Loss of Prime with new impeller

[Steve S.]

I went to the Blue Globe impeller this year in my Oberdorfer and it is causing problems.  I just can't seem to keep a prime.  I checked all the hoses, the seal on the strainer, use new gaskets, and even sanded the face plate of the  pump to a mirror shine.  This is what happens:

I open the seacock at the dock, start'er up and everything is fine.  I head on out and shut her down as soon as the sails are up.  I don't close the seacock again.  Go for a sail and head back usually 4-5 hours later.  (By the way, the wind on the Chesapeake has been fantastic this year, haven't hit a day below 8 knots,  15-25 knots last weekend, 10-15 today, I'm waiting for the payback.)
When we start'er up to head home, the prime is gone.  My wife goes down to the seacock and opens and closes it real fast 2-4 times and the prime comes back.  This never happened with my old rubber impeller, never lost a prime in 5 years.

I still have last years rubber impeller and I am going to install that next time we go out and see if the same thing hapens. 

Anybody else ever have this problem?   

[Ron Hill]

Steve : If everything you say you checked is OK, you've got a mystery!!
I've used Globe impellers since 1990 and it isn't the impeller.  Are you sure that your gasket is "paper thin"?  If you have a grove on the inside of the face plate you need to take it to a machine shop and have it refaced or order another one from DEPCO! 

[Randy Stolze]

  I know this is a reply to an older post (6/06) but I just experienced the same loss of prime problem with the globe impeller.

  I installed the impeller in April and it functioned fine all season. Yesterday when I was on the hard it would not draw the antifreeze up out of the bucket. Upon close examination of the impeller I found that the drive shaft was spinning inside the impeller. The nylon center that Globe uses had weakened and became oblong or out of center. This is really too bad because the impeller vanes looked like brand new. If Globe  puts a metal hub in their impeller it would solve the problem.!

  I am going to cover the boat tosay for the Winter...

[Ron Hill]

Randy : If what you say is true, you got a bad impeller.  The Globe impellers that I've seen/use DO have a metal insert with a flat side to match the shaft.  That insert is bonded to the rest of the impeller.
I'd give them a call at(781)681-6800 and talk to their customer service!

When I winterize I close the thru hull.  Then take the raw water hose off of the closed thru hull and put my thumb over the hose end until I put the hose in the jug of antifreeze.  Then start the engine and watch the antifreeze get sucked up. 
Do the same when you clean the strainer by keeping the hose up so you don't loose the prime.  That is a big "head" for that pump with ANY kind of impeller to overcome.
A thought.