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Thread: Keeping Silicone From Hardening At The End Of The Tube

  1. #1
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    Default Keeping Silicone From Hardening At The End Of The Tube

    This happens every time I buy a tube of silicone.

    I usually cut the tip of the nozzle back just enough to open up a 1/8" hole so I can squeeze out a thin bead. When I put the cap back on the tube I always make sure a little silicone is coming out so there isn't any air in there. A month later The tube is clogged. Sometimes I can poke the clot out and sometimes I can't and have to cut the nozzle back to allow the clot to push out. Now I have a bigger hole at the end of the nozzle than I want.
    Is there any trick prevent this from happening??? What does the mfg. do when they fill these tubes?? There is always air in the nozzle, the silicone isn't right at the end.
    Do they fill the tube with some gas, nitrogen, argon ?? something that doesn't react with the silicon so what's in the end of the tube doesn't start to cure??

    JL.................


  2. #2
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    Regular "RTV" is cured by water, generally vapor in the air. So any dry gas will tend to retard the cure.

    The plastic tube is likely to be slightly permeable to water, unless it is multi-layer, so it would probably eventually cure even if the tube were never opened.
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  3. #3
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    I've tried a number of types of tape over time and found that none of them solved the problem. I recently bought a twin pack of molded push on caps that are supposed to work for such uses. But they too allowed the product to cure to some extent. In the end I've come to think that the best thing is to insert a large size screw in the end so at least it's already in place and ready to grab and pull to yank out the cured plug of the goop in the tube.

    With the taper of the tube if the slug of cured goop is fairly long the tube will need to be slit to allow the plug to be extracted. But then at least the regular tape can then hold it together.

  4. #4
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    I buy the tubes with the removable long tips. Then I leave the tip on and put the cap on when done. When it is time to use it again I remove the whole tip and screw on another one. These are the kind that go in a caulking gun.
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  5. #5
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    it took me a while, but I've learned to throw away those tubes as soon as I use what I need. much less frustrating.

  6. #6
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    Quote Originally Posted by Black Forest View Post
    I buy the tubes with the removable long tips. Then I leave the tip on and put the cap on when done. When it is time to use it again I remove the whole tip and screw on another one. These are the kind that go in a caulking gun.
    They don't come that way anymore. Probably another cost cutting measure.
    As you can see I used to save all the tips and have a few cut back at different positions for various hole sizes.
    I even have one that I cut the threaded part off of that has a small hole. I push it over a tube that has been cut back with a larger hole.

    I was wondering if these tubes are filled in an inert atmosphere or some other gas before the end is hot sealed so the product has a longer shelf life.
    I'll bet the stuff that is rain free in 30 minutes has a shorter shelf life than the older stuff did.
    I can remember having opened tubes of this stuff sitting around for a couple years and still be good. The fast cure has to have something to do with the shelf life.
    Either that or they make the stuff this way on purpose so you have to keep buying it.

    JL.................



    Last edited by JoeLee; 05-14-2018 at 01:34 PM.

  7. #7
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    I find two methods work well for me. a wrap of plastic food wrap held onto the tube with a rubber band works well if you first put a blob of caulk/silicone into the plastic. This blob will harden up but it will only harden up so far. Next time you need it just pull the cured silicone off of the tube's nozzle and you ready to go.

    Another method I use with success is to insert a long nail into the tube, again covered with plastic wrap and a rubber band. The silicone will cure near the nozzle end but once the nail is pulled out a long clear channel is left behind.
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  8. #8
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    Quote Originally Posted by gambler View Post
    it took me a while, but I've learned to throw away those tubes as soon as I use what I need. much less frustrating.
    Only in America

    I try anything possible before I do that - takes resources to make and also money to buy.

  9. #9
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    I always cut off a rubber/nitrite glove finger and stick it over the end with a rubber band holding it on. Works about 50/50. The last time I needed silicone the only tube I had was all plugged up so I just cut it open and scooped out what I needed. It worked great for what I needed (sealing extra holes in outdoor light fixture), but would be a bitch to re caulk a bathtub that way

  10. #10
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    I put a long deck screw down the spout that will reach into the body of the tube. Then I wrap electrical tape around the spout and screw, careful to not leave gaps. If it does harden before I next use it, pulling out the screw usually clears the dried plug and allows further use of the goop.

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