Saw a post on this from 2007. I was wondering what the situation on primerless urethane is now that it's less than a month shy of 2015.

In particular, I called a shop (I'm a consumer) to replace my windshield (actually I would prefer to have it "fixed" - I have wiper scratches - but every place I've called except one says it has to be replaced, they can't fix it. The one that says it's a possibility is coming tomorrow to take a look and give me his opinion on it in person).

So, after calling almost every auto glass place in town, I had a long discussion with one guy that cautioned me to make sure they (whoever I decided to use) used primer if I didn't go with his shop.

So then I started asking informed questions of the next shop. He says he doesn't use primer, he uses primerless urethane. He says he guarantees/warranties the labor for life, but not the glass (other than what the manufacturer provides, 1 year for defects).

So, the question is.... does the primerless guy know what he's doing or not? 28 years in the business, never had a problem, yada yada yada.

Thank you in advance for your help.

I think the first guy was talking about primer on scratches to prevent rust not primer to bond ureathane to glass

so the answer is....it depends. Scarface is right about priming scratches, but ultimately, what primer or prep, or activator is needed depends on the adhesive system being used. Most urethane systems are primerless to other urethane (glue sticks to glue). Many are primerless to glass as well, some use another product to activate the surface and prepare for the bond.

Anyone you use should be able to tell you whether they are certified by AGSC, or any specific adhesive manufacturer. Most of them will have the certificate hanging up somewhere.

Just because they are AGSC certified does not imply that they do a good job, sorry I know a shop that uses a sub par glue and immediately releases customers on the road the glue they use takes many hours to even be close to being safe. They are AGSC certified.

It's like when I worked at Walmart when the boss was coming you wiped down the shelves made sure everything was perfect, when he left they went back to doing whatever they felt like..

IMO urethane brands that uses glass primers seem to bond better. Just my opinion. No hard scientific facts behind my statement. We are Sika ASAP user's

BTW if some glass shop tries to buff away deep wiper scratch's. It will be distorted in that area. Big LIABILITY factor.....

XS i agree with you, Ive used essex express before and i currently use sika MOVEIT and it is great!

I will put this question out there.
Does ANY car manufacturer use PRIMERless to glass urethane at the factory?
I will answer that question.
NO.
More often than not, shops that use PRIMERless to glass urethane,
DO NOT prime the scratches on the body.
Many shops that use PRIMERless to glass urethane do not even purchase primer.
Those who doubt this, should go into any major metropolitan area and ask what kind of urethane they use and what kind of primer they use.
You will find more than 95%, use PRIMERless to glass urethane and more than 50% have NO primer at all. And these numbers could be on the LOW side.

Vehicle manufacturers have been known to use the cheapest stuff to get away with . Alot of aftermarket stuff is superior to factory things

Tires, rims, suspensions, stereos, seats, paint jobs, accessory and performance equipment, I will give you that,
BUT name me ONE PRIMERless to glass urethane that is better than ANY of the PRIMERED, 1 and 2 or even 3 Hour Safe Drive products out there today??
Long pause.............NOPE. They are not a superior product.
Ask your urethane guy if P2G is a superior product compared to ASAP+?
Or better yet, ask yourself which is the superior product?
What are you going to say?
The PRIMERless to glass urethanes start with safe drive times of 3 Hours and grow to 8+ hours at 70.
BUT, Safe Drive times are irrelevant at the factory, 1, 2 or 3hour safe drive times do not make a bit of difference.
Long term resistance to UV degradation, lack of "air pockets" in the urethane due to internal solvent evaporation in the "sealed" or skinned urethane bead, proper lap shear and tensile strengths to meet roof crush and windshield retention in a roll over, and ability of the windshield to stay in the vehicle when an air bag deploys, are what is important, Not cheap. If cheap was the main criteria 428 or 418 would be in a majority of OE installs, not 400HV.
Primer should be used because 95% or more of the windshields frit bands do not offer 100% UV block. Also, PRIMERless to glass urethane has 10% or more solvent content, which has to evaporate. Then the urethane "shrinks" after the solvent flashes off. The Chinese stuff, could be up to 20% solvent, in addition, solvent is cheaper than polyurethane.
Like you said, "Vehicle manufacturers have been known to use the cheapest stuff to get away with", then why don't they use cheaper PRIMERless to glass urethane at the factory?
Look at any NON-Chinese urethane line up.
PRIMERless to glass is on the bottom, in price, safe drive time and usually lap shear and tensile strength.

Urethane for the most part is basically all the same when it's dry. Except maybe the offs**** brand(Asian) It's the drive away time that your going to pay for. The quicker drive away time achieved the more your going to pay. Also you have the high modulus urethane. Designed for high performance applications. Different formula to achieve a stiffer flex bond between glass and pinch-weld. Now we are working on aluminum frames. So many will reformulate for the different adhesion properties. We use P2G+ on our commercial accounts. But we still use the Aktivator...

Being a Monday Morning QB I am going to ask , why instead of being cheap, did you simply not change your wiper blades? I check mine all the time they are a very important safety feature of the car.

Just Saying . . .

I would think you would be playing Russian Roulette to be using a primerless-to-glass urethane with the multitude of processes used in making glass parts today. Many different materials are used for encapsulation as release agents to pop the part from the molds. New frit formulas are being introduced all the time.

Preparing the frit area for bonding is a BIG issue and "Activators" and "Glass Preps" are best suited for this cleaning process. Leaving the process to "years of experience" and using just glass cleaners means the installer is not keeping up with the times / new products.

Adhesive is the least expensive part of glass replacement process, why use the least expensive you can buy? Go for the best. Good, better, best. Where do you rate your safety?

This obviously is my humble opinion.

Andrew,
very few know the proper process.
that you are here i doubt you are a really a customer.

primer is one thing and its important.
but glass prep is equally as important.
if glass prep isnt done proper your primer is pretty useless.
Safe drive away time is also a critical factor.
all have equal value in your safety to me.

pick a company that knows what these are and also backs their work with a lifetime warranty.