OT- heat-sealing fire hose

[darryl]

I have a piece of fire hose that I want to seal at one end. It's an experiment - don't ask Actually, I want to inflate a section to test its rigidity properties- but that's secondary. This stuff is a braided tube covered on the outside with what appears to be vinyl or pvc. The inside is similar, but does have a bit of a rubbery feel to it- though it is not rubber. I want to be able to make air-tight seals in it.

The hose lays flat when not inflated, so it would seem the best way to do this is to glue the end shut, and then probably sew a line across it. I tried goop, which so far has stuck to anything I've tried it on, but it doesn't bond well to this material. I tried heat-sealing, but the inside doesn't seem to respond to the heat as well as the outside. I can heat and bond the outside to itself, but that doesn't help me. I haven't yet tried a heat gun, as I would think the heat would be spread too far and the whole end would get soft. I will try that next, though.

What I'd like is to be able to spread a line of sealant on the inside, and then clamp it closed until it cures, then find that it has actually bonded.

Any ideas on what I could try? I realize that not knowing exactly what material this hose is lined with makes it difficult to choose the right stuff.

[lakeside53]

Forget the goop glue methods. Just fold the end over a few times and clamp it with two aluminum or whatever bars. Leave the "clamp" on...

[darryl]

I did consider crimping something across the end- might still do that. Maybe all I need is to put some dap into it, then crimp on a piece of aluminum or stainless- stainless I think would be better. The dap would only act as a sealant. That might be fine.

One thing I just thought of- there is a repair stuff made for water beds- vinyl basically. Have to see if I have any. I also thought to try poly strippa- anything that might soften the compound enough that it would seal the gap when pinched.

[vpt]

Stick the end in the bench vise?

[Stern]

If it helps, I can tell you when pressurized the hose will go very stiff .... I mean REALLY stiff. Forget gluing the end, do as suggested and fold and clamp. Not sure what your "end goal" is, maybe if we knew that we could help more (I use these hoses all the time and service them).

[Duffy]

Since fire hose is VERY MUCH code regulated, I would think that the various materials used are listed by the manufacturers. Try asking them what the liner is. The appropriate adhesive would then be a fairly easy choice. If I had to pick one without that info, I think that I would opt for urethane since it sticks to most stuff.

[Stern]

Depends on the hose, and there are MANY types. the one he described is probably a double lined municipal one, which is rubber lined. Due to the nature of the hose, gluing it will NOT seal it under pressure, as the rubber glue seam will rupture under pressure, so folding and crimping is really the only way to seal it if you want to put it under pressure. Maximum pressure for the hose is also listed on the hose (test pressure) which should not be exceeded

[1-800miner]

I made a few of them. Chemical glue and aluminum straps riveted together across the ends.
Put a Shrade valve and a bleed off valve on them.
I use them as jacks,work great in awkward places.
But be careful. They will lift faster than you think.

[darryl]

I know I said the inside isn't rubber, though it has a rubbery feel. I assumed it would be a compound of vinyl, but maybe it is rubber. I don't know. It has no markings, but it is a blue color on the outside, black inside, and is 3 inches diameter when inflated. It came with pretty hefty looking fittings on both ends, looking like aluminum. I'm sure it had been removed from inventory since the ends were quite corroded. I nixed the ends and washed the hose so I could bring it into the house. It looks like it's had little use- it's not abraded or brittle in any way. It is a 50 ft length. At any rate, I want to use it as an inflatable ridgepole in a tent-like structure. There would be a few uprights as well, so the 'frame' would stand on its own once inflated.

So far I have sealed the ends using pvc pipe cement, and included a filler tube in one end. I'm sure I can't trust that to hold, but from this first simple test of inflating it with my lungs, it seems that it will do what I want it to. It might take 10-15 psi to do the job, which of course I can't do by lung power alone, but that's not beyond a simple hand pump. The tubing itself looks like it could handle 200 psi- I wouldn't be using a tenth of that.

Actually bonding a sealing strip on the inside would be good, as then I can sew across the tube just outside of that strip without causing leaks. I could still fold the end over and crimp it, but if I can avoid adding that extra material, so much the better. If this is rubber, I can probably use rubber cement, and use a piece of the hose material itself as a sealing strip. Can't hurt to try it anyway.

[darryl]

Hmm, found this stuff called 'chemical vulcanizing cement'. Sounds like it would be the stuff to use.

[jlevie]

As mentioned, fold the end(s) of the hose over two or more times and use a clamp bar. Because the hose opens as it expands it will cause any simple glue joint to peel open.

[1-800miner]

I watched a meth head try the same thing on a ruptured air mattress.
He must have put five hundred staples in the thing,trying to make it hold air.

[WhatTheFlux!]

It's more than likely a synthetic rubber or rubberized PVC compound. Without knowing what compound it's made out of I can't even begin to suggest a solvent.

Typically materials like this are bonded using specific solvents or very specialized adhesives with surface prep and multiple steps.

[darryl]

I've just tried a common rubber cement, but I don't think it's going to hold. I made the rounds today, but as usual the product I'm looking for is going to be classified as industrial and won't be found anywhere around here. I'll probably just use the 3M product I have, a urethane sealant, and do the crimp thing.

[lakeside53]

If you fold it a few times and clamp you likely won't need any sealant.