Cleaning a nozzle on a silicon tube

[landonshaw]

Has anyone perfected a way to clean out a removable nozzle from a silicon tube? I am fixing my hatches and on each hatch not using a lot of silicon. Using a tube with a removable nozzle in a gun. I am able to reuse the silicon left in the tube, but the nozzle is not usable. Thanks

[Pete7]

I am very wary of using silicon on a boat because once its on GRP its the devils work later if you want to clean it off and do something else like paint.

Some of the nozzles I can clean out by stuffing a long screw down the thin end but stuff like sikaflex just dries in the nozzle and the tube if you leave it for more than a few weeks.

Pete

[landonshaw]

The silicon that I am using is made for the sealing of the hatch between the hatch and deck. I will post the name later. Thanks

[jimbunyard]

While the tube is under pressure, drill out the 'plug' with a 3/16" or so drill bit. Be ready to release the pressure when the tube begins to flow. Sometimes you can get the whole plug out; sometimes you have to go to a larger diameter or length bit, sometimes if the hardened part extends into the tube it acts like a check valve and you have to resort to the 'hole-in-the-side-of-the-tube-and-finger' approach.

Another problem with using silicone is that after application it 'bleeds' a residue that does not stay put; this residue will run down over a surface and inhibit adhesion and cause other problems some distance away from where the silicone is applied. There are several solvents that will remove it (and dissolve the silicone as well), such as Dow's DS2025, but they are rather expensive, about 40.00 usd a pint, and very toxic...

[a64pilot]

Removable nozzle? Remove it, let silicone harden, push out from the end or screw a screw into the big end and pull the hardened silicone out, then you have a nice silicone plug you can trim and maybe plug a small hole with, like maybe the drain in your icebox or something.
But yes, silicone on fiberglass is not it's best use.

[skipmac]

I have been able to fully clear nozzles by removing the nozzle, screwing as large a wood screw as will fit in from the bottom and working the solid plug out. If there is any hardened caulk in the top of the tube use the same screw to clear that as well.

I also share the concerns about silicone on a boat. All silicone caulks, marine grade or otherwise, whether made for sealing hatches or bathtubs, are all made with silicone oil. That oil soaks into fiberglass and will then prevent any caulk from ever sticking to that area, including more of the same silicone.

Silicone based caulks I would use sealing a plexiglass pane into the metal frame of a hatch or port but never on wood or fiberglass.

[captmikem]

If you put a little ball or plumbers putty over the end when you finish using it, it won't harden and you can re-use it easily.

M

[neilpride]

Leave it in the fridge after use it.


A long screw do the trick for me...

[Suijin]

Originally Posted by landonshaw

The silicon that I am using is made for the sealing of the hatch between the hatch and deck. I will post the name later. Thanks

That is a an application where I personally absolutely would not use silicone, regardless of what the manufacturer of the hatch recommends. Silicone has terrible adhesion properties, and every deck flexes a bit, particularly under larger hatches. Does not take much to break the seal, and then you're looking at pulling the hatch and rebedding it. For sure I would use something like 4200 or butyl rubber.

[Mark Thurlow]

When you have finished for the day or longer. Remove nozzle and place a couple of layers of plastic in a small circle - say from a store bag , over the end of the tube. Then replace the nozzle to form a seal. The stuff in the nozzle will harden and can be removed - but the stuff in the tube is preserved. Also instead of cleaning the nozzle buy spares readily available in hardware stores.

[Scout 30]

Silicone + boat =

[foufou]

Silicone 2 by GE is paintable

[JPA Cate]

And now, for the brute strength and awkwardness method: dig it out with a small screw driver.

I must say I like the screw-it-out idea. Have to give that a try.

Ann

[SFS]

I've had good luck taking the advice in post #10 (above) one step further:

I take plastic wrap of some kind and secure it around the end of the tube (a rubber band works, but will degrade after long term storage. I've also used the plastic coated wire ties that come on loaves of bread.) When the plastic is in place, squeeze out some of the material from the tube into the plastic. It will form a "ball" at the end of the tube's tip, and will harden, but the material in the tip will not, because it's not exposed to air.

When ready for use, take off the plastic, break off the hardened (or not) "ball" of material, and off you go. I've reused caulking tubes more than 2 years after sealing this way.

[SVTatia]

For sikaflex or any other adhesive that does not have a removable nozzle, I insert a screw as large as it fits in the nozzle before the thing hardens.
Next time you use it, just pull the screw by its head and the hardened stuff comes out with it. This will enlarge the nozzle a bit, but at least you can re use what is in the tube.