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foggysail · 01-10-2010, 17:42

Has anyone checked the prices lately for things such as Catpump's 7070 back pressure regulator??? Oh, the new Cat number is 7370 for those interested. The latest quotes I received today included one listing the price near $1000!!! Another wants almost $400!!! WOW! Maybe the $400 is a bargain and I just fail to see it as such. I am looking for a workaround.

Also the prices I get on pressure vessels (2.5X40) are all near $400 each! Well, not giving up, just looking harder. And I thought the membranes would be expensive??? They are cheap by comparison.

Foggy

**Tellie** · 01-10-2010, 17:59

Quote:

Originally Posted by foggysail

Has anyone checked the prices lately for things such as Catpump's 7070 back pressure regulator??? Oh, the new Cat number is 7370 for those interested. The latest quotes I received today included one listing the price near $1000!!! Another wants almost $400!!! WOW! Maybe the $400 is a bargain and I just fail to see it as such. I am looking for a workaround.

Also the prices I get on pressure vessels (2.5X40) are all near $400 each! Well, not giving up, just looking harder. And I thought the membranes would be expensive??? They are cheap by comparison.

Foggy

Don't forget to value your time. You should keep a good record of time, both hunting down the parts and the amout of time spent researching. It is a real cost when considering how cheap is cheap.

foggysail · 02-10-2010, 07:47

True Tellie, but there are times when I have more time than money.

Foggy

capt_douglas · 02-10-2010, 07:59

The cost of making your own water is not inexpensive. We send out cat pumps out to be rebuilt unless the pump's too far gone. Salt water at very high pressure is incredibly corrosive.

We paid $250 for the 7070 back in 2004, so maybe the $400 one isn't such a bad deal.

foggysail · 02-10-2010, 09:34

Yeah--- you might just be right Capt. Heck, its only money. As to the watermaker, I am tracking my material costs, more later on that as I get deeper into the project. And the pump! I am going with brass and yes, I agree SS is preferred. But there are good reports, even in this thread about brass as long as they are flushed and the membrane requires flusing anyway.

So far, I am having a lot of fun getting the project started. Next is to bite my wallet on pressure vessels ater purchasing the back pressure regulator.

Foggy

capt_douglas · 02-10-2010, 09:56

We looked at brass and SS and eventually decided that brass was better in that most machinists and welders would be willing to consider repair of brass over SS. Considering the work the cat pump does I'm surprised they last as long as they do. When you consider that watermakers are about 20% efficient (1000gal of water to produce 200gal of product), it's even more amazing.

FWIW, I worked for a time on a private island and we had a 5000gpd watermaker. It was a monster with 8 12"x6' membranes and a 4-port Cat pump. We had a brass and stainless cat pump. We got a couple repairs out of the brass pump but most of the time bought a new SS pump as no one would warranty the work. The SS pump case would last about twice as long as the brass so the comparative costs were about equal. You'd look inside the pump and see how pitted 850psi salt water could affect top shelf stainless and shake your head.

We drove the 20hp 3-phase motor from redundant 30KW gensets. The rest of the estate ran on redundant 200KW gensets so the small water maker pumps sipped compared to the big gensets. But hey, it's only money (and 5000 gal of diesel/month).

The ads tell you about product water production and power requirements but seem to neglect the amount of water needed to produce the volume of product water. And the supply water has to go through the LP and HP pumps to get to the membranes.

**Tellie** · 02-10-2010, 10:27

Agreed time can be very cheap. But it is relative. When I built the first two water makers for my boat I was not working, so I had an abundance of time. I found the time spent researching, hunting down parts and constantly redesigning them to fit my boat and my needs was a lot of fun. When I was working full time the total build time would have been streched out a long time. If I calculated the hours invested, then compared them to my then hourly rate and material costs, I could have easily bought a water maker ready made. But where's the fun in that? Of course I have to admit that I am from the Tim Allen school of DIY, bigger must be better. That mistake cost me a few doallars. I refined the second unit to better suit the nature of all water makers. They like to be run for longer periods of time. Dumping product and larger amounts of flush water over board was a waste of precious energy and a bit embarrasing. Another mistake I made was bragging to my boat friends and showing off my contraption. I was forced by beer into agreeing to build two more. The fun started to wear off a bit when my friends could not keep the secret from their friends. So when you get your water maker up and running I will be passing your name around to take the pressure off of me<grin>

foggysail · 02-10-2010, 15:15

The last two are GREAT POSTS!!!

Each contain important, real life experience and advice which is just what I need to help steer through this journey. I AM HAVING FUN! Even little things such as fabricating a keyed collar to fill the void between my motor's 16mm shaft and the 28mm female shaft on the pump. That should be completed this coming week. I ordered a 2" keyed coupling that will fit the motor shaft. It should arrive around Wednesday or Thursday. The plan is to turn the outer diameter to 28mm and cut a key way using my lathe in the basement. My machinest Son will be big help on that task.

I expect many more of these simple show stoppers as I get further into the fabrication. And yes Tellie, I believe we should all have fun even my friends. At this writing, the plan is to build enough for me and not deny my friends of the same experiences.

Foggy

goboatingnow · 02-10-2010, 17:09

Quote:

Don't forget to value your time.

No Tellie, ones leisure time does not have a monetary value. I always find this "opportunity cost" basis of ones time to be a nonsense debate. if you are displacing paid productive work then it might have a point, but most people have a salaried existence with little opportunity to significantly expand their take home pay, and thats not accounting for why you would want to work all the hours god sent. Their leisure time is given at 0$ cost.

Dave

**GordMay** · 03-10-2010, 11:07

I’m not certain that most people are salaried.
Notwithstanding, as Dave notes, leisure time shouldn’t be “costed”.

Why Hourly Wage Earners Are Happier Than Salaried Workers

➥ Why Hourly Wage Earners Are Happier Than Salaried Workers - DailyFinance

**Tellie** · 03-10-2010, 12:18

Hence the word "relative".
It is not uncommon in the world of preparing boats for cruising that a person believes "I'll get it all done in my spare time" Then for many they quickly come to realize that the season/departure date is upon them quicker than they thought. It's where old phrases like "Biting off more than you can chew" come from. Sometimes the valuation of your time becomes very important when it is wasted on getting the smaller things done when the larger things eat holes in your pocket. It's been the cause of more than one dream rotting at the dock

foggysail · 03-10-2010, 12:19

Gord--

I will not take a position on time. Tracking time though helps if one has aspirations to build many. It could provide a base for cost analysis. Other than that, heck I waste more time listening to Wifey complaining "will you stop wasting time!"

Foggy

foggysail · 03-10-2010, 12:25

Quote:

Originally Posted by Tellie

Hence the word "relative".
It is not uncommon in the world of preparing boats for crusing that a person believes "I'll get it all done in my spare time" Then for many they quickly come to realize that the season/departure date is upon them quicker than they thought. It's where old phrases like "Biting off more than you can chew" come from. Sometimes the valuation of your time becomes very important when it is wasted on getting the smaller things done when the larger things eat holes in your pocket. It's been the cause of more than one dream rotting at the dock.

Tellie--

My Brother worked with a mechanical engineer in Florida who built his own 55' aluminum sailboat. He did all the fabrication and assembly including welding. Every few years I checked his progress. After 20 or more years of construction, using every available hour including weekends and vacations he had to launch it before the rigging and inside finish were completed. The lot where he did his construction was sold, he was evicted.

Take longer than planned????? RIGHT ON!!!

Foggy

**Tellie** · 03-10-2010, 12:40

Quote:

Originally Posted by foggysail

Gord--

I will not take a position on time. Tracking time though helps if one has aspirations to build many. It could provide a base for cost analysis. Other than that, heck I waste more time listening to Wifey complaining "will you stop wasting time!"

Foggy

LOL I think I married her sister