343 salt water inlet grills

[Methane Mick]

I cannot remove the two underwater metal grills at the intakes for the engine raw water cooling and the head. The screws can be removed, but even with the moderate use of an old wood chisel, I cannot separate the grills from the hull.
We have a bad mussel problem at my berth and I would really like to give the intakes a good clean and get some anti-fouling paint high up in the intake.
Any suggestions?
Essex Girl

 

[Don S/V ILLusion]

Presuming they were installed with an adhesive, force will be involved. Be prepared to do some glass repair when you rip them off.

 

[BigEasy]

Mick,
I had the same problem last year. Had just bought the boat, had it shipped, & unloaded.
While I was cleaning the bottom to repaint, I tried to clean the mussels unsuccessfully from inside the grill intakes for raw water engine cooling & shaft cooling. The external screws prevent the grill from rotating; however, the grill is an integral / cast part of the thru hull fitting. I had the yard grind them off and replaced with straight thru hulls with no grill. On my previous boat, I had straight thru hull fittings with no grills and never had a problem. Easy to clean out when hauled out and if they should get blocked with foreign debris, it is simple to pull off hose inside boat and blow out the debris or use a long screw driver to unblock the fitting. You can't do that if a grill covers the end of the thru hull. I am sure that there are differing opinions; however, I find that it is more advantageous in my locale to not have the grills.