Fastest Manual Dinghy Pump.
- Thread starter Mark-1
- Start date
dancrane
Well-known member
Very interesting. I'm not surprised that the electric pump was slower, even if it might have been easier.
But I have to ask, how bad were your bellows? And what size is the inflatable?
Last year I tested how quickly I could inflate the Redstart (8ft) with its original Avon pump. It was all done in under three minutes - of hard work I admit, but that's quicker than I had supposed was possible, when I thought I needed something quicker.
I sometimes think if I could fabricate a similar footpump to slightly bigger dimensions, it could be done a lot faster.
.
FairweatherDave
Well-known member
3 minutes of hard work is exactly why I got an electric pump. My back always ached a bit after using the SUP (stirrup) pump. (Foot pumps I have never got on with, much worse). And as was said earlier in that 3 minutes you can be doing other preparations.......My cheat is I drive with a small old car battery in the boot so hooking up the pump is a doddle. But a decent SUP pump is a damn fine thing for inflating anywhere.
Chiara’s slave
Well-known member
I’m pretty fit, and younger than a lot here, and I very much doubt I could beat our electric pump. And as you say, you can be doing other stuff while the electric one does the donkey work.
mjcoon
Well-known member
50% bigger in 3 dimensions is more than 3 times bigger volume...
Mark-1
Well-known member
Not sure the electric was slower - just that the SUP manual pump was so effective that in future I won't bother to get it out/plug it in etc. (I have two electric pumps, one camping pump that can do volume but not pressure and one SUP one that can do volume and pressure but takes an eternity to get the volume in. So for a SUP I use a combination of the two electrics.)
I've got two bellows, one years old, one brand new and unused before the weekend. Pretty sure I don't have a faulty bellows.
The dinghy I tried it on is tiny, 6ft I think. Similar to the Seago Spirit 180.
I shouldn't be surprised. The sup is pumping on both strokes. So even if you assume the same volume per action the SUP is already twice as fast. (The SUP pump is five litres per action.)
My question was whether the SUP 'track pump' style is faster than a foot bellows. Pretty sure it overwhelmingly is. Clearly with an electric pump the sky (well 2200w) is the limit.
Last edited:
Stemar
Well-known member
And more than double the shove to shift the air.
Being an idle git, I'll stick with my leccy one with its own battery.
dancrane
Well-known member
I've always thought a bigger pump would be usefully quicker for the volume work of just getting the tubes approximately full. Would the extra capacity of the pump mean impossible toil for the final part, putting enough pressure in the boat for practical use? It may be characteristic of my tendency to underfill my old Avons, that I've never found inflating them was troublingly arduous when done slowly...just slower than I'd like.
I suppose the size of a pump's chamber is like a bicycle's chainwheel diameter. I'm surprised most bellows-pumps seem under-geared for their purpose, taking more strokes at not much effort per stroke, when fewer, bigger, more resistant strokes might be manageable and faster.
Thinking alternatively, I have two Avons, two pumps, and both boats have two chambers...so I could rig up both pumps simultaneously, one for each foot, to inflate one boat in half the time.
Not guaranteed to be very dignified, but not impossible with toestraps. It might start a dance craze..
Fr J Hackett
Well-known member
No matter what pump or technique or speed you inflate the boat with the energy requirement or work or effort required will be the same.
Mark-1
Well-known member
Thinking alternatively, I have two Avons, two pumps, and both boats have two chambers...so I could rig up both pumps simultaneously, one for each foot, to inflate one boat in half the time.
.
Overkill for the tenders but quite seriously for the sups I've often thought splitters would be handy.
I suppose even for the tender it helps if you're using manual pumps and solves arguments between the kids about who does the pumping.
mjcoon
Well-known member
That assumes 100% efficiency. When you press bellows some of the force goes into a spring (for the return stroke). You don't get that energy back. The same applies to piston friction, of course.
Mark-1
Well-known member
Plus with the foot bellows you do that kind of 'Karake Kid' pose holding your foot above the returning pump trying to guess the optimum point to press again. That must waste energy. In contrast every bit of movement with the SUP/Track Pump style pump is actually moving air.
I fear we've got caught up in inconsequential details now, but this is YBW, after all.