My boat came with a mix of thru hulls that probably were appropriate for the application. Bronze below WL, a couple stainless above and also 4 plastic ones above the Wl, a head pump-out, Bait-well drain, AC discharge, and a FW sink drain. I noticed last year they were looking a little "chalky" on the outside. Inside the looked good, except the sunlight would lighten them up when looking from the inside and each time I looked at them I kept saying...I am going to swap them out with SS thru hull fittings I don't like seeing daylight illuminate the fittings.
The plastic are kinda nice in that they do not stain, have no electrolysis problems and are pretty inexpensive.
Well, today I removed them as I wanted to use the dimensions of the old ones to by new SS ones so I would not have to re-drill any holes.
I removed the clamp on the hoses and gave the hose a tug an 2 out of the 4 fittings snapped clean off. The other two I had to work out of the hole but the two that broke of did so without much effort. The FL sunlight degraded the plastic to the point of near failure.

I ordered 4 SS ones for above the WL and 2 bronze ones for fish-box macerator drains that are right at the WL in the stern.

So, if you have any plastic thru hulls that have seen a few seasons...give them a good look and a tug on the hose.

Same here, mine all broke when I swapped them out.
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I had 2 plastics (threaded to compression) that were not through hulls but through fish box, both broken. Connected the hose from the fish box to the macerator pump, with the break water drained into the bilge.

BTW: I have a plastic (ropelene) boat.

The sun is brutal on plastics unless they put in UV inhibitors. I would venture companies that make these fittings don't put any in at all.

Had the same thing happen several times.

A plastic connection to the bait well pump is the achilles heel of Regulators. Sank my neighbors 31 footer, and damn near got mine (broke off when I bumped it changing a bilge pump).

Same thing happened to us !
we actually had cracks in the hose barbs of 2 of the plastic thruhulls and they all snapped with little to no effort pulling on the hoses.
Now were in the process of swapping all the plastic ones for SS and bronze.
last year we were getting water into the forward bilge , this year were replacing all the thruhulls,pumps,hoses and seacock.

not taking any chances this season.

After reading all this I think I will replace my blidge pump fitting.
Its 1995 original.

Thats the only one I have to worry about, the others are box drains.
Not safety related.

:Edited:
Oh yea I forgot about the two deck drains..

I now have all the critical thru hulls SS above WL and bronze below WL now, the SS thru hulls are a hell of a lot stonger and I think look nicer than the cheap plastic anyway. The fit was very close to the plastic units. It was a clean out and replace job...no big deal.

My boat came with a mix of thru hulls that probably were appropriate for the application. Bronze below WL, a couple stainless above and also 4 plastic ones above the Wl, a head pump-out, Bait-well drain, AC discharge, and a FW sink drain. I noticed last year they were looking a little "chalky" on the outside. Inside the looked good, except the sunlight would lighten them up when looking from the inside and each time I looked at them I kept saying...I am going to swap them out with SS thru hull fittings I don't like seeing daylight illuminate the fittings.
The plastic are kinda nice in that they do not stain, have no electrolysis problems and are pretty inexpensive.
Well, today I removed them as I wanted to use the dimensions of the old ones to by new SS ones so I would not have to re-drill any holes.
I removed the clamp on the hoses and gave the hose a tug an 2 out of the 4 fittings snapped clean off. The other two I had to work out of the hole but the two that broke of did so without much effort. The FL sunlight degraded the plastic to the point of near failure.

I ordered 4 SS ones for above the WL and 2 bronze ones for fish-box macerator drains that are right at the WL in the stern.

So, if you have any plastic thru hulls that have seen a few seasons...give them a good look and a tug on the hose.

Your boat is only two years old, isn't it?

2003...it is 2 years old for me though:)

Worked on the boat yesterday and going there in few.

Checked the very important bildge thru hull and it looked new on the outside. I pulled and twisted and tugged at it on the inside. strong as hell. No need to replace. 16 YO and still fine, took a quick look at the rest all fine also inside and out.

Maybe Proline used good materials back in 95'.
Less work is OK with me.

Bottom painted yesterday.
Replumb the baitwell today (all 1" now) and move the valve.
Wash and wax today, paint the OB bracket. She will dunk this week, if I can get a day off. Spring nuke plant shutdowns keep me hopping.:fury: