My car's sunroof is showing quite a bit of what at first glance appeared to be watermarks.

But that is not the case. It is quite possible that they're comprised of pine resin and some other contaminants that I've been unable to identify.

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I tried to clean them up with a sponge soaked in white vinegar, to no avail. (Although that did work when I cleaned the windshield). Next, I'll try rubbing some baking soda on it, and see what happens. But I suspect that won't work either.

What should I do? Using muriatic acid seems a bit risky and unsafe.

@GopherT, I suspect you may be able to give me a hand here. Thanks.

 

If you think it's pine sap, then try a solvent for pine sap. e.g. https://www.google.com/search?client=ubuntu&channel=fs&q=pine+sap+solvent&ie=utf-8&oe=utf-8

Have you tried scraping with a single edge razer blade?

But Winsol 550 http://www.winsol.com/550.htm is some really cool stuff. I have seen now smaller quantities advertised. It does contain a small amount of Hydrochloric and Hydrofluoric acids (eats glass).

I got some Super Clean on some windows and this removed the etch marks. No amount of cleaning would have removed them.

 

The natural solvent of pine sap is Turpentine.
If you don't have that, try mineral spirits.
If mineral spirits work, but it takes all day, soak the surface in Vaseline (petroleum jelly, petrolatum).
That's a brand name. Very similar to a Mexican word that merely means "grease".

Just remembered, mineral oil (baby oil) is the grade between mineral spirits and petrolatum.

 

VM&P Naptha is a bit stronger than mineral spirits and won't harm the paint. If you add a little (5% to 10%) of xlyene or toluene, it will be even stronger (faster acting) than VM&P alone, but might dull the paint a little. If it is a newer car with a catalyzed clear coat, I doubt the stronger solvent will affect that paint either.

Actually, those spots look more like really bad water spots than pine sap, given the perimeter and color. Do you park under a concrete patio? Concrete "solvent" that contain glycolic acid will work much better than vinegar. (e.g., http://www.homedepot.com/p/SAKRETE-22-oz-Concrete-Mortar-Dissolver-65510207/204675360?cm_mmc=SEM|THD|G|0|G-Pro-PLA|&gclid=CKTUvKPKss4CFQobaQodOn4Bjg&gclsrc=aw.ds ) Also citric acid works much better than vinegar, but not better than glycolic acid. A little ammonia or sodium hydroxide (lye) to the citric acid will help it.

Glycolic acid is also used for chemical peeling skin, but at the concentration in the HD product, just regular vinyl gloves will be enough protection.

John

 

@cmartinez
I used to use turpentine for my tools (saws and pruning shears) when working with pine in the past. I don't like it because it is slow. Evaporates quickly in the sun and redeposit the tar.

If it really is pine, then gear oil works really well. Removes road tar (asphalt), pine tar, gum, not much smell, no risk of fire like other solvents and no evaporation to cause redeposition.

Vaseline as @12 suggests has essentially the same effect (polarity wise) but the oil wets a rag well and wets/flows on to dirty surfaces a bit easier (wets the surface) and wipes up a bit easier than Vaseline in the first pass.

I found this while oiling my chain and decided to use my oil-wetted rag to wipe up the asphalt specs on my exhaust pipes. Normally I am wiping for a few seconds on each one but the gear oil (80W90) wetted them instantly and they came off right into the rag. I was impressed.

 

Does it feel tacky like pine - I was using my phone earlier and now I see it on the desktop screen much better. Did the white boarders appear after you washed with vinegar or were they there to start? You might have something other than pine-based organics there.

Can you feel the contaminants on the surface or are they between the layers of the glass?

I've never seen anything like this. I hope it is not the concrete/mortar. Be careful scratching or scraping it - any bits you rub off could scratch the glass. It will look terrible once you get it clean (if you get it clean).

 

Just remembered, mineral oil (baby oil) is the grade between mineral spirits and petrolatum.

Will try baby oil tonight. And yes, we do have Vaselina down here too . Thanks for the tip, I had forgotten about your car maintenance skills.

GopherT, thanks for your input. I'll be back tonight and let you know how it went.

 

Is it glass or laminated glass? Or a cheap composite that can be affected by UV etc?
Max.

 

When you try to take it off, kitchen dish detergent works nicely.
The basic principle of detergents is an oil soluble shape on one end and a water soluble shape on the other end. The goal is to bind the oils to the water so it will leave when you rinse with more water.

 

When you try to take it off, kitchen dish detergent works nicely.
The basic principle of detergents is an oil soluble shape on one end and a water soluble shape on the other end. The goal is to bind the oils to the water so it will leave when you rinse with more water.

Yeah, I was thinking about how I was going to remove the baby oil afterwards. Thanks again!

Is it glass or laminated glass? Or a cheap composite that can be affected by UV etc?
Max.

It's laminated glass, an it ain't a cheap type... it's an Audi, dude! ... and I'm pretty sure that the stains are on the outside, if that's what you were driving at.

 

Try Brasso, an excellent window polisher.
I have also used Jewelers rouge with a rotary polisher in bad cases.
Max.

 

Try Brasso, an excellent window polisher.
I have also used Jewelers rouge with a rotary polisher in bad cases.
Max.

Worst case scenario... I hope it doesn't come to that... but thanks for the tip!

 

Glad to hear it's truly glass and not polycarbonate, since that would be more challenging.

If your problem is a hydrophobic contaminant (pine resin, for example), any of the solvent suggestions should make short order of it. Add Pine-Sol or Goop hand cleaner to the list of possible cleansers. There's no one answer and they should al work to a degree.

The bad news is that, since vinegar didn't touch it, it could be actually be etched into the glass. I have some stemware at home that I simply cannot get to clear again. It looks like it might be stained with milk or hard water stains, but absolutely nothing will remove it, not even straight muriatic (pool) acid. I did some research and it turns out that glass can become irreversibly etched, particularly by dishwashing detergent, and there's not much you can do about it except to polish it out. That introduces lens effects if you have to go to any depth, so it's not always practical.

 

wayneh:

Your in the US. I could send you some Winsol 550 possibly if I can find a decent container. A Labware container I should have someplace.

 

There is another HF containing prodcut called Whink Rust Remover (http://www.whink.com/where-to-find.htm ). Its HF is said to be 1 to 2.3%; Winsol 550 gives the value as <3%.

The Winsol discussio of silicates is interesting. I found this Lubrizol paper also of interest: https://www.google.com/url?sa=t&rct...nrmdMCH0VVCdPfuXkPzY3A&bvm=bv.129389765,d.eWE

Just FYI, since the phosphatephobia era, it is hard to find a cleaner that doesn't have sodium silicates in it.

John

 

wayneh:

Your in the US. I could send you some Winsol 550 possibly if I can find a decent container. A Labware container I should have someplace.

I'm skeptical that anything can work, but I've read a little on this stuff and I suppose there's a chance. Thanks for your kind offer. I'll send you a PM.

 

I did some research and it turns out that glass can become irreversibly etched, particularly by dishwashing detergent,

I learned that too, the hard way.
All my 10 inch Pyrex pie plates are permanently etched.
I think it's is wrong to sell dishwashing detergent that etches glass.

ps, It's the next day, @cmartinez How did the baby oil work?

 

I learned that too, the hard way.
All my 10 inch Pyrex pie plates are permanently etched.
I think it's is wrong to sell dishwashing detergent that etches glass.

ps, It's the next day, @cmartinez How did the baby oil work?

Are you sure the plates were etched and not simply coated with silicate residue?

John

 

Are you sure the plates were etched and not simply coated with silicate residue?

John

They have had 30 years to get uncoated, and they haven't, so I have to assume it's permanent. Are silicate deposits so persistent that they won't wash off in normal use for 30 years?

 

They are very difficult to remove (see: Lubrizol link). Maybe for every little bit you removed when washing, you added just that much more.

Dish washing detergents (after they became phosphate free) contain silicates, at least the ones I have checked do. Several weeks ago, I noticed some build up on my glassware and switched from "high-temp" wash to regular. That seems objectively to have helped.

John