Concealed joints again!

[SUNRAY]

That rather depends upon whether it's one containing acetic acid, doesn't it? There are one designed for 'electrical use' around.

Been there, seen that done to weatherproof RF connectors, wouldn't do it again even though the manufacturers picked up the tab for 2 riggers.

However, morq's point was obviously that the regs seem to be happy with any 'compound'

 

[morqthana]

OTOH, if it's just twin & earth under the floor/in a ceiling, and you're looking for a compliant solution, just bung in Wagos or Ideals etc, rather than faff about filling a screw terminal JB with Play-Doh or whatever.

 

[JohnW2]

OTOH, if it's just twin & earth under the floor/in a ceiling, and you're looking for a compliant solution, just bung in Wagos or Ideals etc, rather than faff about filling a screw terminal JB with Play-Doh or whatever.

Sure, in practice that's what one would do, if one were bothered about 'compliance'.

However, as I'm sure you understand, the reason I raised the issue was that I suddenly realised (after years of not thinking about this) that the regs really do seem to allow non-accessible screwed joints if one squirts some (unspecified) 'compound' into/over them!

 

[SUNRAY]

OTOH, if it's just twin & earth under the floor/in a ceiling, and you're looking for a compliant solution, just bung in Wagos or Ideals etc, rather than faff about filling a screw terminal JB with Play-Doh or whatever.

I wouldn't use play-doh... it's conductive

 

[JohnW2]

I wouldn't use play-doh... it's conductive

So is 'regular' silicone, until it is fully cured!

 

[morqthana]

I wouldn't use play-doh... it's conductive

Until I read that, I'd never bothered to look at the ingredients.

Play-Doh's current manufacturer, Hasbro, says the compound is primarily a mixture of water, salt, and flour, while its 2004 United States patent indicates it is composed of water, a starch-based binder, a retrogradation inhibitor, salt, lubricant, surfactant, preservative, hardener, humectant, fragrance, and color.

So I guess it would be.

Also I expect rodents would regard it as food.

 

[SUNRAY]

Also I expect rodents would regard it as food.

Oh yes rodents love Play-Doh and coincidently so do small children

 

[JohnW2]

Oh yes rodents love Play-Doh and coincidently so do small children

I imagine that's not quite a 'co-incidence', since I would presume that it's been deliberately formulated to be safe for small children to eat - particularly given that they will have a go at eating most things *(like soil!),even if they don't taste very nice

 

[SUNRAY]

I should have given it a wink

 

[JohnW2]

I should have given it a wink

I gave one on your behalf, but here's another .....

 

[SimonH2]

Sticking with potted joints, as long as the potting compound (at least partially) surrounds the screw heads - then the screws cannot work loose. That only leaves creep - and I remain "unconvinced" thats a problem given the number of screwed joints in a typical house installation (manynof which get no routine inspections.)

 

[JohnW2]

Sticking with potted joints, as long as the potting compound (at least partially) surrounds the screw heads - then the screws cannot work loose.

Yes, but only IF the (unspecified in regs) 'compound' more-or-less 'sets' (which proper potting compound would) - many of the other 'compounds' which have been mentioned would do little, if anything to stop a screw becoming loose. I suppose it comes down to whether one applies common sense or whether one goes literally by 'what the reg actually says'!

That only leaves creep - and I remain "unconvinced" thats a problem given the number of screwed joints in a typical house installation (manynof which get no routine inspections.)

Indeed - and I'm actually not really convinced' about either. In fact, there's probably a fair degree of overlap, since I would have thought that 'creep' (if it happens significantly) is one of the few likely causes of 'screws loosening' in non-accessible JBs, which are usually subjected to minimal stress or mechanical disturbance (leaving the only other thing I can think of being 'thermal cycling', which shouldn't really happen with a well-made joint).

 

[Harry Bloomfield]

(leaving the only other thing I can think of being 'thermal cycling', which shouldn't really happen with a well-made joint).

A properly made joint, especially in the usual brown Bakelite type joint box, is less likely to thermal cycle, than the wire itself. A properly made joint, has the wires overlapping, under the screws, making the resistance lower than the wires.

 

[JohnW2]

A properly made joint, especially in the usual brown Bakelite type joint box, is less likely to thermal cycle, than the wire itself. A properly made joint, has the wires overlapping, under the screws, making the resistance lower than the wires.

Exactly. That's why I wrote (and you quoted):

.... 'thermal cycling', which shouldn't really happen with a well-made joint).