Polish Your iPhone 3G or 3GS’ Scratched Back

I saw this post by Macrumors user Shenaniganz08 and I had to share it, he does a fantastic job of explaining how to polish the scratched up back of an iPhone 3G or 3GS. I’ve posted the tutorial text below, but be sure to follow the link for some fantastic pictures of the process…

Basically all you need for this DIY fix is:

• Sandpaper 320(or 500),800,1000,1500,2000,2500,3000 grit
• 3M Rubbing compound
• Machine Polisher ( Power Drill or small buffer)
• Microfibers
• Sticky tack and or tape

The method is laid out in painstaking detail and the results are fantastic:

Seen a lot of threads of people wondering how to restore an iPhone so I decided to make a DIY guide

Also pretty helpful if you want to de-brand your iPhone :P

Background

My previous iPhone was stolen at the gym, low on funds I decided to buy the cheapest iPhone I could find that worked regardless of condition. I found an iPhone 3G that had being completely abused and had a dark spot on the LCD. On the second picture notice the gouge on the right side, out of of all the blemishes it was the deepest) Still I ended up buying the phone for a really good price. The replacement parts from eBay only cost $16 for the glass and $23 for the LCD ( sanding kit $10) making it a price effective mod.

My first attempt at restoring it was a mild success, since I used mild sandpapers/rushed. But you can see that even with 800 grit sandpaper and about an hour I got it looking better, but it still had tons of deep dents and scratches.

Warning Warning Warning Warning

Do this at your own risk. I am posting this here only to document how I restored a completely busted iPhone. One thing I should mention first is that iPhone Rear plastic has a scratch-resistant coating
The iPhone rear plastic is composed of the following

1) The most inside layer is a thin colored plastic ( black or white).
2) Above that is a clear polycarbonate plastic layer.
3) Above that is the apple logo and writing.
4) Above that finally is a pretty good layer of scratch-resistant coating.

If your phone only has a few light scratches, only use the most aggressive sandpaper you have to, in order to remove the scratches. My recommendation is that you try to remove 90-95% of scratches without trying to remove 100%. This way you keep the scratch-resistant coating, which will protect from future scratches.

Rule of thumb, if you start noticing that you are removing the apple logo, or that you start seeing a darker plastic, you have gone too far (either stop, or continue based on what you are going for) ( Look at #1)

On my phone I had to remove all the scratch-resistant coating because several of the scratches were much much deeper than the coating. It scratches a lot easier now, so if you can avoid doing so, please please please leave the scratch-resistant coating on ( no point in polishing your phone just to see it get marred again)

I can’t stress this enough, If you remove the scratch-resistant coating it will scratch a lot easier ( you have been warned :P )
Last edited by Shenaniganz08 : Mar 4, 2010 at 11:14 PM.
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Old Feb 28, 2010, 04:05 AM       #2
Shenaniganz08
Thread Starter
macrumors regular

Join Date: Jan 2010

Restoring the back

This is a complete and comprehensive wetsanding guide. If you have never wetsanded before, or wonder why you never get good results this should help. This will let you restore anything that is plastic, or using harder/ finer grits you can polish metal/aluminum/painted parts. I apologize for the length of the guide but I think the tips here will help you get great results.

Tools:
Sandpaper 320(or 500),800,1000,1500,2000,2500,3000 grit
3M Rubbing compound
Machine Polisher ( Power Drill or small buffer)
Microfibers
Sticky tack and or tape

If you want to save time and money I recommend just purchasing a 3M headlight restoration kit (available at almost all car part stores)

$10 bucks at amazon right now

http://www.amazon.com/3M-Headlight-L…/dp/B001AIZ5HY

It will have almost everything you need, but you still need to buy 1000,1500 and 2000 grit sandpaper + a microfiber on the side

Directions :

Step 1: Decide and Drysand with first grit

(always when sanding keep a thumb/finger above the camera to avoid scratching the glass lens ! )

Dry sand with the least aggressive sandpaper needed to remove scratches. If you have deep scratches you may have to go down to 320-800, but if you have light scratches, 1000 or 1500 might be enough. The best way to test this is to run your fingernail around your phone and try to find a deep scratch. Start at a high grit ( 1500) and see if that removes the scracthes. If you still see deep scratches, try the next most aggressive grit, etc. For me I had to go all the way down to 320 grit, due to several 2-3mm deep defects. This first step is really time intensive, but make sure you don’t use water, on the first step because it tends to hide scratches. When you dry sand you can see all the fine sanding marks you are making which allows you to see the scratches you haven’t removed. Dry sanding clogs sandpaper, but you can either buy more sandpaper or wash the sandpaper in water and dry it before you use it. Before you finish this first step, make sure all your sanding marks are in one direction; you’ll see why later.

Step 2: Wetsand with remaining grits

1) Use very little water when you wetsand ( don’t want to kill you iPhone)
2) Make sure the previous sanding marks are completely gone before moving on to the next higher grit

The 2nd point is important, and the reason many people get poor results when wetsanding. It’s a simple technique but it takes practice/patience to get right. But here are some tips:

a) Before moving on to a higher grit make sure all your sanding lines are in the same direction. When you first start sanding the part you can sand in any direction you want, but before you move to a higher grit make sure to sand the entire part down in one direction
b) When you have moved to your next higher grit you don’t have to sand in a single perpendicular direction (a common myth). Just try to sand the part down as best you can in any direction. However Before you move on to a higher grit, make sure you sand perpendicular to the grit you before. This will let you know where you have to keep sanding before moving on.

So if your last sanding marks using 800 grit were left to right , the last sanding marks on 1000 should be top to bottom, then 1500 should be left to right, etc

c) Before you move on, dry the part a bit, to make sure all the previous sanding marks are gone ( again water tends to hide scratches )

The most time consuming jumps for me were sanding 800grit lines with 1000 grit , and the 1000 grit lines with 1500 grit. These two are time consuming steps , but make sure you take your time, because the finer grit sandpapers will be unable to remove these deep marks (especially 800 grit lines).

When wetsanding the phone it should look like below, not too much water and a slight white film. I kept all my wetsanding paper in a bowl of water, and then dried it on a towel on my lap before using it on the phone. You want the paper to be wet, but not running !

After 1500

After 3000

In all these pictures you will notice a few things
a) All the sanding marks are in one direction, and you can see that there are Zero sanding marks in any other direction.
b) The phone is dry

You may be wondering why all my sanding marks are lengthwise. When I wetsand I still follow what I said above ( last step is to sand in the perpendicular direction to make sure all the previous sanding marks are gone) but then additionally I lightly sand in the longest dimension of the part, this helps me make sure I haven’t left any deep sanding marks of the similar grit ( ie, I lightly sand 1000 grit sanding line with 1000grit sandpaper so that sanding with 1500 is easier)

Step 3: Cover openings

Before you start polishing make sure you cover up your headphone port, volume buttons, vibrate button and 30 pin dock with sticky tack (that blue stuff). You can cover the camera glass, but the polishing compounds are not abrasiveness enough to scratch it (unlike the sandpaper). Sticky tack is easy to apply, and come off in one piece. Tape will probably work too but I found that the tape kept lifting off when I was buffing. Refer to the #2 in the following picture (the gray stuff)

Step 4: Polish

I used two kinds of polishes (using one will work, but you will have to repeat it multiple times/results will vary)

I used the Orange 3m pad with 3M rubbing compound on a power drill
You can sanding halo marks

You can then finish with the 3M rubbing compound using a microfiber and you will get almost near perfect results !

(Completely optional)

If you have access detailing products or a friend who details cars
I polished with a blue 3M Pad with Meguair’s 205 paint polish ( you can also use Scratch-x since its pretty mild polish).

I then finished with some Meguair’s NXT 2.0 wax

Results = completely flawless mirror finish

The original thread with full step by step instructions with detailed pictures are here.

Seen a lot of threads of people wondering how to restore an iPhone so I decided to make a DIY guide

Also pretty helpful if you want to de-brand your iPhone :P

Background

My previous iPhone was stolen at the gym, low on funds I decided to buy the cheapest iPhone I could find that worked regardless of condition. I found an iPhone 3G that had being completely abused and had a dark spot on the LCD. On the second picture notice the gouge on the right side, out of of all the blemishes it was the deepest) Still I ended up buying the phone for a really good price. The replacement parts from eBay only cost $16 for the glass and $23 for the LCD ( sanding kit $10) making it a price effective mod.


My first attempt at restoring it was a mild success, since I used mild sandpapers/rushed. But you can see that even with 800 grit sandpaper and about an hour I got it looking better, but it still had tons of deep dents and scratches.

Warning Warning Warning Warning

Do this at your own risk. I am posting this here only to document how I restored a completely busted iPhone. One thing I should mention first is that iPhone Rear plastic has a scratch-resistant coating
The iPhone rear plastic is composed of the following

1) The most inside layer is a thin colored plastic ( black or white).
2) Above that is a clear polycarbonate plastic layer.
3) Above that is the apple logo and writing.
4) Above that finally is a pretty good layer of scratch-resistant coating.

If your phone only has a few light scratches, only use the most aggressive sandpaper you have to, in order to remove the scratches. My recommendation is that you try to remove 90-95% of scratches without trying to remove 100%. This way you keep the scratch-resistant coating, which will protect from future scratches.

Rule of thumb, if you start noticing that you are removing the apple logo, or that you start seeing a darker plastic, you have gone too far (either stop, or continue based on what you are going for) ( Look at #1)

On my phone I had to remove all the scratch-resistant coating because several of the scratches were much much deeper than the coating. It scratches a lot easier now, so if you can avoid doing so, please please please leave the scratch-resistant coating on ( no point in polishing your phone just to see it get marred again)

I can’t stress this enough, If you remove the scratch-resistant coating it will scratch a lot easier ( you have been warned :P )


Last edited by Shenaniganz08 : Mar 4, 2010 at 11:14 PM.

Shenaniganz08 is offline Reply  With Quote

Old Feb 28, 2010, 04:05 AM #2
Shenaniganz08
Thread Starter
macrumors regular
Join Date: Jan 2010

Restoring the back

This is a complete and comprehensive wetsanding guide. If you have never wetsanded before, or wonder why you never get good results this should help. This will let you restore anything that is plastic, or using harder/ finer grits you can polish metal/aluminum/painted parts. I apologize for the length of the guide but I think the tips here will help you get great results.

Tools:
Sandpaper 320(or 500),800,1000,1500,2000,2500,3000 grit
3M Rubbing compound
Machine Polisher ( Power Drill or small buffer)
Microfibers
Sticky tack and or tape

If you want to save time and money I recommend just purchasing a 3M headlight restoration kit (available at almost all car part stores)

$10 bucks at amazon right now
http://www.amazon.com/3M-Headlight-L…/dp/B001AIZ5HY

It will have almost everything you need, but you still need to buy 1000,1500 and 2000 grit sandpaper + a microfiber on the side

Directions :

Step 1: Decide and Drysand with first grit

(always when sanding keep a thumb/finger above the camera to avoid scratching the glass lens ! )

Dry sand with the least aggressive sandpaper needed to remove scratches. If you have deep scratches you may have to go down to 320-800, but if you have light scratches, 1000 or 1500 might be enough. The best way to test this is to run your fingernail around your phone and try to find a deep scratch. Start at a high grit ( 1500) and see if that removes the scracthes. If you still see deep scratches, try the next most aggressive grit, etc. For me I had to go all the way down to 320 grit, due to several 2-3mm deep defects. This first step is really time intensive, but make sure you don’t use water, on the first step because it tends to hide scratches. When you dry sand you can see all the fine sanding marks you are making which allows you to see the scratches you haven’t removed. Dry sanding clogs sandpaper, but you can either buy more sandpaper or wash the sandpaper in water and dry it before you use it. Before you finish this first step, make sure all your sanding marks are in one direction; you’ll see why later.

Step 2: Wetsand with remaining grits

1) Use very little water when you wetsand ( don’t want to kill you iPhone)
2) Make sure the previous sanding marks are completely gone before moving on to the next higher grit

The 2nd point is important, and the reason many people get poor results when wetsanding. It’s a simple technique but it takes practice/patience to get right. But here are some tips:

a) Before moving on to a higher grit make sure all your sanding lines are in the same direction. When you first start sanding the part you can sand in any direction you want, but before you move to a higher grit make sure to sand the entire part down in one direction
b) When you have moved to your next higher grit you don’t have to sand in a single perpendicular direction (a common myth). Just try to sand the part down as best you can in any direction. However Before you move on to a higher grit, make sure you sand perpendicular to the grit you before. This will let you know where you have to keep sanding before moving on.

So if your last sanding marks using 800 grit were left to right , the last sanding marks on 1000 should be top to bottom, then 1500 should be left to right, etc

c) Before you move on, dry the part a bit, to make sure all the previous sanding marks are gone ( again water tends to hide scratches )

The most time consuming jumps for me were sanding 800grit lines with 1000 grit , and the 1000 grit lines with 1500 grit. These two are time consuming steps , but make sure you take your time, because the finer grit sandpapers will be unable to remove these deep marks (especially 800 grit lines).

When wetsanding the phone it should look like below, not too much water and a slight white film. I kept all my wetsanding paper in a bowl of water, and then dried it on a towel on my lap before using it on the phone. You want the paper to be wet, but not running !

After 1500

After 3000

In all these pictures you will notice a few things
a) All the sanding marks are in one direction, and you can see that there are Zero sanding marks in any other direction.
b) The phone is dry

You may be wondering why all my sanding marks are lengthwise. When I wetsand I still follow what I said above ( last step is to sand in the perpendicular direction to make sure all the previous sanding marks are gone) but then additionally I lightly sand in the longest dimension of the part, this helps me make sure I haven’t left any deep sanding marks of the similar grit ( ie, I lightly sand 1000 grit sanding line with 1000grit sandpaper so that sanding with 1500 is easier)

Step 3: Cover openings

Before you start polishing make sure you cover up your headphone port, volume buttons, vibrate button and 30 pin dock with sticky tack (that blue stuff). You can cover the camera glass, but the polishing compounds are not abrasiveness enough to scratch it (unlike the sandpaper). Sticky tack is easy to apply, and come off in one piece. Tape will probably work too but I found that the tape kept lifting off when I was buffing. Refer to the #2 in the following picture (the gray stuff)

Step 4: Polish

I used two kinds of polishes (using one will work, but you will have to repeat it multiple times/results will vary)

I used the Orange 3m pad with 3M rubbing compound on a power drill
You can sanding halo marks

You can then finish with the 3M rubbing compound using a microfiber and you will get almost near perfect results !

(Completely optional)

If you have access detailing products or a friend who details cars
I polished with a blue 3M Pad with Meguair’s 205 paint polish ( you can also use Scratch-x since its pretty mild polish).

I then finished with some Meguair’s NXT 2.0 wax

Results = completely flawless mirror finish


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