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Raw water strainer, repair or replace?


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I have an old brass Perko strainer on my boat, one of the tie rods has broken, and it's generally looking a bit old. I can probably repair it, Perko want a comedic $175 (WTAF!!!!) or so for 4 tie rods and a handful of nuts, or I could just get some threaded rod and make my own for about $35. Or, I could rip it out and replace with a modern plastic one for about $50.

I'm leaning towards the latter option, what say the peanut gallery?

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I would take some time and clean up see if there is any wear or corrosion under the scale.  If not re gasket make some new bolts and get another 20 years.  The plastic ones can get brittle on the cap and threads.  Just use 316 SS all thread with nylock nuts and put adheasive heat shrink on the threads between the flanges.  If you want to get super fancy and your dimm are very accurate use acorn nuts and red loctite.

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Been there, done that. Well worth the trouble. Don't forget the clear lacquer to keep her pretty. The backlighting wasn't strictly necessary but I was tired of squinting to inspect the basket and/or trying to locate the missing flashlight.

Before:

large.440467749_2018-08-2311_50_58.jpg.36c5e98533fda81d99bc335383388c85.jpg

After:

large.1342272745_2018-09-0715_31_19.jpg.48e47c16e3972fd03f42f6957591a80a.jpg

 

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^ Beware of the bronze close nipple in your discharge.  Had two from Fisheries rot out due to errosion in our setup after only a couple years. The other pipe fittings seem fine but I think they may have had some poor quality pipe nipples come through.

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1 hour ago, SASSAFRASS said:

^ Beware of the bronze close nipple in your discharge.  Had two from Fisheries rot out due to errosion in our setup after only a couple years. The other pipe fittings seem fine but I think they may have had some poor quality pipe nipples come through.

Thanks for the heads up. I did this job a couple of years ago and got all the parts from Fisheries. How long ago did you purchase your parts and do you remember the brand?

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Fix the one you have or get a bronze replacement - the plastic ones are shitty.

I did this last year to one I picked up at the wrecking yard.

The set of new seals was about $40 but that was the only cost.

Strainer 1.JPG

Strainer after.JPG

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Istream, not sure quite a few years ago was part of the big refit project so lots of time delays. Looking at the pic again I see it's a cast fitting so you're probably ok.  It's possible some of the generic stuff they have come through is just red brass.  The groco and buck Algonquin stuff we put in have held up fine.  I saw a little stain on the discharge where I had a "T' for shaft seal cooling, pulled the whole thing out to clean disassemble and re seal it was only hanging on by 2 threads each side.  A cast fitting would have probably been ok but I needed a close nipple to hit the target.

In a perfect world I would try to move your strainer some to take the load off that hose, the sweep 90 is a good improvement.

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14 minutes ago, SASSAFRASS said:

t's possible some of the generic stuff they have come through is just red brass. 

Yes, I've seen that. "Are you SURE it's bronze?" 

Mr Chandlery man "Pretty sure"

"Thanks I'll look elsewhere".

The two allloys can be hard to tell apart visually

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It's a tough one, I should have known better for sure. The cast stuff of a known brand seems to be safe.  I seem to remember Pete at the PT foundry telling me some way to check but can't think of it now, maybe file or scratch test?  But then you are buying it one way or the other.  Trying to find bronze in Z-town MX not so easy.  Ended up using sched 40 galv to get going, also on the needs to be changed list...

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45 minutes ago, SASSAFRASS said:

Istream, not sure quite a few years ago was part of the big refit project so lots of time delays. Looking at the pic again I see it's a cast fitting so you're probably ok.  It's possible some of the generic stuff they have come through is just red brass.  The groco and buck Algonquin stuff we put in have held up fine.  I saw a little stain on the discharge where I had a "T' for shaft seal cooling, pulled the whole thing out to clean disassemble and re seal it was only hanging on by 2 threads each side.  A cast fitting would have probably been ok but I needed a close nipple to hit the target.

In a perfect world I would try to move your strainer some to take the load off that hose, the sweep 90 is a good improvement.

Thanks, I went back and looked up the order and it's a cast Groco nipple so I'll give it the benefit of the doubt. I agree that the sweep 90 was a good upgrade but even better was to replace that POS brass elbow on the outlet with the bronze elbow that was originally on the inlet. I kept having nightmares of that brass elbow rotting from the inside. Once I got it apart it turned out to be in fine condition but it's only a matter of time with brass.

The outlet tee is feeding the engine via a 45 elbow off the bottom of the run leg and my fridge compressor is feeding off the branch. I was originally a little dubious about having all that bronze dangling down with a large moment arm but those stiff hoses are well-supported and actually give the assembly a fair amount of stability. That said, I've been planning to put a little support block between the tee and the bulkhead to the left in the photo. 

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We have the same style strainer, unfortunately it doesn't have the best sealing arrangement for the cap.  You  need to renew the rubber gasket on it more than you should and the Teflon washer on the cap is made for dropping in the bilge.  It looks salvageable but I would really go over it looking for pink areas and possible de-zincing, brittle stuff especially the ears for the stay bolts.

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Yeah, I'll have a go over it this evening, cleaned off a few small areas and so far underneath that verdigris it's looked a nice bronze colour. Fingers crossed. I'm thinking of just drilling the ears and using a threaded rod with nuts at both ends, I have some zinc plated stuff in the garage that's the right diameter, but not convinced it's the material of choice. Not really bothered if it rusts, I can replace them yearly for the next 40 years and still be ahead of Groco's spare part pricing.

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McMaster will ship to BC but only a business or school, if you know someone setup locally who has used them might be a way to go, local machine shop etc. Probably have to add $20 in shipping.  But would guess SS all thread is probably easier to find locally and should work fine.

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Alrighty, a few hours with the dremel, a bit of measuring and cutting of threaded rod and she's as good as new. Well, almost. Colour looks a bit odd because of the lighting in my workshop, but it's mostly a nice shiny bronze.

Before:

20200229-110859.jpg

 

After:

20200301-161911.jpg

 

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Visibility is fine once there's water in there, just a bit of dust on the glass, strainer basket is all good too. Seals seemed OK and I left the ones on the cylinder itself intact during the process.

I'll see if I can source a pair of the sight glass seals though, they probably need changing.

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Nice job. You just saved yourself several $hundred for a new one.

The seals are available as a set from Groco but they are pricey ($40-ish) and nothing special - don't even fit all that well. Next time I'll cut my own from some inner tube or similar.

By the way, the strainer basket on mine is Monel - maybe yours is too?

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1 hour ago, SloopJonB said:

The seals are available as a set from Groco but they are pricey ($40-ish) and nothing special - don't even fit all that well. Next time I'll cut my own from some inner tube or similar.

Are they flat or an o-ring? Hard to tell from the diagrams, I think flat in which case I can make some easily enough.

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They are flat and they are a bit undersized - they don't fill out to the outside of the fitting so you have to position them carefully to ensure the "glass" sits on them.

I wasn't impressed but they do seal.

I'm just talking about the big seals for the top & bottom of the sight glass - the washers for the lid and lock shaft are fine.

Making them is probably your best bet.

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