I just finished assembly of my Sig Extra. I also own a Sig Cap 231EX, and have allot of trouble with the canopy base cracking. I decided to trim the canopy to fit the Extra, and install it directly to the fuselage without the canopy base.

After trimming the canopy for best fit, I taped off an 1/8" border on the inside edge so the adhesive would attach to the canopy not the paint. The interior was painted with Pactra Racing Finish-RC250 Outlaw Black (Lexan/Poly-carbonate R/C Car Paint). I attached the canopy directly to the covering with Pacer 560 Canopy Glue, after carefully scuffing the covering on the fuselage bond area with sandpaper. After bond, I applied 1/4" trim tape on the outside edge.

I have several airplanes with tinted/painted canopies, and I keep a white towel handy to drape over the canopy in the hot Texas sun. I have had no problems with distortion/heat on those planes, but my Extra hasn't seen the heat yet. Only time will tell how it holds up!

Hope this info helps.

Rex Rutledge