Delta Heat exchanger

[SanAntonioWindshield]

Hi, I bought a Delta heat exchanger recently, which in my understanding is to be used with a moisture evaporator. Well on a hot Texas summer day when out fixing a small chip the windshield was to hot. I had the customer run the A/C but decided to try using the heat exchange tool on the windshield to speed up the cooling down process. I didn't press down hard at all. Well the temperature change casued the small chip to run . I been doing this for 6 years and have only had cracks run about 8 times. 3 bad (this being one of bad ones).

So now I'm scared of it and I definitely don't see how I could use it with a moisture evaporator which would cause even a higher temperature. Someone tell me if I did something wrong and what there experience is with the heat exchanger? Cause I'm scared of them now..

[SanAntonioWindshield]

Hopefully screenman will chime in as I know he uses it a lot but I can certainly understand having that experience causing you to question wisdom of using the tool again. Any time you try something new and you have a crackout it makes you a bit gun shy, and rightly so, but in this case I wouldn't give up on the heat exchanger just yet. It's actually quite useful under the proper circumstances.

What was the approximate temperature of the heat exchanger when you applied it to the glass? I have not experienced a crackout using the tool but I am careful not to apply it or anything else to the glass if it is too cold. For instance, if the heat exchanger was in your car and you were using the A/C the heat exchanger could easily be considerably colder than the ambient temperature which is the recommended temperature for the tool to be used safely and effectively. Even if the tool is quite warm it will still pull heat from the glass rapidly as long as the glass temperature is hotter than the tool temperature so there is no need to apply a cold heat exchanger to a hot windshield. In fact that is not recommended as too rapid of a temperature change to damaged glass can be detrimental.

In order to further reduce your fear of using the heat exchanger again I recommend trying it in conjunction with the moisture evaporator several times on a practice glass, making sure the temperature of the tool is at or above the ambient temperature but at least slightly below the temperature of the glass.

[screenman]

I had one crack out back in the early days of using it and this on a practise glass, I was though pushing the extremes.

Much the same as if you were warming the screen, I would start off very lightly from a bit away from the damaged area and work my way into the centre.

The heat sink has hugely speeded up the way I do repairs since I started using it, drying out was very time consuming thing back then. Try this on your practise glass, make a small starbreak and warm it up a bit and watch those legs close whilst the glass expands, now time how long it takes those legs to open back up again, we have seen 24 hours plus here.

Now do the same and use the heatsink, it is minutes at most.

It is a great time saving tool, but like all tools we should make sure we have practised with it before using it on a hot customers car.

[kennycrane]

The heat exchanger is genius is my opinion, I will basically heat every break to make sure that there is no moisture in them, unless I am convinced that it just happened and by that I mean that I can still see the dust on the break where the rock hit. Usually early in the day my heat exchanger is pretty cold and to me that is a good thing it will cool a break down quicker, but I use it cautiously easing it over heated area slowly. In the years that I have had this tool I have never had a crack out, would never work without it in my tool box.