Dinghy air pump

[K9Kampers]

I bought this 12 volt inflator pump at West Marine the other day. I was looking forward to seeing the inflatable being ready in less than 5 minutes vs. 30+ minutes.


When I rolled out the dinghy, imagine my disappointment when I found two mouse-chewed holes in the Hypalon air chambers! The bottle references the size of the larger hole.

[mastreb]

The mice problem sucks--why would they go after hypalon?

I found our 12VDC inflator to be WAY slower than the accordion foot pump that came with the dinghy. Haven't used the powered inflator since.

[restless]

what a day spoiler! Sorry to hear about such wanton destruction.That would really hack me off!

We have a 12v pump.. an absolute gem. Extended the hose by an extra 2m and use it to suck air out too. Ours came from a camp shop pretty cheap. It doesn't blow up to pressure, maybe 90%, so we top it up with a foot pump or a blast from a scuba tank. The tender has very fat tubes so would take a lot of grunting around to blow up.

In theory, there is no difference between theory and practice;
In practice, there is.
Restless art & engineering

[K9Kampers]

A day spoiler indeed! This would've been our fifth season with the dinghy. It was supposed to be a long term investment, only I forgot to bring it into the basement last winter, leaving it instead in the barn. The other hole is about an inch round, repairable with a three inch patch. Otoh, even if I were to successfully patch the big hole, my wife would not feel confident or safe in a 'repaired' boat. She wants to go sailing next week which means I either have to buy a new dinghy or we'll use the sit-on-top kayak again.

Anyone ever repair a hole this big?

[bartmac]

The 12v inflator we bought is a dual pressure one so it inflates the bulk quickly and then takes it slower to a set pressure and stops...beats the manual way!!....also had thought to use the same pump to pressurise my ballast tank to speed up water evac...set at a very low pressure probably less that 3 or so PSI the inflatable gets

[Crikey]

That could be dangerous over continued use! I don't think the ballast enclosure is designed to handle that kind of pressure without flexing, and eventually cracking.
Don't want to be a naysayer, but have you examined how much the outer surface bows outward while you are inflating it?
R.

[bartmac]

Oh yes....the surface area inside the ballast tank would result in a lot of force being generated....softly softly was going to be my approach

[JohnCFI]

Oh yes....the surface area inside the ballast tank would result in a lot of force being generated....softly softly was going to be my approach

But how softly do you need to be, and how do you know when you have pushed it just too far??

[bartmac]

That's probably why I have not done it yet....but the time taken to drain the ballast on the ramp is concerning.....mainly to other ramp users!!!!

[Crikey]

Put some Snikkers bars into the ballast tank before you go out. When you drain the ramp will amazingly clear out!

[Catigale]

Andrew - definitely repairable.

Only tough part I see is that you are near that seam, which will

This is what you are going to do, need a helper too.

Spec out repair material and glue.

Trim the hole to be roughly square, with rounded corners (no sharp points like the Comet) and then (this will be messy) work a piece of wax release paper inside

Now work a piece of repair Hypalon inside.
Helper now holds hole up, you arrange wax paper, glue surface and position and hold interior repair piece.

Let dry.

Now come back and add a repair piece on the outside - easier. Helper brings cold beer for this step.

Your repair will be stronger that the rest of hull.

....and get a cat...

==^..^==

[Tomfoolery]

That's probably why I have not done it yet....but the time taken to drain the ballast on the ramp is concerning.....mainly to other ramp users!!!!

Pull the vent and the drain valve before you even get it around to the trailer. The ballast tank is long and relatively shallow, so the instant the bunks elevate the bow at all, water will start draining rather aggressively. By the time you get it winched to the bow cushion, and pulled out enough to be sure the stern is sitting centered, then winched again since it tilts away from the cushion as the stern settles, much or most of the water will have drained out.

If you look at how much time most power boaters take before pulling completely out of the ramp, if you do it right, you won't take any longer, while not sitting on the ramp doing nothing but watching water drain. The trick is to give it a head start, long before it's out of the water. And to fiddle around with centering it and adjusting the winch and such while the water drains, since it's the standing around watching the water drain part that's garnering you the dirty looks.

And ditto the compressed air in the ballast tank concerns. A few psi on such a large area is potentially a LOT of force in places that weren't designed to take it. 1 ft of water depth is about .45 psi, and I doubt the ballast is more than that, so do be careful to keep the pressure low if you drain it with a compressor. If you heel the boat onto its side, I'd guess the ballast tank is only around 5 ft wide or less, so even then the max pressure at the bottom of the tank will only be a few psi, but not over the entire tank top surface, of course.