Acrylic tanks

[dan_k]

Hey RC wondering if I could ask some questions about acrylic tanks.
I have a chance to pick up a nice size acrylic tank the problem is it needs some buffing and its 15years old the guy just broke the system down so it holds water.
Now couple questions

First how long can acrylic tank last forever?
The seams scare me on a tank that old

Second is it a pain to buff the scratches out?

Last to the people that own acrylic tanks are you happy with them
Thanks

[SPotter]

I would find out who made it first and see what the reputation of that company is. Would you be using the stand that the tank has been on? I was told that acrylic tanks will mold themselves into the imperfections of a stand over time and if you are going to buy a used acrylic tank that you should also buy the stand it has been on otherwise you will have problems putting it on a new stand. How true that is don't know but something to consider. As far as buffing goes....depending on the severity of the scratches it can be a lot of work. You might want to speak with a local acrylic fabricator and see if they can do it for you.

As far as being happy with my acrylic tank...aside from the occasional scratch that I make from being careless...yes I am vey happy with it.

[dattack]

you would probably want to see how thick the acrylic is and take a picture of the seams. It might have degraded over time depending on the manufacturer , thickness of the acrylic, heat source such as metal halides used around it.

[dan_k]

All great point I never thought of thanks

[slief]

Good advice above regarding finding out who made it. That said, a close inspection of the seams and viewing panes will speak volumes about the quality of the tank. Diffrent manufacturers use different grades of acrylic. Cheaper acrylic will tend to craze or show signs of stress cracks in the material and often along the edges.

if the seams are clear and not showing signs of separation, that is a great sign. Separation is easily spotted by the appearance of salt intruding into the seams/glue joints.

Is there deflection or bowing on the viewing panes? This may be impossible to judge if the tank is empty. Material thickness plays a big role in whether a tank will deflect or not.

Is there crazing in the acylic? If you look through the viewing panes at a slight angle, stress cracking or crazing would be visible. It can occur anywhere in the panes as well as along the edges where they corners are bonded. if you don't see any crazing in the acrylic, that is usually a good sign of quality acrylic.

I had my 480 gallon acrylic display built just over 20 years ago. My tank was built very well with quality acrylic and built with very thick material. After 20 years, I have absolutely no crazing, no deflection and still have perfect seams. Scratch removal on an acrylic tank is very simple and very similar to removing scratches from a car. Wet sand and polish is what it comes down to. Acrylic is relatively soft so it really isn't difficult at all. Especially if the tank is empty. A range of sand paper from 400 grit up to 4000 and a good electric buffer along with novus compound and polish or even automotive grade buffing compound a polish will restore acrylic and remove scratches. Any scratches that I've encountered over the years have been sanded and or polished out. In fact, I even remove scratches from inside the tank while the tank is full by using a wide range of special wet sand paper (Micro Mesh) ranging from 400 grit up to 12,000 grit glued to my cleaning pads that I attach to my Might Magnet scrubbers. I start with the rough stuff and work my way up to the 12000 grit working a slighting larger area with each grade.

At the end of the day, how long an acrylic tank will last is a matter of how well the tank was built. Given the age of condition of my tank, I'd have no issues buying a 15 year old acrylic tank provided it was well built and passed my inspection. Having said that, not all acrylic tanks are created equal so a close inspection is very important.

A