rear window dimensions

[peter52]

Anyone have the dimensions of the rear window on RV12, including thickness?

Thanks

[Stuart Grant]

My uninstalled 2013 flat sheet of Bayer Makrolon Abrasion Resistant polycarbonate Part F-1277-A is a tad under 67-inches wide and 21-5/16-inches deep and 0.135-inches thick including protective covering both faces. It is pre-cut with facets to form approximate curves and has many, many pilot holes at the edges.

Looks like material was changed to plexiglass/acrylic Part F-1277-B in my updated working plan set.

Anybody know why the material change?

I plan to install it close to the end to maintain easier access.

[12vaitor]

Originally Posted by Stuart Grant

Looks like material was changed to plexiglass/acrylic Part F-1277-B in my updated working plan set.

Anybody know why the material change?

The change was due to the cracks that developed from the screw holes near the fuel filler if gas was spilled on the window. Only takes one time and you have cracks. There was an independent effort to make heat formed windows, I ended up with the window buck from that effort years ago. There was some debate with Van's about polycarbonate vs acrylic strength and structural use of the window. There were some good threads on material properties at the time, OBE when Van's eventually came around on the molded acrylic window.

John Salak
RV-12 N896HS

[Tony_T]

Picture of my Lexan window in 2014 after I spilled fuel on it:

[Stuart Grant]

Thanks for the history on the RV-12 rear window. The newer plexiglass/acrylic part is $685 plus possible crating and shipping. I will probably install my Lexan/polycarbonate part and hope for the best.

I remember talk about fuel and Lexan being a bad mix even though the polycarbonate specs say it is gasoline-resistant for 24 hours. I added the fuel tank vent/overflow line and will probably use a pump (Harbor Freight has a great little 2 D-Cell fuel transfer pump for $10) rather than trying to pour through a spout from a jug.

If the consensus is the cracking is an unavoidable problem with Lexan just from vapor, I would prefer to just do a plexiglass part. For me, it is hard enough just installing stuff once.

[Piper J3]

I inherited a new Lexan rear window from a friend who substituted plexiglass during initial build. I used the new Lexan to replace the original crazed Lexan that suffered a fuel splash. New Lexan is holding up beautifully. I now fuel with a FastFlo hand-operated pump and have not splashed fuel on the new window. I little care goes a long way….

[DBRuth]

Before installing my Lexan rear window, I polished the edge in the vicinity of the fuel filler. I also used proseal as a sealer in the same area. Fuel has come in contact with the window on 3-4 occasions, no cracks or crazing yet. It will eventually fail and will be a pain remove with the proseal, but I'm at 8 years now.....fingers crossed 🤞.

[peter52]

thanks for the info, much appreciated!

Originally Posted by Stuart Grant

My uninstalled 2013 flat sheet of Bayer Makrolon Abrasion Resistant polycarbonate Part F-1277-A is a tad under 67-inches wide and 21-5/16-inches deep and 0.135-inches thick including protective covering both faces. It is pre-cut with facets to form approximate curves and has many, many pilot holes at the edges.

Looks like material was changed to plexiglass/acrylic Part F-1277-B in my updated working plan set.

Anybody know why the material change?

I plan to install it close to the end to maintain easier access.

[Stuart Grant]

Originally Posted by DBRuth

Before installing my Lexan rear window, I polished the edge in the vicinity of the fuel filler. I also used proseal as a sealer in the same area. Fuel has come in contact with the window on 3-4 occasions, no cracks or crazing yet. It will eventually fail and will be a pain remove with the proseal, but I'm at 8 years now.....fingers crossed 🤞.

That is very encouraging! I will put the part I have in with great care and hope for the best! Thanks!