heat repairs

[starman]

how many of you heat the repairs? I heat all of mind, but most of the time from the inside of the car,but I have try it on the outside of the car and have found that on stars the legs go away better. has anyone of you try this. Crayton 8)

[Coitster]

Hey Crayton,
I also use heat a lot. I don't heat all the time however most of the time I do. Make sure when you are heating up a chip is to make sure you let the windshield cool down under pressure. There are lots of people that don't heat the window correctly, or they see the chip dissapear (when what happened is they got the windshield too hot and the crack just closed because of intense heat and after they finish and the glass has cooled down the chip looks like it hasn't been fixed). I don't heat the glass up a lot, I just get it warm, and I make sure to let the glass cool under pressure, in case the resin is pushed back out of the crack I can heat it up again.

If there are cracks like a starburst or something, once I get it where I want it, I may of had to heat it up and let it cool down a few times I then cure the cracks under pressure. Then I remove the injector and cure the center of the chip. Also when you cure under pressure resin shrinkage is less of a problem. Chip will look a lot better. The key is knowing how to heat the chip correctly.

WARNING: if you over use heat, and get the window too hot you will crack it out, or resin won't flow into it, but it looks like it's been fixed until it cools down. I hope that helps.
David
Coitster

[starman]

Thanks for the vice I will remmber that. I was told in clss two years ago to heat 5sec on vacum and 5sec on inject two to three cycles. but then I was told to heat sowly on vacum untill the legs go away. but one day I could not get in the car and try it on the outside of car and it work great. Crayton 8)

[Repair1]

Starman,

Heat???? well now that the snow is here I guess this would be a good time to talk about heating your repairs. Me personally use heat very rarely if it

[desertstars]

As we all know, when we heat, we expand the air allowing resin-flow to replace the air. Sometimes that pressure also knocks loose any minute gravel particle that may be lodged in a star crack leg.

To start, make sure your equipment isn't screwed down too tightly to the w/s.

After bridge application, give it time. I usually fill out all the information on my invoice before even checking the progress.

I then pull a vacuum and re-pressure.

If the result at that point is unsatisfactory, that's when I begin to heat.

I use a match, (you'll burn your fingers before you'll crack the w/s) with a circular motion to heat uniformly from the inside of the vehicle. Use a probe or finger pressure to help the flow if necessary.You can then either use a fifty/fifty spray mix of alcohol/water to cool the w/s down or let nature takes it's course.

By all means, let the w/s cool completely in order to check out the end result. I repeat if necessary but no more than two cycles.

As David suggests, I also cure under pressure.

Ordinarily, if there is "black in the crack", one doesn't need to heat. On thin cracks, I have already explained to the customer about "looking 85% better" and the "index of refraction". (I use a dime in the water to illustrate the point--you reach for it and it "ain't" there.) I inform the customer that because of that phenomena they "may" see a "sparkle" at certain angles when the repair is completed.

Almost without exception, they are pleased and happy with the end result.

Good luck.

(Anyone not familiar with that "index" might want to do a Google search--you'll find plenty of info on the subject.)

[Repair1]

Gary that was very well put into words... I couldn't agree more VERY GOOD POST.... you deserve a round of applause
Brian

[desertstars]

Jeez, you've got it right about "patience" and "caring", Gary.

Your use of the butane torch and the caveat of NOT overheating is right on the money, also.

I still use a match and heat from the inside. If I heated from the outside, I would no doubt need a torch.

Since my system works and yours works also, it appears that in this case there's more than one way to skin a cat.

It IS difficult, however, to heat from the inside when the damage is low behind the dash. If I can locate my old pencil butane torch that I hid when I cracked a windshield about thirteen years ago, I'm going to give your method a shot.

Good input.