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Yesterday a loyal customer came in with his 1999 740 BMW. He told me the w/s was leaking. I pushed up from the middle & the glass was loose. He wanted a new w/s anyway so taking it out was not an issue. We took the car apart & just pushed the whole w/s out. Didn’t need a knife at all. A classic example of what I have been saying all along. If you do not use black primer on the w/s the uv light gets thru and breaks down the urethane & it separates from the glass.
He called me this morning to tell me I was correct. We didn’t do the job. BMW did it in 2002. Just before he started using us.
IF YOU DO NOT PRIME THE CERAMIC FRIT WITH BLACK PRIMER THE UV LIGHT WILL BREAK IT DOWN.
And don't get me started on pinchweld primer and temps under 40.
Sglass, we get 2 to 3 of these a quarter. It is absolutely sickening.
One we even figured out who did it and called that shop to inform them the windshield had released. Come to find out they were not using a primer cause the urethane tube said "primerless". So we actually did some research and called that manufacturers tech guy and he told us it is NOT primerless in windshield applications as it would take over 36 hours to meet an SDA in our average temp/humidity.
I think they finally just switched to a faster curing urethane, hopefully they use the primers now as well.
We got a hold of a 1999 Ford F150 last week the OTHER GLASS COMPANY installed just a month ago (@ $150.00 .)They used black primer on the glass and on the pinch weld but to my amazement my tech just pushed the thing right out then used his hand to pull the urethane off of the body.
The Pond Jumpers that just bought this company has a lot of work ahead of them.
I had this same question at one point and contacted the manufacturer (Dow) and got two answers, yes it is primerless to glass and no it isnt. Well I decided to conduct my own test and was quite surprised. We used Dow 418 on three windshields using Dow 413 primer on the cleaned frit and couldnt believe that two of the jobs came back a few months later with failures. Urethane was still bonded to the primer but the primer peeled right off the windshiled. Never had a failure with the same material when not using the primer so I am convinced that particular product is primerless to glass. Just my experience.
We choose have to use 1 hour curing urethanes in our area, weather changes rapidly here. Mainly DOW Express or Sika Move-It.
I agree that there are PRIMERLESS urethanes, but the greatly increased SDAT times are insane for most applications in our area. Customers would never leave their vehicles for 4+ hours.
My understanding is that most primerless urethanes have very extended SDAT because they rely on chemicals (xylene?) in the urethane to create the bond, instead of a seperate primer that has much more xylene. They also are much more dependant on temp and humidity than a self-curing or advanced cure urethane is.
Of course I only pretend to know everything, I really don't and humbly admit that.
The shop I mentioned simply read the LOWEST SDAT listed on the chart (2 hours) and assumed that was a 2 hour SDAT product, and no they were not certified by the urethane manufacturer. Most of those "primerless" products reach (or are tested at) minimum SDAT with 50% hum and 75temp. We run either 90+temp in summer or 20temp in winter, with an avg 22%hum, making that product a 32 hour SDAT most of the year in this area. They were darn lucky noone ever got hurt using that product and releasing those vehicles so early.
Main point is do not blindly trust a salesrep, or even a tech, do some research on your own and conduct test on your own.
It's primerless but you need primer. In 3-5 years sunlite brakes down the urethane and the w/shield pushes out. WHY ARE WE USING URETHANE??? I have never had these problems with u-418 and u-428. They are primerless and work very well. And there is lots of sunshine here.
PPG's Rapid Seal RS200HV has a clear frit primer. It's approved by all the networks. I used it in the past for a couple of years and I liked the product and never had any problems. Just not that crazy about PPG anymore.
I have never seen a factory installed w/s with black primer on the glass. And our Sika rep said not to use 206 primer on the glass as it will not adhere to the glass as well as the urethane does. Siak mandates to use the Aktivator only on the glass UNLESS it is a fritless w/s such as a DW911 or other such w/s.
AGOC: I just read your post about your test and you stated that you used U-413 on the frit. And that it just pulled off. What is even more amazing is there are a bunch of posts after yours and nobody noticed or said anything. U-413 is a Pinchweld primer designed to stick only auto body paint. Not glass or glass frits. You should have used either a the OEM combo of U-401, then U-402 on the glass, or BP5500 or BP5500SA, which are one step glass primers. Then use U-413 or BP5404A on the pinchweld. U-413 will peel off of glass and glass frits every time. Hope this helps. Bye the way for everybody's info. U-418HV is primerless to glass. But there is a UV situation. It is primerless to glass if the glass has a frit band. eg: DW1099. It is not primerless to glass if there is no frit. eg: DW911. In the latter case, either U401, then U402, or BP5500SA must be used.
we have been using sika for about 15 years, they use a clear aktivator and so far i have not seen one that i have done come loose from the glass. and we usually have close to 300 days per year of sunshine. and are around 5500 feet in elevation.
alot of the ones i have seen come loose at the glass have had some sort of black primer that peeled of the glass. we have a lot of dow users around here so i don't know if they are using the wrong primers on the glass or what, but it is common.
When we cut glass for loaders, scrapers, and such we put the 206 on the out side of the glass and then activate the inside of it. So you solve the UV problem and get a good bond.
Its always glass, activator, glue.
Never glass, 206, activator, glue.
I agree. I never put 206 on the glass. I used to know a few guys who would put 206 on older windshields (like DW911) to create a supposed "Frit" effect. Then they would activate it after the 206 dried. I can't imagine that working very well.
Ive never tried it, I was told that you can use a 911 in a 1099 hole but it will not work the other way around. Again I have never tried it.
Again with sika you better activate everything or it will fall out.
All of these windshields(911-1099) are the same size. The difference is in the mirror bracket or the frit on the newer. The frit will cover the vin # at the bottom of the glass on the 911's. Had a customer with a Heavy Duty truck that someone put a 1099 in. Highway Patrol inspected the truck couldn't see vin# because of frit(HD calls for 911). Pull the glass and lo and behold there is no vin# on dash. It's on the left side of the body in door area. But on the pickups it's on the dash. HTH
On HD trucks, many many times the VIN is not located on the dash, and we use the 1099. On pickups it is on the dash so we have a check first to decide which we can use:
We always check to see if the old vinyl dash under the 911 is deformed at all first. If it is NOT, then one can still see the VIN tag without too much effort using the 1099, which we stock, and most cases we are able to supply a 1099 at a lower cost to the customer than the 911. If the dash is deformed, and too close to the glass, then we order and use the 911. I have heard of people 'scrubbing' the frit off to make the VIN window wider on the 1099 when switching it from a 911, but I've never tried. Seems like too much effort to me.
I guess my point on "primerless" urethanes, is that whomever is using "primerless" urethanes better do their homework. And I mean REALLY do their homework.
As others have posted, some manufacturers sell "primerless" urethanes, but will not warranty ANY ISSUES if you did not prime/prep the glass !! And in every case I have researched "primerless" urethanes have a significantly LONGER SDAT. So make sure you are not releasing vehicles to early.
I just don't want any of the kind, hard working people that post on this board getting into liability problems simply because they were unaware of the "primerless" urethane issues.
I have NEVER been able to get a urethane manufacturer to provide me a written statement stating they will fully warranty a "primerless" application issue, if we DO NOT use glass primer/prep. They have all said we must PRIME the glass in an aftermarket application.
But products change, as does the chemical technologies used in them. Maybe this is a good time to call a few of those manufacturers again?
My Sika rep always told me that with glass that does not have a frit band you first activate(wait 10 mins) then apply 206 creating a frit(wait another 10 mins) & then install glass. In other words,
If it doesn't have a frit or has a ceramic, frit it MUST be primed.
Try this: take a w/s with a ceramic frit.
Hold a lght on other side and look thru frit.
See the light??
Thats how UV light gets thru.
I don't know why people just don't prime them all anyway.
I prime EVERY and I do mean EVERY, piece of glass with Activator pads before it is installed. Even if it is an encapsulated part I hit with an activator around the outside edge of the frit in addition to applying the encapsulation primer onm the plastic / rubber. The only exception to this rule is of course Fords Bolt In Parts that require butyl.
Dow told me that the newer vehicles had a primer made into the glue furnished to manufacturers. This did away with the need for a primer over the paint. Aftermarket glue does not have this so 5404 is still needed on replacements with new paint or primer.
are you saying that urethane manufacturers that use a clear glass primer/aktivator rather than a black primer don't work? and what is your evidence.
this was my part of my point from previous post about OEM installs.
I have seen the studies on UV light & urethane break down. The origional post at the top is a case in point. The car was done by BMW (whatever agr shop they use) 5 years ago & we just pushed w/s out.
No primer used and you could see w/s did lay nice in urethane bed. It just let go of glass.
i have seen a few that i believe were uv breakdowns, and the urethane was powdery. and the urethane released but not 100%. usually if they release 100% it is a issue with the urethane like the 3m chem-cure fiasco, or just recently the dow problems.or lack of any primer when required by the adhesive,and thats what i believe you are seeing.otherwise the factories would be using a black primer on the windshield.
last week we replaced a 1217 for a customer that i had done before,back in 1999 when i worked for cascade. at the time we were using sika ultrafastII, it was bonded great, no breakdowns no problems. so that was 8 years in uv light.
It could be a problem with the glass manufacturer having a bad batch of ceramic paint or not applying a thick enough coat to block all uv's. No, that can't be right . They are all equally as good. Just ask Hal or Nags. It has to be an installation problem.