Dry knuckle test

Talk Electrician Forum

Help Support Talk Electrician Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Robint

Active member
Joined
Mar 9, 2024
Messages
25
Reaction score
14
Location
london SE
I have to be careful here because I dont want to send the wrong message, but have any of you old hands heard of the above? I thought it was common knowledge amongst tradesmen who have been properly taught and know what they are doing. It as a tip I picked up in my apprentice years and it to do with checking metal surfaces in an unfamiliar place for any possible earth leakage. I came across a domestic kitchen once where most of the woring area had a lot of stainless steel and the lady of the house said sometimes she would get a tingle. I was only there on a social occasion and so didnt have any tools. But I resorted to the knuckle test and went around with one hand brushing my knuckle on various surfaces. Sure enough I was getting a small zap myself and went to the consumer unit to flip some circuits to isolate the area (as usual not properly labelled) I explained the problem and the Lady agreed to call a local man next morning. I heard later that some cowboy had been in adding extra sockets and failed to connect the earth and through appliances had put some live through to steel surfaces.

I had another occasion when I used the trick on an old garden wall, which amazingly gave a tingle - outdoor lighting with only 2 wire supply - old system.

Its not something I would ever condone or write down - just one of those old scool tricks I learnt.

Another one is never grasp and electrical item that might be live with both hands, old timer leccies always have one hand in their pocket if they have to work on live stuff (its not a sign of idleness I was told. That has been a valuable piece of advice that is ever in my mind

Obviously we cant suggest such practices etc
 
Never called it that, but yes!
There is also the "finger flick" which I will not go into detail about
Remember 'all the brave electricians are probably dead'

Best advice I was given over 55 years ago? 'Always treat it like it’s live, even when you know it’s dead. One day it won’t be dead and burning flesh smells really nasty and hurts'
 
Never called it that, but yes!
There is also the "finger flick" which I will not go into detail about
Remember 'all the brave electricians are probably dead'

Best advice I was given over 55 years ago? 'Always treat it like it’s live, even when you know it’s dead. One day it won’t be dead and burning flesh smells really nasty and hurts'
Ho Hum , I hope you didnt mean that they "died from the finger flick" test
IMHO the finger is not as sensitive as the back of the knuckle or even the back of the hand. Note that if you got a strong zap , it would likely cause you to thump yourself in the chest - fairly harmless. YMMV.
We have non contact volt detectors now which can replace the function of the neon. Ive never used this new tech and would be inclined to stay with my neon which has served me well over the years - but its your call . What do members here think of this new tech?

Its always a bit worrying when you come across some cut off cable with bare ends under a floor board and its not obvious where its from? So I tape it up and put it in a jb labeled "do not use"

BTW I heard it said that most of the House Bashing Leccies true and valuable skill and experience comes from dealing with older housing stock and minimising potential damage to premises appearance and structure - not something you learn in college from a book. So there are tricks of the trade we cant write down for obvious reasons.
 
Back of finger nail is my version of that, but best avoided if possible.

Old housing stock has been my main line of work. They definetly don't teach you anything about that on any courses.
 
Back of finger nail is my version of that, but best avoided if possible.

Old housing stock has been my main line of work. They definetly don't teach you anything about that on any courses.
Yes indeed its dirty secret leccies know - nudge nudge KWIM.

Here's a dilemma you probably cant specifically acknowledge

Pubs - notorious for cowboys bodging addons etc Worse area IMHO was outside lighting, beer gardens etc (those nasty lethal cheap charlie Al halogen floodlights - and later LED versions with no earth connection blatant negligence). Number of times I came across JBs when opened up had significant water inside - but didnt trip RCD. Fortunately rain water is not very conductive. But what do you do? If you go into the Guvnr and say the outdoor wiring is unsafe and need several days upgrade (when the Guv only wanted a light on a new table he put out) you will soon find yourself off his Xmas card list and out of work. He will doubtless go to Joe Bloggs the bodger whole will strap on a new cct for an "earner". Guv says his lights were ok till you came along and said they were not. If you are a local Sole trader, relying on word of mouth largely

That where the whole IEE regs/Part P falls down. Landlords who must have legal yearly inspections will use a tame leccie (often from another County?) To sign off properties KWIM
 
Yes indeed its dirty secret leccies know - nudge nudge KWIM.

Here's a dilemma you probably cant specifically acknowledge

Pubs - notorious for cowboys bodging addons etc Worse area IMHO was outside lighting, beer gardens etc (those nasty lethal cheap charlie Al halogen floodlights - and later LED versions with no earth connection blatant negligence). Number of times I came across JBs when opened up had significant water inside - but didnt trip RCD. Fortunately rain water is not very conductive. But what do you do? If you go into the Guvnr and say the outdoor wiring is unsafe and need several days upgrade (when the Guv only wanted a light on a new table he put out) you will soon find yourself off his Xmas card list and out of work. He will doubtless go to Joe Bloggs the bodger whole will strap on a new cct for an "earner". Guv says his lights were ok till you came along and said they were not. If you are a local Sole trader, relying on word of mouth largely

That where the whole IEE regs/Part P falls down. Landlords who must have legal yearly inspections will use a tame leccie (often from another County?) To sign off properties KWIM
Wow pubs !
brings back memories , like cleaning fluorescent light diffusers that were orange with nicotine or that drip of nicotine on light bulbs or even the extract fans that were full of….nicotine and that fluff which stopped them from working.( once you cut your way through the cigarette smoke)
Best advice I got when I started working with the LEC when visiting substations was to keep both hands in my pockets to stop me from touching the seemingly innocent live bare busbars
 
Pubs - notorious for cowboys bodging addons etc Worse area IMHO was outside lighting, beer gardens etc (those nasty lethal cheap charlie Al halogen floodlights - and later LED versions with no earth connection blatant negligence). Number of times I came across JBs when opened up had significant water inside - but didnt trip RCD. Fortunately rain water is not very conductive. But what do you do? If you go into the Guvnr and say the outdoor wiring is unsafe and need several days upgrade (when the Guv only wanted a light on a new table he put out) you will soon find yourself off his Xmas card list and out of work. He will doubtless go to Joe Bloggs the bodger whole will strap on a new cct for an "earner". Guv says his lights were ok till you came along and said they were not. If you are a local Sole trader, relying on word of mouth largely

https://www.bbc.co.uk/news/uk-england-london-55753100
 
My motto is "never touch anything that my neon screwdriver has not touched first"
Q I'm not gloating, I'm just stating a fact of life - No Part P in Scotland UQ

For my benefit, what do you do up in the Bonny Land - links?

I could never understand the negligence and betrayal of GOV dumping the IEE regs on to the LA Building Control - they had no experience in that area at all (nor funding to take the responsibility, so it was promptly farmed out to contractors - the rest is history
 
Q I'm not gloating, I'm just stating a fact of life - No Part P in Scotland UQ

For my benefit, what do you do up in the Bonny Land - links?

I could never understand the negligence and betrayal of GOV dumping the IEE regs on to the LA Building Control - they had no experience in that area at all (nor funding to take the responsibility, so it was promptly farmed out to contractors - the rest is history
For jobs that require building control anyway, new builds, extensions etc, it is covered by building control. BC will want to see an EIC for the electrical work and that is all. If the local BC don't know you they may check your qualifications. I am known and EIC's accepted in 3 council areas up here.

For anything that does not require building control you just issue an EIC to the customer, just like the good old days down south.

It is probably going to change soon, but I will be retired by then and not bothered.
 
My motto is "never touch anything that my neon screwdriver has not touched first"

A neon screwdriver and/or an industry recognised voltage detector, (that can give an audible warning of a voltage detected with only one probe connected), are your best friends when you suspect that something may be live, that shouldn't be live!
 
Indeed IMHO all consumer units should have a lockable tab on on isolators, in case anyone else working in the premises decides to flip a switch. In the old rewireable fuse days, you could pull a fuse and put it in your pocket.

Maybe disconnect the cct mcb and pull it out and hope there's no cross wiring. With HMOs and dodgy landlords who used cowboys, tenants stealing electric, you never know.
 
Indeed IMHO all consumer units should have a lockable tab on on isolators, in case anyone else working in the premises decides to flip a switch. In the old rewireable fuse days, you could pull a fuse and put it in your pocket.

Maybe disconnect the cct mcb and pull it out and hope there's no cross wiring. With HMOs and dodgy landlords who used cowboys, tenants stealing electric, you never know.

any decent electrician will have a MCB lockout. if you're not going to get that out to lock off the circuit, then you probably wouldnt put a lock through a uilt in lockoff either
 
any decent electrician will have a MCB lockout. if you're not going to get that out to lock off the circuit, then you probably wouldnt put a lock through a uilt in lockoff either
I'd forgotten about those, I didnt do house bashing except as a young fella. Its only come to my attention cos Ive been looking as Solar Systems and find myself amazed at total amateurs messing with dc kit, suck it and see DHs. or thrown together with Cowboy companies (smell like Roofers). We havent got a Gov worth a damn and I dont hold out hope for the next GE lot that get in. So as far as Domestic electrical safety in this new area, no one give a toss. Remember the last mess the Minister made of it dumping BS7671 on the local council BC Part P - then walked away and left the foxes running the chicken house IIRR 16th Ed IEE regs
 
Top