Long Crack repair

[clearquest]

I may be wrong here but arent low viscosity resins just as strong as high viscosity resins? Isn't the only difference really in the thickness and flow rate? As long as the crack is fully and properly filled I see no reason to use anything other than Magnibond. What "stronger" resin are you talking about?

[screenman]

Since switching to Magnibond some years back I have never found the need for so called specialist crack resins.

[Windshield911]

I do long cracks up to 24 inches. I do maybe 3 a week. I've had 1 fail in the last year and that was actually on my own windshield. Alot of customers will pay the money instead of risking a new windshield being put in, as long as the crack repair is done right.

[AGSS]

clearquest, I used a system of long crack repair once that was alegidly the 'founder' of long crack repair and in that system there were several viscosities of resins ranging from 45 to 2500. however its great to find out that good ol magnibond will work all the way thru.

[AGSS]

ahh from what i see windshield911 uses the same long crack system that i was trained on. so...Windshield911, do you also use multiple resins?

[Windshield911]

yes it does and to me works great!! I started using it working with my step father in another city years ago and branched out on my own a year ago. We are over an hour away so we are not competing with each other.I've got 2 friends in south la that have switched to it and really like it.

[Coitster]

I use a 45 CPS resin as a primer resin. Then I switch from resins, from 200, or 400 CPS down near the point of the crack. As I get more toward the edge of the crack I use a 800 to 1,600 CPS resins. I have been fixing glass for 18 years and I just don't think regular chip resins are up to the task. Yea they look fixed but go back 3 months later and I think you will find that it looks like you didn't even fix it. I know some people will disagree with this but I don't care. I have a lot of experiance at this. In order to have a long lasting repair you must use a thicker resin. I personaly wish more people did long crack repair. As a matter of fact it is going to be a huge focus of my business in 2012. Doesn't really take that much longer to do a long crack then a chip repair.
David
Coitster

[screenman]

You only been fixing 18 years, you newbie guy, 24 years here and still having fun. I must admit I once used different resins until I started with Magnibond.

[AGSS]

hey hey Coit good to see ya on here man! i think iam with ya on the thicker resins and long term repairs..however, never used magnibond on a crack. someone please correct me here, isnt the objective to use the thickest resin possible to fill chips for better appereance and stronger holding strength? well, a crack starts out tight and opens up so much that you can almost wedge a razor blade inbeteween..so...wouldnt it work the same? stronger repair, less light refraction with the thicker resins?

[Brent Deines]

hey hey Coit good to see ya on here man! i think iam with ya on the thicker resins and long term repairs..however, never used magnibond on a crack. someone please correct me here, isnt the objective to use the thickest resin possible to fill chips for better appereance and stronger holding strength? well, a crack starts out tight and opens up so much that you can almost wedge a razor blade inbeteween..so...wouldnt it work the same? stronger repair, less light refraction with the thicker resins?

I disagree with pretty much everything you said here. The tensile strength, elongation acid content and many other factors determine how long it will hold up.

Thicker resin is not necessarily stronger resin. Although a higher viscosity resin does often have a higher tensile strength, there is far more to the chemistry that that so the statement is erroneous at best.

In my 25 years of experience I don't think I have ever seen a crack start out with a wider gap than it ends with, except for the possible exception of a crack that starts from a chip and ends at the edge. Typically a crack is tightest at the end farthest from the impact point or in the case of a stress crack the tightest part is the end farthest from the edge of the glass.

Thick resins don't necessarily have a refractive index closer to glass than thin resins. In fact, most quality resins are very close to the refractive index of glass regardless of the viscosity.

You are welcome to your opinion but there is no way I am going to let this topic become a sales pitch for a method that based on theory rather than fact. I think it best to agree to disagree and leave it at that.