Drying out a chip

[jonnyques]

I know there have been several posts latly about this but here goes again. Ive had 2 shield start to crack while drying them out. The first was a large crack that I looked at a as traing job. The lot was cool with replacing it if I couldnt fill it so... I first put in Dryout solution from LR. I then started to heat the crack with a propain heat pen. After a min or so, it cracked out. It left me with the impression that the gas from the evaporating water/ dryout solution would have built preasure, and not being able to escape the crack caused it to crack out. The next one was using the deltas moisture evaporator. I was doing the 20 sec on thing when it also started to crack (just 2 inches) This time my observation was the glass was cool, and I may have not heated enough of the surounding glass and focused too much on the chip. Im thinking that just like cooling glass in the summer, purhaps I should put on the defrost to warm the glass before going to the moisture evaporator. Any Thoughts? This time of year the glass is getting colder and lots of dew in the mornings. Wow another learning curve! Any help or even those little things you do without thinking about them would be great. I feel like I will be seeing more and more wet ones. I guess that was one pro to the hot summer glass... they dryed out fast on their own!
Thanks

[Fasbreak]

I never use Dryout solution and heat. One or the other. Too many problems if you use both.

[StarQuest]

What is it with some techs wanting to use dryout solutions? Can't understand why you'd want to induce anything other than repair resin into a repair. I've heard many say this dryout solution is acetone based:shock:

Isn't acetone often used for cleaning resins out of injectors? If that holds true....what do you think is going to happen when it's in your repair?

I personally wouldn't sleep well at night, knowing little acetone pac men would be eating away at my fill

Just learn how to dry out damage the proper way without taking shortcuts. Drystar, butel pen, torch, hair dryer.....whatever heat source works best! Your finished results will look the same days, weeks, months and years after.

[Fasbreak]

I've used Liquid Resins Dryout Solution a lot! And my repairs look great. My time is too valuable to sit with a heat source and dry out a chip for 20 minutes. I like to make a profit. And we all have our own way of doing things.

[DaveC]

I use Delta's Chip Dryer. Takes 15 seconds and sometimes another 15 seconds if the repair area is very saturated. Naturally, since it is a source of heat, I make sure the windshield is warmed/cooled first and then watch the repair area carefully for signs of spreading,

[glassdoctor]

Wow, there's definitely still some controversy on this subject. As always.

As I have said before, I'm unimpressed by any "dry out" technique or product. IMO, nothing works good enough or safe enough.

The Drystar absolutely does NOT work in 30 seconds unless it's a simple clean bullseye or small chip, then maybe. Anything else takes much longer, more heat cycles.

Also, I don't believe dryout solutions pose any real problems for the repair, unless perhaps there is a lot of the solution still in the break when the repair is done. After it evaporates I think it's fine and I haven't seen any problems from it, even acetone or alcohol. I like the pac men comment though... and in general i would rather not use a soution. But sometimes it's the best bet to get results.

I use a Drystar and the similar coke-can one from LR, as well as various other heat sources like mini torches. I have used several different dry-out solutions. It's all we've got unfortunately.

And heat can crack out a windshield when you least suspect it. Sooner or later it will happen. You just hope when that day comes it's not a job that will screw you bad...

Oh, btw, I also sometimes use vacuum in addition to other techiniques. Use a mighty vac hand pump with a suction cup over the chip and pull a strong vacuum. Let it sit several minutes while I do another car... it can really help. Anyone else find good results using vacuum?

[jonnyques]

I think the main thing I will do is warm the shield first before heating the break to avoid such a temp change in the glass. Ive learned the hard way not to use dryout and heat at the same time For those who have used LR dryout, do you just apply it and let it dryout on its own? I had thought you had to heat it to get it out. To anyone using the DELTA heater, Delta says to us it 20 sec. Do you put it right on the glass? If not how far away? Do you just do 20sec or do you several cycles of 20sec? What I now tricks me is I see the black disappearing from the break and I associate that with the water coming out, when in fact it can just be the glass expanding closing the break. I know its got me a few times into thinking OK just need to keep heating to get that last bit of black out. WORSE CASE if you dont get evey trace of moisture out what happens? Does it just appear black in the break? Does heating the break when filling eliminate any moisture that may be causing a problem? ETC. OR did you just elminate any chance of a perfect repair?
THANKS!!

[Delta Kits]

What I now tricks me is I see the black disappearing from the break and I associate that with the water coming out

Actually, when you're using the moisture evaporator on a break, say, a bullseye, what you're wanting to do is see MORE black.

Moisture sometimes looks milky, sometimes makes the repair look almost completed. When you use the moisture evaporator, you will evaporate the moisture, leaving the black (air).

So when you're heating it, and it looks like the black is going away, too hot.

[gold star wsr]

Moisture is a contaminate that weakens the holdiing power of the resin. In bulls eyes, it also usually results in a 'milky' appearance to the repair. Other contaminates can also produce similar reactions.

[screenman]

The higher the vacuum the lower the boiling point of water is.