Kid Scratch Fever!!!!

[Pez Vela]

Well, it happened! I left my "mag float" on the front of my acrylic aquarium and my four year old was trying to help out dear old dad by cleaning my tank. Unfortunately he did not see a very small strombus snail hanging out on the side of the inside piece. He was cleaning for a good 5 minutes before I walked in to see many swirls of evident scratches all over the front of my tank. Cannot really be mad at him. He sees me do it and only wanted to help......

Now, I have heard of some sort of scratch removal kit which you can actually apply underwater. Has anyone tried this product? I do not even know what it is called. I really do not want to remove everything and start over with a new tank, but I will if I have to and you can bet it wil be real glass! I hate scratches!!!!!!

If anyone has any info to help me fix the problem, please let me know and thanks

mike

[Gawain1974]

The only scratch removers for acrylic that I've seen can only be applied to a dry tank. A kid working at my LFS bought a used acrylic tank that was foggy with scratches. He used a two-part scratch remover, and I was amazed at how wonderful the tank looked afterwards--like brand new. Hopefully you can find that underwater product, but if not, don't write off your acrylic tank just yet. Good luck! :)

[hsvtoolfool]

How big is the tank? A 75g or smaller is not worth the effort
(at least to me). Removing scratches takes a LOT of elbow grease.
If the scratches are deep, leave them alone. You can make the
tank look much worse trying to remove a deep scratch. Lots of
sanding removes so much material that you cause distortion.

#1) Practice on a spare piece of cast acrylic (not extruded).
All but smallest tanks are made of cast acrylic, which is much
harder and stronger than cheap extruded acrylic. Put a simliar
scratch in the piece and go to it.

#2) When it comes time to tackle your tank, use your heavy-duty
cleaning magnet to rub the abrasives against the inside of the
tank. The acrylic dust won't hurt anything in the tank.

#3) Start with 800-grit wet/dry paper from a local auto body
supply store. It's much cheaper there than HomeDepot or Lowe's.

#4) Sand with linear motions; not circles. This is important later
when using Micromesh**. Overlap the scratched area a small
amount to blend the depression you are creating with the flat
surface.

#5) When the area is evenly hazy and the scratch is gone, switch
to 3200-grit Micromesh and cover the previous grit's scratches.

#6) Always sand 90-degrees to the previous grit's orientation.
Micromesh only works when sanding across a previous grit. Also,
this let's you see your progress easier so you can switch to the
next grit at the right time. The area should be evenly hazy with
no cross-hatching before switching to a finer grit.

#7) Overlap the previous grit's area slightly so that each grit
leaves a slightly larger area. This helps blend the work area into
the flat surface.

#8) After the 3,200 Micromesh is done, work your way through
Micromesh 4000, 6000, 8000, and 12,000 grits (remember:
90-degrees between each grit).

#9) Don't skip grits! You sand twice as long using a too-fine grit
on large scratches. You save lots of time and energy using the
proper grits.

After the 12,000-grit Micromesh, the scratch-free acrylic should
look acceptable but not quite new. You must use plastic polish
(Novus) to buff the surface to perfection. Unfortunately, these
products can't be used under water. However, someone in the
forum recently reported using toothpaste (Mentadent or
Colgate?) as a non-toxic, under water polishing compound.
Your milage may vary, but I can't imagine it would cause too
much harm in small amounts, especially if you polish a small
amount once a week. Toothpaste is definitely a mild abrasive
and will polish acrylic. Apply the polish with a foam polishing pad (https://www.micro-surface.com/default.cfm?page_id=90&ID=3WS5&storeid=1)
designed for the job. A soft cotton cloth may be coarser than
the 12000-grit Micromesh.

** Micromesh is a tradename for a special abrasive developed to
polish acrylic airline windows. This is what comes in most acrylic
polish kits, but buying direct you get more sheets for less money.
You probably can't find Micromesh locally. Here's a Dealer (https://www.micro-surface.com/default.cfm?page_id=90&ID=3S3227&storeid=1) which
sells individual 3"x6" sheets for $2 each, which is the best price I
could find on the web. They also sell polishing compounds, one of
which may be useable underwater. Why don't you contact them
and find out for us? ;)