Mineral Deposits

[Mugwump]

It must be toxic, they usually stay away when I have it sprayed all over me.

LOL  In 20 years of working in environmental remediation, we tried very hard to keep from having toxic substances from being sprayed all over us.

Dennis

Hee hee. No worse than Off. Smells nicer too.

'Skin so soft'  by Avon.....a great repellent.....

[Frank The Plumber]

Type F transmission oil. Burns a little if you sit in the sun though. You get a sunburn in like 4 minutes. Ouch. Cures dandruff too.

[Jdmcfast]

WD-40 main ingredient is fish oil it is not toxic, and lots of people spray it on bait to attract fish so I don't think it would be as dangerous as most other sprays

[b125killer]

I like the smell of WD40 not to sure I would use it as bug spray.
here is the MSDS sheet for WD40: http://www.wd40company.com/files/pdf/msds-wd494716385.pdf

[PaulineMi]

These kinds of deposits are probably a combination of salts and calcium/magnesium carbonates and phosphates). The phosphates are supposed to be more difficult to dissolve. Details will depend on your water chemistry.
It is possible that the chemicals may have etched the glass to some slight extent because they would be at very high concentrations just prior to precipitating. This could result in pitting which could look whitish and would not be removed by any amount of dissolving, but you should not feel anything with the razor blade moving over the surface.

I have used a thick phosphoric solution to dissolve deposits on many things. I found it in a beer brewing supply store when I was looking for some live yeast. It is used for sterilizing things used to brew beer.

If you are trying to soak something on a vertical surface, you might try creating a little pocket by loosely covering the area of interest with a piece of some kind of plastic sheet and seal the sides and bottom with some strong adhering tape, and then putting a piece of paper towel soaked with your acidic solution into the pocket so it is in contact with the deposits.

The etching is what I wondered about.  I received a used tank with what I thought was tons of lime deposits on it.  I was never able to get it cleaned up and it was determined that the glass was actually etched.

[PaulineMi]

Type F transmission oil. Burns a little if you sit in the sun though. You get a sunburn in like 4 minutes. Ouch. Cures dandruff too.

Frank....have those sewer fumes gotten to you?       Lol.

[Mugwump]

Type F transmission oil. Burns a little if you sit in the sun though. You get a sunburn in like 4 minutes. Ouch. Cures dandruff too.

Frank....have those sewer fumes gotten to you?       Lol.

You betcha they have.......LOL..

[BallAquatics]

...it was determined that the glass was actually etched.

I've got some grow-out tanks I purchased used from pet stores that are like that.  Mine cleaned up to the point that you need to look just the right way to see the marks.  I've always assumed that they were used as saltwater tanks.

Dennis

[pashley]

i use white vinegar and a razorr blade. let t soak in vinegar for a few minutes and scrape it off.

[BillT]

Quote from: PaulineMi on March 04, 2013, 01:57:50 PM

    ...it was determined that the glass was actually etched.


I've got some grow-out tanks I purchased used from pet stores that are like that.  Mine cleaned up to the point that you need to look just the right way to see the marks.  I've always assumed that they were used as saltwater tanks.

There are different kinds of glass made with different chemical formulations.
Some kinds of glass are probably more susceptible to etching than others.

[b125killer]

How would you get the etched glass cleaned up? could you use abrasive polishing compound? I would guess that you would want to drain the tank for that.

[BillT]

How would you get the etched glass cleaned up? could you use abrasive polishing compound? I would guess that you would want to drain the tank for that.

The etching produces a flawed optical surface. Because it is not smooth, light does not go through it in a coherent manner. Parallel light rays going through a flat surface will allow remain parallel. Light ray going through an etched surface will go off in all kinds of different directions.

Fixing this would involve restoring the flawed optical surface of the glass. A scratched plastic tank can be smoothed out by buffing down the surrounding areas to the bottom of the scratch. This would not be easy with glass. After grinding down the surface flat, you would have to polish it to a very smooth surface where no scratches were visible. This would be like making a lens or a telescope mirror.

An alternative approach would be to somehow fill the parts that are etched down below the surface of the surrounding area and polishing it smooth. Making the area wet with water in some cases fills the flaws and makes it look better. This would be an approximation of such a repair. Ideally the filling material would have optical properties (the optical density or O.D.) that are matched to those of the glass. Can't say I heard of this being done.


A related issue is reflections:
I have made many fish photo boxes out acrylic (clearer than most common kinds of glass). On occasion, I have been annoyed by getting reflections of fish off of the water side surface of the back of the box when the fish are close to the back.
My sister makes displays at the Smithsonian and knows people that know how to minimize reflections so I asked one of them how to make this problem go away. His simple solution was to use a random orbital sander and about 600 grit sanding paper to rough up the water side surface of the back of the box. This should result in a surface that looks pretty clear with the light going through (from backgrounds behind the box) but does not produce a clear reflection because of the uneven surface. This is my plan for the next photo box I will make.