What\'s your method for removing water from chips?

[GP2]

I'm curious to hear what other techs do to remove water from chips. I carry compressed air with me to job sites, and blow the air across (not into) the chip surface to pull water up and out. Rubbing alcohol is then applied to the chip after the first air hit, and then blowing again leaves me with a totally dry chip cavity to work on. What is your technique?

[pbaker]

Sounds like a small air compressor really is a good investment. I use a moisture evaporator, but Ive never used anything else to compare it to for drying out a chip.

[Sneck]

GP2,

Do you just dab a little rubbing alcohol onto the break, or do you really apply a lot to soak the break? (and then give it the second air blast).

[johnnyone]

Apply heat for about 5-10 sec with a lighter

[boyd]

Wait 3-4 hours after a rain til I do the repair.
I think you guys, by being impatient, are sacrificing quality.
If you leave even a microscopic partical of water in the chip, and you trap the water in there with the resin, in the winter when it freezes it will expand and crack the glass. I've never, in 12 years, had someone say they can't wait several hours or even a day when I tell them why.
BOYD

[GP2]

GP2,

Do you just dab a little rubbing alcohol onto the break, or do you really apply a lot to soak the break? (and then give it the second air blast).

After the first air blast I soak a large q-tip with alcohol, then hold it to the chip and let the alcohol wick into the cavities, then comes the second air blast. The amount of alcohol in the q-tip is enough to fill the chip quite a few times over, so yes it does get pretty soaked. This seems to be the best method I've discovered under certain conditions. However I still use Delta's dryer, a lighter, or micro torch if the situation warrants. Rain & snow can't stop me

Keep in mind the risks that come with using compressed air with alcohol for you guys that work in very hot climates, or anyone for that matter when working on a hot day.

[boyd]

I'm going to play "devil's advocate" here, but it's basically how I feel.
Some of you guys, fill the break w/ alcohol, heat it up with a lighter, or even a mini torch? This has to take longer, increases your chances for breaking the glass, increases the chances of leaving some kind of contaminate in the break such as water or alcohol ..... all because you don't want to wait a few hours. Sounds like too much of a rush to me and not worth chance.
Good luck.
BOYD

[GP2]

Recently I was able to work with some state of the art moisture detection equipment used for testing upstream eth-fuel properties in the oil and gas field, my old career. All vehicles in the shop lot contained moisture in their windshield chips and the latest rain was 9 days prior, none of the service vehicles have been washed. The amount of moisture detected was the equivalent of 1/8 to 1/4 average raindrop, or 1-2mm dia. After the first air blast only a few chips showed moisture (star breaks only), after the alcohol and air blast none of the chips had moisture. How senstive is this equipment? We had to run another calibration when a clould passed over the sun, thus effecting the rate of atmospheric evap rate. Waiting a few hours after a rainfall will have no appreciable effect on moisture content in the chips, there will be at least some value of moisture in that chip above atmospheric humidity.

With the air blast technique I use the chances of particulate contamination is significantly reduced. By blowing high speed air across the windshield chip (not into) a low pressure area is created in the cavity, in addition to turbulance, both of which will help dislodge and draw out contaminations from the chip cavity. Not only does the alcohol help displace water it's also works well as a wiking agent for particulates. Best of all it's a mild solvent, further helping dislodge contamination. My chips are about as clean as they can be before resin even gets close to them. Maybe I don't get all particulate contamination out, but I know I've got more out than they guy who did nothing. It all adds up.

Nothing is rushed, the whole process adds about 2 minutes to the entire repair. Which is less time than it takes to clean all the glass inside and out. Additional risk isn't an issue either, there's riskier processes that are standard proceedure for WSR. This company, it's staff, and owners are can do people. There's NO WAY I can tell my clients to wait a few hours, or I can't do it because of rain or similar. It's my job to find a way and to make it work, that's what they're paying for. 90% of our work is appointment 2-3 days ahead, usually booked into a clients' tight schedule wherever they can fit it, often on cars you could sell and buy a house with, we HAVE to be there to fix it, and it has to be done 100% everytime. In the past I've said no due to rain, I lost the job, the referrals, and I felt like a let down all day, I can't believe I made that mistake twice.

[screenman]

Boyd you do not live in my world, it has rained every day for the past 3 weeks. If I did not dry out I would not make a living. I am sorry but by telling people just to wait a few hours you are doing most inexperienced Techs a misjustice. this might apply to your area but come and wait over here until the screens dry out on their own.

GP2 you are spot on man, moisture stays around a lot longer than most people think. I have also used your dry out methods with great success. Certainly on long cracks it also blows water out of the edge trim which would otherwise creep back into the crack before you had filled it.

GP2 Keep up the good work and thank you for the time you spent on a very informative post.

[StarQuest]

GP2 and Screenman,

Your both right, moisture can remain present days after induced (all depends on where your located and climate conditions)

I understand the use of forced air over the damage will speed up the evaporation process of moisture. (forced convection vs natural convention)

I also understand by introducing rubbing alcohol into the break, it will mix and lower the density of any moisture present, therefore also providing quicker evaporation.

I'm not contesting any of these practices or facts either of you have provided so far because they do work.

However, I do have a major concern with introducing any chemicals into a repair that could possibly break down resins or cause PVB deterioration.

It wasn't long ago when I was using denatured alcohol to cut and replace laminated flat glass in school buses. Why? Denatured alcohol instantly melts PVB. Maybe less concentrated (rubbing alcohol) doesn't have this effect to lamination but I not sold on this yet. I believe it to be the same but a much slower rate.

I suggest before any of you use this practice in the field, you first should experiment on your practice shield, wait one to two weeks and then inspect results. If reinspection reveals no problems than maybe this it o.k. to use this method.

For now, I'll just stick with the heat pen, drystar, fan or compressed air over break. Never...have I used rubbing alcohol in any damage. Why? Mainly because that's what I clean my injectors and seals with!