Inspection port for inflatable?

Is there such a thing as an inspection port for an inflatable? It could be some type of rigid or semi-rigid, gasketed bolt through design or a roll seal (like a drybag) or a zipper (like a drysuit) or ??. Anything that allows easy access to the inside.

 

You could use the air inlet if you could borrow one of those drain inspection cameras, or ones they sell from surveillance shops.

They would be better than an large inspection port, as you could travel around the complete insides, instead of hoping the problem was where you put the port.

 

That is a good idea for inspection, thanks. But I wasn't clear about my use for it - it would be so much easier to repair it well if I could get my hands + a patch + glue on the inside, near where the holes are.

 

Do some Googling and you'll learn how to do a repair without having to get your hand inside.

 

I've done that, but I also had someone look at it who has done many repairs and they said "get a new boat - the (big) hole crosses a seam and the strip where the aluminum floor ties in". I tried a few benchtop tests and found the techniques to be not completely reliable (at least when I do them). Heat fusion (fast, 100% strength) worked best for me but I haven't seen anyone recommending that for repairs. Being able to hold some hard backing behind the new seam while rolling it helped. I might succeed by putting my hand in to do the hard part and then doing the easier portion blind.

 

How about a really good sharp knife !!! can access the tube any where !!

 

I designed an inflatable repair method where the patch is made inside. Never tried to contact a manufacturer because I assumed it already existed....

 

Not a bad idea actually. Make a nice clean slit, use it for access to fix the really hard spot, then do the easy slit repair. Now if I only had an electro magnet glue clamp the same shape as the hull.

My lesson - never leave your boat where rodents can chew it up - I have big holes in the worst possible spots. CDK - tell me more. I know some people slosh the inside with liquid latex, but that is only good for tiny leaks.

 

My repair tools is a polymer umbrella folded in the blunt hollow needle of a small syringe containing the bonding liquid. The umbrella is coated on the inside with a dry activator.
The needle is inserted in the puncture, then the plunger pushes the umbrella stem out of the needle together with the bonding fluid. The umbrella unfolds, the bonding liquid cures within 1 minute. Once the pressure is restored the stem sticking out can be cut off with a utility knife.

The bonding liquid is a specially formulated cyanometacrylate that cures into a flexible rubber-like substance, the shape of the umbrella separates it from the activator until the plunger is pressed.

 

Quite interesting. I wonder how close I could get to that by heat bonding a stick of PVC to a circle of fabric, inserting it without a needle and injecting more typical glues (West G/flex, 3M 5200, etc). Inflating the boat should hold it in place while it cures.

 

In the more radical idea department, to get something to press the blind side of a patch tightly against the exposed side, how about small steel balls. Put a flat plate electromagnet on the outside, put the balls on the inside. When finished, dump the balls out the inflation port (or one of the other holes - which is why you couldn't inflate it).

 

Instead of the PVC stick, use a piece of fishing line. Coat the patch with glue, roll it up, insert it and gently pull it in place.

 

Thanks, I will try that.

The most promising gluing method looks like a combination of solvent and heat bonding. Apply the solvent glue, but then also heat up the PVC with hot air (needs to be thermostatically controlled temperature) until it just starts to melt (normally this would not result in perfect coverage and you would have air leaks). You get the uniform and complete coverage of solvent combined with the superior strength and cure speed of bonding by melting.

I tried G/flex. Worked well with one brand of PVC and not so well with another.

 

I switched to HH-66 PVC cement and it works far better than the two cheaper ones I tried. Sand lightly, apply HH-66 to each side, wait 5 min, heat it gently, press together as hard as possible (preferably with a small roller). Wait 24 hours and it can't be pulled apart.