Removing Replacing Thru-hull Strainer

[Vincentc]

I am seriously considering removing the existing strainers over the engine intakes with Groco APHS 2000 perforated strainers.
Oysters growing inside the strainers seriously impair water flow and are a pain to remove. The old strainers have been painted over and it is difficult to see how to remove them. There appear to be 4 phillips head screws which would probably be impossible unscrew. I assume I could drill the screw heads then pry off the strainer and then cut off the protruding screw shafts with an angle grinder.
Any suggestion regarding removal would be appreciated. I've read thru the 2009 thread on external strainers and it sounds like they would help me deal with the oysters.
Thanks
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[SEVEN]

Block off the bottom of the boat with plastic and pour barnacle buster in from inside the strainer and let it set over night. They will be clan as a whistle by morning.

[jrbrein]

Vincent,

We have the same boat and I did this repair last summer.

I used a stainless wire brush attachment on my grinder and CAREFULLY brushed off the built up bottom paint from the screw heads. I used the correct sized screw driver and backed out each screw and was actually surprised how easily they came out. It only took a small flat head screw driver to pry off the strainer from the hull.

I then wire brushed the strainers till they looked brand new and reinstalled 3 or the 4 screws using the same holes and threads with 5200. The 4th screw hole I drilled through the hull and used a 1/4 20 machine screw and placed a stainless washer and bolt on the inside, bedded it with 5200 and I am using this screw to attache a bonding wire to.

I opted to continue using my interior sea strainers for now.


Jon

[Vincentc]

Thanks for advice re barnacle buster the encouraging news regarding strainer screws.
I'll try the wire brush grinder. It took some effort to see that there were screws. At first I thought they were hex head screws.

To my measurement the mains are 1.5" and the air conditioner .75. I've ordered 2000's and a 1250.

I've also decided to try PropGlide (a PropSpeed knockoff) on the props, rudders, shafts and trim tabs.
Barnacle growth on the running gear is a real problem.

Regards,
Vincent

[Vincentc]

The wire brush grinder revealed #2 square drive screws. I used a small drill bit to clean out the paint then tapped the drive into the hole. 10 of the 12 screws came out easily. The drive stripped on two and hopefully a screw extractor out will take care of that.
The screen that is off reveals a good reason to replace with the Groco APHS
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[jrbrein]

Vincent,

When I did mine they were all Phillips head screws and likely not factory originals. This might be the reason mine came out so easily.

Good luck with your project.

Jon