Cutting out skin fittings?

[Tim Good]

I read in the archive that the best way to remove old skin fittings is to use a good hole saw and drill them out. This seems sensible and to just replace the skin fitting with new.

However the ones I need to replace are the scupper type like this:

Would I just grind off the flange bit and then use a hole saw? As anyone removed anything like this. I have tried to remove from the inside but they pretty stuck.

 

[pvb]

I'd use an angle grinder to remove the scupper part, then treat it as an ordinary skin fitting. Some people do use hole saws. I found it was easier to use the angle grinder to remove the inner angle of the skin fitting, until the flange just drops off.

 

[macd]

If you do use a hole saw, you'll need to create something to centre on, such as a tapered plug cut to appropriate length and hammered home.

 

[sailorman]

why not undo the retaining nut on the inside

 

[Tim Good]

why not undo the retaining nut on the inside

Even if I could get at it, the valve is stuck solid. I could struggle for 4 hours with the thing or grind it off and just stick a new one in. I'll be £20 down on the skin new fitting but at least not struggling stuck sweating inside one of my lockers for an evening.

 

[duncan99210]

Rather than a hole saw or angle grinder, both of which risk damaging the surrounding hull. I use a Dremel and a cutting disk to remove the flange from outside: this would work with the scupper type fitting the OP shows. Just take it slowly and it comes off a treat with minimal chance of collateral damage.

 

[Tim Good]

Rather than a hole saw or angle grinder, both of which risk damaging the surrounding hull. I use a Dremel and a cutting disk

I do have a Fein Multitool which might cut it but doubtful.

 

[pvb]

Rather than a hole saw or angle grinder, both of which risk damaging the surrounding hull.

If you just use a grinder on the internal angle of the hole in the skin fitting, the flange drops off with no damage to the hull.

 

[GrahamM376]

As pvb says, use an angle grinder at 90 degrees so the disc cuts the inside edge of the fitting, a few minutes job and no hull damage.

 

[DickB]

Try putting a long Stelson plumbing wrench on either end and twist to brek the seal. Then you can ease it out by unscrewing it through the sealant.

I have taken out two fittings like this. No problem.

Cheers

 

[robertj]

just to carry on a little with another type is, I have the skin fitting that is just a hole on the outside of the hull, no visible skin fitting flange.
Any one know how with this type?

 

[sailorman]

Elanco
Blakes
Simpson - Lawrence

 

[robertj]

none of them, its a normal looking skin fitting on the inside and just a hole on the outside. It might be a flanged skin fitting thats rebated down and filled.

 

[Concerto]

just to carry on a little with another type is, I have the skin fitting that is just a hole on the outside of the hull, no visible skin fitting flange.
Any one know how with this type?

There were skin fittings supplied by Landemores that were designed for racing yachts. There is a plate on the inside of the hull and this has usually 4 bolts through the hull to fix it. The bolts are countersunk and then filled. The outlet pipe was made over length so it could be reduced to be flush with the hull.

 

[PuffTheMagicDragon]

just to carry on a little with another type is, I have the skin fitting that is just a hole on the outside of the hull, no visible skin fitting flange.
Any one know how with this type?

Mine are like that. Wauquiez moulded the bronze 'tubes' into the hull. They were the first thing to go in the mould before the hull lay-up. The part that was embedded within the hull skin was knurled while the exposed part was threaded to take the fittings.

 

[BERT T]

If it's only the valve that's the problem and the skin fitting is fine why not split the valve on opposing sides where it is threaded on to the skin fitting with the angle grinder or dremel and the valve will screw off quite easily. After all you are going to have to get into the locker anyway to fit a new valve.

 

[jwilson]

why not undo the retaining nut on the inside

Because in the case of my boat that would have meant designing and manufacturing a triple-jointed special spanner, as the boatbuilder had clearly fitted the skin fittings and valves to the hull before building and glassing in inner mouldings and furniture round it. Cutting off carefully from outside with an angle grinder was fairly easy and quick. A dremel would have been even easier but slower.