# Glass Polishing



## wiste (Feb 10, 2006)

I initially looked into glass polishing to remove scratches from glass. Using a 3/8-inch drill with speed of 2400 RPM attempts to remove scratches would remove fine scratches after significant effort. A secondary use of glass polishing is to remove hard water composites. The water here is very hard. Hard water deposits are a significant problem. In the future, use of reconstituted RO water seems desirable.

One conclusion, drill speed is essential. My 1/2 drill with 1200-RPM speed made negligible results. The 3/8-inch drill was the fastest drill available at local stores. I have since purchased a 1/4-inch drill online which has a speed of 4500 RPM. Generally, the smaller the supported shaft the higher speeds available. The 1/2 drill is good for high torque operations such as drilling large holes. The 3/8 drill works well for grinding operations and smaller drilling operations. The 1/4-inch drill is good for polishing and cutting operations on PVC and plastic.

A second conclusion, the type of polishing tool is also essential. I purchased a hard felt polishing head
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At 2400 RPM, pressure will heat the glass to the point where cracking the glass due to heat becomes a concern. At this speed radiated heat can be seen from the glass. Keeping the polishing head wet helps with the heat but too much water resulted in the felt separating from the shaft assembly. This was rectified with some glue and less water on the felt.

A third conclusion, the type of polishing compound is essential. The standard glass polishing compound is cerium oxide. Using this compound will produce results with much effort without a significant amount risk of scratching the glass. Additional compounds were purchased (grade 4f, 2f, grade 1/2 and grade 1 pumice) which were coarser.










The grade 1/2 and grade 1 pumice must be used with care to avoid generating light scratches in the glass. However, the careful use of coarser polishing compounds does significantly reduce the effort required to polish.

Exploring the use of higher speed, another possibility was the use of a Dremel tool. Using the felt polishing tool provided with the Dremel kit generated modest returns while destroying the polishing element.



















A hard felt polishing bob was purchased to use with the Dremel tool.










The bob was much more affective and did not deteriorate.










Although the advertisement indicated the bob was for use with a Dremel tool, it was indicated that the shaft was 1/4". This is too large for my Dremel tool and it did not fit. The shaft was in fact too large. A grinding wheel was used to reduce the shaft to a size that would work the dremel tool. At the high speeds generated by the Dremel tool, 15,000 to 35,000, not only is heating of the glass a concern but the felt will start to burn.

I found the Dremel tool is desirable for removal of composites on 29 gallon tanks which are too small for the larger polishing head. Continuous operation of the Dremel tool on its highest speed will result in the tool becoming very hot. So, only short periods of operation would seem appropriate.

Practice helps greatly with getting results. Maybe this information can be helpful, and I would like to hear any tips.


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## aquabillpers (Apr 13, 2006)

That was a very interesting post. I'll know what to look for if I have that problem.

I recently removed a 3 inch scratch with toothpaste (not the gel kind.) I rubbed it into the scratch, removed the excess with a razor blade, and voila! The scratch was no longer visible.

I think it works by eliminating the reflection from the sides of the scratch.

Bill


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## wiste (Feb 10, 2006)

> I recently removed a 3 inch scratch with toothpaste


Innovative, using toothpaste in place of resin. Was that scratch on the outside of the tank?


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## aquabillpers (Apr 13, 2006)

wiste said:


> Innovative, using toothpaste in place of resin. Was that scratch on the outside of the tank?


The scratch was on the outside of the tank and easily felt by a fingernail.

A google search for - scratch toothpaste - will return references to a number of other uses for toothpaste, including tooth cleaning!

Bill


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## Troy McClure (Aug 3, 2005)

This is a great post. I've got a small 1/2" scratch on my Oceanic and want to get it out. I've got a Dremel (the f-it up yourself tool!) and have been contemplating some sort of repare. I'm wondering if filling and polishing it would be a better way to do it, sort of like those eyeglass sprays they have.

Bill - what process did you use? Did you use anything to fill the scratch first?


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## aquabillpers (Apr 13, 2006)

Erik,

I just rubbed the toothpaste into and around the scratch and then scraped off the excess with a razor blade. It took about 20 seconds, max.

Bill


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## Troy McClure (Aug 3, 2005)

Did you use a clean cloth to rub it or a toothbrush? Does it haze the glass around the scratch? What toothpaste did you use? I think I have Colgate Tartar Control...it's definitely a white paste, not a gel.


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## aquabillpers (Apr 13, 2006)

I just put the toothpaste on my finger and rubbed it into to the crack.

I don't think it makes any difference what brand of paste is used, but I used one of the several kinds of Crest.

Bill


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## Troy McClure (Aug 3, 2005)

Incredible. I just re-hung the mirror in my bathroom and noticed some scratches. I figured I'd try out the toothpaste on this mirror before FUBAR-ing my Oceanic....Wow! The scratches are completely gone, which is great to see because some of them were exactly the size and depth of the one on my tank. Thanks Bill! Thanks Colgate!


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