Deep Acrylic Scratches - Help!

[BrainBandAid]

I'm trying to build an aquarium tank with some 1/2 inch thick acrylic that's been in my father's basement for about ten years.
I've cleaned all the crud off it, but there's still some deep gouges.
I've used the Novus brand #2 and #3 polishes, but they're only good for removing hazing and light scrapes.

Anyone ever heard of using a flame of some kind to "melt" the scratches?

Thanks!

 

[blufish]

You will need to sand the scratches out.

Get the supplies here: https://www.micro-surface.com/default.cfm?page_id=175

 

[Slickbaby]

I just spent all weekend modifying a 240 gal tank with the same problems. SCRATCHES! What we did was take 600 grit sandpaper to the whole thing (you can use 200 grit sandpaper if your scratches are really deep, then we moved to pumice stone and rotten stone with a car buffer. Its a ton of work and we're not done yet (we might go to a finer grain polish of some sorts) but it looks pretty good so far. You might try this on a small test piece of acrylic and see if it will work for you.

 

[BrainBandAid]

I just tried an open mesh 120 grit, then a 320 grit, then the novus polishes. It worked alright... the deep scratch was still there, but the sanding was almost removed. I only did a small area on my test piece, so it made kind of a lens, bending the optics a bit.
Except for a few really good dings, the big scratches barely catch a finger nail, so I think it has promise. They run almost the length of the piece, though, so the optical distortion may be unacceptable.
Oh well... it's free!
I think maybe a larger sanding would blend things out better. I like the pumice stone idea... are you using any mechanical/electrical tools?

Oh and BTW, a small torch will "simmer" the surface of the plastic and imbed small bubbles even deeper than the scratch! The scratch was lessened, though.

 

[blufish]

You have to sand a much larger area than just the scratch if you don't want optical distortion - like several inches on either side. Also, wet sanding is better than dry sanding for heat dispersion and to maintain the life of the abrasive.

 

[BONDQ]

Gosh, seems like alot of trouble if the pieces are assembled into a tank yet.

I can certainly understand refinishing an existing tank, but if you account for all your time, sweat and materials/tools that you need, it has to be mighty expensive to take badly scratched acrylic and try to fix it.

I'm saying something, because I'd hate to see you go to all of the trouble, only to dislike the end result after going thru all of the steps.

 

[BrainBandAid]

4X8' sheet of 1/2inch acrylic with scratches: free.
4X8' sheet of new 1/2inch acrylic: $300-400 plus shipping.

And if it doesn't come out good enough, I can always just buy a new sheet. Cant hurt to try, I guess. Just a weekend with alot of sanding!