How to remove tough through hull fitting

[JC Reefer]

Hello, I have through hulls that I’d like to rebed. They are loose enough that they are spinning but the nut is still really tight. Does anyone have any tricks to holding the fitting in place so that I can remove the Nut without damaging the threads?

[skipmac]

On the inside of the thru-hull you should see a couple of tabs or ears projecting into the opening. You can buy a tool with slots on the side that fits inside the thru-hull with the little tabs in the slots. Hold that tool to prevent the thru-hull from turning while you loosen the nut.


Lacking the tool, access to buy one I have carved a piece of medium-hard wood to fit inside and used that to hold the thru-hull.

[skipmac]

A picture. They are stepped so one tool fits most sizes of thru-hulls.

[skipmac]

Plan B. Get two more nuts that fit the threads of the thru-hull. Install on the end of the threaded section, use two wrenches to tighten the two nuts together to lock onto the shaft. Hold the two locked nuts while loosening the original nut. Once that's moving freely loosen and remove the two locked nuts.

[Orion Jim]

Sometimes judicious use of a heat gun is enough to keep you from more drastic means.

[AKA-None]

All else fails use a dremel

[US1Fountain]

I prefer to use a box wrench, or deep well socket on situations like these. An adj wrench can actually distort the nut enough to clamp down harder on the threads since its only working with 2 corners, Not quit as bad as a pipe wrench. Where as the socket or combination wrench works on all 6 corners

[Toccata]

Feine tool (reciprocating tool) Metal cutting blade
Hold it vertically, cut the nut in 2 places it will fall off.

[ronstory]

...and an attempt to be smart and lazy... Kroil or PB blaster on the threads and let them soak in.

Then try Skipmac's ideas of using the tabs or double nuts.

[Poche]

Originally Posted by ronstory

...and an attempt to be smart and lazy... Kroil or PB blaster on the threads and let them soak in.

Then try Skipmac's ideas of using the tabs or double nuts.

I've used Kroil...Pb Blaster...Seafoam...WD...brake fluid. Brake fluid works as good and it's cheaper.

[Minggat]

An adjustable wrench is not always your friend. The flats don't always stay parallel, which can result in rounded corners on the nut. They are very handy, until they make your life much harder

[ronstory]

If you go the brake fluid route, be careful. It's corrosive, so keep it away from anything painted.

[Boatyarddog]

Originally Posted by JC Reefer

Hello, I have through hulls that I’d like to rebed. They are loose enough that they are spinning but the nut is still really tight. Does anyone have any tricks to holding the fitting in place so that I can remove the Nut without damaging the threads?Attachment 206375Attachment 206376

I'd outright replace this one, you see any pinkish color in the thru hull?
For the $30.00 you'd spend.
Go to harbor freight or even a grinder, saws all, Dremel, cut that nut off its crap.
And push it out with a 2x4 or mallet.
Replace it.
It's so much easier with a new piece.��
Cheers, SV Cloud Duster

[NahanniV]

You are going to a lot of trouble and expense to do this job.
I would replace the thru hull at the same time.

Once you decide to do that it’s a 5 min job:
Grind off the mushroom head on the outside of the hull, keeps the mess outside and usually easier access.
Push the remaining threaded part in while it’s still hot, scrape out any sealant, easiest while it’s still hot from the grinding.

[Taipe]

When attempting removal of a thru-hull fitting, external grinding should be done ONLY as a last resort due to the risk of damaging the hull. If it is ever necessary to sabotage the nut a/o the threaded side either can usually be cut from the interior side of the hull with less risk.