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this is a unique phenomenon. My model surface has some fine scratches that won't sand out. It's weird. It's as if the scratches run the thickness of the part. Is it the paper I'm using? It's fairly old and tattered. Maybe a rougher grit?
 

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If fine grain wet sanding won't do it, maybe some primer will hide them? I've had numberous models that were many rounds of primer/sand/primer before the surface got decent looking.
 

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Is it a scratch or a small tear in the surface of the plastic?

If its a tear it will never sand out. You'll have to look and it with a magnifying glass. You may have make a shallow cut with an exacto and then putty it.
 

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Mages,

Your problem might be with your torn and tattered sandpaper. Quit being a Scot and use some NEW paper already! :rolleyes: The fresh grit could be the answer to your problem.

Or possibly you've got "ghosts" in your plastic - impressions of the flaws that appear in the color of the plastic but are no longer present in the plastic itself. A shot of primer will tell you for sure.

This isn't clear plastic, I hope - ?

Mark McG.
 

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He could also be sanding that "High Gloss" plastic that the snap together Revell kits are molded in. That stuff's a real pain to try and fix because it has a slightly "Rubber" property about it. The only thing you can really do in that case is primer it and then sand on the primer with the finer coats of sandpaper.

Also, don't use sandpaper with less than 240 grit. Anything lower is too abrasive and you'll end up with deep scratches that will never come out....ESP if you use 40 grit! :D
 

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For general sanding I use black wet and dry paper around 350 grit. Always sand wet and don't use totally ragged out paper. For $.75 for a 10 inch square sheet at Ace buy some new stuff...

If the scratches are deep you may sand a dimple in the plastic trying to remove them. You can get some Tamiya Liquid Surface Primer and brush that on. Its a thick, solvent based, liquid putty. TLSP is in the same vein as the hard to find Gunze Mr. Surfacer stuff, but I think it is better. When the Primer is dry, wet sand it down again.

If your sandpaper is too coarse it may be leaving more scratches. You can try to buff out scratches with finer sand paper, or a piece of an old cotton tee shirt and some Tamiya Polishing Compound or something similar. Even cheap gritty tooth paste and a cotton cloth will work wonders.
 

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Try filler primer

Try using filler primer. Duplocolor makes the best, rustoleum also produces a filler primer. A few light coats and 99% of scratches and dimples are filled, then go over with very fine grit sandpaper.
Mike
 

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Try using filler primer. Duplocolor makes the best, rustoleum also produces a filler primer. A few light coats and 99% of scratches and dimples are filled, then go over with very fine grit sandpaper.
Mike

I agree with Mike and would add that maybe if you shot it with a coat of Future it would fill in the scratches.

Max Bryant
 
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