Hi all,

I'm helping a mate who has just bought a second hand silent compressor
(on my recommendation) and the one he bought was know faulty, 'spares
or repair' etc.

On testing there was no output (as advertised) but long-short, I
partially stripped it (someone had been there before me) and found the
reed valved and 'cylinder head' had a fair amount of carbon build up
on them.

One reed just sits on a couple of location pins so can be removed and
it and it's seats cleaned easily but the other is trapped behind a
support (that manages the maximum opening) so I can't really get in /
under that to clean it all.

I've had it in an ultrasonic cleaning tank at 60 DegC and whilst it
did seem to remove (or soften) quite a lot of it, I'm not sure that it
is properly cleaned in all the little crevices.

So, to the chemists probably, is there a reasonably 'safe' / chemical
way I could remove this black stuff (carbonised mineral oil deposits?)
without melting my fingers or the alloy / steel parts or should I
drill the rivets out, strip it down and cleaning it mechanically (the
stuff does scrape off reasonably easily from those bits now) and
re-attach it with some small nuts and bolts?

Cheers, T i m

p.s. It may be that the fixed reed is bent slightly so might need
removing to reset, or it could simply be held up slightly by said
deposits. If it makes the compressor work, mate would invest in a
service kit but they aren't cheap.

On 20/10/2017 11:37, T i m wrote:
Hi all,

I'm helping a mate who has just bought a second hand silent compressor
(on my recommendation) and the one he bought was know faulty, 'spares
or repair' etc.

On testing there was no output (as advertised) but long-short, I
partially stripped it (someone had been there before me) and found the
reed valved and 'cylinder head' had a fair amount of carbon build up
on them.

One reed just sits on a couple of location pins so can be removed and
it and it's seats cleaned easily but the other is trapped behind a
support (that manages the maximum opening) so I can't really get in /
under that to clean it all.

I've had it in an ultrasonic cleaning tank at 60 DegC and whilst it
did seem to remove (or soften) quite a lot of it, I'm not sure that it
is properly cleaned in all the little crevices.

So, to the chemists probably, is there a reasonably 'safe' / chemical
way I could remove this black stuff (carbonised mineral oil deposits?)
without melting my fingers or the alloy / steel parts or should I
drill the rivets out, strip it down and cleaning it mechanically (the
stuff does scrape off reasonably easily from those bits now) and
re-attach it with some small nuts and bolts?

Cheers, T i m

p.s. It may be that the fixed reed is bent slightly so might need
removing to reset, or it could simply be held up slightly by said
deposits. If it makes the compressor work, mate would invest in a
service kit but they aren't cheap.

Caustic soda is used for decarbonising two stroke exhausts. It wont
harm the metal.

Cheers
--
Clive

On 20/10/2017 12:18, Clive Arthur wrote:
On 20/10/2017 11:37, T i m wrote:
Hi all,

I'm helping a mate who has just bought a second hand silent compressor
(on my recommendation) and the one he bought was know faulty, 'spares
or repair' etc.

On testing there was no output (as advertised) but long-short, I
partially stripped it (someone had been there before me) and found the
reed valved and 'cylinder head' had a fair amount of carbon build up
on them.

One reed just sits on a couple of location pins so can be removed and
it and it's seats cleaned easily but the other is trapped behind a
support (that manages the maximum opening) so I can't really get in /
under that to clean it all.

I've had it in an ultrasonic cleaning tank at 60 DegC and whilst it
did seem to remove (or soften) quite a lot of it, I'm not sure that it
is properly cleaned in all the little crevices.

So, to the chemists probably, is there a reasonably 'safe' / chemical
way I could remove this black stuff (carbonised mineral oil deposits?)
without melting my fingers or the alloy / steel parts or should I
drill the rivets out, strip it down and cleaning it mechanically (the
stuff does scrape off reasonably easily from those bits now) and
re-attach it with some small nuts and bolts?

Cheers, T i m

p.s. It may be that the fixed reed is bent slightly so might need
removing to reset, or it could simply be held up slightly by said
deposits. If it makes the compressor work, mate would invest in a
service kit but they aren't cheap.

Caustic soda is used for decarbonising two stroke exhausts.Â* It wont
harm the metal.

Cheers

I woul be very wary of using caustic soda (sodium hydtoxide) as it
attacks aliminium and I would suspect that it might attack aluminium
alloys.At best I would apply a drop if solution to a an area where
corrosion would not be a problem. Be aware that dissolving caustic soda
solid in water releases a large amount of heat. It also attacks skin so
wear gloves and goggles

Malcolm

On Fri, 20 Oct 2017 12:18:46 +0100, Clive Arthur
wrote:

snip

Caustic soda is used for decarbonising two stroke exhausts. It wont
harm the metal.

Good idea, thanks, I'll give it a go. ;-)

Cheers, T i m

On 2017-10-20, Malcolm Race wrote:
On 20/10/2017 12:18, Clive Arthur wrote:
On 20/10/2017 11:37, T i m wrote:

So, to the chemists probably, is there a reasonably 'safe' / chemical
way I could remove this black stuff (carbonised mineral oil deposits?)
without melting my fingers or the alloy / steel parts
^^^^^
I assume that's aluminium alloy.


Caustic soda is used for decarbonising two stroke exhausts.Â* It wont
harm the metal.

I assume those exhausts are just steel, not "alloy / steel". It won't
harm the steel.


I woul be very wary of using caustic soda (sodium hydtoxide) as it
attacks aliminium and I would suspect that it might attack aluminium
alloys.

It does. One method of last resort for removing stuck aluminium alloy
seatposts from steel bike frames is to dissolve the seatpost with
caustic soda.

On Fri, 20 Oct 2017 12:51:39 +0100, Malcolm Race
wrote:

snip

I woul be very wary of using caustic soda (sodium hydtoxide) as it
attacks aliminium and I would suspect that it might attack aluminium
alloys.At best I would apply a drop if solution to a an area where
corrosion would not be a problem. Be aware that dissolving caustic soda
solid in water releases a large amount of heat. It also attacks skin so
wear gloves and goggles

Thanks for the cautions Malcolm.

FWIW we had a bag of 'Soda crystals' that we put a spoonful of in the
washing machine now and again and that suggests it can also be used
for cleaning BBQ stuff. It (as you say) also cautions against allowing
it in contact with aluminium so I've just put the steel reed valve
block in the solution for now. ;-)

If that does get damaged somehow it would be fully replaced in a
service kit (so we have little to lose etc).

Cheers, T i m

On 20/10/2017 12:18, Clive Arthur wrote:
On 20/10/2017 11:37, T i m wrote:

So, to the chemists probably, is there a reasonably 'safe' / chemical
way I could remove this black stuff (carbonised mineral oil deposits?)
without melting my fingers or the alloy / steel parts or should I
drill the rivets out, strip it down and cleaning it mechanically (the
stuff does scrape off reasonably easily from those bits now) and
re-attach it with some small nuts and bolts?

Cheers, T i m

p.s. It may be that the fixed reed is bent slightly so might need
removing to reset, or it could simply be held up slightly by said
deposits. If it makes the compressor work, mate would invest in a
service kit but they aren't cheap.

Caustic soda is used for decarbonising two stroke exhausts.Â* It wont
harm the metal.

Depends a lot what the metal is. Steel won't but aluminium alloys will
dissolve rapidly in caustic soda and some engines are made of that.

I'd be inclined to try some combination of white spirit and Swarfega to
soften the carbonised black gunge.

--
Regards,
Martin Brown

On 20 Oct 2017 13:05:12 +0100 (BST), Alan Braggins
wrote:

On 2017-10-20, Malcolm Race wrote:
On 20/10/2017 12:18, Clive Arthur wrote:
On 20/10/2017 11:37, T i m wrote:

So, to the chemists probably, is there a reasonably 'safe' / chemical
way I could remove this black stuff (carbonised mineral oil deposits?)
without melting my fingers or the alloy / steel parts
^^^^^
I assume that's aluminium alloy.

Sorry, yes, it's an 'aluminium head and I have no idea if it / how it
is alloyed. ;-)


I woul be very wary of using caustic soda (sodium hydtoxide) as it
attacks aliminium and I would suspect that it might attack aluminium
alloys.

It does. One method of last resort for removing stuck aluminium alloy
seatposts from steel bike frames is to dissolve the seatpost with
caustic soda.

Good tip. ;-)

FWIW, I'm currently experimenting with the steel reed block in some
'Soda Crystals' (Sodium carbonate decahydrate) as we had some here. Is
that likely to do anything as one of the uses it mentions on the
packet is to clean pans, hobs and BBQ stuff (that sound like a carbon
type of buildup)?

Cheers, T i m

On Fri, 20 Oct 2017 13:50:34 +0100 (GMT+01:00), jim k wrote:

snip

So, to the chemists probably, is there a reasonably 'safe' / chemical
way I could remove this black stuff (carbonised mineral oil deposits?)
without melting my fingers or the alloy / steel parts or should I
drill the rivets out, strip it down and cleaning it mechanically (the
stuff does scrape off reasonably easily from those bits now) and
re-attach it with some small nuts and bolts?


Carburettor cleaner?

That's a good thought and I have a can here. I'll give it a try and it
would also be good for blasting any bits away from under the reed
valve etc.

I'll see what it looks like once out of the washing soda soak. ;-)

Cheers, T i m

In article ,
T i m wrote:
So, to the chemists probably, is there a reasonably 'safe' / chemical
way I could remove this black stuff (carbonised mineral oil deposits?)
without melting my fingers or the alloy / steel parts or should I
drill the rivets out, strip it down and cleaning it mechanically (the
stuff does scrape off reasonably easily from those bits now) and
re-attach it with some small nuts and bolts?

Carburettor cleaner. From any decent car accessory shop.

--
*I got a job at a bakery because I kneaded dough.*

Dave Plowman London SW
To e-mail, change noise into sound.

T i m Wrote in message:
Hi all,

I'm helping a mate who has just bought a second hand silent compressor
(on my recommendation) and the one he bought was know faulty, 'spares
or repair' etc.

On testing there was no output (as advertised) but long-short, I
partially stripped it (someone had been there before me) and found the
reed valved and 'cylinder head' had a fair amount of carbon build up
on them.

One reed just sits on a couple of location pins so can be removed and
it and it's seats cleaned easily but the other is trapped behind a
support (that manages the maximum opening) so I can't really get in /
under that to clean it all.

I've had it in an ultrasonic cleaning tank at 60 DegC and whilst it
did seem to remove (or soften) quite a lot of it, I'm not sure that it
is properly cleaned in all the little crevices.

So, to the chemists probably, is there a reasonably 'safe' / chemical
way I could remove this black stuff (carbonised mineral oil deposits?)
without melting my fingers or the alloy / steel parts or should I
drill the rivets out, strip it down and cleaning it mechanically (the
stuff does scrape off reasonably easily from those bits now) and
re-attach it with some small nuts and bolts?

Cheers, T i m

p.s. It may be that the fixed reed is bent slightly so might need
removing to reset, or it could simply be held up slightly by said
deposits. If it makes the compressor work, mate would invest in a
service kit but they aren't cheap.


Carburettor cleaner?
--
Jim K


----Android NewsGroup Reader----
http://usenet.sinaapp.com/

T i m wrote:
On Fri, 20 Oct 2017 12:51:39 +0100, Malcolm Race
wrote:

snip

I woul be very wary of using caustic soda (sodium hydtoxide) as it
attacks aliminium and I would suspect that it might attack aluminium
alloys.At best I would apply a drop if solution to a an area where
corrosion would not be a problem. Be aware that dissolving caustic soda
solid in water releases a large amount of heat. It also attacks skin so
wear gloves and goggles

Thanks for the cautions Malcolm.

FWIW we had a bag of 'Soda crystals' that we put a spoonful of in the
washing machine now and again and that suggests it can also be used
for cleaning BBQ stuff. It (as you say) also cautions against allowing
it in contact with aluminium so I've just put the steel reed valve
block in the solution for now. ;-)


Sodium hydroxide (caustic soda)and soda crystals (sodium carbonate)are
different.



If that does get damaged somehow it would be fully replaced in a
service kit (so we have little to lose etc).

Cheers, T i m

On 20/10/2017 14:13, FMurtz wrote:
T i m wrote:
On Fri, 20 Oct 2017 12:51:39 +0100, Malcolm Race
wrote:

snip

I woul be very wary of using caustic soda (sodium hydtoxide) as it
attacks aliminium and I would suspect that it might attack aluminium
alloys.At best I would apply a drop if solution to a an area where
corrosion would not be a problem.Â* Be aware that dissolving caustic soda
solid in water releases a large amount of heat.Â* It also attacks skin so
wear gloves and goggles

Thanks for the cautions Malcolm.

FWIW we had a bag of 'Soda crystals' that we put a spoonful of in the
washing machine now and again and that suggests it can also be used
for cleaning BBQ stuff. It (as you say) also cautions against allowing
it in contact with aluminium so I've just put the steel reed valve
block in the solution for now. ;-)


Sodium hydroxide (caustic soda)and soda crystals (sodium carbonate)are
different.

Soda crystals are more commonly known as washing soda (sodium carbonate
decahydrate). This gives an alkaline solution which will attack
aluminium but not as vigorously as caustic soda

Malcolm



If that does get damaged somehow it would be fully replaced in a
service kit (so we have little to lose etc).

Cheers, T i m

On Fri, 20 Oct 2017 14:42:44 +0100, Malcolm Race
wrote:

snip

Soda crystals are more commonly known as washing soda (sodium carbonate
decahydrate). This gives an alkaline solution which will attack
aluminium but not as vigorously as caustic soda

So, would it still have a similar cleaning effect for my needs?

Cheers, T i m

On 20/10/17 13:56, T i m wrote:
On 20 Oct 2017 13:05:12 +0100 (BST), Alan Braggins
wrote:

On 2017-10-20, Malcolm Race wrote:
On 20/10/2017 12:18, Clive Arthur wrote:
On 20/10/2017 11:37, T i m wrote:

So, to the chemists probably, is there a reasonably 'safe' / chemical
way I could remove this black stuff (carbonised mineral oil deposits?)
without melting my fingers or the alloy / steel parts
^^^^^
I assume that's aluminium alloy.

Sorry, yes, it's an 'aluminium head and I have no idea if it / how it
is alloyed. ;-)


I woul be very wary of using caustic soda (sodium hydtoxide) as it
attacks aliminium and I would suspect that it might attack aluminium
alloys.

It does. One method of last resort for removing stuck aluminium alloy
seatposts from steel bike frames is to dissolve the seatpost with
caustic soda.

Good tip. ;-)

FWIW, I'm currently experimenting with the steel reed block in some
'Soda Crystals' (Sodium carbonate decahydrate) as we had some here. Is
that likely to do anything as one of the uses it mentions on the
packet is to clean pans, hobs and BBQ stuff (that sound like a carbon
type of buildup)?

Cheers, T i m

caustic will dissolve olefins - that is members of the CnHm format that
are not too polymerised. It does that by sticking an OH on one end of
the chain, thus rendering the olefins into soluble detergent.

Insofar as the black gunge is in fact hydrocarbon, it will remove it.
However if it's pure carbon, it won't, and what you need there is red
hot oxygen.

Tht will simply oxidise it and probably rust the steel a bit at the same
time.

--
€œA leader is best When people barely know he exists. Of a good leader,
who talks little,When his work is done, his aim fulfilled,They will say,
€œWe did this ourselves.€�

ۥ Lao Tzu, Tao Te Ching

On 20/10/2017 13:59, T i m wrote:
On Fri, 20 Oct 2017 13:50:34 +0100 (GMT+01:00), jim k wrote:

snip

So, to the chemists probably, is there a reasonably 'safe' / chemical
way I could remove this black stuff (carbonised mineral oil deposits?)
without melting my fingers or the alloy / steel parts or should I
drill the rivets out, strip it down and cleaning it mechanically (the
stuff does scrape off reasonably easily from those bits now) and
re-attach it with some small nuts and bolts?


Carburettor cleaner?

That's a good thought and I have a can here. I'll give it a try and it
would also be good for blasting any bits away from under the reed
valve etc.

I'll see what it looks like once out of the washing soda soak. ;-)

Cheers, T i m

Isnt there something to remove carbon etc from car Airflow
sensors/gauges ? Seem to remember some advice when I replaced the one on
my old diesel Golf .

On 20/10/2017 15:20, T i m wrote:
On Fri, 20 Oct 2017 14:42:44 +0100, Malcolm Race
wrote:

snip

Soda crystals are more commonly known as washing soda (sodium carbonate
decahydrate). This gives an alkaline solution which will attack
aluminium but not as vigorously as caustic soda

So, would it still have a similar cleaning effect for my needs?

Cheers, T i m

I honestly don't know.. It does attack aluminium so try a patch test on
an unimportant area. It will attasck aluminium foil, albet slowly
(immersing a tarnished piece of silver in a solution of washing soda
containing aluminium foil will clean the silver converting the silver
compounds back to silver. It is the chemical reaction between the
silver and aluminium which does the work)

Malcolm
should have said I have a chemistry degree and taught the subject for a
considerable number of years

On 20/10/17 13:24, T i m wrote:
On Fri, 20 Oct 2017 12:51:39 +0100, Malcolm Race
wrote:

snip

I woul be very wary of using caustic soda (sodium hydtoxide) as it
attacks aliminium and I would suspect that it might attack aluminium
alloys.At best I would apply a drop if solution to a an area where
corrosion would not be a problem. Be aware that dissolving caustic soda
solid in water releases a large amount of heat. It also attacks skin so
wear gloves and goggles

Thanks for the cautions Malcolm.

FWIW we had a bag of 'Soda crystals' that we put a spoonful of in the
washing machine now and again and that suggests it can also be used
for cleaning BBQ stuff.

That a is sodium carbonate. Almost completely useless at anything, but
safe for muppets to have in their possession.




--
Religion is regarded by the common people as true, by the wise as
foolish, and by the rulers as useful.

(Seneca the Younger, 65 AD)

In article ,
Robert wrote:
Isnt there something to remove carbon etc from car Airflow
sensors/gauges ? Seem to remember some advice when I replaced the one on
my old diesel Golf .

Commonly called carburettor cleaner. Dissolves all the gunk you get with
burning petrol and oil. And is safe on most metals and plastics etc as
found in a car.

--
*Consciousness: That annoying time between naps.

Dave Plowman London SW
To e-mail, change noise into sound.

"Dave Plowman (News)" Wrote in message:
In article ,
T i m wrote:
So, to the chemists probably, is there a reasonably 'safe' / chemical
way I could remove this black stuff (carbonised mineral oil deposits?)
without melting my fingers or the alloy / steel parts or should I
drill the rivets out, strip it down and cleaning it mechanically (the
stuff does scrape off reasonably easily from those bits now) and
re-attach it with some small nuts and bolts?

Carburettor cleaner. From any decent car accessory shop.


Like I said earlier.
--
Jim K


----Android NewsGroup Reader----
http://usenet.sinaapp.com/

It pongs as well.
I suppose if one is not sure of the materials its a bit awkward on how to
advise on a suitable solvent.
Brian

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

Blind user, so no pictures please!
"Malcolm Race" wrote in message
news
On 20/10/2017 12:18, Clive Arthur wrote:
On 20/10/2017 11:37, T i m wrote:
Hi all,

I'm helping a mate who has just bought a second hand silent compressor
(on my recommendation) and the one he bought was know faulty, 'spares
or repair' etc.

On testing there was no output (as advertised) but long-short, I
partially stripped it (someone had been there before me) and found the
reed valved and 'cylinder head' had a fair amount of carbon build up
on them.

One reed just sits on a couple of location pins so can be removed and
it and it's seats cleaned easily but the other is trapped behind a
support (that manages the maximum opening) so I can't really get in /
under that to clean it all.

I've had it in an ultrasonic cleaning tank at 60 DegC and whilst it
did seem to remove (or soften) quite a lot of it, I'm not sure that it
is properly cleaned in all the little crevices.

So, to the chemists probably, is there a reasonably 'safe' / chemical
way I could remove this black stuff (carbonised mineral oil deposits?)
without melting my fingers or the alloy / steel parts or should I
drill the rivets out, strip it down and cleaning it mechanically (the
stuff does scrape off reasonably easily from those bits now) and
re-attach it with some small nuts and bolts?

Cheers, T i m

p.s. It may be that the fixed reed is bent slightly so might need
removing to reset, or it could simply be held up slightly by said
deposits. If it makes the compressor work, mate would invest in a
service kit but they aren't cheap.

Caustic soda is used for decarbonising two stroke exhausts. It wont harm
the metal.

Cheers

I woul be very wary of using caustic soda (sodium hydtoxide) as it attacks
aliminium and I would suspect that it might attack aluminium alloys.At
best I would apply a drop if solution to a an area where corrosion would
not be a problem. Be aware that dissolving caustic soda solid in water
releases a large amount of heat. It also attacks skin so wear gloves and
goggles

Malcolm

Dave Plowman (News) wrote:
In article ,
Robert wrote:
Isnt there something to remove carbon etc from car Airflow
sensors/gauges ? Seem to remember some advice when I replaced the one on
my old diesel Golf .

Commonly called carburettor cleaner. Dissolves all the gunk you get with
burning petrol and oil. And is safe on most metals and plastics etc as
found in a car.

There is also brake cleaner but the real stuff (the one
with(Tetrachloroethylene and Methylene Chloride is a bit hairy to
use.(with heat it can make phosgene.)

On 20/10/2017 11:37, T i m wrote:
Hi all,

I'm helping a mate who has just bought a second hand silent compressor
(on my recommendation) and the one he bought was know faulty, 'spares
or repair' etc.

On testing there was no output (as advertised) but long-short, I
partially stripped it (someone had been there before me) and found the
reed valved and 'cylinder head' had a fair amount of carbon build up
on them.

One reed just sits on a couple of location pins so can be removed and
it and it's seats cleaned easily but the other is trapped behind a
support (that manages the maximum opening) so I can't really get in /
under that to clean it all.

I've had it in an ultrasonic cleaning tank at 60 DegC and whilst it
did seem to remove (or soften) quite a lot of it, I'm not sure that it
is properly cleaned in all the little crevices.

So, to the chemists probably, is there a reasonably 'safe' / chemical
way I could remove this black stuff (carbonised mineral oil deposits?)
without melting my fingers or the alloy / steel parts or should I
drill the rivets out, strip it down and cleaning it mechanically (the
stuff does scrape off reasonably easily from those bits now) and
re-attach it with some small nuts and bolts?

Cheers, T i m

p.s. It may be that the fixed reed is bent slightly so might need
removing to reset, or it could simply be held up slightly by said
deposits. If it makes the compressor work, mate would invest in a
service kit but they aren't cheap.


No easy answer IMHO. Certainly no chemical "magic bullet".

T i m wrote:
Hi all,

I'm helping a mate who has just bought a second hand silent compressor
(on my recommendation) and the one he bought was know faulty, 'spares
or repair' etc.

On testing there was no output (as advertised) but long-short, I
partially stripped it (someone had been there before me) and found the
reed valved and 'cylinder head' had a fair amount of carbon build up
on them.

One reed just sits on a couple of location pins so can be removed and
it and it's seats cleaned easily but the other is trapped behind a
support (that manages the maximum opening) so I can't really get in /
under that to clean it all.

I've had it in an ultrasonic cleaning tank at 60 DegC and whilst it
did seem to remove (or soften) quite a lot of it, I'm not sure that it
is properly cleaned in all the little crevices.

So, to the chemists probably, is there a reasonably 'safe' / chemical
way I could remove this black stuff (carbonised mineral oil deposits?)
without melting my fingers or the alloy / steel parts or should I
drill the rivets out, strip it down and cleaning it mechanically (the
stuff does scrape off reasonably easily from those bits now) and
re-attach it with some small nuts and bolts?

Cheers, T i m

p.s. It may be that the fixed reed is bent slightly so might need
removing to reset, or it could simply be held up slightly by said
deposits. If it makes the compressor work, mate would invest in a
service kit but they aren't cheap.

CBY to trawl through all the replies but try EGR Valve Cleaner (Exhaust
gas recirculating) These get coked up with tarry carbon and possible
very similar to your valve/cylinder head.

Bob

On Fri, 20 Oct 2017 18:02:19 +0100, Bob Minchin
wrote:

snip

CBY to trawl through all the replies but try EGR Valve Cleaner (Exhaust
gas recirculating) These get coked up with tarry carbon and possible
very similar to your valve/cylinder head.

Actually, that does look quite like to sort of carbony gunge I'm
seeing so that could be another thing worth a go, thanks. ;-)

Cheers, T i m

T i m wrote:
On Fri, 20 Oct 2017 18:02:19 +0100, Bob Minchin
wrote:

snip

CBY to trawl through all the replies but try EGR Valve Cleaner (Exhaust
gas recirculating) These get coked up with tarry carbon and possible
very similar to your valve/cylinder head.

Actually, that does look quite like to sort of carbony gunge I'm
seeing so that could be another thing worth a go, thanks. ;-)

Cheers, T i m

Another possibility might be the stuff used to clean cooker/oven parts.
It is a liquid that you dunk shelves, burners etc in. I think it is used
cold and must be fairly "frisky" to burned on carbon and yet presumably
benign to metals. I think it is called Oven Pride but not sure as it is
not in my "department".

I'm a bit concerned that this compressor seems to have been run so hot
that it would burn the oil. My compressor does get hot - too hot to keep
my hand on but that should not decompose oil.

Bob

On 20/10/2017 19:13, Bob Minchin wrote:
T i m wrote:
On Fri, 20 Oct 2017 18:02:19 +0100, Bob Minchin
wrote:

snip

CBY to trawl through all the replies but try EGR Valve Cleaner (Exhaust
gas recirculating) These get coked up with tarry carbon and possible
very similar to your valve/cylinder head.

Actually, that does look quite like to sort of carbony gunge I'm
seeing so that could be another thing worth a go, thanks. ;-)

Cheers, T i m

Another possibility might be the stuff used to clean cooker/oven parts.
It is a liquid that you dunk shelves, burners etc in. I think it is used
cold and must be fairly "frisky" to burned on carbon and yet presumably
benign to metals. I think it is called Oven Pride but not sure as it is
not in my "department".

I'm a bit concerned that this compressor seems to have been run so hot
that it would burn the oil. My compressor does get hot - too hot to keep
my hand on but that should not decompose oil.

Bob
Beware, this may contain sodium hydroxide. see my earlier posts

Malcolm

On Fri, 20 Oct 2017 19:13:56 +0100, Bob Minchin
wrote:

T i m wrote:
On Fri, 20 Oct 2017 18:02:19 +0100, Bob Minchin
wrote:

snip

CBY to trawl through all the replies but try EGR Valve Cleaner (Exhaust
gas recirculating) These get coked up with tarry carbon and possible
very similar to your valve/cylinder head.

Actually, that does look quite like to sort of carbony gunge I'm
seeing so that could be another thing worth a go, thanks. ;-)

Cheers, T i m

Another possibility might be the stuff used to clean cooker/oven parts.
It is a liquid that you dunk shelves, burners etc in. I think it is used
cold and must be fairly "frisky" to burned on carbon and yet presumably
benign to metals. I think it is called Oven Pride but not sure as it is
not in my "department".

Ah yes, I've used such bought from the Poundshop to (quite
effectively) to clean the grilles from our oven. I think you mixed up
the chemical, tipped it into a big Ziplok bag, added the metalwork and
then moved it about a bit to 'coat' all the metal bits then leave it
for a while to do it's stuff. You then took the metal bits out and
they were all clean and shiny. ;-)

I'm a bit concerned that this compressor seems to have been run so hot
that it would burn the oil.

Me too.

My compressor does get hot - too hot to keep
my hand on but that should not decompose oil.

The thing is, these particular 'silent' compressors only have a 50:50
duty cycle with a maximum on time of 30 mins. So, let's say it was
being run hard (a worse duty cycle) and using the older mineral(?) oil
then I'm wondering if it was a possible cause of it starting to coke /
sludge up.

As soon as that happens, some carbon get under the (fairly light) reed
valve and it not make pressure, even if not being used it would then
run continuously (and silently) and could therefore run pretty hot and
for a long time?

The rest of the guts 'look' ok, the bore isn't scored and there
doesn't appear to be any crank / gudgeon / big-end noise and because
it was so lacking in oil (and obvious signs of being opened), a good
chance any oil that was in there was still in there when they noticed
it wasn't working was tipped out rather than burnt out.

The oil is drawn up the wet sump though the spinning crankshaft /
armature and then just spray lubricated all the bits at the top (big
end, piston / bore, top bearing etc).

The bits in question can be seen on the bottom half of the 'Pump
Diagram' page (4) seen on the link below:

https://www.bambi-air.co.uk/uploads/...20Handbook.pdf

The reed valves in question are either side of the 'Valve plate' (item
26). One is just trapped against the gasket and held in place with two
dowel pins but the other is held down under the raised 'horseshoe' /
end stop you can see in the diagram. This would allow that reed to
'open' about 2-3 mm at the top of the 'U' before being restrained by
said plate. The ends of the retaining plate are riveted to the main
valve plate and it's that bit I'm trying not to disassemble (by
drilling out the rivets, cleaning and possibly re-setting the 'spring'
in the reed and re-assembling using countersunk machine screws and
possibly locking nuts (not sure the nylon would survive the heat in a
Nylock nut)?

Cheers, T i m

Malcolm Race wrote:
On 20/10/2017 19:13, Bob Minchin wrote:
T i m wrote:
On Fri, 20 Oct 2017 18:02:19 +0100, Bob Minchin
wrote:

snip

CBY to trawl through all the replies but try EGR Valve Cleaner (Exhaust
gas recirculating) These get coked up with tarry carbon and possible
very similar to your valve/cylinder head.

Actually, that does look quite like to sort of carbony gunge I'm
seeing so that could be another thing worth a go, thanks. ;-)

Cheers, T i m

Another possibility might be the stuff used to clean cooker/oven parts.
It is a liquid that you dunk shelves, burners etc in. I think it is
used cold and must be fairly "frisky" to burned on carbon and yet
presumably benign to metals. I think it is called Oven Pride but not
sure as it is not in my "department".

I'm a bit concerned that this compressor seems to have been run so hot
that it would burn the oil. My compressor does get hot - too hot to
keep my hand on but that should not decompose oil.

Bob
Beware, this may contain sodium hydroxide. see my earlier posts

Malcolm
It is possible Malcolm but compared with the dire warnings on the now
banned "Kleen-off" which was NaOH in a gel, this stuff has less warnings
and at the same time we have been more H&S conscious, so I'm minded to
think it might be OK with metal bearing in mind that many hob burner
parts are diecast aluminium.

Bob

T i m wrote:
On Fri, 20 Oct 2017 19:13:56 +0100, Bob Minchin
wrote:

T i m wrote:
On Fri, 20 Oct 2017 18:02:19 +0100, Bob Minchin
wrote:

snip

CBY to trawl through all the replies but try EGR Valve Cleaner (Exhaust
gas recirculating) These get coked up with tarry carbon and possible
very similar to your valve/cylinder head.

Actually, that does look quite like to sort of carbony gunge I'm
seeing so that could be another thing worth a go, thanks. ;-)

Cheers, T i m

Another possibility might be the stuff used to clean cooker/oven parts.
It is a liquid that you dunk shelves, burners etc in. I think it is used
cold and must be fairly "frisky" to burned on carbon and yet presumably
benign to metals. I think it is called Oven Pride but not sure as it is
not in my "department".

Ah yes, I've used such bought from the Poundshop to (quite
effectively) to clean the grilles from our oven. I think you mixed up
the chemical, tipped it into a big Ziplok bag, added the metalwork and
then moved it about a bit to 'coat' all the metal bits then leave it
for a while to do it's stuff. You then took the metal bits out and
they were all clean and shiny. ;-)

I'm a bit concerned that this compressor seems to have been run so hot
that it would burn the oil.

Me too.

My compressor does get hot - too hot to keep
my hand on but that should not decompose oil.

The thing is, these particular 'silent' compressors only have a 50:50
duty cycle with a maximum on time of 30 mins. So, let's say it was
being run hard (a worse duty cycle) and using the older mineral(?) oil
then I'm wondering if it was a possible cause of it starting to coke /
sludge up.

As soon as that happens, some carbon get under the (fairly light) reed
valve and it not make pressure, even if not being used it would then
run continuously (and silently) and could therefore run pretty hot and
for a long time?

The rest of the guts 'look' ok, the bore isn't scored and there
doesn't appear to be any crank / gudgeon / big-end noise and because
it was so lacking in oil (and obvious signs of being opened), a good
chance any oil that was in there was still in there when they noticed
it wasn't working was tipped out rather than burnt out.

The oil is drawn up the wet sump though the spinning crankshaft /
armature and then just spray lubricated all the bits at the top (big
end, piston / bore, top bearing etc).

The bits in question can be seen on the bottom half of the 'Pump
Diagram' page (4) seen on the link below:

https://www.bambi-air.co.uk/uploads/...20Handbook.pdf

The reed valves in question are either side of the 'Valve plate' (item
26). One is just trapped against the gasket and held in place with two
dowel pins but the other is held down under the raised 'horseshoe' /
end stop you can see in the diagram. This would allow that reed to
'open' about 2-3 mm at the top of the 'U' before being restrained by
said plate. The ends of the retaining plate are riveted to the main
valve plate and it's that bit I'm trying not to disassemble (by
drilling out the rivets, cleaning and possibly re-setting the 'spring'
in the reed and re-assembling using countersunk machine screws and
possibly locking nuts (not sure the nylon would survive the heat in a
Nylock nut)?

Cheers, T i m

Given the warnings in the manual about ensuring no leaks to avoid
damage, it seems that the 50:50 is a warning to the user not to exceed
50:50 duty rather than saying the compressor itself is controlled to run
at max 50:50.
I wonder if the thermal trip device has failed shut and that a leak
present has meant the unit has cooked itself. Modern copper wire has a
very high temperature enamel so possibly not a concern but could have
led mineral oil to burn.
Bob

On 20/10/2017 19:21, Malcolm Race wrote:
On 20/10/2017 19:13, Bob Minchin wrote:
T i m wrote:
On Fri, 20 Oct 2017 18:02:19 +0100, Bob Minchin
wrote:

snip

CBY to trawl through all the replies but try EGR Valve Cleaner (Exhaust
gas recirculating) These get coked up with tarry carbon and possible
very similar to your valve/cylinder head.

Actually, that does look quite like to sort of carbony gunge I'm
seeing so that could be another thing worth a go, thanks. ;-)

Cheers, T i m

Another possibility might be the stuff used to clean cooker/oven parts.
It is a liquid that you dunk shelves, burners etc in. I think it is
used cold and must be fairly "frisky" to burned on carbon and yet
presumably benign to metals. I think it is called Oven Pride but not
sure as it is not in my "department".

I'm a bit concerned that this compressor seems to have been run so hot
that it would burn the oil. My compressor does get hot - too hot to
keep my hand on but that should not decompose oil.

Bob
Beware, this may contain sodium hydroxide.Â* see my earlier posts


It may, except Chrome is dissolved by sodium hydroxide, so not sure if
it will for a oven cleaning product also targetting chrome wire shelves?

On Fri, 20 Oct 2017 20:55:58 +0100, Bob Minchin
wrote:

snip


https://www.bambi-air.co.uk/uploads/...20Handbook.pdf

The reed valves in question are either side of the 'Valve plate' (item
26). One is just trapped against the gasket and held in place with two
dowel pins but the other is held down under the raised 'horseshoe' /
end stop you can see in the diagram. This would allow that reed to
'open' about 2-3 mm at the top of the 'U' before being restrained by
said plate. The ends of the retaining plate are riveted to the main
valve plate and it's that bit I'm trying not to disassemble (by
drilling out the rivets, cleaning and possibly re-setting the 'spring'
in the reed and re-assembling using countersunk machine screws and
possibly locking nuts (not sure the nylon would survive the heat in a
Nylock nut)?


Given the warnings in the manual about ensuring no leaks to avoid
damage, it seems that the 50:50 is a warning to the user not to exceed
50:50 duty rather than saying the compressor itself is controlled to run
at max 50:50.

Correct.

I wonder if the thermal trip device has failed shut and that a leak
present has meant the unit has cooked itself.

That was my thought / fear Bob. ;-(

Modern copper wire has a
very high temperature enamel so possibly not a concern but could have
led mineral oil to burn.

TBF, the only sign of anything untoward is this buildup on the
*outside* of the valve plate and inside of the cylinder head (if that
means anything to anyone).

The air is drawn in via a sort of plenum chamber us sucked into the
head via the reed inside the valve plate and then blown back out
though the horseshoe reed, round the head and back out though another
manifold / reservoir chamber, before being discharged out through the
delivery pipe to the reservoir (though a non return valve).

As the piston is ringless, they predict a certain amount of oil
bypassing the piston and so getting into the cylinder and potentially
out though the output reed / head.

Cheers, T i m

On 20/10/17 20:58, Fredxxx wrote:
except Chrome is dissolved by sodium hydroxide
????

On 21/10/2017 01:01, Tjoepstil wrote:
On 20/10/17 20:58, Fredxxx wrote:
except Chrome is dissolved by sodium hydroxide
????

Are you suggesting that shiny oven shelves are not made of chromed steel?

Don't you think any oven cleaning product might be careful how much
sodium hydroxide they put into their magic formula?

Just in case you don't know:
https://www.wikihow.com/Remove-Chrome-Plating

In article ,
Fredxxx wrote:
On 21/10/2017 01:01, Tjoepstil wrote:
On 20/10/17 20:58, Fredxxx wrote:
except Chrome is dissolved by sodium hydroxide
????

Are you suggesting that shiny oven shelves are not made of chromed steel?

I'd hope they are SS these days.

Remember seeing a barbecue with chrome plated grills. Didn't last long and
soon became a rusty mess.

--
*When the going gets tough, the tough take a coffee break *

Dave Plowman London SW
To e-mail, change noise into sound.

On 21/10/2017 11:35, Dave Plowman (News) wrote:
In article ,
Fredxxx wrote:
On 21/10/2017 01:01, Tjoepstil wrote:
On 20/10/17 20:58, Fredxxx wrote:
except Chrome is dissolved by sodium hydroxide
????

Are you suggesting that shiny oven shelves are not made of chromed steel?

I'd hope they are SS these days.

Remember seeing a barbecue with chrome plated grills. Didn't last long and
soon became a rusty mess.

I'm sure you're right. Just a thought.

On 21/10/17 11:56, Fredxxx wrote:
On 21/10/2017 11:35, Dave Plowman (News) wrote:
In article ,
Â*Â*Â* Fredxxx wrote:
On 21/10/2017 01:01, Tjoepstil wrote:
On 20/10/17 20:58, Fredxxx wrote:
except Chrome is dissolved by sodium hydroxide
????

Are you suggesting that shiny oven shelves are not made of chromed
steel?

I'd hope they are SS these days.

Remember seeing a barbecue with chrome plated grills. Didn't last long
and
soon became a rusty mess.

I'm sure you're right. Just a thought.


Well sometimes I aqctually learn something new here. It appears that
chrome is dissolved by caustic, but *very slowly* which is a good thing
because I have been using caustic to clean fatty gunk off chrome since
forever.

With no apparent ill effects.,




--
The lifetime of any political organisation is about three years before
its been subverted by the people it tried to warn you about.

Anon.