Removing scratches on a acrylic tank

conradchu · 03/31/2009, 06:11 PM

Hi,

I wanted some advice on removing scratches on my 55g truvu acrylic.

Does anyone have any experience removing scratches, preferably using a buffer or some rotary tool? I removed scratches before using a a small block and that took forever so I want a more effective way (last time the block was too hard and wasn't able to get rid of the bigger scratches).

Reason speed is an issue is I'm planning on temporarily removing livestock and draining the tank. I'll keep live sand in and some of the live rock in there and I assume a little of the scratch removal solution might get on there, but it's more like toothpaste so I'm sure I can keep it off the sand.

Second question, on my tank, there are some really fine scratches, that appear to be inside the acrylic. I cannot confirm, but you certainly can't feel them by touch and you only see them when looking at the tank from angle. I'll try to take a picture, but they're really fine and consistently over the front face of the tank. Are these stress marks? If so, should I be worried. The actual aquarium seams look fine. The tank does bow a little, but not any more than what I've seen on other people's acrylics. It is a TruVu so I assume it the acrylic thickness was to spec.

Thanks
Conrad

125G Reefer · 03/31/2009, 06:21 PM

Outside scratches, are easy. Use Novus system #1, #2, #3. Unless they are REALLYLLLLYYLYLYYY nasty scratches, then I'd go with wet sand paper starting at 400 then 600 then 1000 then 2000, then use the Novus. On the inside of the tank, look into a kit that Foster SMith sells. The Novus is really good with the buffer.

conradchu · 03/31/2009, 07:59 PM

I've used Novus #1,2,3 and before. Is there a reason you would use the Dr. Foster Smith on the inside? Is it more reef safe? (I don't see any mention of it on the website http://www.drsfostersmith.com/produc...fm?pcatid=3883). Is it reef safe because it's just fine sanding paper and not fluid based (except for the final finish).

I ideally want to use a buffer on the inside, since those are mainly where the scratches are at. But I guess they don't have those crystal sand papers for a buffer.

Chandlerpelhams · 03/31/2009, 08:10 PM

Okay, one of my other hobbies is building electric guitars which involves painting, sanding and buffing the finish to a mirror shine. I have also worked on some acrylic tanks and after years of frusturation with advice people have given me online and reading forums and tutorials PLEASE DO NOT USE 400 GRIT SANDPAPER!!!!

This is INCREDIBLY too aggressive for your tank. I have had a lot of success with using 1500-2000 grit and than buffing for the outside of a tank. The trick is to have a squirt bottle of water and be constantly spraying the area you are trying to sand. If you can, it would help you ALOT to purchase Mcguires mirror glaze unigrit sandpaper - 1000 grit

I know this is only 1000 grit but it gives you an idea. This sandpaper has a much more even grit than the cheapo 3M sandpaper you would find at autozone so it sands faster and doesn't create large scratches in your tank.

If you choose to sand on the outside you will need to buff it as well, and you will NEED an actual buffer with a buffing pad. As for polishing compound I like the mcguires #2 which is a soft particle and will break down as you buff so it can prevent someone who is new to buffing from putting too big of scratches from an aggressive compound. Another lesson learned the hard way - don't buff in one area for too long! The heat from the buffer can cause the acrylic to get cloudy.

As for the scratches on the inside - you only need to sand them, no buffing is required. The water will fill in the micro scratches from your sanding and you will be unable to see them.

If you want to, PM me and I can mail you a 1/2 sheet of 2500 grit for you to try on the inside of your tank before you spend money on a whole pack. Either that or try and get in touch with a local body shop and see if they will sell you a couple of sheets.

Good luck and let us know how it turns out!

125G Reefer · 03/31/2009, 10:21 PM

Just for the record, the thread said, if they were bad scratches. I polished a 115g Acrylic, scratched all to hell. Started actually with 320 grit sandpaper all the way down to 2000 wet sand, then to the Novus. Polished up you would could not imagine.

Foster Smith for the inside because that is what that one is made for I believe.

Chandlerpelhams · 03/31/2009, 11:40 PM

From my experience, starting at 320 is just going to make a lotttttt of extra work for yourself, I'd stick with 1500 mcguires paper, it will take a pretty serious scratch out of acrylic fairly quickly and can be buffed out without stepping up to a higher grit.

The Foster Smith product costs $25 - get youself a good rubber sanding block <---- also VERY important and a peice or 2 of 1500 grit sandpaper and you'll save quite a bit of money, especially since you had to buy it anyways to to the outside of the tank.

conradchu · 04/01/2009, 12:30 PM

Here are the pictures of my tank.

http://www.flickr.com/photos/conradchu/3404335499/
http://www.flickr.com/photos/conradchu/3404335473/
http://www.flickr.com/photos/conradchu/3404335447/
http://www.flickr.com/photos/conradchu/3405146900/

You'll see large scratches but also small straight scratches. I was wondering if those small straight scratches are stress marks in the acrylic cause I don't exactly feel them with my fingers when I'm cleaning the tank. Is the tank still safe?

Any ideas?

Thanks

MarineGirl411 · 04/19/2009, 12:19 PM

I think that looks like crazing. Anyone else?

125G Reefer · 04/19/2009, 02:30 PM

Yikes.Looking hard at those pics, I don't think you are going to be able to get those out. It looks as if those are spider cracks in the acrylic itself. If you run your finger over them, can you feel anything? Or is it just smooth. THey look like they are imbedded on the acrylic based off looking at the last photo. If you can feel those dings then you will be able to get them out, but....Its goin to take you a very long time to do it as they go very deep into the acrylic.

stang02 · 04/19/2009, 05:10 PM

the problem also with the depth is if you polish too hard in any one area you could distort the viewing panel

conradchu · 04/20/2009, 12:34 PM

Thank for all your replies.

Yeah, I cannot feel the small scratches, so I think they're inside the acrylic. I decided to get a new tank altogether rather than risk something happening to this tank

Thanks for all your help!

tkeracer619 · 04/20/2009, 12:43 PM

Good idea. That is crazing, not fixable.

03/31/2009, 08:10 PM	#4
Chandlerpelhams Registered Member Join Date: Feb 2008 Location: Raleigh Posts: 30	Noooooo! Okay, one of my other hobbies is building electric guitars which involves painting, sanding and buffing the finish to a mirror shine. I have also worked on some acrylic tanks and after years of frusturation with advice people have given me online and reading forums and tutorials PLEASE DO NOT USE 400 GRIT SANDPAPER!!!! This is INCREDIBLY too aggressive for your tank. I have had a lot of success with using 1500-2000 grit and than buffing for the outside of a tank. The trick is to have a squirt bottle of water and be constantly spraying the area you are trying to sand. If you can, it would help you ALOT to purchase Mcguires mirror glaze unigrit sandpaper - 1000 grit I know this is only 1000 grit but it gives you an idea. This sandpaper has a much more even grit than the cheapo 3M sandpaper you would find at autozone so it sands faster and doesn't create large scratches in your tank. If you choose to sand on the outside you will need to buff it as well, and you will NEED an actual buffer with a buffing pad. As for polishing compound I like the mcguires #2 which is a soft particle and will break down as you buff so it can prevent someone who is new to buffing from putting too big of scratches from an aggressive compound. Another lesson learned the hard way - don't buff in one area for too long! The heat from the buffer can cause the acrylic to get cloudy. As for the scratches on the inside - you only need to sand them, no buffing is required. The water will fill in the micro scratches from your sanding and you will be unable to see them. If you want to, PM me and I can mail you a 1/2 sheet of 2500 grit for you to try on the inside of your tank before you spend money on a whole pack. Either that or try and get in touch with a local body shop and see if they will sell you a couple of sheets. Good luck and let us know how it turns out!

04/19/2009, 12:19 PM	#8
MarineGirl411 Registered Member Join Date: Jun 2006 Posts: 2,583	I think that looks like crazing. Anyone else? __________________ I am a reefaholic and there is no cure. =) Current Tank Info: 90 gallon reef, Cardiff Nano Seahorse tank.

04/20/2009, 12:43 PM	#12
tkeracer619 Registered Member Join Date: Jan 2006 Location: Westminster, CO Posts: 17,289	Good idea. That is crazing, not fixable. __________________ Hobby Experience: 9200ish gallons, 26 skimmers, and a handful of Kent Scrapers. Current Tank: Vortech Powered 600G SPS Tank w/ 100gal frag tank & 100g Sump. RK2-RK10 Skimmer. ReefAngel. Radium 20k.

03/31/2009, 06:11 PM	#1
conradchu Registered Member Join Date: Mar 2009 Location: Alameda, CA Posts: 10	Removing scratches on a acrylic tank Hi, I wanted some advice on removing scratches on my 55g truvu acrylic. Does anyone have any experience removing scratches, preferably using a buffer or some rotary tool? I removed scratches before using a a small block and that took forever so I want a more effective way (last time the block was too hard and wasn't able to get rid of the bigger scratches). Reason speed is an issue is I'm planning on temporarily removing livestock and draining the tank. I'll keep live sand in and some of the live rock in there and I assume a little of the scratch removal solution might get on there, but it's more like toothpaste so I'm sure I can keep it off the sand. Second question, on my tank, there are some really fine scratches, that appear to be inside the acrylic. I cannot confirm, but you certainly can't feel them by touch and you only see them when looking at the tank from angle. I'll try to take a picture, but they're really fine and consistently over the front face of the tank. Are these stress marks? If so, should I be worried. The actual aquarium seams look fine. The tank does bow a little, but not any more than what I've seen on other people's acrylics. It is a TruVu so I assume it the acrylic thickness was to spec. Thanks Conrad

03/31/2009, 06:21 PM	#2
125G Reefer Moved On Join Date: Feb 2009 Location: Glendale,AZ Posts: 913	Outside scratches, are easy. Use Novus system #1, #2, #3. Unless they are REALLYLLLLYYLYLYYY nasty scratches, then I'd go with wet sand paper starting at 400 then 600 then 1000 then 2000, then use the Novus. On the inside of the tank, look into a kit that Foster SMith sells. The Novus is really good with the buffer.

03/31/2009, 07:59 PM	#3
conradchu Registered Member Join Date: Mar 2009 Location: Alameda, CA Posts: 10	I've used Novus #1,2,3 and before. Is there a reason you would use the Dr. Foster Smith on the inside? Is it more reef safe? (I don't see any mention of it on the website http://www.drsfostersmith.com/produc...fm?pcatid=3883). Is it reef safe because it's just fine sanding paper and not fluid based (except for the final finish). I ideally want to use a buffer on the inside, since those are mainly where the scratches are at. But I guess they don't have those crystal sand papers for a buffer.

03/31/2009, 10:21 PM	#5
125G Reefer Moved On Join Date: Feb 2009 Location: Glendale,AZ Posts: 913	Just for the record, the thread said, if they were bad scratches. I polished a 115g Acrylic, scratched all to hell. Started actually with 320 grit sandpaper all the way down to 2000 wet sand, then to the Novus. Polished up you would could not imagine. Foster Smith for the inside because that is what that one is made for I believe.

03/31/2009, 11:40 PM	#6
Chandlerpelhams Registered Member Join Date: Feb 2008 Location: Raleigh Posts: 30	From my experience, starting at 320 is just going to make a lotttttt of extra work for yourself, I'd stick with 1500 mcguires paper, it will take a pretty serious scratch out of acrylic fairly quickly and can be buffed out without stepping up to a higher grit. The Foster Smith product costs $25 - get youself a good rubber sanding block <---- also VERY important and a peice or 2 of 1500 grit sandpaper and you'll save quite a bit of money, especially since you had to buy it anyways to to the outside of the tank.

04/01/2009, 12:30 PM	#7
conradchu Registered Member Join Date: Mar 2009 Location: Alameda, CA Posts: 10	Here are the pictures of my tank. http://www.flickr.com/photos/conradchu/3404335499/ http://www.flickr.com/photos/conradchu/3404335473/ http://www.flickr.com/photos/conradchu/3404335447/ http://www.flickr.com/photos/conradchu/3405146900/ You'll see large scratches but also small straight scratches. I was wondering if those small straight scratches are stress marks in the acrylic cause I don't exactly feel them with my fingers when I'm cleaning the tank. Is the tank still safe? Any ideas? Thanks

04/19/2009, 02:30 PM	#9
125G Reefer Moved On Join Date: Feb 2009 Location: Glendale,AZ Posts: 913	Yikes.Looking hard at those pics, I don't think you are going to be able to get those out. It looks as if those are spider cracks in the acrylic itself. If you run your finger over them, can you feel anything? Or is it just smooth. THey look like they are imbedded on the acrylic based off looking at the last photo. If you can feel those dings then you will be able to get them out, but....Its goin to take you a very long time to do it as they go very deep into the acrylic.

04/19/2009, 05:10 PM	#10
stang02 Registered Member Join Date: Apr 2009 Posts: 237	the problem also with the depth is if you polish too hard in any one area you could distort the viewing panel

04/20/2009, 12:34 PM	#11
conradchu Registered Member Join Date: Mar 2009 Location: Alameda, CA Posts: 10	Thank for all your replies. Yeah, I cannot feel the small scratches, so I think they're inside the acrylic. I decided to get a new tank altogether rather than risk something happening to this tank Thanks for all your help!