Rain X Question

I have always been taught that the reason RainX interferes with good repairs is because it interferes with the bonding between the resins and the glass.

Lets look at a bullseye….

If the bullseye is filled and cured, the repair resin would be retained mechanically by the outer layer of glass. If pit filler were used and it bonded molecularly with the repair resin that bond should keep it in place. This would be especially true if the bullseye were “drilled” which would expose a clean glass surface along the inside of the drilled area which would not be contaminated with RainX and allowed for an additional mechanical bond. It would seem to me that now one would have a several types of bond on the pit which should retain it. I have seen “lost” pits, however, where the loss was attributed to “RainX”.

Could it be that RainX is not interfering with the resin/glass bond but really altering the adhesion properties of both resins to the point that neither mechanical nor molecular bonding are very good anymore? Why does Pit filler seem to be more susceptible to RainX than repair resin?

Should the repair resin be cured first and then the pit filler added and cured? I have never seen it done that way, but, maybe it would prevent the resins from mixing and encourage a mechanical bond between the two. Maybe repair resin and pit filler won’t bond to each other and have to cure in a transitional zone between the two “liquid” resins.

Anyway….. Although I have never argued with the RainX explanation I have always questions it’s validity. If anyone know the “scientific” answer I would be interested to know it TOO!




</p>

In hopes of not being too scientific or technical.. I believe the answer is quite simple. Rain-X has a petroluem base.. Resins will not adhere to a petroleum coating.. Why is it normally occurring to the pit surface area? Rain-X is applied very thin.. I believe the bottle states "USE SPARINGLY". And it evaporates very quickly. Thus, the combination of being applied thin and the evaporation factor would lead us to believe that a very minute amount of the Rain-X product actually gets into the break area. However, much like a drop of water, it can lead to disasterous repairs, long term. There is no known solution to preventing this problem if indeed the break has been contaminated. Surface Rain-X can be removed with a cleaner, such as the Step#1 cleaner that JanVil sells.. Hope this helps.

</p>