Removing the raw-water intake strainer on a 25D

[Joe Myerson]

After reading a recent posting on this board, I've decided to replace the raw-water intake strainer on my 25D with a hinged Groco bronze strainer, which should be easier to keep clean. The present piece of hardware is a favorite of barnacles and shell-worms, and I'm always surprised that my trusty 1GM can still run at the end of the season.

The existing strainer, undoubtedly the original, is so crusted with 30 years' worth of bottom paint and God-knows-what that I can barely find the screws that hold it to the hull, let alone locate the slots in the screwheads. And I have no idea what kind of adhesive/bedding compound was used to attach the strainer to the hull.

I'm trying slopping large quantities of Strip-Eze on the fitting, hoping that it will help remove the generations of gunk from the fitting.

Any hints/suggestions from the experts on this board?

Thanks again folks,

--Joe

[John Ring]

Joe,

I don't think there's any bedding on the basket strainer, just four machine screws, and lots of old bottom paint. If it was set up like my old CD28, you should see the tail end of the screws coming up through the hull around the intake seacock. You will need to fill these old holes with epoxy as the new strainer will have a different hole pattern. Those nice Groco hinged strainers come in 3.6", 5.2", and HUGE. Order the size (3.6" or 5.2") that will place the bolts were it's easier to get at them inside the hull. The hinge always goes forward.When you drill your new hole pattern for the new strainer be sure the four holes come up inside someplace where you can get at them to tighten the nuts. I used some 4200 around the outside of the four new holes, between the strainer and the hull, to seal the new holes. Never had any problems.

Good luck,
John
CD36 Tiara
http://home.comcast.net/~ringj/

[Joe Myerson]

Joe,

... you should see the tail end of the screws coming up through the hull around the intake seacock. You will need to fill these old holes with epoxy as the new strainer will have a different hole pattern.

Thanks, John.
Obviously, I should be working at those screws from the INSIDE of the hull, since the heads seem to be completely obscured, even after efforts to clean off the old strainer.
Your other advice is very useful, too. I'll have to epoxy the old holes, drill new ones and be sure to put the hinge facing forward. That last detail is so intuitively obvious that I'm likely to forget it.

--Joe

[Jeff G]

I replaced mine a few years back with an internal Groco strainer. In retrospect, I should have kept the external strainer. It was better at keeping jellyfish out of the seacock. Here's how I got my strainer off. I took a wire wheel on a drill and cleaned out most of the paint and corrosion. The the slots in the heads of the screws were completely eaten away by years of corrosion. No way to insert a screwdriver. I ended up drilling through the top of the screw head with a drill that was slightly larger than the screw shaft. The heads popped off and I was able to remove the strainer. I clamped a Vise Grip to the remaining screw shaft and unscrewed it. All but 1 of the screws came out. That screw broke below the surface so I drilled a counter sink bit into the hull and just filled it with epoxy. Drilled and filled the other holes and then added some bottom paint.