Disaster struck.

[HBCC]

Hi guys,
Had a bit of a nightmare today and looking for some advice.

Basically tried to fill a combination chip today with an impact point too big for my injector ( Which I realised after trying to pressurize the injector, I really thought I had it covered. ) Now I have resin leaking down the windscreen and inside the chip leaking into legs with absolutely no way to put any pressure on.

I explained to the customer the problem I was having (impact too big for the injector) as he was hovering (Which was not helping) and pit filled, cured and scraped. I was left with around 6 legs cured with differing amounts of resin and air pockets. I gently drilled the centre of the 2 legs which I could tell had no resin in them at all and filled them, cured, scraped and polished.

This was seriously the worst repair I have done and even now an hour later I am still feeling ****** with myself. The customer was in good spirits and seemed happy with the job.

If you do not mind answering a few questions I have please read on.

Pit filling the large entry point, curing, drilling, injecting, pit filling, curing, scraping and polishing should have been what I should have done ?

Will pit filling and curing an entry point prevent resin being injected after drilling into the cured pit filler ?

Is drilling directly into a leg something that should ever be done or should you always drill just past the end and run the leg into it ?

If for some reason or other in the future I have resin leaking out of my injector seal during a repair what should I do ?

[HBCC]

Thanks for the video Korey, Will this work on any type of chip ? Is all pit resin thick enough not to fill any part of the chip which could cause problems ?

[Brent Deines]

Always check to be sure the seal will completely cover the impact point before you inject any resin. If you are not 100% sure, cap and drill it 1st. Use a pit filler with at least 3000cps for best results. Keep in mind that when you cap and drill before filling you create a very small injection point which is helpful in maintaining consistent vacuum and pressure so there is no harm in capping a pit if you have even the slightest doubt about the end seal covering it. You'll find the damage fills quicker than normal in most cases.

"Pit filling the large entry point, curing, drilling, injecting, pit filling, curing, scraping and polishing should have been what I should have done?" It certainly sounds that way.

"Will pit filling and curing an entry point prevent resin being injected after drilling into the cured pit filler?" Not if it is done properly. If the pit area is so large and/or deep that a cured 3000+cps pit filler blocks access to the glass below (basically this means the PVB is exposed) a repair probably should not be attempted. However, we did have a recent forum discussion about covering extremely large pits with a chip saver 1st, then curing pit resin over the top and drilling into the open cavity below. It can be done but in most cases I would not recommend it.

"Is drilling directly into a leg something that should ever be done or should you always drill just past the end and run the leg into it?" On short cracks like you have described here I would drill into the point where the crack appears to be the widest. Impossible to say without seeing it but aside from trying a new end seal 1st I may have done exactly what you did under the circumstances. We've all had repairs go afoul and had to do whatever was necessary to get them properly filled.

"If for some reason or other in the future I have resin leaking out of my injector seal during a repair what should I do?" If you are sure the seal covers the impact point but you still get leakage it is possible your seal was damaged, your seal is installed incorrectly, or you have excessive injector angle, etc. Remove the bridge, install a new seal and try again. If you still cannot stop the leak there is not much else to do except what you did in this case. Be sure you are blocking the UV during the entire process so there is no chance of premature curing.

No doubt someone will bring up large pit adapters so I will also add that Delta Kits injectors are designed to work with minimal pressure and minimal vacuum. Large pit adapters will not work well with a Delta Kits injector or any other injector utilizing a similar concept. Personally I have not found them to be very effective with high vacuum/pressure systems either but as always, I suggest following mfg recommendations for the system being used.

[clearquest]

When I have to cap off a pit to prepare it for drilling in to, I make sure that I have my uv light already on
and right there next to my work so I can move it into place the moment my curing tab is in place. I also usually place the pit resin just off to the side of the pit and use the tab to quickly move the resin over the pit and cover as quickly as possible while getting my light in place. I try to make the process as quick as possible to avoid letting the resin seep and settle into the pit prior to curing. I really dont know if this helps but it seems to work for me.

[HBCC]

Thank you both for the detailed explanations. Info is hard to find sometimes and this forum kicks ass for helpfulness.

Might there be some info/documentation I can read about the different CPS of resins ? Also a definition of CPS would help me immensely. Is this some sort of viscosity score ?

Thank you.
Paul.

[Brent Deines]

Cp or cps as related to viscosity stands for centipoise. Here is a basic explanation for cps. http://www.tedpella.com/company_html/viscosity.htm Tons of info on the Internet if you still have questions.

A lot of people think that it means how thick a liquid is. That is not entirely accurate but generally speaking the thicker something is the higher the viscosity, which is measured in cps.

We can send you viscosity about Delta Kits resins but not all manufactures publish the viscosity of their products. It's also important to understand that the viscosity is generally a range so you can't really put a lot of faith in the fact that one mfg says their resin is 10cps and another says theirs is 20cps. Those would both be very thin resins and often very difficult to distinguish the difference in viscosity. Other factors to consider are that temperature has a dramatic effect on viscosity and different types of equipment are used to measure viscosity. This makes direct comparisons very difficult even if all mfgs are following the same ASTM standard.

Using motor oil for an example, it is difficult to tell the difference between 40W oil and 50W oil, especially when it is hot. http://www.bobistheoilguy.com/viscosity-charts/

My recommendation is based on the fact that we have used resin in the 2000-2500cps range that flows a bit faster than we would like for capping pits but resins in the 3000+cps range seem to do the job quite well in all but the largest and deepest pits. The higher viscosity the better for capping pits.