On Mon, 22 Nov 2004 08:02:26 GMT, Zak strung
together this:

I have repaired it with Araldite Rapid.

I wouldn't even entertain the idea of repairing it.
Buy a new one, WW2 has finished now.
--

SJW
A.C.S. Ltd
Please reply to group or use 'usenet' in email subject

Zak wrote:

The ceramic end on the 500W bulb in my quartz halogen floodlight has
cracked.

I have repaired it with Araldite Rapid.

Will the temperature of the bulb be too much for the adhesive?

I have a feeling that Araldite can not be used at very high temps but
can't find a Google reference which gives any real information.


No glue will sucessfully stick your bulb back together permanently.

--
Grunff

"Zak" wrote in message
...
The ceramic end on the 500W bulb in my quartz halogen floodlight has
cracked.

I have repaired it with Araldite Rapid.

Will the temperature of the bulb be too much for the adhesive?

I have a feeling that Araldite can not be used at very high temps but
can't find a Google reference which gives any real information.

these bulbs are only 50p each from screwfix, it cannot be worth the
aggravation of attempting anything more than clean the contacts in the way
of maintenance.

mrcheerful

The ceramic end on the 500W bulb in my quartz halogen floodlight has
cracked.

I have repaired it with Araldite Rapid.

In all my time, I've never heard of someone attempting to fix a light bulb.
Unless you are based in South Georgia or Tristan da Cunha, buy a new bulb,
it will be cheaper than the Araldite.

Christian.

"Zak" wrote in message
...
The ceramic end on the 500W bulb in my quartz halogen floodlight has
cracked.

I have repaired it with Araldite Rapid.

snip

This has got to be a troll.

don't know if i will be the only one to attempt to answer your question
rather than pass comment, but i doubt the glue will hold up to the extreme
temperatures the bulb produces...why not try it and see? in fact you
probably have done by now...did it work?

Steve

"Zak" wrote in message
...
The ceramic end on the 500W bulb in my quartz halogen floodlight has
cracked.

I have repaired it with Araldite Rapid.

Will the temperature of the bulb be too much for the adhesive?

Almost certainly it will probably catch fire :-(

I really don't see the logic of pratting about like that for a £1-50 lamp

In uk.d-i-y Zak wrote:
The ceramic end on the 500W bulb in my quartz halogen floodlight has
cracked.

I have repaired it with Araldite Rapid.

Will the temperature of the bulb be too much for the adhesive?

I have a feeling that Araldite can not be used at very high temps but
can't find a Google reference which gives any real information.

It will fail.
I would wrap it in wire, to keep it together when it fails.
But expect to need to replace.

"Zak" wrote:
The ceramic end on the 500W bulb in my quartz halogen floodlight has=20
cracked.
=20
I have repaired it with Araldite Rapid.
=20
Will the temperature of the bulb be too much for the adhesive?
=20
I have a feeling that Araldite can not be used at very high temps but=20
can't find a Google reference which gives any real information

You could also use Duct Tape (Gaffer Tape) - the high temp version. :-).

I do recall a high temp "dope" for sealing up vacuum system (OK to about
10^-5 Torr, I think). Sealed holes in glass and was flexible enough to
handle temp variations without losing seal.=20

Can't remember what it was called.

Tomasso.

Tomasso wrote:

"Zak" wrote:
The ceramic end on the 500W bulb in my quartz halogen floodlight has
cracked.

I have repaired it with Araldite Rapid.

Will the temperature of the bulb be too much for the adhesive?

I have a feeling that Araldite can not be used at very high temps but
can't find a Google reference which gives any real information

You could also use Duct Tape (Gaffer Tape) - the high temp version. :-).

I do recall a high temp "dope" for sealing up vacuum system (OK to about
10^-5 Torr, I think). Sealed holes in glass and was flexible enough to
handle temp variations without losing seal.

Can't remember what it was called.

Glyptal thermoset resin (phtalic anhydride, glycerin, red pigment...).

--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
http://www.mazepath.com/uncleal/qz.pdf

On Mon, 22 Nov 2004 18:48:06 -0000, "r.p.mcmurphy"
strung together this:

don't know if i will be the only one to attempt to answer your question

well, if you read the whole thread first you'd notice that you are in
fact the second person to post a answer to the question rather than an
alternative method.
--

SJW
A.C.S. Ltd
Please reply to group or use 'usenet' in email subject

"Zak" wrote:
The ceramic end on the 500W bulb in my quartz halogen floodlight has
cracked.

I have repaired it with Araldite Rapid.

Will the temperature of the bulb be too much for the adhesive?

I have a feeling that Araldite can not be used at very high temps but
can't find a Google reference which gives any real information


Aradite rapid joins can be pulled apart by heating to 150C. Standard
aradite is much stronger w.r.t heat.

--
--
Ron Jones

Don't repeat history, see unreported near misses in chemical lab/plant
at http://www.crhf.org.uk

Lurch wrote in message . ..
On Mon, 22 Nov 2004 18:48:06 -0000, "r.p.mcmurphy"
strung together this:

don't know if i will be the only one to attempt to answer your question

well, if you read the whole thread first you'd notice that you are in
fact the second person to post a answer to the question rather than an
alternative method.


a crack will let air in, result: instant filament failure.
araldite hasnt got the remotest chance of surviving the temp.

To repair it youll need to be able to weld the quartz, and do so while
the bulb is in a semi vacuum with bromine or iodine added. Halogens
are about the least repairable of all bulb types.


NT

In article , "N.
Thornton" says...
Lurch wrote in message . ..
On Mon, 22 Nov 2004 18:48:06 -0000, "r.p.mcmurphy"
strung together this:

don't know if i will be the only one to attempt to answer your question

well, if you read the whole thread first you'd notice that you are in
fact the second person to post a answer to the question rather than an
alternative method.


a crack will let air in, result: instant filament failure.
araldite hasnt got the remotest chance of surviving the temp.

It's not the envelope that's cracked.

On Mon, 22 Nov 2004 08:02:26 GMT, Zak wrote:

The ceramic end on the 500W bulb in my quartz halogen floodlight has
cracked.

I have repaired it with Araldite Rapid.

Will the temperature of the bulb be too much for the adhesive?

I have a feeling that Araldite can not be used at very high temps but
can't find a Google reference which gives any real information.

Hi,

Try baking it in the oven for a while, then check the strength of the
bond while it's hot.

I've got a feeling that the heat may soften the epoxy too much, if it
does then fire cement or superglue could be better alternatives.

cheers,
Pete.

On Tue, 23 Nov 2004 14:53:30 -0000, Rob Morley
strung together this:

It's not the envelope that's cracked.

Either way, it's a stupid idea to repair a halogen tube.
--

SJW
A.C.S. Ltd
Please reply to group or use 'usenet' in email subject

Rob Morley wrote in message et...
In article , "N.
Thornton" says...

a crack will let air in, result: instant filament failure.
araldite hasnt got the remotest chance of surviving the temp.

It's not the envelope that's cracked.

AFAIK there isnt anything else on a 500w halogen bulb that could crack.

NT

"Lurch" wrote in message
...
On Mon, 22 Nov 2004 18:48:06 -0000, "r.p.mcmurphy"
strung together this:

don't know if i will be the only one to attempt to answer your question

well, if you read the whole thread first you'd notice that you are in
fact the second person to post a answer to the question rather than an
alternative method.

actually i did read the whole thread and not one answered the op's question.

Steve

In uk.d-i-y N. Thornton wrote:
Rob Morley wrote in message et...
In article , "N.
Thornton" says...

a crack will let air in, result: instant filament failure.
araldite hasnt got the remotest chance of surviving the temp.

It's not the envelope that's cracked.

AFAIK there isnt anything else on a 500w halogen bulb that could crack.

Apart from the ceramic endy bits that the OP specifically said had cracked.

On Tue, 23 Nov 2004 20:41:54 -0000, "r.p.mcmurphy"
strung together this:

actually i did read the whole thread and not one answered the op's question.

You've obviously got some missing posts then, I can see another that
answers the question quite clearly here.
--

SJW
A.C.S. Ltd
Please reply to group or use 'usenet' in email subject

"Lurch" wrote in message
news
On Tue, 23 Nov 2004 20:41:54 -0000, "r.p.mcmurphy"
strung together this:

actually i did read the whole thread and not one answered the op's
question.

You've obviously got some missing posts then, I can see another that
answers the question quite clearly here.
--

SJW
A.C.S. Ltd
Please reply to group or use 'usenet' in email subject
Oh well. but it seems that so many just want to make comment rather than
answer questions sometimes!

Steve

Ian Stirling wrote in message ...
In uk.d-i-y N. Thornton wrote:
Rob Morley wrote in message et...

It's not the envelope that's cracked.

AFAIK there isnt anything else on a 500w halogen bulb that could crack.

Apart from the ceramic endy bits that the OP specifically said had cracked.

ok araldite still wont stand a chance, need something high temp.
car accessory places might have something.

NT

On Wed, 24 Nov 2004 09:32:12 -0000, "r.p.mcmurphy"
strung together this:

Oh well. but it seems that so many just want to make comment rather than
answer questions sometimes!

Yes, but in this case all the answers either said ''don't do it'' or
''don't do it because...''.
I agree, some threads offer absolutely no useful responses whatsoever,
this one said the same thing in different ways.
Anyway, who cares, as I've said before, this is usenet, it's all
******** and nonsense anyway.
--

SJW
A.C.S. Ltd
Please reply to group or use 'usenet' in email subject

N. Thornton wrote:

ok araldite still wont stand a chance, need something high temp.
car accessory places might have something.

The smallest purchasable quantity of a suitable adhesive will probably
cost at least ten times as much as a new lamp.

--
Andy

In uk.d-i-y Grunff wrote:
Andy Wade wrote:

The smallest purchasable quantity of a suitable adhesive will probably
cost at least ten times as much as a new lamp.


That's if there was a suitable adhesive, which there isn't.

There are many high temp ceramic adhesives.
Fire cement might well work.
You'd need to bake in the oven at 250C to set it.

Andy Wade wrote:

The smallest purchasable quantity of a suitable adhesive will probably
cost at least ten times as much as a new lamp.


That's if there was a suitable adhesive, which there isn't.

--
Grunff

Ian Stirling wrote:

There are many high temp ceramic adhesives.
Fire cement might well work.
You'd need to bake in the oven at 250C to set it.


IME fire cement isn't very adhesive. It has good cohesion, and will stay
in place forming a pretty good seal, but its adhesion to other materials
isn't great.


--
Grunff

Uncle Al wrote:
Tomasso wrote:

"Zak" wrote:

The ceramic end on the 500W bulb in my quartz halogen floodlight has
cracked.

I have repaired it with Araldite Rapid.

Will the temperature of the bulb be too much for the adhesive?

I have a feeling that Araldite can not be used at very high temps but
can't find a Google reference which gives any real information

You could also use Duct Tape (Gaffer Tape) - the high temp version. :-).

I do recall a high temp "dope" for sealing up vacuum system (OK to about
10^-5 Torr, I think). Sealed holes in glass and was flexible enough to
handle temp variations without losing seal.

Can't remember what it was called.


Glyptal thermoset resin (phtalic anhydride, glycerin, red pigment...).

You are showing your age. Glyptal went out about 1970. The two
sealants of choice are Torr-Seal (Varian) or equivalent, an epoxy which
goes to 10^-9 Torr and ~ 120 C, or silicone based resins that you can
use (with luck) to 450 C The former have structural strength. The
latter are strictly paint on and the replacements for glyptal (I
remember glyptol, but that could be age).

josh halpern

"Joshua Halpern" wrote:
...or silicone based resins that you can use (with luck) to 450 C =20
...strictly paint on and the replacements for glyptal=20

The silicone one is the one I remember.

For reasons that REALLY make no sense to me now, I had to
thermally decompose sodium azide (NaN3) under high vacuum...

Even in those days I was a theoretician, but for some reason got
tied up in this weird system (optical pumping Na Zeeman hyperfine
- primitive, but was able to vary a lot of conditions).=20

I may be showing my age, too.

Tomasso.

Grunff wrote in message ...
Ian Stirling wrote:

There are many high temp ceramic adhesives.
Fire cement might well work.
You'd need to bake in the oven at 250C to set it.


IME fire cement isn't very adhesive. It has good cohesion, and will stay
in place forming a pretty good seal, but its adhesion to other materials
isn't great.


IME fire cement has more or less no adhesion at all, it merely sits in
place, and is very weak. Its one and only good point is that it can
cope with high temps, it really seems to have nothing else good about
it.

High temp silicone may work, it can do upto 300C, and halogen capsules
run at around 250C. But a new bulb is cheaper.


NT

"Ron Jones" wrote in message ...

Aradite rapid joins can be pulled apart by heating to 150C. Standard
aradite is much stronger w.r.t heat.

JAAMOI, are Standard and Rapid of similar strengths at, say, -5C to
40C? I've often wondered, and used standard where strength is an
issue, 'just in case'.

Regards,

Paul.

Paul wrote:
"Ron Jones" wrote in message
...

Aradite rapid joins can be pulled apart by heating to 150C.
Standard aradite is much stronger w.r.t heat.

JAAMOI, are Standard and Rapid of similar strengths at, say, -5C to
40C? I've often wondered, and used standard where strength is an
issue, 'just in case'.

Regards,

Paul.

Personally, I've usually found the Standard is better - so long as you can
properly secure the mend for the full setting time of 3 days!!

--
--
Ron Jones

Don't repeat history, see unreported near misses in chemical lab/plant
at http://www.crhf.org.uk

"N. Thornton" wrote=20
ok araldite still wont stand a chance, need something high temp.
car accessory places might have something.

I went to a car accessory place and found an epoxy + iron "muffler =
putty"
product. It bonds to almost everything and has a continuous working=20
termperature of 260 C.=20

It was $14 for maybe 100 gm. To repair the ceramic part of the quartz
bulb, I expect this would be fine. To repair quartz, no way!

Tomasso.

In article ,
"Tomasso sometimes makes things up" writes:
I went to a car accessory place and found an epoxy + iron "muffler putty"
product. It bonds to almost everything and has a continuous working
termperature of 260 C.
It was $14 for maybe 100 gm. To repair the ceramic part of the quartz
bulb, I expect this would be fine. To repair quartz, no way!

As it happens, the max working temperature of the pinch seal is
250C in a halogen lamp. Besides obvious things like overrunning
the lamp or lack of ventilation, something which does sometimes
result in their failure is overheating the pinch seal caused by
bad lampholder contact generating heat. (That could also be the
cause of the ceramic end cap breaking.)

Another issue with glueing such things is differential expansion
as they change temperature. This can cause fine cracks in glass/
quartz/cintered aluminium oxide, which lets the fill gas out and
air in. A high pressure halogen lamp which has such a crack and
has filled with air whilst cold will often explode at switch-on.
If it cracks whilst hot, the halogen will escape and the filament
will more quickly evaporate and condense on the inside of the tube.

--
Andrew Gabriel

"Andrew Gabriel" wrote in message
...
In article ,
"Tomasso sometimes makes things up" writes:
I went to a car accessory place and found an epoxy + iron "muffler putty"
product. It bonds to almost everything and has a continuous working
termperature of 260 C.
It was $14 for maybe 100 gm. To repair the ceramic part of the quartz
bulb, I expect this would be fine. To repair quartz, no way!

As it happens, the max working temperature of the pinch seal is
250C in a halogen lamp. Besides obvious things like overrunning
the lamp or lack of ventilation, something which does sometimes
result in their failure is overheating the pinch seal caused by
bad lampholder contact generating heat. (That could also be the
cause of the ceramic end cap breaking.)

Another issue with glueing such things is differential expansion
as they change temperature. This can cause fine cracks in glass/
quartz/cintered aluminium oxide, which lets the fill gas out and
air in. A high pressure halogen lamp which has such a crack and
has filled with air whilst cold will often explode at switch-on.
If it cracks whilst hot, the halogen will escape and the filament
will more quickly evaporate and condense on the inside of the tube.

--
Andrew Gabriel

I thought the 'pinch seal' was the little bobble in the middle where they
seal it off after gas filling, rather than the end seals?

Scrim