What would you do with this fitting?

[Roger Long]

This fitting on my Yanmar, just downstream from the RW pump, has a NPT thread but has to end up oriented with the nipples exactly straight up to remain clear of the alternator.

It feels like it will want to stop turning just as the nipples are pointed straight towards the alternator. It's the usual NPT (or whatever metric equivalent is used in civilization) conundrum, can I make another turn without breaking it or stripping it? Aside from the normal fear of breaking a probably irreplaceable part or stripping the threads in my engine block, there is the issue that I probably can't exert enough force to make another 3/4 turn without pulling the engine out of the boat.

I've been living with it slightly loose with lots of pipe dope on it and it only leaks a tiny bit. The big pain is every time I need to change the zinc which always ends up tighter than the fitting. Working with two wrenches in the confined space isn't pretty.

So, what do you suggest? All I can think of is a pipe dope that will set up very hard.

Speaking of pipe dope, is Master Plumber TFE suitable for salt water use?

 

[FourPoints]

could you fit a washer in there?

 

[Ralph Johnstone]

I Know Whay I'd Like To Do With It ..................

............... but that wouldn't solve the problem.

Your only option here appears to be to take a bit further cut on either the male thread or the female thread. It's unlikely you'd have much luck in cutting the male thread (which you show) as the guide on the threader would hit the body of the (looks like a strainer) before the cutters would engage.

Your only other hope would be to use a pipe tap on the female thread in the engine block ........................ and that's providing there's enough room to get close to the threaded hole and swing a pipe tap.

Knowing how compact Yanmars are, a good dose of luck would also be in order.

 

[woodster]

there is a pipe dope called "EXSPANDO" we used to use it in hydrolic elevators pipeing it it holds when nothing else will ....you could use it and regulate your fitting to where you need it and then let it set for a couple of days.....i am not sure that you can remove it at a later date...but it did hold well with no leaks....i will try to find a source if you like....

regards

woody

 

[Allan12210]

I'm with Ralph on this one. Using the correct pipe tap and a square head socket or crowsfoot wrench, get an extra 1/2 turn into the block.That should give you the ability to rotate to the orientation you want and make a seal that can be taken apart later.

 

[kloudie1]

JB Weld.. so that you don't have to re-work every time you change the zinc.

 

[Roger Long]

JB Weld..

That may be the answer. It isn't necessary that this fitting ever be removed. It is there only because the same functions couldn't easily be cast into the block.

Maine Sail used to be in the heating and plumbing business. I'll be interested to see what he things when he checks in again.

 

[kloudie1]

I am watching as well for his input .. We were just working on the exact same fitting on my buddy's boat.. changing zincs .. It moved a bit and I wondered if it would leak if moved back.. we were lucky , it didn't leak.. but we discussed removing the alternator and stuff to get it out and figured if we did have to, JB Weld was the way it was going to be repaired. His is set in a very thick pipe dope today, and that seemes to heal itself to some extent.. I think that dope was original to the engine from back in '78.
I always thought that fitting was an "oops" from Yanmar's marine conversion.

 

[Maine Sail]

Remove the nipple, will probably need Aero Kroil or similar penetrating oil. Buy a new close nipple, or the length you desire, and use a good higher temp pipe dope on both ends of the new nipple. Thread it in and tighten down until aligned to your liking and tight enough. With NPT fittings, and a good dope, there is almost always more "alignment room".. Hercules Real-Tuff is the pipe dope I use most..

 

[Roger Long]

Remove the nipple....

It's part of the casting.

 

[Maine Sail]

It's part of the casting.

That sucks. Often times with fittings like that they are female tapped then nipples are used. I would clean the threads up with a drill & soft brass brush then use a good pipe dope like Real-Tuff. You should be able to get it to line up with a good pipe wrench. Nothing wrong with teflon tape with dope too. I would avoid something like JB Weld as you may need to get that fitting out at some point in the future. In my experience with JB once it is together it makes 3M 5200 look like Silly Putty.....

 

[Roger Long]

You should be able to get it to line up with a good pipe wrench.

I have to bring the engine out into the cabin first to get enough room to swing the wrench.

Want to help

 

[Ron20324]

I have a similar situation trying to install a 45-degree fitting so it points in the right direction- but doesn't. It bottoms out about 3/4 of a turn short, so I'm thinking I can grind little off the male threads of the fitting. Would that work for you, Roger?

 

[kloudie1]

I agree with Maine that JB will make it un-removable , but then couldn't think of a reason to remove it unless it corroded through .. in which case, the Dremel and cutting wheels would get it out.. We were able to use a big crescent across the top to get the thing to move then the square boss on the zinc to better position it once it was a bit loose.. I like the idea of the really thick pipe goop.. , but it diid look like the gear case and stuff could be easily worked without disturbing the inlet nipple.. One just has to remember to hold it firmly in place before trying to unscrew the zinc. Thanks for the input, Maine.. Going to pick up some Real-Tuff just to have it in the box..

 

[woodster]

I have a similar situation trying to install a 45-degree fitting so it points in the right direction- but doesn't. It bottoms out about 3/4 of a turn short, so I'm thinking I can grind little off the male threads of the fitting. Would that work for you, Roger?

Ron if you are bottoming out on the small end of the threads that will work....but if it is bottoming out on the large end i dont think it will change anything ...the only thing you may do is cut the treads a little higher on the large end.......or if you have the room and access you could use a tap and cut the threads deeper in the female threads...some times just taking a tap and cleaning the female threads will give you what you need....

regards

woody

 

[Roger Long]

Would that work for you, Roger?

No, because the fitting is coming up against the taper, not bottoming out. If this were a normal situation with room to work, I would just force it with a big pipe wrench. If I broke or stripped it, I would just go buy another one. I can't get enough force on it in the engine compartment to either force or break it, hence, this thread.

I'm leaning towards the JB at this point because I can't see any circumstance in which it would need to be removed. There's a zinc right inside it so no sign of wastage and it's not in a location on the engine where it obstructs anything I might need to work on.

I'll give it one more try dry fit now that I've aggressively cleaned both threads. Maybe that will be enough.

Later:

Just got back from trying the dry fit. No way that fitting is going to go around again. Part of the problem is lack of clearance to get a pipe wrench on it for turning in that direction due to the shape of the engine block.

I got the Real Tuff and I think I'm going to punt and just use that. I've lived with the problem this long using inferior thread compound. Trying it on, I remembered using a long heavy screwdriver wedged into the block recess to keep it from turning backwards when removing the Zinc. I'm going to use tape and dope and turn it to the exact position the screwdriver holds it so it won't be backed slightly when removing the zinc. I can get a pipe wrench on to hold it when tightening the plug with the zinc.

 

[OldCat]

It feels like it will want to stop turning just as the nipples are pointed straight towards the alternator. It's the usual NPT (or whatever metric equivalent is used in civilization) conundrum, can I make another turn without breaking it or stripping it?

I'd add a bit of thread to the MALE part. If the die won't go down far enough to do that - grind off some of the die on the entry side. You don't need to start the thread, so the lost bit of entry on the die won't matter. The taper on the thread will still be maintained. Tapping the female part means getting all the chips out - yuck. Fit it by hand, look at it to see that there are no other obstructions - then decide if this will work given how the whole system fits together.

OC

 

[Don12364]

When I worked for a plumber during my college vacation in 1953 we would have used a 'paste & hemp' seal with a back nut. i.e. wind strands of hemp in the threads of the fitting and coat with plumbers mastic paste.

In today's parlance wind a thin back nut fully on to the male thread and then put teflon tape or pipe sealant on the threads. Screw the fitting to where you need it and wind the back nut down to lock the assembly.
It looks as if your male thread has enough length to take a 1/8" thick nut even though the male thread may not reach full interference in the female one. Rely on the teflon to ensure a watertight seal.

 

[Roger Long]

we would have used a 'paste & hemp' seal with a back nut.

I think that was the answer I was looking for but it's all back together. I didn't think I could get a nut to go on the tapered threads even after cutting or grinding it thin.

Anyway, some Teflon tape to thicken it up a bit got it pretty tight in the right position. I'll still have to use a second wrench or back it up with a screwdriver when unscrewing the zinc but that's only once a year. At least it isn't so loose now that it moves when I bump the hose while adjusting the alternator belt. That felt a bit cheesy.