Introduction: Resealing Half Used Caulk Tubes

Picture of Resealing Half Used Caulk Tubes

It always frustrates me when I do a caulking or sealant job around the house to have to throw away a half used tube of caulk or silicon sealant or construction adhesive. I would use the provided caps and/or tape the tip, however no matter what I did the tube would be bad by the next job.

Here is a simple technique that will extend the life of a half used tube.

Step 1: What You Need

Picture of What You Need

Here is what you need:

   1.  A circle of material cut from a milk jug.
   2.  A lighter or candle.

Make sure the nozzle or tip of the tube is clean of caulk.

Step 2: Use the Lighter

Picture of Use the Lighter

Use the lighter to heat the center of the material that you cut from the milk jug. Move the heater in the circular motion until you see the material turn transparent. The transparent area should be about 1 1/2  to 2 1/2 inches in diameter.

Step 3: Seal the End of the Tube

Picture of Seal the End of the Tube

When you have the material transparent, quickly push the material down over the tip. The softened material will stretch forming a molded cap. If the material of the tube's nozzle is polypropylene (same material as the milk jug), the materials will sometimes bond. If you materials are not the same, you will just have a tight fitting cap.

Step 4: Trim

Picture of Trim

After everything is cool, trim the new cap you have made. If you want you can even add tape around the base of the new cap.

This technique will not keep your half used tube fresh forever, but it will extend the time that it takes the tube to go bad by a long time.


carlos66ba (author)2010-09-27

I usually stick a screw into the "nozzle" and cover the end with duct tape. Then I place the whole thing inside a zip-lock bag. I have used caulk that had been open more than one year without problem this way. YMMV.

Doug Paradis (author)carlos66ba2010-09-27

I will have to give that a try. I haven't had any luck with duct tape (never tried it with a screw), but I really like the idea of putting it in a zip-lock bag after sealing.
Thanks for sharing!

THX 1138 (author)Doug Paradis2017-04-30

I read that silicone sealant cures by reacting with water coming from the air so if you put desiccant in the zip-lock bag, that should also reduce the rate at which it cures, if not stop it from curing altogether.

SteveB153 (author)2016-02-10

Just heat melt close the end of an old plastic nozzle from a previous use then screw that onto the part used tube. Basically you've made a plastic cap which the makers should have sold with the pack anyway. They dont becausde they want you to buy fresh tubes each time.

richard.goodbar (author)2015-03-23

A golf tee has worked for me, the taper will snug to various sizes.

seaprogrammer (author)2014-12-06

What about dipping in melted wax? And spread petroleum jelly around the plunger lip to seal that end?

I also wonder if dipping in white or wood glue would work? I think water can get to some of that stuff after it's cured, so I don't know about its moisture or air/oxygen permeability...

...or a coat of epoxy?

doo da do (author)2013-02-18

I stick a large nail in the end

john5247 (author)doo da do2013-11-03

Tried it - only works for a few hours or overnight if you're lucky.

john5247 (author)2013-11-03

Excellent! I have given up on hot glue and use silicone a lot these days - but often the jobs are small and weeks apart. I'll try the milk carton stuff, but use a hot air gun to avoid the carbon blacking from the flame. I might also try hot glue stick melted to clear with hot air. I did wonder though whether it is the coarse screw thread on the nozzle that let the air in. Maybe I'll try the seal directly on the end of the cartridge ......

laskaslinks (author)2011-11-19

I have always just stuck a nail into the end of the tube. When you need it again - pull the nail out. Thing of it as an easier step than finding a rod or a wire nut. I have never had a tube dry out using this method. I will advise that it's better to cut the tube open at a 90* angle and pay attention when sliding the nail back in... it will irritate you if you do this tired and puncture through the side (too messy too)

JIONER (author)2010-11-27


rimar2000 (author)2010-09-27

Pardon, your method is good, but mine is better: I search a cylindric plastic or metalic solid rod (no wood), with diameter equal to the tip's hole. Preferably, a little snug. I insert the rod some 5 to 7 cm into the peak, so when I want use newly the caulk I pull out the rod, and ALL THE CAULK IS FRESH! Only a bit of dried caulk cover the rod, less than 0.5 mm thickness. Each three or four uses I must clean this dried caulk to reuse the same rod. If something here does not mean, tell me,

I don't speak English but Spanish. Maybe using another words the idea could be understable.

Doug Paradis (author)rimar20002010-09-27

I am loving hearing about all the way folks attack this problem. I still think my way is better because, I would have a hard time finding the right sized rod. If I can find some appropriate rods, I will definitely give this method a try. I might even do both, sort of like a wine cork and foil.
Thanks for your sharing your method.

DIY Dave (author)2010-09-27

You could just screw a wire nut on the nozzle.

hilly-wa (author)2010-09-27

In addition to sealing the nozzle, I stuff several plastic grocery bags into the open end of the caulk tube to seal the "push end".

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