Alone bolt tightening

PabloPicasso

PabloPicasso

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Ok, so I'll be on my own, inside the hull and want to tighten the nuts on the inside against protruding bolts. The bolts were put in from the outside with sealant that's been left to cure.

I could try putting two nuts on the end of the bolt to stop the bolt rotating (& breaking the seal) while I clamp the nuts down.

Or grind a slot in the end of the bolt with a dremmel, and use a screwdriver to prevent the bolt moving

Any comments or tips on successfully doing this?
 
The problem with locknuts is that tighening up the locknuts sometimes moves the bolt a little. It depends upon how much movement you could tolerate. The advantage with a slot is that you can avoid (and see you have avoided) any movement although it depends upon how tightly the nut needs to be tighened up.

If the nut only needs to be nipped up, I would use the slot. If the nut needs to be really tight, locknuts might be better.

If you have a lot of spare thread and are nipping-up only, you could use a mole wrench at the top of the thread. If you ever need to remove the nut just cut off the damaged thread.

Richard
 
RichardS said:
The problem with locknuts is that tighening up the locknuts sometimes moves the bolt a little. It depends upon how much movement you could tolerate. The advantage with a slot is that you can avoid (and see you have avoided) any movement although it depends upon how tightly the nut needs to be tighened up.

If the nut only needs to be nipped up, I would use the slot. If the nut needs to be really tight, locknuts might be better.

If you have a lot of spare thread and are nipping-up only, you could use a mole wrench at the top of the thread. If you ever need to remove the nut just cut off the damaged thread.

Richard
Click to expand...

If I grind a slot, as you say, I'll be able to see if the bolt has moved. I guess I could use lock nuts and a slot.
 
bigwow said:
I always ask a neighbour to hold a spanner on the bolt, in 30 years only ever had one refusal.
Click to expand...

Yes I could, but only space for one in the confines of where the bolt is. I could ask a neighbour to jam the Bolt with a screwdriver from the outside though. But it's how to be certain the bolt does t move and break the seal. I'd prefer to be sure and self reliant. It's no good blaming 'Fred' when you're offshore taking in water
 
Depends on what is on the outside but you can sometimes use a ring spanner or socket and wrench held in position against something (taped or tied). Alternatively, a pair of molegrips on the outside bolt head may suffice if it turns against something solid.

However, much easier to get someone to hold the spanner!
 
Jaguar 25 said:
Depends on what is on the outside but you can sometimes use a ring spanner or socket and wrench held in position against something (taped or tied). Alternatively, a pair of molegrips on the outside bolt head may suffice if it turns against something solid.

However, much easier to get someone to hold the spanner!
Click to expand...

Countersunk screw head on the outside. Difficult to resist the torque applied with a spanner with just a screwdriver.

So, a slot or Mole grips on the tail end of the thread seem the best plans so far...
 
If you have access to an electric wheel nut gun as used on auto lug nuts,or even the drill type battery version,it spins the nuts very fast without turning the bolt.
 
Use a square shafted screwdriver and mole - if you can find a way to secure the screwdriver/mole assembly (which sounds almost impossible :( )

Extra long bolt, the nut to tighten on the 'inside' two nuts locked to each other at the end of the shaft, tighten inner bolt and hold outer 2 nuts with another spanner - but you've covered that one already!

Jonathan
 
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Been removing all the deck fittings off my boat recently ready for refurb & paint on my own and I've used mole grips on the nuts inside the boat while removing the screws from on deck. Fortunately has worked with everyone I've done so far. So hand tighten and then add grips and tighten from above.
 
PuffTheMagicDragon said:
^^^ +1 ^^^
Click to expand...

I would go for the slot rather than the flats ..... much easier and quicker and unless the nut has to be tight, less likely to slip that homemade flats and an adjustable which will always always slip, even on professional flats! :(

If happy to destroy the threads with flats, go for the mole grips ....... takes two seconds and no filings everywhere. :)

Richard
 
In the future, tighten the bolts when the sealant is not set. I think it is pure myth that you won't break the seal, and the seal under the hardware will be just fine so long as you camfer the bolt holes to leave little space. I don't think I'm the only one with this opinion.

Second, so long as you lube the nuts and use proper washers, there should be very little tendency for the bolt to turn. A carefully positioned Vice Grip will easily hold it. IF slotted, use over length bolts and then trim them.
 
RichardS said:
I would go for the slot rather than the flats ..... much easier and quicker and unless the nut has to be tight, less likely to slip that homemade flats and an adjustable which will always always slip, even on professional flats! :(

If happy to destroy the threads with flats, go for the mole grips ....... takes two seconds and no filings everywhere. :)

Richard
Click to expand...

You have more control with a spanner than a screwdriver ;) even hand ground flats with an adjustable. Use a cut off wheel to produce the flats rather than a bobbin grinding wheel. If you can't make that work, put the dremmel away and never pick one up again.

Threads will still work after you have ground flats, it takes very little effort to open out the slot with a screwdriver and render the threads useless, unless it's a large bolt.
 
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prof pat pending said:
You have more control with a spanner than a screwdriver ;) even hand ground flats with an adjustable. If you can't make that work, put the dremmel away and never pick one up again.
Click to expand...

Movement-free hand-ground flats with an adjustable ....... absolutely no chance! :)

If you could make that work you'd be on your mega-yacht in the Caribbean. :encouragement:

Richard
 
I can and have made that work, like most engineering problems you just need to think them through and apply a bit of common sense ;)

I performed much more difficult bodges in 35 years as an engineer, none of which will get me a mega-yacht :(
 
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thinwater said:
In the future, tighten the bolts when the sealant is not set. I think it is pure myth that you won't break the seal, and the seal under the hardware will be just fine so long as you camfer the bolt holes to leave little space. I don't think I'm the only one with this opinion.

Second, so long as you lube the nuts and use proper washers, there should be very little tendency for the bolt to turn. A carefully positioned Vice Grip will easily hold it. IF slotted, use over length bolts and then trim them.
Click to expand...
+1.
I would 'lube' the nuts with loctite, as, because the fitting is bolted down onto flexible sealant, it will move a bit under load and the bolts may tend to work loose.
I prefer to torque the fasteners while the sealant is wet, with a proper chamfer on each hole, filled with sealant.
But with care and good vice grips you should be ok.
 
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