the fact that the leftovers will be chucked away.

RazMan - 20/7/10 at 04:16 PM

I put a Biro cap over the end which delays the inevitable hardening for maybe a couple of weeks but basically, use it or lose it There must be a market for smaller tubes of PU adhesive and I would love to buy a couple for those smaller jobs. I discovered that some of the black gasket compounds are almost identical and I have used them with good results.

Also remember it has a limited shelf life so even if you have a few unopened tubes hanging around in the workshop, they will go off after a year or so.


[Edited on 20-7-10 by RazMan]

Canada EH! - 20/7/10 at 04:31 PM

I usually stick an old nail the size of the nozzle inside the nozzle then pull it out with pliers when i need to use it again. Works for me.

stevegough - 20/7/10 at 04:48 PM

quote:
Originally posted by Canada EH!
I usually stick an old nail the size of the nozzle inside the nozzle then pull it out with pliers when i need to use it again. Works for me.


wot he said, but I use a woodscrew, - screw it in, clamp in the vice, and pull it out whilst increasing the pressure using the pump action of the gun. Or, indeed, get another nozzle.

Wadders - 20/7/10 at 05:23 PM

It's moisture in the air that cures it once opened. Putting it in an airtight freezer bag helps, but iv'e never found a definitive way to stop it going off.

Al.

dave r - 20/7/10 at 05:34 PM

fridge does work, but i find that the piston at the other end of the tube tends not to be a good enough seal, and you break the mastic gun, breaking the cured sikaflex at the end


we use a sika product at work that is in sausage tubes, that go in a different gun.... anyone know if you can buy pu adhesive in this style package ?

dazzx10r - 20/7/10 at 05:48 PM

I use a self tapping screw in the end of the nozzle, seems to last ok for me, when re-using it i have found its best to warm the tube

russbost - 20/7/10 at 05:53 PM

I use a similar product, which uses a different gun & comes in sausage tubes (like a plastic bag), I'm not sure if it's actually a PU sealant & wouldn't use it for anything that was "stiction critical" but it is way better than silicon for adhesion & miles cheaper than sika + it doesn't go off, just leaves a little solid bung at the end of the nozzle that you can easily remove. By the time you've used a couple of tubes you've more than paid for the gun & are saving money - to say nothing of saving your temper when the bl**dy Sika has gone solid in the tube again!!!

twybrow - 20/7/10 at 06:29 PM

I go for a woodscrew, then a wrap of clingfilm, and make sure you store it somewhere cool and dry. It is warmth and moisture that sends it off. My last tube was still usable 6 months after I opened it...