Pipe thread sealant.....thru hull and bait well pump

[Capt. Debbie]

like everything so many opinions.

Pipe dope is NOT made for bronze. Throw that idea out.
5200 is made to NEVER come off without risking destroying the fittings. Like crazy gluing it on.


To simply seal the Teflon tape does fine. Some are not gasoline tolerant. But the water is not that polluted.

Remember... Eventually you may need to remove the male connector in the bronze thru hull fitting(that should NOT be replaced). That will answer your question easily on what works best.

You did not mention the hose clamps used? If an option- doubled up hi quality Stainless Steel. Not Chinese shit SS foisted on us from a backwards culture that are 25 cents each.


It's not high pressure so it's not stressed out. Also remember that any leaks will be below the boat's water line and air above that. SO even holed high enough up will stop leaking when the pump is off. A small point to be remembered it if you need a repair.

Also since the thru hull is obviously below the water line to work what's your plan to plug it if the ball valve freezes with a broken hose? An expandible rubber stopper or some kind of plug secured VERY close by.

So.. just a few thoughts.

Originally Posted by Duffman

Installing new bait well pump. Male plastic fitting on pump to bronze female on thru hull. What to seal threads with?

My head is spinning with what I have read......

Use 5200.....don’t use 5200
Use 4200....don’t use 4200
Use Teflon tape
Use pipe dope
Use Teflon tape with a coating of pipe dope. Some are no good with gasoline ( not a problem).
Etc etc

Pump manual (shurflo) simply states “seal with thread sealer”

Was at Edison boat show last week looking in bilges and every connection was sealed with some kind of liquid dope. Salesman had no clue what was used in fit up.

If I didn’t read so much into it I didn’t even realize some sealers will actually eat away at the plastic.

Just looking for some suggestions as I over think the hell out of this!