Pit Filler Fails

[wilz]

I have been following up on some of my repairs lately and have noticed that some of my repairs especially the ones within the sweep of the windshield wipers looking like the pits were'nt filled. I just don't understand why they are not holding? Anyone has had a similar experince?

[mafsu]

What resin are you using?

[Mr Bill]

Could it be that you are not finishing the repair so that it is flush with the windshield?
It could be catching on the wiper blade.

[wilz]

Pit filler resin from Glass Mechanix. I am pretty sure that it is flush as if it was one as the windshield.

[GlassStarz]

You live in an are wgere it gets hot and humid moisture in the glass from the humidity will keep the PF from bonding also etreme heat and cooling will shrink and swell the PF eventually it may lose bond and fall out it getts 30 below f here sometimes you see the PF has fallen out on old repairs here as well. A old WR guru told me if you dont finish with PF but just top it off with the same resin you are useing before you cure this will be less likely to happen havnt run any test to see if its true though

[mafsu]

O.k. now for some better questions.

Do you wipe the pit area before you apply the pit resin? If so stop. I don't have a scientific reason why but allowing the pit resin to cure along with the uncured thinner resin already in the pit will allow for a better bond.

How are you scraping the excess resin? If you don't hold your razor at a 90-degree angle to the windshield when scraping you could be sabotaging your pit resin by pulling it up along the edges of the pit.

How long are you allowing the resin to cure before scraping? Give it another minute before scraping and see if that makes a difference.

As Glassstarz said you do live in a rough climate for the pit resin to hold up in.

[Brent Deines]

Pit resin should never, I repeat, never "fall out", regardless of the weather conditions. All resin shrinks over time, and being made of acrylic, wipers will eventually wear the surface, but the shrinkage should be minimal, and a properly repaired chip should never look as though it had not been filled.

If it only happened once, I might attribute the problem to Rain-X that had not been properly removed, but you make it sound as if this is a regular occurrence.

I hate to state the obvious, but it may be time to try a new resin. I have tested some pit resins that barely stick to the glass in the best of conditions, so it is clear that those will not hold up to weather and wipers. Most manufacturers will send you free samples, so you have nothing to lose by taking advantage of their offers.

If you are like me, you don't want to experiment on a customer's vehicle, so play with the samples on some practice glass. A real simple 1st test is to cure a drop of resin on a sheet of clean un-damaged glass, noting the cure time. Scrape the resin off with your blade at a 90 degree angle as you would on a typical repair, and count how many strokes it takes to completely remove it. Also note how it looks and feels as it is being removed. It should not ball up or flake off, but leave a clean, smooth surface with each stroke of the blade.

To check the clarity of the cured resin, duplicate the 1st test, but stop scraping when you have about 1/32" of material remaining on the glass, and polish it for 30 seconds with a good pit polish. The resin should be very clear, and the color of the glass should show through.

Next, repair sample break on a scrap of glass and leave it outside where it will be exposed to the elements. Check it on a regular basis to see how the weather affects the pit resin. You may not find out which resin holds up best for a long time, but in many cases you will find one you like by running the first two tests. Run this last test anyway. A year or two from now, the results will boost your confidence in the resin you use.

I have thrown samples up on the roof and in the back of my truck, and left them for years, just so I could be absolutely sure I was using the best available resin.

Of course there are more scientific laboratory tests that we use to test the resin products we sell, but these are easy real world tests that will tell you a lot about the resin you are using. If you order samples from several companies, you can compare them side by side.

May the best resin win!

[mrchip]

Brent...i really appreciate your candor and subjecttivity in your post...not taking the high road and just pushing your product..you've got class!!:eusa_clap :eusa_clap

[wilz]

Great Forum

I never considered at all the volatile factors that could attribute to the pit failing. I hope this not to be true as it will not give other resin a chance here.

Me doing pit fills is almost by the book. Cure for a good 2 minutes, remove film tabs, coming off with a stripping sound. Blade held at a 90 degree angle to the surface of the glass to remove excess resin.

Some good thoughts on probaly using the same resin from a repair to pit filling, however could still be debateable because of the difference in resin vicoscity and pit sizes. One other good opinion was not to clean the repaired area before pit filling. However would it make a difference if the surface was clean and the pit area untouched?

Like many of you wsr techs out there, feel at home with the type of resin and kits that you use would best describe the best way i feel about mine. Anything new would be considered less.

Brent Deines, if you strongly feel that my resin is failing me and that there may be other resin that would ensure the quality of my repair remains, would delta consider sending me a sample to this side of the globe for tests?

[glassdoctor]

I did a test on my own work vehicle once with good reputable brands and all of them degrade over time.

I don't mean to sound negative, I don't believe there is any resin that will still look good and after a couple years, or even less. At least not in my environment. Much depends on "garage time" etc of the car of course so "results may vary.

I have a demo w/s that stays in my garage and the pit fills on it look great after many years...