Tools for through hulls

[lustyd]

Hi all, I'm replacing my through hulls and trying to work out what tool I need to undo the massive nuts on the inside of the hull. I don't have a spanner or adjustable that comes even close to fitting the nut. Through hulls that are getting removed are Raymarine ST800 plus a bunch of plumbing through hulls of varying sizes.

Is there some generic tool I can use, or are they specific to the fitting? My new TruDesign ones have a specific tool, but I don't yet have those!
Thanks

 

[PaulRainbow]

Hi all, I'm replacing my through hulls and trying to work out what tool I need to undo the massive nuts on the inside of the hull. I don't have a spanner or adjustable that comes even close to fitting the nut. Through hulls that are getting removed are Raymarine ST800 plus a bunch of plumbing through hulls of varying sizes.

Is there some generic tool I can use, or are they specific to the fitting? My new TruDesign ones have a specific tool, but I don't yet have those!
Thanks

Waterpump pliers easily undo things like the ST800 fittings, should do seacocks too, if they are not too tight or corroded. If you find a really stubborn one, chances it will just turn in the hull, mine did on my last boat. I used a multitool to cut a but off of the side of the nut, with one really stubborn one (seized nut) i cut a piece off of each side and knocked the two remaining sections off with a hammer and blunt chisel.

 

[capnsensible]

I saw this technique in action when I changed all the Hull valves on my two school yachts.....Jenneau 36.2 and Junneau 35.

I got a local boat fixer to do the job with me assisting. I held the inside of the valve steady with a large adjustable spanner. He used.....carefully.....a disc cutter on the outside. Cut away a piece of the flange at a time until it came off. Took very little time. Each boat was done in a few hours. Lots of sikaflex on refitting the new ones.

Hope it goes well! Like lots of boat jobs, thinking about it too deeply (theory) is harder than the practical!

 

[Dunx]

The skin fittings won’t really have any afterlife use so consider grinding them odd from the outside, it’s quick and efficient and a one person job.

 

[capnsensible]

There you go!

 

[bobgarrett]

Use a Dremel to cut the flange off the outside. With a small enough cutter you can put it inside the pipe and cut outwards.

 

[Praxinoscope]

In the past I have used a ‘basin wrench’ they cost less than about £10 in stores such as screwfix B&Q etc.

 

[Boathook]

I use water pump pliers but care is needed when tightening up the new fitting not to over tighten or damage the nut.
All my old fittings did unscrew so I haven't had to resort to cutting the flange off
You could use a large adjustable spanner like Superwide Jaws Adjustable Wrench 8" (200mm) | Toolstation if it is big enough.

 

[Tranona]

Another vote for removing the outside flange and then pulling the whole assembly out from the inside. Takes a matter of minutes rather than hours struggling to undo nuts. Angle grinder if you are careful, Dremel for slightly slower precision or cone drill if you have one.

 

[lustyd]

Didn't know they were called waterpump pliers! Thanks all. Not planning any reuse just hoping for an easy life and would rather undo a nut and hammer outwards than grind outside but will if I have to.
Curiously, in the meantime I found a very old post from PRV talking about tile hole cutters that he used on both his boats. I then found the Trudesign doc which essentially says the same thing and looks quite easy https://trudesignplastics-com.s3.am.../docs/47/0fab29c9f7d8654c8189eac3a69e139b.pdf

Plan now is to take ALL the tools and try each method in turn until success is achieved. The 36.2 has a lot of through hulls so I'm keen to have lots of options available when we go to the boat

 

[Graham_Wright]

I made a long box spanner really for tightening the nut but just as useful for removing it. The fitting was buried in the engine space and not accessible by normal spanners.

 

[Tranona]

Didn't know they were called waterpump pliers! Thanks all. Not planning any reuse just hoping for an easy life and would rather undo a nut and hammer outwards than grind outside but will if I have to.
Curiously, in the meantime I found a very old post from PRV talking about tile hole cutters that he used on both his boats. I then found the Trudesign doc which essentially says the same thing and looks quite easy https://trudesignplastics-com.s3.am.../docs/47/0fab29c9f7d8654c8189eac3a69e139b.pdf

Plan now is to take ALL the tools and try each method in turn until success is achieved. The 36.2 has a lot of through hulls so I'm keen to have lots of options available when we go to the boat

Try cutting of the flanges first - then you won't bother with undoing anything inside other than detaching (or more likely) cutting off the hose as well as I expect you will want to replace some of them as well.

One of these will do the job as well. ebay.co.uk/itm/403685315679?var=0&mkevt=1&mkcid=1&mkrid=710-53481-19255-0&campid=5338268676&toolid=10044&customid=EAIaIQobChMI9MSVu7eN_gIVQZ7tCh0mKgDQEAQYFiABEgKSqPD_BwEThe flange is very thin and soft.

 

[lustyd]

Yes all hoses will be replaced. The reason I would prefer to push outwards is just that it's easier to break the sealant that way and saves the job of removing the flange. Good idea with the drill bit, I already have one on the boat and the self centring will save faffing with bungs

 

[Norman_E]

Jeanneau do seem to fit quite a lot of through hulls and I reduced the number when I completely re-plumbed my 45.2. There was even one 38mm one in the aft heads with just a banking plug on the inside. I removed it and both shower outlets with the shower water and kitchen sink water sent to a grey water tank with deck pump out.

 

[Daydream believer]

+1 for a wood bung in the hole & drill out with a hole saw if you have one of the correct size.

 

[Tranona]

Yes all hoses will be replaced. The reason I would prefer to push outwards is just that it's easier to break the sealant that way and saves the job of removing the flange. Good idea with the drill bit, I already have one on the boat and the self centring will save faffing with bungs

You do not need to break the sealant between the hull and the flange. The flange will stay stuck to the hull (maybe!) but will prise off easily. The seal on the inside will also break easily by pulling the valve etc inwards.

 

[Never Grumble]

For removing skin fittings I have used both a grinder and conical step drill, the latter was much easier to control and worked really well with no risk of slipping like there is with a grinder.

 

[Pye_End]

Stick 'big adjustables' into ebay and you will find some that go up to 68mm with stubby handles for not much money. Sometimes it is easier to take the nut off and push through, but if this takes more than it's fair share of time and effort, then taking the flange off is quick and easy - just be a bit cautious if using a grinder that it doesn't get so hot that it scorches the hull.

 

[RJJ]

Angle grinder. Really easy, no risk to the hull if you do it properly.

Properly means counterintuitively going straight at the flange, with the disk perpendicular to the hull. Mincing around at an acute angle is no good. You can easily see when you have nearly ground through the flange.

 

[BobnLesley]

I'm another who angle-grinds and knocks inwards, then if they're beyond adjustable spanner size, a strap or chain wrench; as a bonus either an AF or metric strap wrench will work equally well