Raw Water Strainer (Failing) - Replacement Options?

[dawntreader]

As part of my regular maintenance I remove the front cover to my heat exchanger to ensure that it is clean. Bearing in mind that the exchanger is fed with raw water which comes via the strainer I was surprised to find some 'large' pieces of (mussel) shell in the bottom of the cover. As this debris should have not have gotten past the raw water strainer I inspected this part too.

The strainer should slide into two grooves specifically manufactured for the purpose of properly locating the strainer in place. However, I have now discovered that it is possible to re-fit the strainer with the locating edges not properly located but with the appearance of being properly located. Closer inspection also reveals that even if fitted properly it appears that there is a sufficient gap in the strainer inlet recess to allow 'larger' debris to pass through without being caught.

Are there better options on the market to the one supplied by Bavaria and has anyone fitted them?

[Yngmar]

Vetus is usually a safe bet when it comes to quality. However, their prices may make you rethink replacing the thing

[Salty]

Hi Dawntreader, this is a subject I wrote about in a reply a couple of years ago under the subject of Volvo D130 saildrive, but it would come up if you search for "Mussel." Yes, the raw water strainer that was fitted as standard some years ago was a particularly poor piece of equipment, and there are plenty around that are vastly superior. Indeed I had just sold one that I had spare shortly before finding my engine was beginning to overheat. As I think I mentioned at the time, a combination of mussel shells and impeller vanes shed while under the previous ownership, had blocked some seventy to eighty percent of the tubes within the heat exchanger tube nest. So I was fortunate that no significant damage had been done. Further investigation also revealed that mussels had set up home within the saildrive cooling water intake, where they had grown to the point that they could not have got out even if they wanted to, so part of my routine maintenance now is to make sure each time the boat is lifted out that any livestock within the saildrive water inlet is fully removed.