Sunday, January 27, 2008

Bilge Pump

I made a bilge pump today, it was based on this design.


  • 3 : 1 inch 10-24 machine bolts w/nuts (you only need one nut)
  • 1 : 24 inch dowel 1/2 inch diameter
  • 1 : 24 inch pvc pipe 1 inch diamter
  • 1 : PVC L connector
  • 1 : PVC End cap
  • 1 : cupboard pull
  • 2 : 1 inch squares of duct tape
  • 1 : 1 inch disk of plastic (I am temporarily using balsa, might use the plywood from the boat)

It should cost you around $10 at home depot. I used a tap on the holes where the bolts were threaded, I don't know if that is absolutely necessary. The duct tape was folded on itself and then cut into a circle. I used the outer diameter of the pipe as the size, the plastic or wooden disk is the inner diameter. I pushed the pipe on anything that needed to be a circle so that I could cut it accurately.

The pump works great (tested in the sink) and really gets the water moving. On the handle I had to drill the hole all of the way through, and then use a 1/2 inch bit to only drill down about half way. Normally a cupboard pull is held from the other side.

For all you haters out there, now at least I won't sink if the boat leaks :-p.


Emma said...

haha the fact that you had to make this shows that you doubt your boat's ability to float as well :)

sstc said...

No, i just like cool (cost effective) technology...

do YOU have a pump?

I think not.

In fairness, every boat takes on water some time in its life. The captain must test the limits of the boat. He/She must find what sea state finally conquers the boat. This pump will aid me in my quest.

Sara said...

can't wait to try it out with you :)

Anonymous said...

I think captains actually try to figure out what "sea state" won't conquer the boat. Semantics sure, in the same way lim x=>0+ and lim x=>0- are distinct...

But yes, bilge pumps are essential. Even light catamarans which could presumably have sealed hulls include several drainage hatches. If man has learned anything during his time on this planet, it is that you can't keep the water out.

One interesting bit of equipment on the 420cm sailboats of GT Sailing's fleet is the autobailer. When moving quickly, one may open the autobailer to use the vessel's forward motion to draw water out of the hull. I fully grasp the reasons why that might not be a good idea for a rowboat, but I thought I would mention it.

sstc said...

The autobailer is a neat bit of equipment. I don't know if it applicable, because it seems to remove water from between hulls, and not from the crew compartment.

Definitely not useful on this boat. But who knows, we could add a mast and make it a sailboat.

Anonymous said...

Well, it's not applicable because the boat probably won't be moving fast enough to draw more water out than it lets in while it's open. It definitely removes water from the cargo and crew spaces... I mean, you can stick your toe in it during a tack if you're not careful.