How do you keep sealant cartridges from hardening?

[salar]

Like the title says, how do you keep Sikaflex, PU18 or similar between uses? Whatever I do there is always a plug of dried sealant under the cap after a week or two, which is a pain to clear. What's your trick?

 

[Neil]

I dunno and I'd be interested in the answers - I've had more unfinished and hardened tubes of sealant than most people have had hot dinners (as the saying goes). I usually end up piercing the tube halfway down to get some stuff out, and then it's the bin. What I need is a 10 pack of 10 or 20 mL tubes of Sikaflex. Usually, I only need a smidgin for a couple of bolt holes, and then it's curtains for the rest of the tube

 

[Tranona]

Puttibg it in the freezer with cling film over the spout will help.

It is moisture curing so inevitably you will get a cured lump at the end where it has been exposed to the moisture in the atmosphere.

 

[Cloven]

What I need is a 10 pack of 10 or 20 mL tubes of Sikaflex. Usually, I only need a smidgin for a couple of bolt holes, and then it's curtains for the rest of the tube

Sounds like a marketing opportunity for some enterprising company. I would happily go along with this idea.

 

[NormanS]

You can get small tubes of Sikaflex (80 or maybe 100ml?). They are not as manageable as the 300ml tubes, and have key which you use by winding up from the bottom of the tube. IIRC they cost more than half of the normal tubes for about one quarter of the volume.

 

[Neil]

I have a tube of urethane sealant for waterproofing, and the recommendation is to put it in the freezer; not sure this would apply to Sikaflex, though

 

[Neil]

You can get small tubes of Sikaflex (80 or maybe 100ml?). They are not as manageable as the 300ml tubes, and have key which you use by winding up from the bottom of the tube. IIRC they cost more than half of the normal tubes for about one quarter of the volume.

Yes, I have a couple of hardened ones of those on the boat - one with some duck tape over the hole that I made in the side - I'll probably have to buy another for the next job. Though, at that rate, you'll probably pay through the nose for a 10 mL tube (in comparison to the 300 mL)

 

[ghostlymoron]

Sealant is meant to go off or it wouldn't do its job. I try to save up jobs so that I can do several sealant jobs at the same time. I've given up trying to seal the end of the end nozzle and just poke out the hard stuff next time.

 

[ripvan1]

I usually leave the spout on and change it upon next use, dig out the hardened lump with small screwdriver or if hardened more then drill down to find the good stuff, on the assumption that it hardens from the outside.

If this fails then parallel cuts down the tube with a stanley knife and folding back of this strip normally finds some treasure. Strip of tube can be folded back and wrapped with cloth for fure use before binning.

Haven't tried the freezer route but have been using same tube for almost a month and haven't resorted to cutting tube yet.

 

[Lakesailor]

I use Sabatack. It doesn't harden in tube.

 

[bluerm166]

2 layers of baco foil close around the nozzle and squeeze a little out to seal.

 

[colind3782]

It's like Colmans making their money from the mustard left on the side of the plate. I would think that for 90% of the jobs we use 10% of the tube, the rest contributing to the manufacturers' profits.

 

[ribdriver]

As Bluerm said, although I tend to use wide masking tape. Stick a piece over the end and stuck to itself so you essentially have a pocket that is sealed. Imagine a bag over the end that is sealed up. Squeeze out enough sealant/adhesive so it fills the pocket. Mind it doesn't ooze out everywhere.

That's it. When you need to use it again, simply remove the tape which will now contain a solid lump. The nozzle and tube will still have uncured contents.

 

[J Neeves]

As mentioned, stick it in the freezer. I'm guessing we have some that is over 12 months old and quite usable. Most of these sealants require water to set off, freezer burn on your meet indicates freezers are dry (but cling film the top anyway). Its expensive stuff, even more extensive in small tubes.

Never clean prior to using with turps, the seal will be not nearly as good as if you use soapy water. Never use turps to clean the work area after - it will seep under the seal and and reduce the strength of the joint - keep turps as far away from sealant as possible.

Jonathan

Jonathan

 

[dgadee]

Fridge works fine. Used to use freezer which worked, too. Fridge keeps stuff fresh for months. Just used some this afternoon which was there since June.

 

[Actionmat]

i take off the nozzle, put a plastic bag over the hole in the cartridge and screw the nozzle back on. You're left with a hardened lump in the nozzle that needs to be cleared, but the cartridge is unaffected and ready for use.

 

[coopec]

The answer to this problem is just sooooooooooooooooooo easy!!

After using the cartridge screw off the spout, put 3 or 4 layers of cling wrap (very thin plastic wrap) over the thread, screw the spout back on tightly. Put 3 or 4 layers of cling wrap over tip of spout, fold back and secure with a rubber band twisted 10 or so times around the spout to ensure an air tight seal. The contents will last up to the shelf life of the product.

 

[duncan99210]

i take off the nozzle, put a plastic bag over the hole in the cartridge and screw the nozzle back on. You're left with a hardened lump in the nozzle that needs to be cleared, but the cartridge is unaffected and ready for use.

+1

 

[charles_reed]

I use Sabatack. It doesn't harden in tube.

But does it harden in the hole? I've used a couple of the polymer sealants - take about 48hrs to set in Greece and last in the tube for about 6 months.
As Tranona says keeping them in the freezer will slow down all of them but I prefer to not be ripped off by Akzo-Nobel and have found many UK manufacturers of equally good if not better products.

 

[salar]

Y

The answer to this problem is just sooooooooooooooooooo easy!!

After using the cartridge screw off the spout, put 3 or 4 layers of cling wrap (very thin plastic wrap) over the thread, screw the spout back on tightly. Put 3 or 4 layers of cling wrap over tip of spout, fold back and secure with a rubber band twisted 10 or so times around the spout to ensure an air tight seal. The contents will last up to the shelf life of the product.

I'm doing that but it still hardens, although not as quickly as if I had left it completely open.