Looking for spray sealant with a nozzle

I've a feeling that what you're after would be single-use only. Once used it would be almost impossible to clean the thin tube, and if it dries quickly (organic-based solvent) it would be even more of an issue.

Could you find something that because less viscous with heating? Not sure if that applies to silicone/etc, but when I did some Waxoyl-ing I'd first warm up aerosol cans in a kettle (not boiling) to make it more runny.

Theo

Paint sprays work fine as long as you invert them and blow out clean propellant. This is how the aerosol mastics work too (reading their instructions).

Off the wall suggestion, one of the tyre sealing solutions . Some cyclists use come in small squeeze bottles with thin nozzles.

Or Gorilla glue which has some of the characteristics of foam do a version in an aerosol..

GH

Years ago was able to buy a large size hypodermic needle and plastic syringe to apply epoxy adhesive deep into the wobbly joints of an old chair I was restoring. So something of that sort which you would fill with whatever sealant you want to use, then dispose of it.? TW

And silicone sealant is soluble in white spirit if you want it to flow better. TW

Yes, that would work, it would require quite fluid sealant.

I think that's maybe my basic issue, I need some sort of sealant that is less viscous than standard mastic. Unlike the normal use I don't need to be able to make a bead stick on a vertical surface, I need to be able to squirt it into the end of a (maybe) 1cm x 1cm (or less) hole and be able to squeeze it in easily.

I have some syringes like that, as you say the short plastic 'nozzle' where you insert the needle may well be enough for my needs. All I need is a simple way to fill one with low viscosity mastic.

As I had the parts to hand I've just tried it

A 20ml plastic syringe and some silicone sealant from Screwfix. No problem getting it out of the inbuilt nozzle.

As the sealer is very viscous it's a continous but very slow firm push on the plunger.

I also tried it with a with a wide needle. It does work but much more difficult. Around 10 seconds of _VERY_ firm pressure on the plunger before the sealer emerges slowly from the end of the needle. It continues to flow slowly if the pressure is maintained. You may have to maintain the (high) pressure for many minutes as the bead of silicon is around 1mm diameter with the wide needle I had.

How deep is the hole? You may find it difficult to fill unless you can get the nozzle to the back of the void as with a very viscous sealer all you may do is trap air behind a thin layer of sealer if you only pump from the front of the hole. Although messy, you could force the sealer to the back of a hole with the back end of a drill bit etc. before adding more sealer.

Yes, that last is exactly my problem, I want some 'runny' mastic, I'd then probably be able to do what I want with the standard tube and gun.

The usual problem with regular syringes is the needle will pop off the end if these is too much pressure - fine if the pressure is being relieved via the needle tip but if there's any kind of blockage the needle will pop off and there will be an explosive decompression of the fluid[*]

I think some syringes have a mechanism where you can lock the needle in place, which will presumably allow more pressure to build up?

Theo

Carpet spray on glue

Luer lock

How about some slightly diluted decorator's caulk?

cheers, jim

How do I get it into something to squirt it with?

That's the difficulty, if I get some mastic and make it thinner then I need somehow to get it back into a tube to squirt it from. The best idea so far would seem to be using one of those fat hypodermic squirter things but straightforward 'thin' mastic would be much easier.

How deep is the hole, and in what material? It would be useful to have more detail.

There's a couple of places involved. Two long rectangular steel 'tubes' on the side of steel superstructure, i.e. the superstructure is one face of the tube. Both are maybe 30cm long, one about 1.5cm x

The problem I'm trying to address is condensation inside the tubes which drips water onto the surface below.

Seal the ends by wrapping the cables and ends with heat-shrink tape?