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  #11  
Old 08-26-2019, 07:24 PM
Kyle Boatright Kyle Boatright is online now
 
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Location: Atlanta, GA
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Quote:
Originally Posted by kkmarshall View Post
That's what I want to figure out as well. I have small paint cracks on the corners of the other windows also though none are as long as were on the window that failed. Curious how you are able to identify it as Lord adhesive? Van's tech support wasn't sure from the pics. He said Weld-on is white and this looks cream colored. Is that the color of Lord?
Thanks for posting the pics for me by the way.
I could be wrong, but this looks like the Lord Adhesive I used... It is slightly off-white.
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  #12  
Old 08-26-2019, 07:40 PM
kkmarshall kkmarshall is offline
 
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Ok,thanks for the insight.
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  #13  
Old 08-26-2019, 09:52 PM
rvbuilder2002 rvbuilder2002 is offline
 
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Quote:
Originally Posted by Kyle Boatright View Post
I could be wrong, but this looks like the Lord Adhesive I used... It is slightly off-white.
Thanks for posting that info.

I am not familiar with the Lord product so we couldn't make a call for certain based on the photo (colors don't always show in photos what they really are).
I would have been surprised if this failure was with Weldon considering the nearly clean de-lamination from the composite. When the structural testing was done, failure of the windows always occurred through the thickness of the adhesive, and generally left a bonded layer of adhesive on the composite that had to be ground off to bond in windows for another test.
If this had been Weldon my guess would have been a possible surface prep. error. I guess that could still a factor if it was Lord adhesive.
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  #14  
Old 08-26-2019, 10:00 PM
Kyle Boatright Kyle Boatright is online now
 
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Quote:
Originally Posted by rvbuilder2002 View Post
Thanks for posting that info.

I am not familiar with the Lord product so we couldn't make a call for certain based on the photo (colors don't always show in photos what they really are).
I would have been surprised if this failure was with Weldon considering the nearly clean de-lamination from the composite. When the structural testing was done, failure of the windows always occurred through the thickness of the adhesive, and generally left a bonded layer of adhesive on the composite that had to be ground off to bond in windows for another test.
If this had been Weldon my guess would have been a possible surface prep. error. I guess that could still a factor if it was Lord adhesive.
It would still be interesting to get a piece of Keith's window and compare the adhesive on it with a samples of weld-on and lord. Matching colors over a computer screen probably isn't good enough to be absolutely certain.

My fear (?) with all of these adhesives is that if we're seeing cracking at the window edges, maybe the heat/shrink cycles are enough to shear the adhesive over time, particularly if the joint wasn't perfect from the beginning.
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  #15  
Old 08-26-2019, 11:09 PM
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BJohnson BJohnson is offline
 
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Location: Federal Way, Wa
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Default Poor bond prep

A good bond failure is a cohesive failure where the bonding agent fails leaving material on both components. This would also be the case with a poorly mixed adhesive resulting in poor strength. This applies to either a single overload event or a cyclical load.

A bad bond failure is an adhesive failure like what is shown in the photo where the adhesive has separated fairly cleanly from the substrate. This generally is caused by poor surface prep. In this case it appears that the separation is almost 100% of the area including imprinting from pinholes. There also appears to be no scuffing of the surface to prep for bonding.

A simple way to test for surface contaminates is to mist some water onto the surface. If it forms a continuous film then the surface is likely clean. If it beads up, the surface is contaminated.

Judging by the photos, poor bond prep is a likely cause.
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  #16  
Old 08-27-2019, 05:57 AM
kkmarshall kkmarshall is offline
 
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Of course it doesn't show in the photos,but the composite of the door frame does have sanding marks on it that appear to have been made by approximately the correct grit sandpaper called out in the plans. Contamination of the surface by something before bonding certainly could be the cause though. I will check with Van's and see if they would like a shard sent in to inspect. I would like to use Lord based on comments posted here in the past on how everyone hates working with Weld-on. But not if Lord gives an inferior bond!
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  #17  
Old 08-27-2019, 06:04 AM
n700jl n700jl is offline
 
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Default Thank you for sharing this information

Really great information. It might help if a layer of fiberglass was laid over the top of the window edge to capture the plexiglass. This might be a way to prevent this. I also have window edge cracks. I will be inspecting very closely today!
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  #18  
Old 08-27-2019, 06:41 AM
togaflyer togaflyer is offline
 
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The bonding failure, as others said, could be from poor prepping to squeezing out to much material when it was installed, leaving only a skin coat to adhere the window. Going forward, I would recommend the Cee Bailey’s windows. Their windows will require only minimal trimming. Also, google “Glasair Sportsman 2x2 window installation. There is a 5 part series how to do it. My windows were installed that way. There is no exterior fiberglass work when installing windows with this method.
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  #19  
Old 08-27-2019, 07:41 AM
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BrianDC BrianDC is offline
 
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Very interested to see what comes from this. Not sure if anyone else has reported a window loss event like this or not, but with lots of folks discussing alternatives to the Weldon product its good to know that this seems to be a very rare occurrence.


Also, am I the only one that is going to comment on the drapes installed in your -10. Not only that they are installed, but they look to have survived the window loss. Awesome! Looks like a very comfortable interior.
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  #20  
Old 08-27-2019, 08:05 AM
Scott Hersha Scott Hersha is offline
 
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I bonded my plexi on my showplanes fastback RV8 with a product called PRO-SET. I called the Gougeon Brothers in Bay City, MI (West System) and asked them what I could use for this application. This application is very similar to what is done on the RV10 windows with plexiglass laid up on a fiberglass substrate. Pro-set is what they recommended. Itís a thickened epoxy structural adhesive. Spaceship I was put together with this adhesive and it made to outer space. It is compatible with all West System epoxies and will even wet out cloth. I donít remember whether I used 175/275, or 176/276, but you can click on the epoxy type in the link and it will show you the properties. Working time was over an hour, so I didnít have to hurry. I roughed up the inside and outside of the plexi and the fiberglass joggle where they overlap and cleaned it well with isopropyl alcohol before applying the adhesive. The adhesive had the consistency of creamy Jiff peanut butter. I drilled a 1/4Ē hole in the plexiglass every 4Ē on the overlap area and countersunk the hole on the outside (holes were deburred/sanded to make them very smooth). This made the adhesive that oozed out through the hole act like an epoxy rivet with the flush Ďheadí on the outside. You could mix some flox in the mixture in those spots to give it more strength if you wanted to, but I donít think that is necessary. I then laid 2 or 3 layers of cloth on the outside overlapping onto the fiberglass canopy structure before the PRO-SET cured. This layer wetted into the epoxy rivets to form a very strong bond. I had 1/8Ē holes drilled every so often to hold the assembly in place with clecoes until it cured. These were easily filled and sanded later. The plexiglass is held firmly in place between fiberglass on the outside, and the fiberglass frame on the inside.

https://www.prosetepoxy.com/standard...bly-adhesives/
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