What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Glassing in the windows

T

togaflyer

Well Known Member
While at SnF I looked at a few composite planes. Cessna, etc. I noticed the windows had sealent adhesive around the edge between the cabin top and the window, with a little lap edge over the window. The paint job only went up to the edge of the sealent. I.E. like the install of a front windshield of a car.

Do you glass around the plexiglass for structural support, or is it for appearance.
Can you just fill the gap between the window and cabin with black adhesive instead of glassing over both. It seems like you would not have issues with glassing over dissimilar materials, and chances of cracking or crazing.
 
It's appearance. The inside flange is visible from outside. Vans should have designed the windows to mount from the inside.
 
togaflyer said:
While at SnF I looked at a few composite planes. Cessna, etc. I noticed the windows had sealent adhesive around the edge between the cabin top and the window, with a little lap edge over the window. The paint job only went up to the edge of the sealent. I.E. like the install of a front windshield of a car.

Do you glass around the plexiglass for structural support, or is it for appearance.
Can you just fill the gap between the window and cabin with black adhesive instead of glassing over both. It seems like you would not have issues with glassing over dissimilar materials, and chances of cracking or crazing.
Click to expand...

Like aerhed stated, it's appearance.

I'm not aware of anyone that has glassed over the seams to have a problem with cracking. It's now a little over three years and I have neither cracking or crazing.

Most of the issues that I'm aware of tend to used Weldon per the plans.

bob
 
I used Sika adhesive and have cracking problems with just one layer of glass. I would use the Lord adhesive if I did it again, and use at least 3 layers of glass. An alternate would be to install the window with Sika adhesive and paint up to the joggle. Use proseal around the gaps just as it is done for the Cirrus aircraft. This would leave a black reveal on the glass. That was my original intent, but changed my mind unfortunately.

If I built another 10,I would modify the joggle so the window would install from the inside. Then the window install would be a piece of cake and cracking would not even enter the picture. In my opinion, Vans really screwed up on this part of the design, not from a structural, but from a cosmetic standpoint. Even Vans -10 has cracks all the way around every window.
 
Last edited:
My paint shop is putting a small bead of proseal around the window openings, mostly to protect the edge of the paint. That way you don't have a hard paint edge that can be battered by rain and such.

And it looks good, too. This is the same way the finish Cirrus windows.
 
Bill.Peyton said:
If I built another 10,I would modify the joggle so the window would install from the inside. Then the window install would be a piece of cake and cracking would not even enter the picture.
Click to expand...

Can you offer some thoughts on how this could be done? Would it take filling the outside joggle with glass and resin and then creating an inside joggle?
 
I've thought about this a bunch. I think a reverse of the current flange and thicker glass with a step routed around the window perimeter the same depth as the flange.
 
I think I posted this sometime before, but the way I would mount from the inside would be:
For the rear, lay up glass in the current joggle to obtain flush with the outside of the cabin cover. I would route out a joggle on the inside. For bonding I would use Sika adhesive and the black activator, which would leave a black reveal around the inside of the window. I would of course use the headliner and the trim around the inside of the window to finish off the inside. The outside joggle would be tapered to the glass. I think it would look every bit as good as today's method, but would allow replacement of the glass and eliminate the cracking some seem to have.
For the door windows, I would cut the window opening smaller by 1" or so. Fill in the outside joggle and route out a joggle for the glass on the inside. Leaving the opening smaller would allow for sufficient bonding of the door half's around the outside perimeter of the window. Using Sika adhesive with the black activator would leave a nice reveal on the inside.
 
Multi step process

What I did on my Cozy was to lay 1/4" stripping tape on the plexi against the edge of the glass window hole. This is a spacer for the next step which is to lay another 1/4" tape alongside the first, on the plexi again and inside (toward center of window) the first layer. Now peel off the the first piece of tape, the one against the fiberglass edge, and mask off the window overlapping the second layer of stripping tape. You now have 1/4" of exposed plexi around the window perimeter. Now just put a slight bevel on the fiberglass edge with sand paper and sand the 1/4" exposed plexi with 220 grit. Now you can lay a nice little micro fillet between the glass and plexi, sand when cured so it's very thin where it meets the tape. Leave the tape for the last step which will be primer and finish paint.
This will make a very nice edge onto the plexi with a nice little painted fillet.
BTW, the heavy PVC tape (acrylic adhesive) they sell for wrapping black iron gas lines will pull cleanly off the plexi even after extended time.
Tim Andres
 
tim2542 said:
BTW, the heavy PVC tape (acrylic adhesive) they sell for wrapping black iron gas lines will pull cleanly off the plexi even after extended time.
Tim Andres
Click to expand...

FYI, it's called 10 mil pipe wrap, and it's about 2" wide.

Regards

-Marc
 
Tim, could you add black color additive to the micro fill to match black window adhesive. This could dress out the fiberglass window flange. I think it might blend in well.
 
Sherwin Willimas Fill Bond

Been seeing the Sherwin Williams Fill Bond stuff used more and more. It is a very flexible material looks like it would work in many places like around the windows and on blending all the empennage fiberglass tips. Anybody have any experience with this product. I did order a tube to try it out but have not gotten around to it yet.

https://youtu.be/JiBsAg4qycY
 
Bill, I just finished installing the door windows that Glassair method. I used black Silpruf. So far I'm very happy with the turn out. The Silpruf has a long curing time. Up to 20 days for full strength. When we get home after Christmas I will be able to verify the final outcome. One door is done, the other I need to clean up. I plan to have the joggle painted when the plane is painted, then after I will fill and float the joggle with Silpruf. No glassing around the windows. Plan to do the same with the rears and the windscreen. Just need to decide what I plan to do with the windscreen fairing.
 
Do you glass around the plexiglass for structural support, or is it for appearance.
Can you just fill the gap between the window and cabin with black adhesive instead of glassing over both. It seems like you would not have issues with glassing over dissimilar materials, and chances of cracking or crazing.
Reply With Quote
Click to expand...

Here are a couple of pics

https://goo.gl/photos/2Q9MURjgDxZNDWQP7

https://goo.gl/photos/1fpmarJyrdEsccvs6

Installed as per Vans instructions, plus 2 layers of lightweight glass to cover the transition from acrylic glass to fiberglass cabin structure. No cracks, no crazing, no issues at 425 hours.
Inside trim is optional.
Can't imagine installing the windshield from the inside in one piece???
I am not sure what it is about the windows but more than any other part of the aircraft, builders want to reinvent a better way to do it.
If you follow the plans and add some cosmetic touches you'll end up with a
show plane finish.
 
Ernst Freitag -

What did you use for the inside trim on the windows as shown on your second photo? It looks good and so may be something I want to consider for my RV-10 when I install the windows.

Thanks
Dave M.
 
videos

Bill Boyd said:
videos
Click to expand...
Those videos are excellent! Having built a Lancair, I used similar techniques. Rather than Silpruf (which I didn't know about until today), I used 3M 2216 structural adhesive. Also, I used greased up AN960 washers and regular clecos. Maybe I missed it, but you'll want to solvent-clean the fiberglass before sanding with 80 grit. I used "Prep-Sol" wax and silicone remover.
 
You must log in or register to reply here.
Back
Top