Re-polishing or replacing sheet plastic.

[nate80]

So this is a bit of an odd one and not quite quad related.  Ok, not at all quad related - specifically it';s guitar related  - but the material is definitely relevant to drone builds and repairs.

I';ve got a couple of smallish covers on the back of a new to me, but very second hand, guitar I bought that are made of very simple sheet plastic.  I';m not sure what plastic exactly.  ABS or acrylic maybe?

They';re just flat sheet black glossy plastic each measuring about 5" x 2.5" and they';re pretty scratched up.  The scratches are deep enough to catch your fingernail in.  Here';s one:

[attach=1]

Is there any easy-ish or realistic way to bring the plastic back so it looks like new?  A quality plastic repair kit or something?

Or would I need to get new ones cut by a plastic fabricator specialist?  I';m guessing that would probably cost more than the guitar';s worth!?

Thanks

[Doug]

First thing is to find out what sort of plastic it might be what make Guitar is it we may be able to find something out with that info.

Think they normally use something that is quite hard such as trafolyte or similar


Doug

[Bajadre]

Maybe wet and dry sanding then a dremel buff wheel might shine it back up I would imagine it would be cheaper finding a replacement or getting someone to cut one out unless you have a dremel etc

[shawdreamer]

If its ABS then fine wet and dry it till flat then if you want the reflective finish back a quick minute or so in a acetone vaping chamber (pretty easy to diy one together) will see it back to almost mirror finish.

[richardg6paj]

It will probably be PVC or possibly an ABS type material. Scratch plates are usually made of Traffolyte or as it is called now ABET rigid engraving material which is what I have used to make scratch plates and the like. It is made up of 3 or more plies of resin in different colours, for example black/white/black or white/black/white etc. and is quite brittle due to it being very hard and is used mainly for making panel labels for electrical control boxes. The other material is Gravoply which looks similar but is much softer.
If you';re stuck I';ll make you one out of Traffolyte/Abet after Christmas, but I will need a very accurate pattern to work from.

[nate80]

Thanks for all the replies guys.      The covers are from the rear of a Maverick X1, a fairly rare UK produced guitar.  One covers the underside of the Floyd Rose bridge and the other covers up the volume and tone regulators.  Maverick went bust back in 2006 I think so off-the-shelf parts are a bit like hens teeth!   

It';s hard to be sure as it';s only 2mm thick, but from looking at it side on it looks like it';s made up of 4 plies of black plastic.  The top layer that';s on show is high gloss, the bottom is like satin - still shiny but not quite as gloss as the top layer.

I have a dremmel and thought about using some plastic polish I have for my car light lenses, but I read that if it';s not the right type of plastic it';ll be ruined and the gloss finish removed.

Thanks very much for the kind offer to make up something after Chrimbo Richard.  That';s much appreciated.  If I';m at a dead end I';ll let you know.   ::)

I guess there';s not a simple way of determining what type of plastic it is?  I read burning plastic and watching the reaction can reveal what type it is, but I';d prefer not to burn it as it';s all I currently have!   

[richardg6paj]

Sounds as though it might Gravoply. Traffolyte is usually 1.5mm or 3mm thick and normally 3 ply. But as I said it is very hard and doesn';t melt.
Dont forget if you polish you will be going through the top layer revealing whatever is underneath.

[Powernumpty]

If you have any of the white thermal paste from computer heatsink assembly try that with a cloth.
It won';t do the deep scratches but does brings up light scuffing. Don';t use too much, do a small area at a time and apply enough pressure to get the cloth warm.

[orfordness]

To polish plastic try toothpaste, or a pro kit of Micro Mesh

https://www.amazon.co.uk/d/DIY-Tools/Micro-Mesh-Cushioned-Abrasive-Cloth-Polishing-Sheets/B003RTABUK
We used to use these kits on Harrier canopies (real,ones!)
Steve

[nate80]

On closer inspection in daylight the plastic may not be ply at all.  It';s so rough finished that it';s extremely hard to tell.  It looks ply on one side, a solid sheet on 2 sides and solid but with one lacquer-like coating on the court side.  I really haven';t got a clue what type of plastic it is.

I think Im going to take the plunge and try sanding and polishing it as if it';s wrecked it just means I have to get new ones made, which I was thinking may be the answer anyway.

If you have any of the white thermal paste from computer heatsink assembly try that with a cloth.
It won';t do the deep scratches but does brings up light scuffing. Don';t use too much, do a small area at a time and apply enough pressure to get the cloth warm.

I don';t have any thermal paste unfortunately.

To polish plastic try toothpaste, or a pro kit of Micro Mesh

https://www.amazon.co.uk/d/DIY-Tools/Micro-Mesh-Cushioned-Abrasive-Cloth-Polishing-Sheets/B003RTABUK
We used to use these kits on Harrier canopies (real,ones!)
Steve

Thanks for the useful info and link.  I';ll give toothpaste a bash but I';ve tried that before and I think these scratches are too deep to make much of an improvement.  I just ordered 28 various sanding sheets 150-3000 grit and a polishing kit.

I';ve got the guitar to polish too.  I';ve bought some professional guitar polish and a few micro fibre cloths.  I';m not looking forward to that job!

[richardg6paj]

Might be Acrylic, in which case fine wet and dry would do it and then polish with Autosol.

[orfordness]

I think you';ll be impressed with the micro mesh kit...

[Friskle]

i have got scratches out of plastic sheet by using T-Cut for car paintwork.

[Samslimer]

Greygate plastic polish and a fine mop wheel works well.