Use of acetone.

[splitpit]

How many of you use acetone to clean out contaminated cracks or as an aid in the dry out process. I don't use it but I've heard some do with success.

[Layne]

I don't use it at all. I would think that it would degrade the laminate. I do know that it is more flammable than gasoline.

[splitpit]

I've heard of swabbing it into a crack for clean out purposes or using it to displace moisture. I think it would evaporate so quickly that it wouldn't damage the pbv layer.

[Brent Deines]

This have been covered a number of times in the past. I think it is a very bad idea. Layne is right on the money. Besides, there is no need to use anything other than heat to dry out a break, and it doesn't help clean anything out anyway. Try it on an old nasty junk yard glass to see for yourself.

I know others here disagree, but in my opinion it is simple common sense that you never use a solvent in the break.

[splitpit]

I guess I should have researched old posts before inquiring. Sorry about that.
What made me think about it was i asked my son to pick up some paint thinner at the hardware store for a home project. He brought home acetone instead because they told him it works just as well.

[splitpit]

Out of curiousity I'm going to use some on a practice shield I keep around for trade show purposes. I'll create a variety of damages.... bullseyes, stars, combos....and give them all a heavy dose of acetone. I'll allow all of them to evaporate out completely. I'll repair some and I'll leave some open and unfilled. Then I'll just let this practice windshield sit and see the effects over a year or so. I'm curious if the damage to the pbv layer will be noticeable immediately or if it will be gradual over time. Also want to see if the repaired ones will suffer any ill effects from the acetone treatment. I'm going to place this particular practice shield outside on the east side of my shop, so it also gets 6 or 7 hours of sunlight on it each day like a car would. I'll inspect the shield closely over time and see what happens.

[Brent Deines]

Acetone is a good cleaner, just not one that I feel should be used around PVB in my opinion.

Your's will be in interesting test, however all you have to do is drop a piece of PVB in the acetone to see what it does to it. Alcohol has the same effect. This is yet another instance where I believe it is best to err on the side of caution. Even if you don't see a difference in the repair, and I'm not sure you will, the possibility that you may be compromising the integrity of the windshield should be enough to keep you from using it in a break.

There was recently a huge debate about whether windshield repair should be allowed or not simply because the brief exposure to water and air prior to the repair process could cause the PVB to deteriorate. An absurd argument to be sure, but one that some had hoped would be the end of windshield repair. Whether you agree with me or not about the use of solvents to clean or dry out repairs, please think very carefully about giving any ammunition to opponents of windshield repair.

Before you do your testing (on test glass only), inject some water contaminated with a little oil, soil, and maybe a few bits of rubber from a wiper blade into the breaks and allow it to dry completely. Then try to use the acetone to clean out the break. I have tried this unsuccessfully on several occasions, but I would be interested in your results.

As for using a solvent on a cotton swab, you would only be able to clean the pit area, which can easily be cleaned with a probe or by scuffing with a carbide bur.

Personally I have not run into very many breaks that had a great deal of visible contamination, other than in the surface or pit area. Some very large or very old breaks will have visible contamination deep within the break, but in my experience that is the exception to the rule. These are the ones that I would like to be able to clean out, but I have tried a number of techniques including vacuum pumps and solvents, with little benefit. I have never tried these techniques on a customer's windshield mind you, only on test windshields from wrecking yards.

I'm glad to hear you are doing some testing on your own and look forward to you sharing your results. I think too often technicians fail to do enough testing and rely on the advice of others. Advice from others can be very good or very bad depending on the source, so I think it's good to be a little skeptical.

[InventorOfDryStarPatent]

Originally Posted by Brent Deines

Acetone is a good cleaner, just not one that I feel should be used around PVB in my opinion.

Your's will be in interesting test, however all you have to do is drop a piece of PVB in the acetone to see what it does to it. Alcohol has the same effect. This is yet another instance where I believe it is best to err on the side of caution. Even if you don't see a difference in the repair, and I'm not sure you will, the possibility that you may be compromising the integrity of the windshield should be enough to keep you from using it in a break.

There was recently a huge debate about whether windshield repair should be allowed or not simply because the brief exposure to water and air prior to the repair process could cause the PVB to deteriorate. An absurd argument to be sure, but one that some had hoped would be the end of windshield repair. Whether you agree with me or not about the use of solvents to clean or dry out repairs, please think very carefully about giving any ammunition to opponents of windshield repair.

Before you do your testing (on test glass only), inject some water contaminated with a little oil, soil, and maybe a few bits of rubber from a wiper blade into the breaks and allow it to dry completely. Then try to use the acetone to clean out the break. I have tried this unsuccessfully on several occasions, but I would be interested in your results.

As for using a solvent on a cotton swab, you would only be able to clean the pit area, which can easily be cleaned with a probe or by scuffing with a carbide bur.

Personally I have not run into very many breaks that had a great deal of visible contamination, other than in the surface or pit area. Some very large or very old breaks will have visible contamination deep within the break, but in my experience that is the exception to the rule. These are the ones that I would like to be able to clean out, but I have tried a number of techniques including vacuum pumps and solvents, with little benefit. I have never tried these techniques on a customer's windshield mind you, only on test windshields from wrecking yards.

I'm glad to hear you are doing some testing on your own and look forward to you sharing your results. I think too often technicians fail to do enough testing and rely on the advice of others. Advice from others can be very good or very bad depending on the source, so I think it's good to be a little skeptical.

During the development of Drystar,
I did just that, I got a broken glass and chiped off a piece and peeled the PVB off, put it in acetone....yuk! The acetone attacked the PVB.

[screenman]

Suprisingly so do some uncured resins.

[InventorOfDryStarPatent]

Originally Posted by screenman

Suprisingly so do some uncured resins.

Exactly! That is why a good uv initiator and enough time for curing is so important.