Engine Water Strainer Parts/Replacement?

Discussion in 'Main Morgan 38 Sailboat Forum' started by Marc H. Pearl, Jul 8, 2019.

  1. Marc H. Pearl

    Marc H. Pearl Member

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    I made the silly mistake of attempting preventative maintenance while 500 miles from home. Motored through lots of seaweed on my way to the Bahamas and thought checking the strainer would be a good idea. Unfortunately when I went to tighten the wingnuts the bronze bolt broke. Had to improvise for the 500 mile trip back home. Good thing I have a reliable bilge pump.

    Can I find a replacement bolt for the Perko Strainer I have, or if that piece was corroded should i assume the rest is too and should be replaced? Any suggestions?

    Sorry, I've done it before but can't figure out how to add a photo.
     
  2. Marc H. Pearl

    Marc H. Pearl Member

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    Oh well. It looks like the photos were being attached after all.
     
  3. terry_thatcher

    terry_thatcher Terence Thatcher

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    usually bronze does not fail. I wonder if someone used a brass bolt. You should be able to tap around the strainer to see if it is sound. I have a plastic one, can't remember manufacturer. Never fails, but it isn't as strong as bronze.
     
  4. Travis

    Travis New Member

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    Marc,
    Smart work with the wire and screw! I had to solve this problem recently too...

    I couldn’t find a bronze version of that bolt anywhere, and ended up fabricating a replacement out of a longer bolt from a specialty hardware store. It took about 30 minutes.

    Bronze or otherwise, the drilled end of those bolts are the weak point of the raw water filter in my opinion - maybe the weakest point in the entire cooling system. They are just too tempting to over-torque once the gasket starts getting stiff.

    Making the replacement was simple - file the bolt flat where it matters, drill a new hole for the pin, and cut to the appropriate length.

    You can see the measurements I used in the photo attached. I do not recall the bolt size, but I can find out if you need...
     

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  5. Marc H. Pearl

    Marc H. Pearl Member

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    Travis, thanks. I found one online but it's $20 for 1 bolt. I will take your suggestion and try to manufacture one myself. p.s. Look how pretty your strainer is. I want mine to look like that.
     
  6. Travis

    Travis New Member

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    Marc,
    Thanks - Cleaning it up was a cathartic experience, but it was more work than we bargained for!

    The previous owner said the raw water inlet probably hadn't been closed in years, and he had no idea when the last time the filter was cleared. We found a ton of mussel shells in the filter that had clearly been growing in there for some time as they were way to big to have been sucked in..

    The unit came out of it's place ok, but was reasonably difficult to service. Particularly, the 4 long bolts that were holding the whole assembly together were badly corroded, and a real pain to remove and replace. We had to drill one or two of them out and carefully re-tap the threads (see video #2 below). Finding 1/4-20 bronze bolts at ~10" length was even more difficult than finding the one you're working on now. We ended up using threaded rod instead...

    In retrospect, we probably went a little overboard. I like the design of these raw water filters, but if I had to do it again, I might try to find a newer-style unit to swap in. The main reason we stayed with this one was because matching up new fittings and routing new hoses was going to be an even bigger pain than just fixing this one up and slapping it back in.

     
    Last edited: Jul 9, 2019
  7. dave_a

    dave_a Dave Ahlers

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    Marc, Perko's still in business and they offer replacement parts.
    https://www.perko.com/images/sparepart_diagrams/0500.pdf
    PS. soak that strainer in vinegar and it will look close to new.

    Travis - I went to the hardware store, bought a sheet of cork and cut gaskets. Looked a lot like yours.
    The Perko gaskets were too expensive. Turned out the cork I bought was slightly thinner, causing not a water leak, but with the engine running it would draw air in. Lost an impeller. Which ironically was the same cost as the Perko OEM gaskets. I saved $0 dollars. Just offering that up to you just in case.
     
  8. Travis

    Travis New Member

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    Dave,

    Thanks, you have a good point. It’s important that the material is both thick enough and flexible enough, or else you end up having to crank those wingnuts too tight in order to get a seal.

    I also noticed that they list two gasket types on the Perko document you linked: Cork for the “older model” and rubber for the current model. Seems we are not the first to realize that the design could be improved.

    I wonder why they don’t recommend switching to rubber?
     

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