Re: [Paddlewise] Electrodynamic hydropurgation devices

-----Original Message-----
From: Peter Treby <ptreby_at_ozemail.com.au>

>Does anyone have experience of higher capacity electric pumps? I have heard
>ideas that the Rule 500 is more reliable than the Rule 1100.

Peter, this is copied from a post by Wes Boyd on Feb 4, 1999:

   I may be stepping on Philip Wylie's toes with this, but this is the
content
   of an e-mail to him from Laurie Ford that was posted on the Baidarka
list last
   year. (I saved it since it seemed like one of those key things you want
to
   remember.)

    "As for electric pumps - in the last 20 years there is only one type
that I
    would recommend, and I have tried out several others. The RULE 500
(usedto
    be 400) is the only one that never gives any trouble. Others have had he
    impeller disintegrate, or the housing develop leaks...."


>I wonder if two
>Rule 500 pumps connected to two separate batteries and switches would be a
>solid system, despite the weight?

They would probably be a solid system, but the weight of the batteries in an
otherwise empty or near-empty kayak might begin to affect the trim of the
boat, with resulting differences in weathercocking and such.  In any case,
I'm not sure that the 2-minute gain would amount to much advantage.  After
all, the hands-free activity of the pump allows the paddler to manage the
boat defensively while it is emptying, and that's the main thing.

>When using the electric pump, as the water is pumped out a vacuum is
created
>in the cockpit space causing the spray deck to suck down. I open a gap in
>the body tube of the spray skirt to relieve this and keep the pump going at
>full capacity. This wouldn't be possible if both hands are on the paddle
>working hard. Has anyone tried a small hole in the deck to get over this?
>The hole would be small enough to only let in a few drips, perhaps like the
>bulkhead holes described in other posts which relieve pressure variation in
>bulkhead compartments and stop rubber VCP hatches bulging.


Has this been a serious problem for you?  I'd imagine that a quick "burp",
accomplished by partial lifting of an edge of the spray skirt for a second
or so, would be sufficient to relieve the vacuum.   In most instances, one
wouldn't have a full cockpit and still have the spray skirt on.  I guess the
most likely scenarios for this would be after a re-entry and roll or any
other kind of re-entry (assisted or otherwise) in surf, when the paddler
would need to replace the spray skirt before pumping out.

    Bob V



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