Anyone Tried Making your own Watermaker?

[Orchidius]

You all make very valid points, and financially it's probably not really viable to make your own system if it's going to be similar in design as the kits on the market today.

My interest in this topic comes from being part of the niche market that was quickly deemed too small to consider developing a product for. Even though this is true, it leaves me with a problem. The small hand-held "survival" watermakers are too cumbersome and slow to get any decent amounts out of, but the "big" electrical systems are way too powerful/efficient/expensive. My main watertank is little over 30gal, I don't have a head/shower with running water and one small sink with a footpump. We live a fairly spartan existence on the boat, but crossing the Atlantic would still require stuffing the boat with jerryjugs of fresh water just to be sure. A watermaker that could supply us with a small source of water to cook and drink in case of shortage without costing as much as I paid for the whole boat simply doesn't exist right now.

From the above I derive the following (correct me if I'm wrong):

- Assembling your own kit from parts you've sourced yourself is a fun project, but not financially viable
- A hand-powered device is such a pain to use for a tiny amount of water it's truly for survival purposes
- A stair-stepper powered contraption still to be designed would not produce the right amount of pressure/flow to make it work efficiently. With the added risk of only producing very small amounts of water as well

Essentially, if the above summary is correct, that would mean I'm doomed to stick to my jerryjugs...?

[s/v Beth]

I've had people tell me I can't do it before. My own parents told me I wasn't smart enough to be a doctor along with lots of others.
Yeah, I think out in the ocean I would probably wash with sea water. How I envision the little device would be a pump that would work when electricity is out, allowing you to make water when you have a battery failure. You don't need much water for survival- 1-4 quarts a day. I had to laugh when you thought 1.2 gph was trivial- all I would need to do is pump one hour a day!
So- naysayers aside, I will go it alone. But if you get struck by lighting out in the Pacific, and have 2 weeks to your port, think of me when your working on your solar stills!

[SV Windrush II]

I'm still with ya Newt, I want a manual backup watermaker also. Lets stick our heads together and make it work!

Sent from my SGH-T999L using Cruisers Sailing Forum mobile app

[Tellie]

Originally Posted by Orchidius

You all make very valid points, and financially it's probably not really viable to make your own system if it's going to be similar in design as the kits on the market today.

My interest in this topic comes from being part of the niche market that was quickly deemed too small to consider developing a product for. Even though this is true, it leaves me with a problem. The small hand-held "survival" watermakers are too cumbersome and slow to get any decent amounts out of, but the "big" electrical systems are way too powerful/efficient/expensive. My main watertank is little over 30gal, I don't have a head/shower with running water and one small sink with a footpump. We live a fairly spartan existence on the boat, but crossing the Atlantic would still require stuffing the boat with jerryjugs of fresh water just to be sure. A watermaker that could supply us with a small source of water to cook and drink in case of shortage without costing as much as I paid for the whole boat simply doesn't exist right now.

From the above I derive the following (correct me if I'm wrong):

- Assembling your own kit from parts you've sourced yourself is a fun project, but not financially viable
- A hand-powered device is such a pain to use for a tiny amount of water it's truly for survival purposes
- A stair-stepper powered contraption still to be designed would not produce the right amount of pressure/flow to make it work efficiently. With the added risk of only producing very small amounts of water as well

Essentially, if the above summary is correct, that would mean I'm doomed to stick to my jerryjugs...?

First, I would personally be hesitant to cross the Atlantic with 30 gals in the tank and another 30-40 strapped on deck. It can be done but "Spartan" is the serious word. Secondly, what is your budget willing to stretch to? Having a small watermaker on a boat your size with the holding capacity you have has been done many times. Having the capability to make your own water on a trip like this can make a huge happiness difference to you and the other person in the "We" you speak of. Taking a fresh water shower every day really adds to the comfort of crossing the Atlantic. Having fresh water coming out of your galley sink is a bonus as well. I believe you are in my backyard. I have a situation where I might have a one time offer on one or two brand new VT150s in about two weeks for $4,500 each. That's about what the 80E goes for which uses twice the power and half the production. It's a very good deal going to someone. 6.5-7.5gph will make a huge difference in your cruising comfort.

[Tellie]

Originally Posted by s/v Beth

I've had people tell me I can't do it before. My own parents told me I wasn't smart enough to be a doctor along with lots of others.
Yeah, I think out in the ocean I would probably wash with sea water. How I envision the little device would be a pump that would work when electricity is out, allowing you to make water when you have a battery failure. You don't need much water for survival- 1-4 quarts a day. I had to laugh when you thought 1.2 gph was trivial- all I would need to do is pump one hour a day!
So- naysayers aside, I will go it alone. But if you get struck by lighting out in the Pacific, and have 2 weeks to your port, think of me when your working on your solar stills!

Go for it Doc If you build it they will come.
But I carry 200 gallons of water on my boat which is topped off every other day out at sea by my watermaker. If I take a lighting strike and I'm two weeks from port I still have 200 gallons to see me through. Think of me when you're pumping away every day for an hour.

[colemj]

Originally Posted by Orchidius

From the above I derive the following (correct me if I'm wrong):

- Assembling your own kit from parts you've sourced yourself is a fun project, but not financially viable
- A hand-powered device is such a pain to use for a tiny amount of water it's truly for survival purposes
- A stair-stepper powered contraption still to be designed would not produce the right amount of pressure/flow to make it work efficiently. With the added risk of only producing very small amounts of water as well

Essentially, if the above summary is correct, that would mean I'm doomed to stick to my jerryjugs...?

It can be financially viable and save you money to assemble your own. You will need time to hunt auction sites, comb through clearance sales, etc. Even if you don't do that and just buy off the shelf retail, it will still cost you less - just not much less. Of course, your time is counted free in all of this.

One problem with the stair-stepper, etc approach is that it will be difficult to use when on passage. Particularly if you have a small monohull. I can't imagine the space or balance or energy needed to go at one for a couple of hours while in the middle of an ocean passage.

Mark

[colemj]

Originally Posted by s/v Beth

I've had people tell me I can't do it before. My own parents told me I wasn't smart enough to be a doctor along with lots of others.
Yeah, I think out in the ocean I would probably wash with sea water. How I envision the little device would be a pump that would work when electricity is out, allowing you to make water when you have a battery failure. You don't need much water for survival- 1-4 quarts a day. I had to laugh when you thought 1.2 gph was trivial- all I would need to do is pump one hour a day!
So- naysayers aside, I will go it alone. But if you get struck by lighting out in the Pacific, and have 2 weeks to your port, think of me when your working on your solar stills!

I don't think anyone is telling you it is not possible, they are telling you it is not practical.

To summarize, you wanted to build an inexpensive manually operated watermaker instead of buying the expensive small electrically operated ones. Now you qualify that with only needing it for survival conditions (BTW, if your batteries are out, won't you be too busy with that sextant, sight reductions and steering to make water?).

For survival conditions, Pur makes a manual unit that makes 1qt/hr. It costs $1,000 USD. If you want to build one, in addition to the motive mechanism and pressure amplifier, you will need to convince someone to make you a single custom membrane to work for your application. It is highly unlikely - I will bet impossible - that you could put such a machine together for less than $1,000 - even if you had 10 others wanting one, because 10 is not enough for a volume discount on custom manufacturing.

Turning to an inexpensive manual replacement for an electrical unit, someone suggested hooking two Pur 35's up to a stair stepper. The Pur 35's sell for $2,700 USD, so two of them will cost you as much as a single higher output electrical unit - and you haven't bought the stair stepper or any of the additional mechanicals needed for the conversion.

If you try to roll your own Pur 35 to hook to your stepmaster, you will run again into the problem of custom manufacturing - you simply cannot make your own special size, special flow membranes. And unless you have a full machine shop and volume breaks on raw materials, you will need to rely on custom manufacturing for the pressure vessels, endcaps and pump mechanics too.

This just is not a well-thought out plan. It is no way comparable to you getting through medical school in spite of someone thinking you couldn't. Here, it is a lack of understanding of watermakers, how they operate, and what is required. Your med school example was just a lack of someone else not understanding you.

But please do prove me wrong. I will be very happy if you do, because it will truly be a breakthrough in water making.

Mark

[a64pilot]

Just carry a little Honda. I bet it would still work after a lightning strike

[SV THIRD DAY]

Originally Posted by s/v Beth

I've had people tell me I can't do it before. My own parents told me I wasn't smart enough to be a doctor along with lots of others.
Yeah, I think out in the ocean I would probably wash with sea water. How I envision the little device would be a pump that would work when electricity is out, allowing you to make water when you have a battery failure. You don't need much water for survival- 1-4 quarts a day. I had to laugh when you thought 1.2 gph was trivial- all I would need to do is pump one hour a day!
So- naysayers aside, I will go it alone. But if you get struck by lighting out in the Pacific, and have 2 weeks to your port, think of me when your working on your solar stills!

$2200 for your life raft...we have one in our ditch bag.
Of course I'm a cheap cruiser just like everyone else...so we bought a used one off Ebay and installed new membrane. I have my son give it some pumps and then pickle it every 6 months but sure hope to never really need it!
PUR Survivor 35 LS Manual Watermaker

[s/v Beth]

Rich, you have one of these. Is the hand pumping by compressing the lever towards the membrane? Does it spring back or do you have to force it up too? Seems like you could put it on a wheel mechanism attached to a couple of pedals....
Anyway, got my work cut out for me. I will not beat this dead horse further. My wingman and I will discuss it over a meal at Nanaimo.

[SV THIRD DAY]

Originally Posted by leightonyachts

Thanks for all the good input Rich,

After checking out your website, models and prices. I am now struggling to legitimize building my own, considering I can purchase a RO unit for about $4k, I just cannot afford other models that I have seen for $6-10k.
I appreciate you keeping your prices down so that it makes it more reasonable to purchase.
The only thing I was wanting is a DC powered unit so I can run it off my batteries instead of a Inverter or my Diesel engine.

I plan on having a lot of solar, wind and water power generation on board that I believe can keep up with the batteries on a good day while my watermaker is running to fill up my 200 gal fresh water tanks.

Can you change out the AC motor to a CD motor? I see that Lesson makes a 12v 1hp DC motor

Buy 12 Volt Electric Motors | Replacement 12v Electric DC Motors

Thanks!

Ah...yes anything can be done but the question is will you be happy with it? We do have some clients that asked us to swap out the 1.0Hp AC Motor with a 1.0Hp 12v DC motor and the client gets what the client wants so we did it....BUT.......

A 1.0Hp motor will use 80A...yes 80A of DC power. I don't know of any cruising boats without lithium Ion batteries that can really run a 80A DC load off of their batter banks with wind and solar. Sure it works on paper....but I've been out cruising with folks that went this approach and they end up having to run their engine and high output alternators every time they want to make water. They just can't do it from their 900AH battery bank off wind and solar.

So 80A is a killer, then why not cut the power in half from a 1.0Hp down to 0.5Hp and cut the Hp pump volume in half as well to cut your fresh water flow rate down from 20GPH to lets say 10GPH. Well that unit will still use 40A....and honestly, I know that just won't work well out in the real world of cruising. There are some water maker companies out there (SK Watermakers, Echotec Watermaekrs, and US Watermakers) that do offer this type of 12v option but unless you want to lock yourself into always running your motor and alternator to make water...the non-energy recovery piston pump water makers just don't make sense in 12v.

leightonyachts If you want 12v powered water maker by wind and solar....well....this is where an energy recovery water maker like a Spectra really kick ass frankly and I point clients in that direction all the time because I know they won't be happy trying to run such a huge load from their battery bank. Since 99.999% of Build It Yourself water makers are using non-energy recovery piston pumps....they are all either AC driven or Engine driven by an clutch.

[SV THIRD DAY]

Originally Posted by s/v Beth

Rich, you have one of these. Is the hand pumping by compressing the lever towards the membrane? Does it spring back or do you have to force it up too? Seems like you could put it on a wheel mechanism attached to a couple of pedals....
Anyway, got my work cut out for me. I will not beat this dead horse further. My wingman and I will discuss it over a meal at Nanaimo.

Absoutely....the handle needs "up pull" as well as "down pull" to keep an even pressure on the unit and water dribbling out of the tube. Newt...they also already sell a 12v motor to electrically work this unit. It's like another poster commented...if there was a market....builders would build it. I was talking to Ray with Spectra at the Oakland Boat Show (he's a very nice guy) and he commented that more and more of their sales are for the larger output water makers and certainly all of our 20, 30, and 40 GPH water makers fall into that caregory.

Here's the problem....it doesn't cost that much more to make a higher output water maker than it does a low output water maker and the cruisers of today are not interested in showering once/week with a hudson garden sprayer. They want the comforts of home out on the water. We can debate this style "right or wrong" all day long...but as someone who supplies gear to the cruising community, I make a living by giving people what they want and that seems to be higher output water makers.

[Tellie]

Originally Posted by s/v Beth

Rich, you have one of these. Is the hand pumping by compressing the lever towards the membrane? Does it spring back or do you have to force it up too? Seems like you could put it on a wheel mechanism attached to a couple of pedals....
Anyway, got my work cut out for me. I will not beat this dead horse further. My wingman and I will discuss it over a meal at Nanaimo.

Here's a quick thing to discuss over a glass of wine or two. Think rock and roll stabilizers.

[SV THIRD DAY]

Originally Posted by Tellie

Here's a quick thing to discuss over a glass of wine or two. Think rock and roll stabilizers.

I love it...tie my rocker stopppers into powering a water maker pump....
We BOTH may have already had too much wine today...

[Tellie]

Originally Posted by SV THIRD DAY

I love it...tie my rocker stopppers into powering a water maker pump....
We BOTH may have already had too much wine today...

I was wonder if someone would pick up on it. Of course the more wine the more Rube Goldberg it gets.

PS Ray had better sung my praises.