Dryout Alternatives?

[candyman]

Thanks for the information. I used the dryer to warm: It didnt occur to me that water would be in the break since it was not raining at the moment and they had the heat on for a while. I own one of the heat sink (exchangers). Iam going to check that out. Candyman

[screenman]

Whilst certainly the evaporating point of water is lower in a vacuum, where does the moisture go to? The break and the means of making a vacuum are one thing, so how does the moisture know that you want it out of the break and into the vacuum device. This method was taught over 20 years ago, but I think todays methods of Drystar or torch and a heat sink work far better. Personaly I also see no need to heat such a big area, it just takes longer too cool again a Novus method, which we have modified over the years.

[wdoctor]

Whilst certainly the evaporating point of water is lower in a vacuum, where does the moisture go to? The break and the means of making a vacuum are one thing, so how does the moisture know that you want it out of the break and into the vacuum device. This method was taught over 20 years ago, but I think todays methods of Drystar or torch and a heat sink work far better. Personaly I also see no need to heat such a big area, it just takes longer too cool again a Novus method, which we have modified over the years.

The moisture dries out/evaporates just like like rain on pavement dries and evaporates when the sun warms(heats) it. I'm not relocating the moisture into the vacuum device-I never pop the syringe off the windshield and have moisture in it. It may have been taught over 20 years ago, but the NWRA still endorsed the use of the method not that long ago.(NGA/NWRA certification reference manual from '99)

For those of you that also use a torch, do you just heat it and let it set until it cools off and is dry? That is basically what I do, except I add the suction cup/vacuum device to speed up the dry-out process. The vacuum works the same in the summer. For example, if I get to a vehicle and it has recently rained and the sun is out and the windshield is warming up nicely, but not dry yet, I can apply my suction cup/vacuum, put the vehicle in the shade and not even have to heat the windshield. I can bet that this dries out the break faster than if I let it just sit in the sun wait.

I'm not knocking the Drystar or similar tools-they may work for those who know how to use them. My process works for me, and I think I'm just too scared to try them, escpecially when I see posts from others saying they've had crackouts with them.

[Mr Bill]

I tried a torch on a practice windshield and the windshield cracked..
POW!!!!
Too much heat too fast.
I have never had a problem with the drystar.

[screenman]

How did you do that? Good job it was on a practise glass. The blowtorch is infinitely adjustable heat wise, just hold it further away for less heat and closer to for more. I have both Drystar and blow torch in the kit and they both get used in equal amounts.

[Mr Bill]

How far away from the glass do you normally hold the torch ?

[wdoctor]

How far away from the glass do you normally hold the torch ?

I keep the flame an inch maybe two from the glass, but the trick again is the heat constantly in a circle around the break. I start close with small cirlce and then work in and out(still in a circle) until hot enough. I don't know what temp. is hot enough, but I can still hold my hand on it comfortably before applying my vacuum. I've been using this method since I started WSR 10 years ago and have had no problems.

[screenman]

Depends on how quick I want it to heat up, certainly I get quite close, but then again I have been doing repairs a while. I try to only get the damage hot, much the same as the drystar does, the reason for this is I want it to cool down again quickly. In tests I have run I find I can dry out quicker using heat and the heat sink than I can with a vacuum. In fact I am still not any where near convinced a vacuum aids drying out, even though it was the method I used for many years. As I get older I am tending to question why I do something rather than just doing it.

I do know that placing moisture in lower air pressure for example a vacuum lowers the evaporation point, however how does the moisture decide that you want it in the pump and not the chip. As when you put the 2 together they become one chamber.

[chipfix]

I do know that placing moisture in lower air pressure for example a vacuum lowers the evaporation point, however how does the moisture decide that you want it in the pump and not the chip. As when you put the 2 together they become one chamber.

Vaporized water occupies about 1,600 times the volume of an equal mass of liquid water.It will be forced out of the chip.

[screenman]

I know at what extent water vaporises, I am just trying to get us discussing where it goes to in an enclosed container, which when you put a vacuum over a damage that is what it becomes. As most of you know I spend a fair amount of time practising my dry out techniques and if there is a better way I sure want to know about it.

I have experimented with creating a low pressure area in the damage by passing compressed air over the top of it, without success. I have timed heated and vacuum pump. heated and no vacuum pump, no heat and vacuum pump, in fact I have even tried standing on one leg a kissing the glass. At the moment the best way I find through continuous experimenting is by heating the damage and using the heat sink, this seems to work quickest and best for the UK environment.

Tomorrow it is back to some more experimenting, as per usual.