[GB]

We have an outside light - an oblong plastic thingy - in a rather
exposed position. I opened it up to change the bulb, and there was some
water inside. What's the best way to stop this?

I thought of putting a couple of drain holes in the bottom, but that
seems too bodgy even for me.

The two parts of the lamp push together with a flange, but there's no
rubber seal between them. Is there any simple way of making a seal that
will still allow me too open the lamp again to change the bulb?



It looks similar to this one:

http://www.screwfix.com/p/lap-anti-v...ack-240v/31250

But that one is waterproof!

[Bob Minchin[_4_]]

GB wrote:
We have an outside light - an oblong plastic thingy - in a rather
exposed position. I opened it up to change the bulb, and there was some
water inside. What's the best way to stop this?

I thought of putting a couple of drain holes in the bottom, but that
seems too bodgy even for me.

The two parts of the lamp push together with a flange, but there's no
rubber seal between them. Is there any simple way of making a seal that
will still allow me too open the lamp again to change the bulb?



It looks similar to this one:

http://www.screwfix.com/p/lap-anti-v...ack-240v/31250


But that one is waterproof!
Drain holes in the lowest point are the way to go.

An outside container is very difficult to fully seal as thermal
expansion/contraction will act as a pump admitting small amounts of
water vapour laden air. The water condenses and stays inside and on the
next heating cycle the air gets pushed out but the water does not and so
it slowly builds up as the cycle repeats.
You still really need some sort of seal against driving rain. I often
use a silicone grease - Dow Corning MS4* smeared over the sealing faces
and wipe off any excess that squeezes out when you fit the cover.

* I think it has another name now (DC4?) but my toothpaste sized tube
will see me out so I've not bought any of the new name stuff.

[Dave Liquorice[_2_]]

On Fri, 10 Feb 2017 10:37:02 +0000, Bob Minchin wrote:

An outside container is very difficult to fully seal as thermal
expansion/contraction will act as a pump admitting small amounts of
water vapour laden air. The water condenses and stays inside and on the
next heating cycle the air gets pushed out but the water does not and so
it slowly builds up as the cycle repeats.

Double plus 1. Not many people realise/know that.

So although holes seem bodgy it's the only way. Only need one at the
lowest point and it doesn't need to be very big 1mm is ample. Much
bigger and a decent blow will manage to force water in, not to
mention letting in spiders or other wild life.

--
Cheers
Dave.

[GB]

On 10/02/2017 12:30, Dave Liquorice wrote:
On Fri, 10 Feb 2017 10:37:02 +0000, Bob Minchin wrote:

An outside container is very difficult to fully seal as thermal
expansion/contraction will act as a pump admitting small amounts of
water vapour laden air. The water condenses and stays inside and on the
next heating cycle the air gets pushed out but the water does not and so
it slowly builds up as the cycle repeats.

Double plus 1. Not many people realise/know that.

So although holes seem bodgy it's the only way. Only need one at the
lowest point and it doesn't need to be very big 1mm is ample. Much
bigger and a decent blow will manage to force water in, not to
mention letting in spiders or other wild life.


Thanks! So, tiny hole to allow air in and out, and use grease to seal
it. Brilliant! Why didn't I think of grease?

Curiously, we have two of these, one under the eaves in a very sheltered
position. That was bone dry inside, so I'm not 100% sure that
condensation is really an issue. It's possibly simpler than that.

[GB]

On 10/02/2017 12:58, GB wrote:
On 10/02/2017 12:30, Dave Liquorice wrote:
On Fri, 10 Feb 2017 10:37:02 +0000, Bob Minchin wrote:

An outside container is very difficult to fully seal as thermal
expansion/contraction will act as a pump admitting small amounts of
water vapour laden air. The water condenses and stays inside and on the
next heating cycle the air gets pushed out but the water does not and so
it slowly builds up as the cycle repeats.

Double plus 1. Not many people realise/know that.

So although holes seem bodgy it's the only way. Only need one at the
lowest point and it doesn't need to be very big 1mm is ample. Much
bigger and a decent blow will manage to force water in, not to
mention letting in spiders or other wild life.


Thanks! So, tiny hole to allow air in and out, and use grease to seal
it. Brilliant! Why didn't I think of grease?

Curiously, we have two of these, one under the eaves in a very sheltered
position. That was bone dry inside, so I'm not 100% sure that
condensation is really an issue. It's possibly simpler than that.



Mind you, the dry one is south-facing, so gets lots of sunlight on it.

[John Rumm]

On 10/02/2017 10:15, GB wrote:
We have an outside light - an oblong plastic thingy - in a rather
exposed position. I opened it up to change the bulb, and there was some
water inside. What's the best way to stop this?

I thought of putting a couple of drain holes in the bottom, but that
seems too bodgy even for me.

That's actually fairly normal practice - a 3mm hole at a low point...

The two parts of the lamp push together with a flange, but there's no
rubber seal between them. Is there any simple way of making a seal that
will still allow me too open the lamp again to change the bulb?

Get a tube of silicone grease from CPC. That will help seal, but does
not set or prevent you pulling it apart later.

It looks similar to this one:

http://www.screwfix.com/p/lap-anti-v...ack-240v/31250


But that one is waterproof!

or change the fitting for a waterproof one (although even waterproof
ones may still leak a bit)

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

[Andrew Gabriel]

In article ,
Huge writes:
On 2017-02-10, Dave Liquorice wrote:
On Fri, 10 Feb 2017 10:37:02 +0000, Bob Minchin wrote:

An outside container is very difficult to fully seal as thermal
expansion/contraction will act as a pump admitting small amounts of
water vapour laden air. The water condenses and stays inside and on the
next heating cycle the air gets pushed out but the water does not and so
it slowly builds up as the cycle repeats.

Double plus 1. Not many people realise/know that.

So although holes seem bodgy it's the only way. Only need one at the
lowest point and it doesn't need to be very big 1mm is ample. Much
bigger and a decent blow will manage to force water in, not to
mention letting in spiders or other wild life.

The spiders get in anyway. I have no idea how.

(Over the last few weeks I have dismantled all the outside electrics
in the so-far fruitless search for the nuisance RCD trips, and they
all had spiders in them. Even the IP44 junction boxes.)

Spiders can generate RCD trips.

My parents have a desk fan (class 2 - double insulated) which
has a 2-core cable and a plastic body. I was initially rather
surprised that it caused an RCD trip. The culprit was found in
the plug - a spider's web/nest between the live and earth.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

[Graham.[_11_]]

On Fri, 10 Feb 2017 15:04:16 -0000 (UTC),
(Andrew Gabriel) wrote:

In article ,
Huge writes:
On 2017-02-10, Dave Liquorice wrote:
On Fri, 10 Feb 2017 10:37:02 +0000, Bob Minchin wrote:

An outside container is very difficult to fully seal as thermal
expansion/contraction will act as a pump admitting small amounts of
water vapour laden air. The water condenses and stays inside and on the
next heating cycle the air gets pushed out but the water does not and so
it slowly builds up as the cycle repeats.

Double plus 1. Not many people realise/know that.

So although holes seem bodgy it's the only way. Only need one at the
lowest point and it doesn't need to be very big 1mm is ample. Much
bigger and a decent blow will manage to force water in, not to
mention letting in spiders or other wild life.

The spiders get in anyway. I have no idea how.

(Over the last few weeks I have dismantled all the outside electrics
in the so-far fruitless search for the nuisance RCD trips, and they
all had spiders in them. Even the IP44 junction boxes.)

Spiders can generate RCD trips.


So can ants. I once had a chain of them like a U-link between E & L in
my boiler junction box.


--

Graham.
%Profound_observation%

[ARW]

On 10/02/2017 12:55, Huge wrote:


The spiders get in anyway. I have no idea how.

(Over the last few weeks I have dismantled all the outside electrics
in the so-far fruitless search for the nuisance RCD trips, and they
all had spiders in them. Even the IP44 junction boxes.)



Have you still not done the divide and conquer by fitting RCBOs?


--
Adam

[Harry Bloomfield[_3_]]

on 10/02/2017, Bob Minchin supposed :
Drain holes in the lowest point are the way to go.

An outside container is very difficult to fully seal as thermal
expansion/contraction will act as a pump admitting small amounts of water
vapour laden air. The water condenses and stays inside and on the next
heating cycle the air gets pushed out but the water does not and so it slowly
builds up as the cycle repeats.
You still really need some sort of seal against driving rain. I often use a
silicone grease - Dow Corning MS4* smeared over the sealing faces and wipe
off any excess that squeezes out when you fit the cover.

* I think it has another name now (DC4?) but my toothpaste sized tube will
see me out so I've not bought any of the new name stuff.

+1

I always add a series of tiny drain holes to any fitting which is
outside in the weather. No matter what you do, water will get in, just
make sure it can get out more easily.

[newshound]

On 2/10/2017 10:15 AM, GB wrote:
We have an outside light - an oblong plastic thingy - in a rather
exposed position. I opened it up to change the bulb, and there was some
water inside. What's the best way to stop this?

I thought of putting a couple of drain holes in the bottom, but that
seems too bodgy even for me.

I'd go with the holes (I have done this myself, in the past). An
interesting philosophical question, when does a sound, pragmatic DIY fix
become a bodge?

That's of course assuming the holes are sufficiently far from the wires
that worst case driving rain, or even direct spray with a hose if you
are in the habit of doing that sort of thing, won't get on the exposed
connections.

[[email protected]]

On Friday, 10 February 2017 20:26:23 UTC, newshound wrote:
On 2/10/2017 10:15 AM, GB wrote:
We have an outside light - an oblong plastic thingy - in a rather
exposed position. I opened it up to change the bulb, and there was some
water inside. What's the best way to stop this?

I thought of putting a couple of drain holes in the bottom, but that
seems too bodgy even for me.

I'd go with the holes (I have done this myself, in the past). An
interesting philosophical question, when does a sound, pragmatic DIY fix
become a bodge?

A repair that is effective, reliable, safe, works ok & looks ok is good. Anything that fails those is a bodge.


NT

[Brian Gaff]

Might also be a nice idea to have some silica Gell inside as well.
However, some floodlights that look like they were built to withstand a
nuclear attack on a nearby 'listed' building still get water inside,
apparently, so I think the point is that there will always be some moisture
in sealed units.
Brian

--
----- -
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please!
"Bob Minchin" wrote in message
news
GB wrote:
We have an outside light - an oblong plastic thingy - in a rather
exposed position. I opened it up to change the bulb, and there was some
water inside. What's the best way to stop this?

I thought of putting a couple of drain holes in the bottom, but that
seems too bodgy even for me.

The two parts of the lamp push together with a flange, but there's no
rubber seal between them. Is there any simple way of making a seal that
will still allow me too open the lamp again to change the bulb?



It looks similar to this one:

http://www.screwfix.com/p/lap-anti-v...ack-240v/31250


But that one is waterproof!
Drain holes in the lowest point are the way to go.

An outside container is very difficult to fully seal as thermal
expansion/contraction will act as a pump admitting small amounts of water
vapour laden air. The water condenses and stays inside and on the next
heating cycle the air gets pushed out but the water does not and so it
slowly builds up as the cycle repeats.
You still really need some sort of seal against driving rain. I often use
a silicone grease - Dow Corning MS4* smeared over the sealing faces and
wipe off any excess that squeezes out when you fit the cover.

* I think it has another name now (DC4?) but my toothpaste sized tube will
see me out so I've not bought any of the new name stuff.

[ARW]

On 10/02/2017 22:39, Huge wrote:
On 2017-02-10, ARW wrote:
On 10/02/2017 12:55, Huge wrote:


The spiders get in anyway. I have no idea how.

(Over the last few weeks I have dismantled all the outside electrics
in the so-far fruitless search for the nuisance RCD trips, and they
all had spiders in them. Even the IP44 junction boxes.)



Have you still not done the divide and conquer by fitting RCBOs?

Can't bring myself to spend that amount of money with no guarantee of
improving matters. Haven't had one for a couple of weeks now, after
taking the feed to the Klargester & workshop out of circuit.



Fair enough.


BTW RCDs are like women - they are both over sensitive and will not
tell you why they turned off



--
Adam

[John Rumm]

On 10/02/2017 12:55, Huge wrote:
On 2017-02-10, Dave Liquorice wrote:
On Fri, 10 Feb 2017 10:37:02 +0000, Bob Minchin wrote:

An outside container is very difficult to fully seal as thermal
expansion/contraction will act as a pump admitting small amounts of
water vapour laden air. The water condenses and stays inside and on the
next heating cycle the air gets pushed out but the water does not and so
it slowly builds up as the cycle repeats.

Double plus 1. Not many people realise/know that.

So although holes seem bodgy it's the only way. Only need one at the
lowest point and it doesn't need to be very big 1mm is ample. Much
bigger and a decent blow will manage to force water in, not to
mention letting in spiders or other wild life.

The spiders get in anyway. I have no idea how.

(Over the last few weeks I have dismantled all the outside electrics
in the so-far fruitless search for the nuisance RCD trips, and they
all had spiders in them. Even the IP44 junction boxes.)

Bit like one of my PIRs:

http://wiki.diyfaq.org.uk/index.php/...nTheWiring.jpg


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

[newshound]

On 2/12/2017 11:15 AM, Huge wrote:
On 2017-02-12, John Rumm wrote:
On 10/02/2017 12:55, Huge wrote:
On 2017-02-10, Dave Liquorice wrote:
On Fri, 10 Feb 2017 10:37:02 +0000, Bob Minchin wrote:

An outside container is very difficult to fully seal as thermal
expansion/contraction will act as a pump admitting small amounts of
water vapour laden air. The water condenses and stays inside and on the
next heating cycle the air gets pushed out but the water does not and so
it slowly builds up as the cycle repeats.

Double plus 1. Not many people realise/know that.

So although holes seem bodgy it's the only way. Only need one at the
lowest point and it doesn't need to be very big 1mm is ample. Much
bigger and a decent blow will manage to force water in, not to
mention letting in spiders or other wild life.

The spiders get in anyway. I have no idea how.

(Over the last few weeks I have dismantled all the outside electrics
in the so-far fruitless search for the nuisance RCD trips, and they
all had spiders in them. Even the IP44 junction boxes.)

Bit like one of my PIRs:

http://wiki.diyfaq.org.uk/index.php/...nTheWiring.jpg

Yep. They all looked like that.


"Life will find a way".

[newshound]

On 2/10/2017 8:42 PM, wrote:
On Friday, 10 February 2017 20:26:23 UTC, newshound wrote:
On 2/10/2017 10:15 AM, GB wrote:
We have an outside light - an oblong plastic thingy - in a rather
exposed position. I opened it up to change the bulb, and there was some
water inside. What's the best way to stop this?

I thought of putting a couple of drain holes in the bottom, but that
seems too bodgy even for me.

I'd go with the holes (I have done this myself, in the past). An
interesting philosophical question, when does a sound, pragmatic DIY fix
become a bodge?

A repair that is effective, reliable, safe, works ok & looks ok is good. Anything that fails those is a bodge.


NT

I can see some circumstances where adding a "drain hole" might cause an
enclosure to fail the IP "knitting needle" test. That said, my view is
that anyone who tries to poke a knitting needle through a hole in an
electrical enclosure probably deserves to be zapped. Which is why we are
in philosophy territory: what constitutes "safe"?

[Vir Campestris]

On 12/02/2017 20:53, newshound wrote:
"Life will find a way".

The slug that crawled up the cable from our pond pump into the back of
the breaker was _not_ alive after the power tripped.

Andy

[Johnny B Good]

On Sat, 11 Feb 2017 08:10:58 +0000, Brian Gaff wrote:

Might also be a nice idea to have some silica Gell inside as well.
However, some floodlights that look like they were built to withstand a
nuclear attack on a nearby 'listed' building still get water inside,
apparently, so I think the point is that there will always be some
moisture in sealed units.

Unless you can make the weather seals *gas-tight*, moisture will
eventually accumulate inside such fittings. Silica-gel will only delay
the inevitable unless you include a heating element to dry it out on a
regular basis.

Aside from the issues of ingress by suicidal flora and fauna, it's often
best to have as much ventilation as possible without compromising
protection against horizontal driving precipitation. In some locations,
this might be defeated by the more severe forms of precipitation which
can be driven by up-draughts a considerable way towards any exposed
connections taking shelter from the elements in such an 'open air'
protective shroud.

One thing to consider, if adding a couple of 3 or 4 mm drain holes in
something like a PIR controlled 300 or 500 watt halogen security
floodlight, is the possibility of rainwater being rapidly sucked into the
enclosure when the lamp switches off causing a rapid drop in temperature
which generates a vacuum. The resulting spray could well impinge on the
still hot lamp's envelope causing it to crack or shatter from the ensuing
localised rapid cooling. Even something as apparently humble as a drain
hole needs to be properly engineered if you wish to minimise interference
by Murphy of "Murphy's Law" fame.

The modern world of manufacturing seems to be tackling the issue of
Murphy's Law by, in effect, waving two fingers at Murphy and saying, "We
can make them faster than you can break them!" Things can be designed to
be proofed against Murphy's Law, it's known in the trade as "Over-
Engineering", something not normally countenanced by the "Bean-Counters"
so we rarely see such wonders in real life these days. :-(

--
Johnny B Good

[[email protected]]

On Monday, 13 February 2017 03:10:10 UTC, Johnny B Good wrote:

One thing to consider, if adding a couple of 3 or 4 mm drain holes in
something like a PIR controlled 300 or 500 watt halogen security
floodlight, is the possibility of rainwater being rapidly sucked into the
enclosure when the lamp switches off causing a rapid drop in temperature
which generates a vacuum. The resulting spray could well impinge on the
still hot lamp's envelope causing it to crack or shatter from the ensuing
localised rapid cooling.

You're way overestimating things. There is no possibility of spraying.


NT

[Johnny B Good]

On Sun, 12 Feb 2017 22:46:50 -0800, tabbypurr wrote:

On Monday, 13 February 2017 03:10:10 UTC, Johnny B Good wrote:

One thing to consider, if adding a couple of 3 or 4 mm drain holes in
something like a PIR controlled 300 or 500 watt halogen security
floodlight, is the possibility of rainwater being rapidly sucked into
the enclosure when the lamp switches off causing a rapid drop in
temperature which generates a vacuum. The resulting spray could well
impinge on the still hot lamp's envelope causing it to crack or shatter
from the ensuing localised rapid cooling.

You're way overestimating things. There is no possibility of spraying.

Shhh... Don't let "Murphy" hear you say things like that. :-)

--
Johnny B Good

[ARW]

On 12/02/2017 21:14, Vir Campestris wrote:
On 12/02/2017 20:53, newshound wrote:
"Life will find a way".

The slug that crawled up the cable from our pond pump into the back of
the breaker was _not_ alive after the power tripped.

That reminds me I have a new thread to make.


Bloody slugs.

--
Adam