My fault-huge scratch in my acrylic tank...

[dcr]

Hi all, I haven't posted here in a very long time due to zero problems or complaints with my tank...until today. I was cleaning some red algae off of my acyylic tank, and I must have got a piece of sand on the scraper, and I dug an 18 inch scratch right across the front of the inside. Can this be removed, and if so, while there is water still in the tank? I am so mad that I am considering a 55 glass tomorrow just so I don't have to look at it another second.

 

[bigmac]

From what I've read you can buff it out with some fine sand paper. Use the magnet to hold the sand paper in place. You'll want to start with a fine grade and go finer.
I'd link you to a good thread but that's not allowed here

 

[atcone]

There is a repair kit available the can be used under water. I got mine from the LFS. It cost about $40.00 really steep for what you get. I have seen it on line for about half that. can't remember where though. Never really used it because it was too small for my job. You may have luck doing a search. Also if the scratch is not deep you should be ok. I bought a second hand 100 clarity plus flat back hex tank, stand & hood for a fraction of the cost of a new one, but it was full of scratchs. I was able to sand and buff out 95% of them looks like a new tank, only one or two small deeper scratches. My repair job was on the whole tank so I bought wet/dry sand paper from the local auto store.started with 600 grit then progressed to 2500 grit for the final. the kit I mention above did have a good sanding block in there that I used. Then an auto buffer using the novus acrylic cleaner products. Good luck.

 

[dcr]

I can feel it with my thumb nail as I pass over it, so it is deep enough for that, but I'm not sure if it is too deep to remove. I found a product online for $22:
Removes scratches from acrylic Aquariums.
Crystal pad, the sanding material in this kit, has been used to polish plastic surfaces for over 20 years in the aircraft industry. The abrasive crystals are cushioned within a thin soft resilient material. This cushion allows the large abrasive crystals to recede into the soft material creating an even cutting plane.
Can be used wet or dry.
Removes scratches even under water!
Includes 8 different progressive grades of crystal pads, sanding block, 3/4 oz. bottle of final polish liquid abrasive with anti-static agent, flannel cloth and molded plastic case.
Economical to use. Outlasts common abrasives up to 7 times in dry applications, and up to 15 times with wet applications.
Restores your acrylic aquarium to it's original new luster!

 

[krux]

wet dry sand paper from an auto detailing shop, get 2000, 4000, 8000, and 12000 grit. get a small block of acrylic, or other non reactive material to use as a sanding block. sand as normal, with the exception of your arm being submerged in the tank. the fine acrylic dust is completely inert.
start with 8000 sanding directly over the scratch. if it doesnt diminish after a minute or so of sanding, move down a grit and continue as far as 2000, below that you have a major scratch that will take a silly long time to fix with the tank full. as soon as the scratch starts to blend in to the surrounding area, cover the entire length of the scratch until it is no longer visible, and then move up a grit and repeat to whatever level you desire.
with the tank full of water, you will see slight cloud at 4000, and it will be clear at 8000. 12000 will make the acrylic clear when the tank is empty and dry, but hopefully you won't be looking at it in that state. if you ever empty the tank and want to finish the process, get a nice soft cloth and some novus polish... enough elbow grease and you will never know a scratch existed.
if you live near a detail painting/hotrod shop, you should be able to go in and if they are friendly you can get single sheets from them. total cost will be less than 10 bucks.
plan on spending a few hours by the way for a scratch that long if you want to go all the way to 12000.