Sizing through hull fittings

I changed the thru hulls, ball valves and tails on a Jeanneau MOBO a few years ago and on the originals, the skin fitting nut was half glassed in, I had to grind off the nut and split it. Also, I could not move the larger 1.5" ball valve off the fittings so in the end, cut them off. Gits to get out, but thankfully brass cuts and grinds relatively easily, just makes a mess. If I did some again that would not undo easily, I would do what someone has already said and just carefully cut away the outside rim of the fitting and pull the lot through inside.
 
The last sentence offends my innate sense of frugality - at least try to remove them by unscrewing before you resort to the angle grinder! They often come off without trouble and you don't risk damaging your hull.
Tried that on my Jeanneau: access for spanners so truly awkward for heads skin fittings I soon resorted to angle grinder from outside, very easy and quick, brass cuts easily. There was some dezincification on mine, at 8 years, would probably have lasted a few years more (except for a couple of hose tails), but it's the sort of job that's better done.
 
The last sentence offends my innate sense of frugality

What does the frugal person do with a bag of old seacocks? Even assuming that he can unscrew them in the first place, which seems unlikely in my experience (done the job on two boats now).

If you want to weight them in for scrap, they won't care how many bits they're in.

Pete
 
On a previous seacock thread someone referred to an offset diamond cutter - I assumed for a Fien Multitool.

Can anyone know of a source please?

I have a couple of those (available from Bosch dealers, Shark Blades and probably ebay) but for removing skin fittings neatly and quickly I use an appropriate sized hole saw and an Ooops arbor to centre in the fitting, absolutely no chance of gel coat damage and particularly useful if you intend to use a larger fitting.
 
Last edited:
I have a couple of those (available from Bosch dealers, Shark Blades and probably ebay) but for removing skin fittings neatly and quickly I use an appropriate sized hole saw and an Ooops arbor to centre in the fitting, absolutely no chance of gel coat damage and particularly useful if you intend to use a larger fitting.

All the diamond blades I have seen when googling are semi circular and they appear to be used for removing grout in tiles. I can see no reference for brass. Then there is bi metail blades and titanium blades for dealing with nails.
 
for removing skin fittings neatly and quickly I use an appropriate sized hole saw and an Ooops arbor to centre in the fitting

I improvised something very similar to remove the seacocks on Ariam, using one of the standard softwood bungs knocked into the outside of the fitting to centre the saw.

Pete
 
Need to look at the sizes of my hole cutters and see if it can be set up similat to an Ooops arbor. Certainly looks a neat way of doing it - thanks.

I assume with brass there is a risk of brass clogging any grind wheel.
 
All the diamond blades I have seen when googling are semi circular and they appear to be used for removing grout in tiles. I can see no reference for brass. Then there is bi metail blades and titanium blades for dealing with nails.

Indeed, that's why I don't use them for brass, great on GRP though, and I have the normal "finger" type as well as semi circular, they Are a Bosch part
 
What is an Ooops Arbor? Neither Google or I seem to know!

Yes I had to look it up and found a demonstration on U tube. IIRC my hole set has one for smaller size cutters and a large holder for larger size cutters. If one can fit inside the other instead of the pilot drill I am the proud owner of an Ooops arbor and didn't know it!!

Still struggling to identify the best Fein Multitool blade as I am doing the lots should be able to try a couple of ways and determine which is best with minimal risk of gel coat damage.
 
Top