Fixing a scratched DVD- an observation

[Gordon Abbot]

I posted this on r.v.desktop.

Since both programs are freeware (ISO buster is both free and pay)
decided to post here also.

I had a badly scratched disk which I tried to clean with no joy. When
cleaning does not work (and it usually does not), I use DVDdecrypter to
work through the errors.

This time I tried ISO buster since it is highly recommended for fixing
disks. It took forever to go from 94% (where the scratch started to 95%
and then failed (locked up more than once after several re-trys), so
went back to DVDdecrypter.

DVD D worked faster and recovered the disk with no hangups. Plus I was
able to work with it in the background. I had to leave ISO buster alone
and do nothing else while it did its thing. Went into Freecell withdrawal.

The other nice thing is I could watch the progress with DVD D since it
shows just what it is doing and where it stands reading and writing in
the file. It took 1 1/2 hours to fix the disk. Turned out there were two
files that had problems.

I have no ax to grind here, but just an observation. (I set DVD D to
ignore all read errors.)

GA

 

[Bill Turner]

When cleaning does not work (and it usually does not),

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

I have yet to see a scratched DVD or CD I could not fix. I work in a
library, so I see a lot of them.

The best method is to use a cloth buffing wheel in a drill press, with
buffing compound made specifically for plastic. Do not use metal
buffing compound - way too coarse.

100% success rate so far.

Mr Bill

 

[newbie]

Bill Turner wrote:
|> Gordon Abbot wrote:
|>
|> > When cleaning does not work (and it usually does not),
|> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|>
|> I have yet to see a scratched DVD or CD I could not fix. I work in a
|> library, so I see a lot of them.
|>
|> The best method is to use a cloth buffing wheel in a drill press,
|> with buffing compound made specifically for plastic. Do not use metal
|> buffing compound - way too coarse.
|>
|> 100% success rate so far.
|>
|> Mr Bill

Can you further elborate.
Regards.

 

[Steve H]

Bill Turner wrote:
|> Gordon Abbot wrote:
|>
|> > When cleaning does not work (and it usually does not),
|> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|>
|> I have yet to see a scratched DVD or CD I could not fix. I work in a
|> library, so I see a lot of them.
|>
|> The best method is to use a cloth buffing wheel in a drill press,
|> with buffing compound made specifically for plastic. Do not use metal
|> buffing compound - way too coarse.
|>
|> 100% success rate so far.
|>
|> Mr Bill

Can you further elborate.

There are a couple of types of buffing wheel ( or mops ) widely
available. The more common type is that found in car accessory shops,
which consists of a pad of (typically ) lambswool stuck onto a flat
disk, These are designed to be used in powered hand drills.
The industrial type of buffing wheel consists of many discs of calico
stapled together, and is designed to be used with an arbor. The wheels
can be bought in varying degrees of hardness. One for the softest
wheels goes by the name 'Swansdown'. You can buy arbors to fit hand
drills. An industrial mop is the better bet.

http://thepolishingshop.co.uk/Spindles___Adaptors.htm

http://www.proopsbrothers.com/acatalog/Online_Catalogue_Polishing_42.html


Buffing wheels use blocks of polish called 'buffing soap'. This comes
in a wide variety of grades.

http://thepolishingshop.co.uk/Large_800g_Bars.htm#hyfin

The range runs from extremely fine polish, such as 'Rouge', through to
coarse polishes such as 'Tripoli'.
A special polish is required for plastics, though more often than not
this turns out to be a polish developed for another application...such
as polishing stainless steel. These polishes tend not to leave any
deposits ( unlike Rouge and Tripoli, which are quite greasy ).
I use Hyfin simply because it's what I use in my workshop for
finishing brass, but any decent supplier should be able to advise you
of which type of soap you need depending on what brand they stock.
One bar of soap should last you quite a few years, and if all you're
doing is polishing cds then a 4"x3/4" swansdown mop will last equally
as long.
Bear in mind that the mop needs to rotate at quite a high speed, so
you'll need a fairly decent drill.

There's something of an art to polishing CDs...Ideally they should be
polished in a line from the centre hole to the rim downwards rather
than parallel to the rim.
What you have to watch for is that you keep the disc moving at all
times or the friction of the mop will cause the plastic to melt.
Best bet is to practice on a few old magazine cover disks until you
get the hang of it.
The rotation of the wheel must run towards you - that's to say that
looking at the wheel side on, it revolves anticlockwise with you
standing on its left. If you imagine the side of the mop to be a
clockface, the item to be polished should be presented to the mop at
about the 7-8 o'clock position. Higher than that and it might get
thrown into you, lower than that and it might get snatched out of your
hand.
You 'load' the mop by presenting the bar of polish lightly to it, then
you present the disk to the mop. Trial and error will tell you when to
apply more polish - but overloading the mop is as bad as underloading
it. To finish the job, just decrease the pressure of the disk against
the well and hold off the polish. If there are any residues they can
be cleaned off with a little lighter fluid on a ball of cotton wool.

I would strongly advise the use of goggles and a simple breather mask.

A simple setup is a real boon if you have kids who have gaming
machines. Word soon gets round that you can 'fix' damaged disks, and
you might well find you can turn a small profit from polishing
Playstation disks.

Given that this method is based on my having access to professional
kit, I'd be interested to read Bill's method.

Regards,

 

[pbestrox]

There are a couple of types of buffing wheel ( or mops ) widely
available. The more common type is that found in car accessory shops,
which consists of a pad of (typically ) lambswool stuck onto a flat
disk, These are designed to be used in powered hand drills.
The industrial type of buffing wheel consists of many discs of calico
stapled together, and is designed to be used with an arbor. The wheels
can be bought in varying degrees of hardness. One for the softest
wheels goes by the name 'Swansdown'. You can buy arbors to fit hand
drills. An industrial mop is the better bet.

http://thepolishingshop.co.uk/Spindles___Adaptors.htm

http://www.proopsbrothers.com/acatalog/Online_Catalogue_Polishing_42.html


Buffing wheels use blocks of polish called 'buffing soap'. This comes
in a wide variety of grades.

http://thepolishingshop.co.uk/Large_800g_Bars.htm#hyfin

The range runs from extremely fine polish, such as 'Rouge', through to
coarse polishes such as 'Tripoli'.
A special polish is required for plastics, though more often than not
this turns out to be a polish developed for another application...such
as polishing stainless steel. These polishes tend not to leave any
deposits ( unlike Rouge and Tripoli, which are quite greasy ).
I use Hyfin simply because it's what I use in my workshop for
finishing brass, but any decent supplier should be able to advise you
of which type of soap you need depending on what brand they stock.
One bar of soap should last you quite a few years, and if all you're
doing is polishing cds then a 4"x3/4" swansdown mop will last equally
as long.
Bear in mind that the mop needs to rotate at quite a high speed, so
you'll need a fairly decent drill.

There's something of an art to polishing CDs...Ideally they should be
polished in a line from the centre hole to the rim downwards rather
than parallel to the rim.
What you have to watch for is that you keep the disc moving at all
times or the friction of the mop will cause the plastic to melt.
Best bet is to practice on a few old magazine cover disks until you
get the hang of it.
The rotation of the wheel must run towards you - that's to say that
looking at the wheel side on, it revolves anticlockwise with you
standing on its left. If you imagine the side of the mop to be a
clockface, the item to be polished should be presented to the mop at
about the 7-8 o'clock position. Higher than that and it might get
thrown into you, lower than that and it might get snatched out of your
hand.
You 'load' the mop by presenting the bar of polish lightly to it, then
you present the disk to the mop. Trial and error will tell you when to
apply more polish - but overloading the mop is as bad as underloading
it. To finish the job, just decrease the pressure of the disk against
the well and hold off the polish. If there are any residues they can
be cleaned off with a little lighter fluid on a ball of cotton wool.

I would strongly advise the use of goggles and a simple breather mask.

A simple setup is a real boon if you have kids who have gaming
machines. Word soon gets round that you can 'fix' damaged disks, and
you might well find you can turn a small profit from polishing
Playstation disks.

Given that this method is based on my having access to professional
kit, I'd be interested to read Bill's method.

Wow...thanks for the detailed explanation and recommendations! I know I'll
check this out.

I myself use sandpaper...a grit #2 ... basically a rock.

 

[Thip]

('scuse me for top posting--too lazy to scroll down)

I have a DVD burner and a DVD reader. All the so-called experts claim that
burners read better than readers. My experience has been the opposite--when
I have to do the toothpaste thing, I pop it in the reader, fire up
DVDdecrypter, and away it goes. I just rescued a badly scratched copy of
"Scarface" that way.

 

[Bill Turner]

Given that this method is based on my having access to professional
kit, I'd be interested to read Bill's method.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

My method is the same as yours except I have the wheel rotating away
from me instead of towards. Probably doesn't make much difference,
really. That's just the most convenient direction for my setup. Steve's
advice is excellent in all respects.

Mr Bill

 

[newbie]

How do you do with toothpaste?
Will you please show the way how you do it?
Buffing seems to need expert hand and good practice.
Regards.

Thip wrote:
|> ('scuse me for top posting--too lazy to scroll down)
|>
|> I have a DVD burner and a DVD reader. All the so-called experts
|> claim that burners read better than readers. My experience has been
|> the opposite--when I have to do the toothpaste thing, I pop it in
|> the reader, fire up DVDdecrypter, and away it goes. I just rescued
|> a badly scratched copy of "Scarface" that way.
|>
|> news[email protected]...

 

[Ed]

How do you do with toothpaste?
Will you please show the way how you do it?
Buffing seems to need expert hand and good practice.
Regards.

Thip wrote:
|> ('scuse me for top posting--too lazy to scroll down)
|>
|> I have a DVD burner and a DVD reader. All the so-called experts
|> claim that burners read better than readers. My experience has been
|> the opposite--when I have to do the toothpaste thing, I pop it in
|> the reader, fire up DVDdecrypter, and away it goes. I just rescued
|> a badly scratched copy of "Scarface" that way.
|>
|> news[email protected]...

Take a small amount of toothpaste on a very soft rag (microfiber towel will
work) and with the tip of your finger, rub the toothpaste in with light
pressure. Wipe the film off with a damp cloth (again microfiber) and if you
still see the scratch repeat the process. Do this only on the bottom side
(the side that faces the laser lens. If you have a scratch on the label
side, do not attempt to remove. If that scratch is through the label the
disk is toast.

The data is stored just under the label so using toothpaste on the under
side is okay.

I was able to restore a Win98 CD that had a 1/2 inch wide scratch all the
way around the center of the underside with toothpaste. All my friends told
me that the disk was a total loss, but after I was done it worked just
fine. I still have that disk and use it to install Win98 for others. It's
much easier to just tell them to bring the CD key instead using their disk.

Ed

 

[Thip]

How do you do with toothpaste?
Will you please show the way how you do it?
Buffing seems to need expert hand and good practice.
Regards.

Ed's method is different from mine--I dab white toothpaste on the scratches,
then rub lightly with a dampened finger from the center out and back in (not
around the disk). Rinse well, dry with a lint-free cloth. Repeat if
needed, but take it easy! This method has only failed me twice out of
hundreds of old CD's and DVD's.

 

[David]

Take a small amount of toothpaste on a very soft rag (microfiber towel will
work) and with the tip of your finger, rub the toothpaste in with light
pressure. Wipe the film off with a damp cloth (again microfiber) and if you
still see the scratch repeat the process. Do this only on the bottom side
(the side that faces the laser lens. If you have a scratch on the label
side, do not attempt to remove. If that scratch is through the label the
disk is toast.

The data is stored just under the label so using toothpaste on the under
side is okay.

I was able to restore a Win98 CD that had a 1/2 inch wide scratch all the
way around the center of the underside with toothpaste. All my friends told
me that the disk was a total loss, but after I was done it worked just
fine. I still have that disk and use it to install Win98 for others. It's
much easier to just tell them to bring the CD key instead using their disk.

This should be used with caution as toothpaste is quite a coarse
abrasive. It would be better to obtain a finer abrasive, preferably
water-based. You should use a VERY light, rotary motion over the area
from the centre to the edge when performing this sort of repair and
press only lightly. Do not rub around the entire disc. Deep scratches
can be very difficult to remove.

I have removed abrasions caused by the drive door closing
unexpectedly, I obtained a CD Repair Kit which may be available from
Tandy. (Mine was from Dick Smith Electronics in Australia and Both DSE
and Tandy are owned by, I believe, Coles). It works by having a
circular pad which is rotated over the surface of the disc through a
gearing system in the case.

 

[Colin Elphick]

"(Mine was from Dick Smith Electronics in Australia and Both DSE
and Tandy are owned by, I believe, Coles)."

Woolworths.

 

[Michael Salem]

Steve H wrote about repairing scratched CDs, starting:

There are a couple of types of buffing wheel ( or mops ) widely
available.

I copied his posting into another newsgroup interested in the topic, and
had an interesting reply from someone who know about polishing, but
hasn't tried it on CDs.

I wrote there:

There's an interesting thread on cleaning CDs which I'll quote in case
anyone's interested.

<test quoted from this thread>

Response:

I've been tempted but have no disks that couldn't be read with the
'repair' stuff I've got.

I would certainly have gone the routes suggested but:

1) Melting the plastic would have worried me, I would therefore have
taken the water-based abrasive route. That pretty well means a somewhat
slower buffer and a squeegee bottle full of water.

2) Holding things like these disks against a fast-rotating buffer is
potentially hazardous. Either abraded/burned (friction is significant)
fingers or the reception of the disk into the face/gut at high speed are
significant risks.

3) I would be inclined to a wet drill-based 'lambswool' buffer, with the
disc nailed to a bench. It may be that no actual abrasives are needed.

4) NB Its the devil of a job producing scratch-free mirror surfaces.
Extreme cleanliness is required as you move up the grades. Certainly
once a buffer has been used for one grade it can NEVER be used for a
finer grade ever again.

Best wishes

 

[Bill Turner]

2) Holding things like these disks against a fast-rotating buffer is
potentially hazardous. Either abraded/burned (friction is significant)
fingers or the reception of the disk into the face/gut at high speed
are significant risks.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

1. I've done dozens if not hundreds of disks and never burned/melted
one. The plastic in a CD or DVD is quite resistant to melting.

2. I have the buffing wheel rotating such that if it 'grabs' the disk,
and it sometimes does, it flings it away from me, not toward me. Common
sense, guys. And I always wear safety goggles. We're talking light
pieces of plastic with no sharp edges here, not large chunks of metal.

Mr Bill

 

[Steve H]

Steve H wrote about repairing scratched CDs, starting:


I copied his posting into another newsgroup interested in the topic, and
had an interesting reply from someone who know about polishing, but
hasn't tried it on CDs.

I wrote there:

<test quoted from this thread>

Response:

I've been tempted but have no disks that couldn't be read with the
'repair' stuff I've got.

I would certainly have gone the routes suggested but:

1) Melting the plastic would have worried me, I would therefore have
taken the water-based abrasive route. That pretty well means a somewhat
slower buffer and a squeegee bottle full of water.

You'd have to go some to melt the plastic. I wouldn't even have
mentioned it save for the fact that people might be inclined to really
'work' on a deep scratch. My industrial mop runs at something like
15,000 rpm, with 1/2 horsepower - and even with a 6" mop I've never
melted a disc...though I could if I wanted to!
I would say that the biggest risk of damage comes from the temptation
to flex the disc against the wheel.

2) Holding things like these disks against a fast-rotating buffer is
potentially hazardous. Either abraded/burned (friction is significant)
fingers or the reception of the disk into the face/gut at high speed are
significant risks.

That's why I noted the working position - at around the 7 o'clock
mark. In the event of a slip, the work gets thrown down. To run a real
risk of burned fingers you'd need professional kit. A buff on a
domestic power drill might just about warm your fingers.

3) I would be inclined to a wet drill-based 'lambswool' buffer, with the
disc nailed to a bench. It may be that no actual abrasives are needed.

Wet polishing carries a few risks of its own, most notably the fact
that a wet mop may pick up ( and will hold ) bits of grit. Absolute
cleanliness is required...and plenty of protective clothing ( it's
pretty messy! ). Also, with a static workpiece you have to address the
issue of polishing radially

4) NB Its the devil of a job producing scratch-free mirror surfaces.
Extreme cleanliness is required as you move up the grades. Certainly
once a buffer has been used for one grade it can NEVER be used for a
finer grade ever again.

This is pretty much true, but in practice I've not found it necessary
to reproduce a mirror finish. It could be done, using a separate wheel
and a finer buffing soap, but I've found the finish left by a
medium/fine soap to be more than adequate.
A 'finishing stroke' ( a light pressure against an unloaded soft mop )
gives, effectively, a finish that's about half a step finer than that
with a loaded mop with the work held against it at normal pressure.

Regards,

 

[Ed]

This should be used with caution as toothpaste is quite a coarse
abrasive. It would be better to obtain a finer abrasive, preferably
water-based. You should use a VERY light, rotary motion over the area
from the centre to the edge when performing this sort of repair and
press only lightly. Do not rub around the entire disc. Deep scratches
can be very difficult to remove.

Of course you should use caution. You should use caution with ANY method of
removing scratches from a CD/DVD. I did say use light pressure. I didn't
say, though to use a circular motion. My bad.

I have removed abrasions caused by the drive door closing
unexpectedly, I obtained a CD Repair Kit which may be available from
Tandy. (Mine was from Dick Smith Electronics in Australia and Both DSE
and Tandy are owned by, I believe, Coles). It works by having a
circular pad which is rotated over the surface of the disc through a
gearing system in the case.

The toothpaste method is much less costly and works just fine.

Ed