Does anyone have a method to touch up a front glasss that is bubbling?

r


--
"Any sufficiently advanced technology is indistinguishable from
magic."

Arthur C. Clarke (1917 - ), "Technology and the Future"

Does anyone have a method to touch up a front glasss that is bubbling?


Why not give McIntosh a call? They often get older gear in for repairs, and
they should be able to make it like new. What model are we talking about?

Stuart Welwood
http://members.aol.com/StuWelwood

(StuWelwood) wrote in
:


Does anyone have a method to touch up a front glasss that is bubbling?


Why not give McIntosh a call? They often get older gear in for repairs, and
they should be able to make it like new. What model are we talking about?

Stuart Welwood
http://members.aol.com/StuWelwood



Stuart,

The model is MI3. I called Audio Classics, Mc, and Terry at
McIntoshAudio.com. The glass is not available from any of the above sources
for the MI3. Terry described a procedure to repair the bubbled paint/ink
areas so I think I am good to go. I know why the ink bubbles and there is no
hope. It is going to happen. I am sure Mc really didn't know what was going
to happen, it is just a shame that it does. Lets look at it this was, what
does one expect from a 30+ year old piece of gear?

On a different note, the MI3 I have has an open HV winding. I was going to
make a tripler using the remaining 330VAC tap. What sort of additional load
does a tripler present to that tap? It has been too long since I messed with
circuits of this nature.

r


--
"Any sufficiently advanced technology is indistinguishable from
magic."

Arthur C. Clarke (1917 - ), "Technology and the Future"

What's the method to go about it?

Dieter

Rich Andrews wrote:
(StuWelwood) wrote in
:


Does anyone have a method to touch up a front glasss that is bubbling?


Why not give McIntosh a call? They often get older gear in for repairs, and
they should be able to make it like new. What model are we talking about?

Stuart Welwood
http://members.aol.com/StuWelwood




Stuart,

The model is MI3. I called Audio Classics, Mc, and Terry at
McIntoshAudio.com. The glass is not available from any of the above sources
for the MI3. Terry described a procedure to repair the bubbled paint/ink
areas so I think I am good to go. I know why the ink bubbles and there is no
hope. It is going to happen. I am sure Mc really didn't know what was going
to happen, it is just a shame that it does. Lets look at it this was, what
does one expect from a 30+ year old piece of gear?

On a different note, the MI3 I have has an open HV winding. I was going to
make a tripler using the remaining 330VAC tap. What sort of additional load
does a tripler present to that tap? It has been too long since I messed with
circuits of this nature.

r

Rustoleum gloss black is not quite black enough. Pretty close, but it will
be visible under all but dim lighting. I haven't found a black enough black
enamel yet, but haven't done much hunting. The bubbling, I believe, is
simply air penetration under the edge of the paint, gradually progressing
further along. It doesn't happen very often at the edges of the whole panel
because the frame bits literally hold down the paint.

--
Stephen Sank, Owner & Ribbon Mic Restorer
Talking Dog Transducer Company
http://stephensank.com
5517 Carmelita Drive N.E.
Albuquerque, New Mexico [87111]
505-332-0336
Auth. Nakamichi & McIntosh servicer
Payments preferred through Paypal.com
"Rich Andrews" wrote in message
.44...
"tap1n" wrote in
et:

How does Terry say to go about repairing that bubble?




The method is basically simple. Remove the bubbled/damaged paint/ink and
paint it. Terry said to use an X-Acto knife to remove the damaged paint,
(I
used a single edged razor blade) and then drip Rustoleum gloss black
(Audio
classics says to use gloss black model paint) on the area. If lettering
is
involved, then you are out of luck as that gets lifted with the black. I
am
going to attempt to repair the panloc bubbles as well but it may require
the
dexterity of a surgeon and a little luck to preserve the lettering. Mc
should have never used epoxy to hold those panloc grommets in place. They
shouldn't have glued foam to the painted glass either. If one has an
airbrush, that might work, but one would have to experiment. I am going
to
go for the Rustoleum. I trust Terry's restoration experience over AC's.
AFAIK Terry is a perfectionist and I like that when it comes to appearance
issues. (:)

Mc used some sort of foam with adhesive on the edges of the glass to
prevent
the glass from rattling. My theory is that either the foam or the
adhesive
combined with moisture causes the paint to bubble and lift. The panloc
issue
is caused by epoxy? that holds the plastic grommet to the front panel. It
seems that the grommet was never really tight against the front so pushing
on
it lifts the paint and lettering. I ran an idea by Terry and he has yet
to
reply so I am hesitant to say what it is.

I forgot to ask Terry if one could use a clear coat to preserve the rest
of
the faceplate. I would be extremely hesitant as it might cause the entire
faceplate to bubble.

r






"Rich Andrews" wrote in message
.44...
(StuWelwood) wrote in
:


Does anyone have a method to touch up a front glasss that is
bubbling?


Why not give McIntosh a call? They often get older gear in for
repairs,
and
they should be able to make it like new. What model are we talking
about?

Stuart Welwood
http://members.aol.com/StuWelwood



Stuart,

The model is MI3. I called Audio Classics, Mc, and Terry at
McIntoshAudio.com. The glass is not available from any of the above
sources
for the MI3. Terry described a procedure to repair the bubbled
paint/ink
areas so I think I am good to go. I know why the ink bubbles and there
is
no
hope. It is going to happen. I am sure Mc really didn't know what was
going
to happen, it is just a shame that it does. Lets look at it this was,
what
does one expect from a 30+ year old piece of gear?

On a different note, the MI3 I have has an open HV winding. I was
going
to
make a tripler using the remaining 330VAC tap. What sort of additional
load
does a tripler present to that tap? It has been too long since I messed
with
circuits of this nature.

r


--
"Any sufficiently advanced technology is indistinguishable from
magic."

Arthur C. Clarke (1917 - ), "Technology and the Future"






--
"Any sufficiently advanced technology is indistinguishable from
magic."

Arthur C. Clarke (1917 - ), "Technology and the Future"

Hi Rich,

I have successfully repaired a couple of Mac faceplates by using the
technique as you describe . . . the paint I used (though I haven't tried a
bunch of different types) was Krylon spray semi-gloss black, squirted first
into a small bottle (beware of vapors), and then applied to the glass via a
Q-tip. The thin consistancy and fast drying seemed to work well . . . brush
marks were completely avoided.

The color match was quite acceptable, but the opacity wasn't . . . a patch
of gaffer's tape (after the paint had cured for 24 hrs.) on top of the paint
patch fixed this.

I have seen a few MI3 faceplates damaged as you described . . . I would
guess that the bubbling at the edges was caused by a chemical reaction with
the particular foam tape that was used for a time, as the problem seemed to
become much less common in newer units . . . though maybe it was just
because they were newer.

I seem to recall that the last MI3 I saw had an open HT secondary as well,
and one of the sources you mentioned had a replacement (of new manufacture)
available. It wasn't exactly cheap . . . but way less than what finding an
MPI-4 or pristene, working MI3 would be. But that was at least five years
ago . . .

I have also seen a problem with paint lifting on a number of Mac faceplates
where the plastic light-diffuser is stuck on with 2-sided tape. Early
versions of some units (C-26's seem to come to mind) had screws that held
the light-diffuser to the panel endbrackets in addition to the tape; in
later editions these screws were left out. I think that paint lifting was
being caused by flexing/shifting of the panel bracket assembly relative to
the faceplate (esp. on the units with the screws installed), and caused the
paint to eventually lift. I recommend that you DO NOT install screws from
the end brackets into the light-diffuser.

Hope this helps,

Kirk Patton

"Kirk Patton" wrote in
:

Hi Rich,

I have successfully repaired a couple of Mac faceplates by using the
technique as you describe . . . the paint I used (though I haven't tried
a bunch of different types) was Krylon spray semi-gloss black, squirted
first into a small bottle (beware of vapors), and then applied to the
glass via a Q-tip. The thin consistancy and fast drying seemed to work
well . . . brush marks were completely avoided.

The color match was quite acceptable, but the opacity wasn't . . . a
patch of gaffer's tape (after the paint had cured for 24 hrs.) on top of
the paint patch fixed this.


I am going to give Krylon a try but as far as opacity is concerned, I think I
would give it a few more coats of paint. I am afraid that the gaffers tape
would react to the remaining coating.


I have seen a few MI3 faceplates damaged as you described . . . I would
guess that the bubbling at the edges was caused by a chemical reaction
with the particular foam tape that was used for a time, as the problem
seemed to become much less common in newer units . . . though maybe it
was just because they were newer.


Hard to say, but I think mine is a later unit as the original sale date was
12/26/68.

I seem to recall that the last MI3 I saw had an open HT secondary as
well, and one of the sources you mentioned had a replacement (of new
manufacture) available. It wasn't exactly cheap . . . but way less than
what finding an MPI-4 or pristene, working MI3 would be. But that was
at least five years ago . . .

It seems that the HV winding is quite prone to fail due to an open. Adding a
voltage tripler to the remaining PS circuitry solves the problem. I have
seen more than one reference to that sort of fix.


I have also seen a problem with paint lifting on a number of Mac
faceplates where the plastic light-diffuser is stuck on with 2-sided
tape. Early versions of some units (C-26's seem to come to mind) had
screws that held the light-diffuser to the panel endbrackets in addition
to the tape; in later editions these screws were left out. I think that
paint lifting was being caused by flexing/shifting of the panel bracket
assembly relative to the faceplate (esp. on the units with the screws
installed), and caused the paint to eventually lift. I recommend that
you DO NOT install screws from the end brackets into the light-diffuser.

I don't have a bracket of that nature and thanks for the tip.


Hope this helps,

Kirk Patton






--
"Any sufficiently advanced technology is indistinguishable from
magic."

Arthur C. Clarke (1917 - ), "Technology and the Future"

"Stephen Sank" wrote in
:

Rustoleum gloss black is not quite black enough. Pretty close, but it
will be visible under all but dim lighting. I haven't found a black
enough black enamel yet, but haven't done much hunting. The bubbling, I
believe, is simply air penetration under the edge of the paint,
gradually progressing further along. It doesn't happen very often at
the edges of the whole panel because the frame bits literally hold down
the paint.





Stephen,

I am quite pleased with my test results tonight!

I went to Home Depot and all they had was spray Rustoleum in a can. Stopped
at Lowes and they had Valspar brand. I tried the gloss black and under the
incandescent lights, it looks like an exact match! I will look again in the
daylight and see what it looks like. I sprayed some in a disposable cup
similar to a condiment cup one would get from a carry out restaurant, and
poured it on my test glass. Dense and really black. I think the spray paint
has more pigment in it because the spray puts on a thinner coat than a brush
would. As a result, the paint is "blacker" than the stuff in a can.

If things look good in the daylight, I will do a compatibilty test to see if
the spray paint will react with the paint that is there. If it doesnt react
too badly, then I am good to go!

I will keep you posted.

r

--
Stephen Sank, Owner & Ribbon Mic Restorer
Talking Dog Transducer Company
http://stephensank.com
5517 Carmelita Drive N.E.
Albuquerque, New Mexico [87111]
505-332-0336
Auth. Nakamichi & McIntosh servicer
Payments preferred through Paypal.com
"Rich Andrews" wrote in message
.44...
"tap1n" wrote in
et:

How does Terry say to go about repairing that bubble?




The method is basically simple. Remove the bubbled/damaged paint/ink
and paint it. Terry said to use an X-Acto knife to remove the damaged
paint,
(I
used a single edged razor blade) and then drip Rustoleum gloss black
(Audio
classics says to use gloss black model paint) on the area. If
lettering
is
involved, then you are out of luck as that gets lifted with the black.
I
am
going to attempt to repair the panloc bubbles as well but it may
require
the
dexterity of a surgeon and a little luck to preserve the lettering. Mc
should have never used epoxy to hold those panloc grommets in place.
They shouldn't have glued foam to the painted glass either. If one
has an airbrush, that might work, but one would have to experiment. I
am going
to
go for the Rustoleum. I trust Terry's restoration experience over
AC's. AFAIK Terry is a perfectionist and I like that when it comes to
appearance issues. (:)

Mc used some sort of foam with adhesive on the edges of the glass to
prevent
the glass from rattling. My theory is that either the foam or the
adhesive
combined with moisture causes the paint to bubble and lift. The panloc
issue
is caused by epoxy? that holds the plastic grommet to the front panel.
It seems that the grommet was never really tight against the front so
pushing
on
it lifts the paint and lettering. I ran an idea by Terry and he has
yet
to
reply so I am hesitant to say what it is.

I forgot to ask Terry if one could use a clear coat to preserve the
rest
of
the faceplate. I would be extremely hesitant as it might cause the
entire faceplate to bubble.

r






"Rich Andrews" wrote in message
.44...
(StuWelwood) wrote in
:


Does anyone have a method to touch up a front glasss that is
bubbling?


Why not give McIntosh a call? They often get older gear in for
repairs,
and
they should be able to make it like new. What model are we talking
about?

Stuart Welwood
http://members.aol.com/StuWelwood



Stuart,

The model is MI3. I called Audio Classics, Mc, and Terry at
McIntoshAudio.com. The glass is not available from any of the above
sources
for the MI3. Terry described a procedure to repair the bubbled
paint/ink
areas so I think I am good to go. I know why the ink bubbles and
there
is
no
hope. It is going to happen. I am sure Mc really didn't know what
was
going
to happen, it is just a shame that it does. Lets look at it this
was,
what
does one expect from a 30+ year old piece of gear?

On a different note, the MI3 I have has an open HV winding. I was
going
to
make a tripler using the remaining 330VAC tap. What sort of
additional
load
does a tripler present to that tap? It has been too long since I
messed
with
circuits of this nature.

r


--
"Any sufficiently advanced technology is indistinguishable from
magic."

Arthur C. Clarke (1917 - ), "Technology and the Future"






--
"Any sufficiently advanced technology is indistinguishable from
magic."

Arthur C. Clarke (1917 - ), "Technology and the Future"







--
"Any sufficiently advanced technology is indistinguishable from
magic."

Arthur C. Clarke (1917 - ), "Technology and the Future"