impellers?

No, just see little reason to suffer fools and don't mind pointing out idiocy when it is posted as advice or fact.

If you have experience or knowledge to contribute to those who feed and care for centrifugal pumps, jump in, but if all you have is a silly ditto perhaps you should look at what lies behind your own contribution.

Are you still smarting over the diesel efficiency thread? Get over it and move on.

You can argue the legality of that with the marina while they stop referring work to you and tell you how they set the rules on their property. Then they begin to hassle the boat's owner for a copy of his liability insurance covering you as mechanic. As I said before, the closer you come to being a full-time captain or engineer (his regular captain or the vessels manager, etc.) the further they'll generally let you go and I think most captains can figure out where the line is, but if they think you're taking work away from them things will get tense. Instead, I just keep a book of who's good in different fields and get the right people. Why pretend I'm a more than a shade tree mechanic when others are better. I'd rather save the hassle, do the job I was hired for and get the owner and the marina properly taken care of. Now, I have a couple of marinas that I've known for 30 years or more and I'm sure they'd let me do anything I wanted, but generally I figure every man to his trade.

I have been asked more than once to work on others boats, not help but do the work.
My reply is always " I don't take work from the yard "
Partly because the yard is a good group of capable people but mostly because I don't want to work on every tom dick and harry's boat.

There's a sign that I've seen at virtually every marina "Contractors must check in at office".

You can "point out idiocy" and "suffer fools" without being the an ogre. Few want to listen to advice from a person with such uncouth angry words. The forum and yourself would be better if you lighten up.

Hi,

When your Mama has repaired the rips in you nightie and got your toys back in the cot maybe you could spend a few minutes and read the earlier posts in this thread before making such a statement.

Marmot is a very knowledgeable poster. He like many other professionals doesn't bear fools lightly. If you take offense at his words then maybe you should look at another field of interest yourself, all he did was point out some misleading info from a previous poster.

Inaccurate and misleading info posted in threads that are read by others looking for info/support just creates confusion and wastes time and money. It does not enhance the credibility of this Forum where many people contribute valuable info for the benefit of others.

. Changing a Racor would certainly fall into the 'anybody can do it or emergency repair' catagory. I was referring more to the cap that runs the boat on occassion. He shouldn't be changing pumps or doing serious mechanical work.
Up here every yard has mechanics in house or have certain ones they have a relationship with. Anybody new coming onto their property needs the OK of the marina or they'll find themselves persona non grata.

The sarcasm has on occassion gotten a bit out of hand and uncalled for, but we're all big boys here. I must say that in recent months there seems to be a visable effort to tone that down and I think that has helped turn more lurkers into contributors. Sometimes though it is hard for a sarcastic SOB like me to resist the urge to write 'Yo S... for brains what are you thinking', but I remind myself that it may well come right back at me the next day. TV commercials are geared to a 3rd grade level because that's the average intelligence level. Even the news is put into 30 second sound bites because that's the average attention span. Pitiful though that might be. Anyone looking over the threads will see certain people I will never be best buds with, but that's not why I'm here. Like most I'm here to learn and teach. Sometimes that's done by bouncing ideas (good, bad, sometimes rediculous, and sometimes obnoxious) off each other. I for one hope all those thoughts and ideas keep coming (tempered with thought and consideration).

Giving out advice, correcting improper statements, sharing knowledge and experience are all forms of teaching. Teaching and being a jerk is decidedly less effective than teaching and not being a jerk. Simple as that.

"Apparently not." Marmot tapped into the reply box in one of his increasingly rare expressions of sarcasm.

I can live with that as it doesn't bother me as much as bothers you.. Please refer to post #32.

Comparing a Globe Impeller to the "others"

Gentlemen,

I try any peek at these forums once a week or so to keep abreast of things from a different perspective. This may be my first post, but I'm not really sure of how I should as I kind of lost my focus reading this thread because of all the politics involved......But I'm going to give it a try anyway.... If you want to hang me, that’s fine—I can’t handle it..

Did anyone actually answer the question about whether Globe impellers are any good? If it was answered, I guess I missed it…………I can certainly see if the wrong answer pops up what can happen, but I will relay some personal experience with them under actual use and with reasonably controlled testing.. Keep in mind that this is only what we experienced, and may or may or be reflective of similar experiences of actual use in other situations..

Maybe 15 years ago we had our first direct experience with a Globe impeller.. We were called in on a job that the owner was complaining of intermittent over heating issues. All would be fine for a while and then a quick overheat, and then it would be fine.. After spending a few hours looking at this and that & doing some testing, we removed a recently installed new Globe impeller that was installed about 2 weeks earlier after a 2 year old Sherwood impeller in a Cummins 6BTA 5.9 had bit the dust.. The globe impeller looked as new, but after installing a factory neoprene based impeller, the problem disappeared.. Because of the design the Globe impeller, it would loose prime at times and we surmised it did not conform well with the used and slightly worn surfaces Sherwood pump cam or inner wear plate..

Over the next few years, we saw a few similar issues and heard of more with the Globe impellers ( priming and / or flow issues using a polyurethane compound based impeller) but then about 3 years ago, we got involved in the design of a “dry run system” that needed to be developed for the U.S. military.. This is what happened over a six month testing period.

I need to keep this very basic from here on, but a new type “system” needed to be designed that would allow a typical marine engine using a rubber impeller seawater pump for a main part of the aux cooling system to run dry for minutes at time, both before and after a “mission” and not create any other issues with a factory cooling system on the very high performance engines that the military required…We are talking of engines in the 5-12 Liter class with maximum HP levels above 70 HP per liter………

To be sure, the “dry run” Globe impeller was tested many times (it seemed like a simple solution to a requirement that had to be met), under many different conditions, but was discounted due to two main reasons.. First, the impeller during normal operation would not pump the required water flow to keep the engine cool at higher cruise RPM’s or WOT operation, although the “factory impeller” had no issues along these lines… But even worse was the fact that after running dry for a few a few seconds or minutes, it could not be counted on to “Re-Prime” when the high speed crafts were launched into the water.. But yes, the Globe impeller could run dry without burning up, but without all the other needed conditions that needed to be met ( like pumping water, or enough water to meet requirements) , using them could not be considered… A completely different approach was finally developed that met the needed requirements and is still in Beta testing today two years later..

Anyway, this is what we have seen and worked with first hand.. Take this experience for what is worth as to their effectiveness and whether they will be right for your application..

Tony

Hi,

SBMAR- Thanks for sharing your practical experiences and knowledge with everyone here.

Thanks for posting back with your results to date. Don't worry about the fire, all you need is a pump with a good impeller to keep it under control

Now I get it, Polyurethane is just more flexible than the stock neoprene and won't conform to the pump housing at high load/speed.

Ahh, why wouldn't you just change the stock impeller every year and quit worrying? It's way cheaper than a re-power.