Spectra 380C recommission questions

[Tellie]

Originally Posted by GRIT

I've seen first hand the problems caused by corrosion of the NB fittings, and it cost me a small fortune on my 2 year old pump. I now have a spectra rebuilt pump, but it has the bronze fittings too.

Would you sell a kit to change these fittings to stainless Steel? And maybe even the flexible stainless flexible pipe you prefer?

I have a cape horn extreme, and would be very interested in purchasing such a kit.

Thanks.
Paul.

Hi Paul,

No problem. The fittings are a bit spendy but a lot less than a rebuild and it will solve a lot of future issues with the Clark pump saving even more. The flexible hp piping is not SS but flexible tubing and we stock plenty of it. If you change out the fittings to SS you don't need to change out the SS tubing. Not to do business here on the forum, here is my E-mail address. Please feel free to contact me there as well. Talk soon.

HaldenMarineService@yahoo.com.

[GRIT]

Thanks Tellie. I sent an e-mail.

I'm sure there're plenty of folks who are interested in knowing there's a solution to the corrosion problem.

Thanks so much for all your contributions to the forum.

Cheers.
Paul.

[Capt.Don]

Originally Posted by Tellie

....I have seen Clark pumps destroyed within two years due to the damage from corroding NB fittings. These are after the prefilter and when this corrosion starts to flake off it gets into the cylinders and pistons plus a host of other moving parts inside the Clark pump and scores these parts thus losing compression and requiring a re-build of the pump....

FWIW - I just went through this with my 3 1/2 year old Clark pump.

Towards the end of the spring sailing season, our Ventura 200 stopped making potable water and showed asymmetrical pressures. Through a series of incremental replacing parts and retesting, I'm of the belief that the nickel/bronze fittings corroded, bits of rust flaked off and scored the annular rings. Oddly, the HP tubes also corroded around the ferrules and I had trouble resealing.

I've since replaced the annular rings, spool valve, the two HP stainless tubes, a few o-rings and 4 of the nickel/bronze fittings. Unit tests well in my garage w/artificial ocean and hopefully will work as good as new once on the boat.

I debated whether to replace the nickel/bronze fittings with stainless. Since I was working under a bit of a time crunch, I didn't want to introduce new variables into the system while diagnosing and testing. Now that everything's back in order and I'm more comfortable with the pump, I may reconsider replacing the fittings, though I've got a couple of years before I worry about this.

A few other comments. Spectra support was great. Spectra parts are very $$$$$$$. Because of the corrosion, I'm thinking about removing the nickel/bronze fittings after each season when pickled/stored - thoughts?

I would recommend that anyone who relies on their Spectra watermaker to go through the process of disassembling and rebuilding the Clark pump. The pump is very elegant and pretty easy to work with.

Don

[GRIT]

We installed our Spectra in the spring of 2020, and used it without issue for nearly a year.

Good friends of ours have been using their spectra for 20 years without issue. They have the stainless fittings, and they never rinse their unit, but make water every day.

After talking to them, and several folks on this forum with similar experiences, (there's a thread about it), and the fact that I never had to rinse my Village marine unit on our old boat, I decided I didn't need to be so finicky, about flushing every drop of salt water out of the system.

I ran my flush for about half the time as I had previously, until the pressure gauge read just above 3bar, instead of just under 2.5 bar, as we usually did, then shut it down. This (I thought) would save me some water from the tank, as we only had a 200l tank, and flushing was using 40l or more on a 4 minute flush.

See the results of not flushing enough, after only 6 weeks, below.

We replaced the worn parts, and it worked fine, for a while. Eventually the asymmetry returned with a vengeance, with no flow on one side at all. We think there was still debris in the lines somewhere, that had worked it's way back into the system.

Frustrated, we ordered an exchange unit. You pay $3500, and they send you a new clark pump, which you exchange with your old one. You then send the old one back, and they refund part of your deposit. In our case, $2200. I assume the refund depends on the condition of your returned unit.

It's a great option, as we'd have been stuck at marinas trying to get water every few days, due to our small tank. (Our boat is still "in build", and we only had a 200l tank.) We now sport 400l, in two tanks! Posh!

We're back to flushing down to 2.5 bar, and will consider installing a salinity tester on the brine discharge, and rinse until we reach 1000 ppm.

I've placed an order for the stainless fittings from Tellie, and will have them installed in record time, and be glad to be rid of the crappy ones that act more like brass than bronze.

Cheers.
Paul.

[Capt.Don]

Paul,
The Spectra support folks told me that the corrosion was due to not flushing long enough. I disagree with them. We always flush 2 1/2-3 minutes after each use, which uses 1/5'th of our water production. They also told me that the system is sufficiently flushed when the salinity drops below 1000ppm. In my garage testing, my flush was less than 1000ppm in about a minute (will retest back on the boat). I don't believe flushing will solve this problem.
Don

[GRIT]

That may be true, as 6 weeks is a very short period of time for real bronze to look like that did. Perhaps it started right away, from new. Though I have a hard time thinking it's any kind of electrolysis, as:

The batteries, inverters, deckwash pump, electric toilet, and all our instruments are in the other hull, 20 feet away, and we only go to marinas in Canada for July Aug, and we don't have shorepower.

Either way, I've ordered the stainless fittings from Tellie, and I'll be glad to have them.

I took this up with Spectra at the time, and they insisted that the fittings were designed for their purpose, and that I couldn't use Stainless (as Tellie mentioned, they disagree on that point). I've already spent over $2000 on repairs/replacement on this 2 year old unit, and the stainless fittings is my last kick at the can for having a reliable Spectra watermaker. If I have to do any more repairs, I'll sell it, and build my own; which was my intention from the beginning.

I should add that Spectra was very helpful throughout, and even sent me new pistons and annular rings when I had my first failure. But the best aftersales service in the world isn't worth having my watermaker fail in the middle of nowhere, and force me to drink coconut water until I get back to civilization.

I've been rinsing the new unit religiously, and have owned it for about 6 weeks now. When I get my stainless fittings from Tellie, I'll install them, and inspect the bronze ones. If there's even a hint of corrosion, I'll know it's nothing to do with rinsing.

Cheers.
Paul.

[Tellie]

Flushing is not the solution. Replacement with all SS "IS" the answer.

[GRIT]

I've just replaced my fittings with stainless too.
The bronze fittings corroded in less than 3 months, again.. this in a factory rebuilt Clark pump.

If someone started a class action suit, I'd sign right up. So far, in addition to the purchase price, we've spent $2200, on repairs, in 30 months.

Those bronze, but probably really brass, fittings are just not suited to the marine environment.

Yes, we do rinse our unit after every use, until I'm making water at 2.4 bar. I had measured this to be 1000 ppm out the brine, but I'll have to recheck those numbers, and I'll be documenting it on video.

After having helped to repair several units last winter in the Bahamas, I can say for certain that I'm not alone in my frustration with Spectra.

I had mine for sale here on CF, but had to remove it after I opened it up and found more corrosion and some internal damage resulting from corrosion debris flowing through the unit.


Cheers.
Paul

[GRIT]

A quick question for Tellie, if he's willing.

I just changed all my bronze fittings to the stainless one's Tellie supplied. Thanks Tellie.

Upon disassembly of the Clark pump, when I removed the cylinders, two of the "speedy sleeves" in the main pump block came out enough that they protruded from the block about 4mm each. Are these supposed to be bonded into the block? Or do they expand when the bolts are tightened? I inserted a bolt, and tapped them back in.

I ask because if they're supposed to be bonded (on my 3 month old factory rebuilt pump), I'd like to have them re-bonded. Otherwise, the remaining two bolts will take the lion's share of the load, and will likely fail early.

The cylinders had to come off the pump housing, because the two bronze fittings fitted to the square part of the cylinder (the base) were on so tight, I had to build a jig to hold them, while I fought with a big wrench to get them out. They seemed to be bonded into the block, as they turned hard all the way to the end; even though they have rubber o-rings on them, they were incredibly tight in the block.

Thanks for your help in advance.

Cheers.
Paul.

PS
Those photos (in my previous post) are of the fittings on the membrane housing, the rest of the fittings looked in very good shape, not new looking, but no debris hanging off of them.

[GRIT]

For those still reading this thread. I said I'd measure the salinity of the brine after rinsing, and here are my results.

I rinsed for 1 minute (both pumps) until the pressure dropped to 2.5 bar. I then shut down one pump, and after 6 more strokes of the clark pump, bringing the pressure to roughly 2.4 bar, I measured the salinity of the brine at 920.

That settles the salinity claim of 1000 ppm which Spectra claims is the cause of the corrosion. I'd say it's a pretty sure bet the salinity was below 1000ppm.

What's making these fittings corrode? I have no idea.

Tellie, could you tell me about the inserts mentioned in my last post? Are they pressed in, glued in, or do they expand when the bolt's tightened?

Cheers.
Paul.