Stubborn prop nut and more!

If it is really 1.4" (1 13/32") that could be a 13/16" Whitworth nut, if they kept to standard for this odd nut. Very uncommon size. Heaven knows where you would get a spanner.
1.4" is 35.56mm - too big for a 35mm spanner.
1 3/8" is a bit under 35mm.
Not difficult to get a 35mm or a 1 3/8" (34.925mm) AF spanner.
Suggest you need to measure very carefully.
 
RichardS said:
But what is the "adapter" Alan? Who has mentioned this apart from you? :confused:

Richard
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tbh was assuming there was a ready made one by the shape of the nut.

I think I'd find a socket that just slipped over the nut, the drill and tap some hardened bolts or grub screws to bite onto the flats.

It reminds me of turn keys i've seen somewhere. The end looks like a solid steel rod that has a channel milled through it.

I wonder if one of those needle sockets that were so popular about 10 years back, often used to get security wheel nuts off would do the trick?
 
I'll go and remeasure the nut again

To be honest I didn't think this would be so difficult! I assumed this nut was a fairly standard arrangement on prop shafts !

So it seems I have not just a stuck nut, but a weird non-standard stuck nut to boot.
 
Heat can help but it's more help when the two metals involved are different as they different thermal expansion rates, such as a bronze prop and a SS shaft. Heating and cooling means that one will expand more than the other and hence separate them. Your nut being stainless the same as the shaft means they will expand at the same rate, it may still help separate the nut from the back of the prop a bit. Temperature wise you can easily go to 200C or pretty hot, the only thing to damage would be the rubber shaft bearing, but the prop will disperse a lot of the heat quite quickly. The right sized spanner and a large lever is usually the key.
 
Not boot - it's Aft lol!

Don't loose heart, working on boats can be vexing. Often said you don't buy a boat, but a hole in the water you pour money into :).

If your on a marina, wanda around the other owners, asking if anyone knows a marine mechani, you eill get asked your problem, with a bit if luck get some help.

My experience is many of the boating fraternity are extremely helpful, assisting another in sorting boat problems out or lending a tool.

Otherwise, if you can remove the prop shaft, take it to a local garage, i bet it will take only a few minutes when held in a bench vice to remove this troublesome nut eith stilsons and heat.

Alan
 
forgive my rare posting,
but im experienced in these situations, as ive worked on oil /gas burners older than noah,s dog. find a spanner slightly smaller and carefuly file ie make your own . im sure any one who uses tools has one time or another altered tools .( true) a pipe fitter i no cut one out of plate steel didnt want to use stilsons as with the grip they cut up nuts ,but if not bothered about the nuts use stilsons
 
Tranona said:
Pretty sure it is irrelevant which way the prop rotates. No way can the nut come off when the shaft is turning as the prop is on a taper with a key and the nut is pinned to the shaft. It will be normal anti clockwise to undo.
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My previous boat had a RH propeller, and a LH thread for the nut. Standard Fleetwood of Lossiemouth sterngear.
 
If the OP gets really desperate it would be possible to weld two spanners together, open ends opposite to make a special tool. Use a grinder to make it fit and possibly weld and iron bar or tube to the spanner handles to give it some force.
 
Lots of great suggestions here.

My first tack is going to be to track down a large open ended spanner of the right size.......again going back to basics, I'm assuming a spanner marked 1 3/8 fits a nut of 1 3/8 distance across the flats??

I like the idea of filing a slightly smaller spanner to be an exact fit.

I will try heat and extending the leverage and see what happens.
Noone has mentioned penetrating fluids so assuming they are of limited use? (It's already had copious WD40 on it of course)

Loath to use destructive methods such as Stilsons or grindingoff as yet, as sods law dictates it will be a double nightmare replacing the nut (and the entire Christmas present budget I imagine!)

This still leaves the issue of which way to turn the damn thing!!!
 
Tim O said:
Lots of great suggestions here.

My first tack is going to be to track down a large open ended spanner of the right size.......again going back to basics, I'm assuming a spanner marked 1 3/8 fits a nut of 1 3/8 distance across the flats??

I like the idea of filing a slightly smaller spanner to be an exact fit.

I will try heat and extending the leverage and see what happens.
Noone has mentioned penetrating fluids so assuming they are of limited use? (It's already had copious WD40 on it of course)

Loath to use destructive methods such as Stilsons or grindingoff as yet, as sods law dictates it will be a double nightmare replacing the nut (and the entire Christmas present budget I imagine!)

This still leaves the issue of which way to turn the damn thing!!!
Click to expand...

Your spanner assumption is correct ...... but it depends upon how accurately you have been able to measure the across flats. However, with an AF that size, I think some oversize latitude is possible. Undersize can always be ground out, of course.

This is what I would do to determine the thread rotation. Assuming that you cannot see the end spiral of thread by looking straight down the shaft then take a fine piece of stiff wire and push it gently down between the "nut" and the thread and note the distance you have pushed it in with a fine felt pen or a slight bend in the wire or fingernail. The gently push it in a few degrees round the shaft in both directions and note any difference in length. Try this in several different places around the shaft and eventually you will hit the very end of the thread with one measurement and miss the end of the thread and hit the next thread slightly to one side or the other. Once you know which side of the short length you need to go to find the long length, you will have your answer. It will only a small difference but you will detect it on a thread of that size.

Richard
 
If only I could find a big box of spanners!!!!

Think I'll just buy something off eBay like the links I posted early in the thread and take it from there

Or I'll ask around the yacht club next time I can get down there!

Good advice re thread direction, will try that technique
 
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