Combination chips

[shawn2369]

I am new. I have done some practice and just started to work on customers cars. I am having some difficulties with combination chips. I am doing the cycle of pressure and vaccum at least twice on these chips. I have had a couple where the legs to the chip have reached maybe 1 inch past the bullseye part of the chip. In most situations they appear to be filled with resin. I had one the other day where one of the legs did not looked filled. Is there a way to test this out? Also what is the best way to deal with it. I considered drilling into it and then making a small bullseye to fill. I have not done any thing to yet as I though I would ask some others. It is on my own car so it can wait and the practice would be good. I appear to be having some difficlties with these ones. Any tips with these chips would be appreciated.

[Kgobin]

I had one the other day where one of the legs did not looked filled. Is there a way to test this out?

Did you see any black or green in the legs? Did you look at the angle from multiple angles? What was the temperature of the glass?

[h2oman]

When you are new it sometimes seems like each chip should be repaired the same and be consistent right? Each chip is seldom the same. Be careful not to cut yourself short and go with 2 cycles of each. Sometimes it may take more than 2 cycles each. You might try 3 or 4 or 5, however many it takes to do it right the first time.

[Brent Deines]

I completely agree with both Kgobin and h2oman.

In some cases it is difficult to tell if a crack is filled or not, which makes pre-inspection extremely important. As Kgobin mentioned, you must inspect the damage from multiple angles, prior to injecting resin and throughout the repair process to monitor the progress of the repair. You should be able to see the resin filling the legs of every star break and crack so you do not have to guess whether they have filled properly when the repair is completed.

Sometimes both the inner and outer layers of glass are damaged. When this happens the cracks in the outer glass should fill but the cracks in the inner layer of glass will not because there is no way for the resin to get past the PVB. This is my least favorite type of repair because you cannot always tell in advance if there are cracks to the inner layer of glass and in most cases there is no way to fill cracks in the inner layer of glass without drilling through the PBV or drilling from inside the vehicle and performing and inverted repair, neither of which is typically recommended.

[shawn2369]

Hi, I did look at the cip from many different angles. I cleand out the pit very good too. I can not see any color in the crack part. What I see is clear and when the sun catches it, it has a high shine to it or reflects the sun. Other chips I have done did not turn out like that. I will take the advise for sure to do some extra cycles on these chips. I will investigate more to see if there is something deeper. Should the repair on a combination break have a bit of flowering around it?

[Brent Deines]

Not seeing any color is good but seeing a "high shine" is not. If you are not sure the appearance of the crack changed as you filled the damage I would be a little concerned that the crack is not properly filled.

If the rest of the damage was filled properly but a bright shiny small crack remains, that often indicates the crack is in the inner layer of glass. Sometimes it is a single crack but in most cases there will be a number of small bright shiny cracks, not just one, if the inner layer of glass is damaged. Small cracks on the inner layer of glass are typically very fine (thin) as well, which creates the shiny appearance rather than the black appearance that is typical of a wider crack.

Please note that I am only throwing out possibilities based on my experience. I have no way to know for sure what happened in this case.

[shawn2369]

Brent what you are talking about seems to be very close to what I am seeing. I have done a few of these combination chips. I seem to be having difficulties with them. Is there a way to fix the inner layer? I think you are right. One the legs on the chip I am speaking about is shiny. After looking at it again and for some time now I am thinking it has not been filled. What do I do about this. Should I put a small bullseye into and fill it that way? I do not think you can redrill the main pit and try filling again. If I use a bullseye what do you recommend for the placement on the leg? Middle or end?

[Brent Deines]

I'm hesitant to try and give advice on this one because I have no way of knowing for sure if the damage is in the outside layer or not.

If the damage is in the outside layer and you need to fill a crack that did not fill on 1st attempt, I would drill the end of the crack and pop a mini-bullseye, then fill it from there. You are correct in thinking that re-drilling the filled impact point won't likely give you access to the crack that did not fill.

If the damage is in the inner layer of glass the process would be the same but if you have never done it before you might want to give me a call. I think it would be easier to explain any differences over the telephone.

I don't see a lot of damage to the inner layer of glass. Most combination breaks should fill properly from the outside with little trouble. However, when you do run into damage to both the inner and outer layer of glass from the same impact, it can be difficult to improve the cosmetic appearance as well as we would like. On the bright side, for reasons I cannot explain, minor damage to the inner layer of glass don't tend to crack out, or at least that has been my experience.

[shawn2369]

Brent, thanks for the advice. I will monitor this chip to see if it speads out. I have been practicing making the mini bullseye and filling them. I have also done some reading on this. I know to find the end of the crack before drilling. As it is my own car I will give it a go. Would it help you to see a photo of the chip. I have never done that but I am willing to try.

[shawn2369]

Brent, maybe I will give you a call just to make sure I am doing it right. Can you e mail me your number. Perhaps I call this week.