Drilling strainers for raw water intake

[pjbori]

Hello,

I'm in the process of replacing a few of my corroded seacocks and thru-hull fittings. My raw water intake thru-hull has an external strainer mounted to the boat that I will need to remove by angle grinder in order to remove the old thru-hull. I've found replacement strainers. However, it will be my first time drilling/screwing into fiberglass below the waterline and kinda freaked out about it (the boat is on the hard FYI). Is it completely safe to do? Doesn't it initiate/exacerbate osmosis by opening up a tiny entrance for water particles? How can I do this in the safest possible way and avoid water damage once the boat is back in the water?

Thanks in advance!

[Gary Mc]

Any strainer that I have seen is part of the thru hull fitting so it would come out when you remove the thru hull? Is yours a separate piece? A picture would be good.

Also is your hull cored? that makes big difference on how you do the work.

[alamoana]

Like Gary Mc above said, the external strainer is most probably attached to the main tube of the thru hull, just back out the nut inside and push the whole thru hull through the bottom of the boat. it may be a little stuck but a hammer will help. Good luck

[Tetepare]

FWIW I installed ours by “glueing” with marinerex. No screws. And it stayed five years, last I knew it was still on the boat.