Removing Stainless Steel Through-Hull Fittings

[Baddox]

I want to replace some stainless steel through-hull fittings at the next lift-out. They are ¾ and 1 ½ inch fittings which I expect won’t release by unscrewing and will be a little too tough to use a step-drill on.
Are there better alternative methods of removal to consider before attacking the fittings with a grinder?
My approach will be to stuff a wet rag into the fitting and slowly remove the flange with and angle grinder, hoping that the rag will keep the temperature of the metal down enough to prevent overheating the fibreglass.

 

[waynes world]

If a spanner wont work then grind it as you want to but bit at a time or poor coolant over it/fill it with water.

 

[RJJ]

If a spanner wont work then grind it as you want to but bit at a time or poor coolant over it/fill it with water.

I'd have a squirty bottle of water on hand.

You could do a few cuts and move to the next one, etc in rotation.

 

[PCUK]

Shouldn't be a problem to unscrew with big Stilsons.

 

[rogerthebodger]

I have used a angle grinder on the outside to grinding off the outer flange by rotating the angle grinder using a grinding disk across the outer flange and rotate the grinder to cut the outside flange off. Then knock he rest of the fitting to the inside.

 

[Iliade]

Wire brush the corrosion off the threads and it should undo with a spanner.

If you must cut it, a large nut splitter would be ideal. It should nee possible to hire one,