sanding canopy fairing
I have just finished the canopy fairing of my RV 7 doing the epoxy fiberglass fairing on the front.
I seem to have a bit of sanding to do and wondered some things:
1/ Has anyone used powered sanders like my Black and Decker mouse sander?
2/ Did you start off with 80 grit and go up to 220?
3/ Is it necessary to form a block of 4" radius to achieve the final form or could you freehand it with the powered hand sanders.
Oh and yes i have searched the forum, i am looking for recent information, thanks for any sent.
I just finished priming the spot putty yesterday and I must give Bruce Hill credit for the information I got from him, "Thank you, Bruce!!!" My first attempt with the blackened resin delaminated from the plexi, so I ground it off below the W/S level and then "primed" the plexi with the coloured resin and let it cure before laying up the fiberglass. (Tip from a local fiberglass guru)
1. HAND sand only
2. 40 grit, 80, 150, 220.
3. No. It is only used in the very front. What I did for the initial sanding, was just hold half a sheet of 40 grit with a 6" long piece of 4" PVC pipe. It makes it easier if you glue the sand paper on - I didn't bother - and sand the fiberglass, sanding with a partial rotating motion, moving/pushing the "sanding pipe block" from the top of the fiberglass that starts below the windshield down to the aluminum at about 45% angle. Sand only on the down stroke - not coming back toward you. You'll have no control.
From my 30++ years in autobody repair, I've found you often have to sand contours in panels, so this airplane job was a breeze.
To protect the plexi, I used 3M "fine line" masking tape as the edge for the fiberglass, where the finished line is going to be, about 1"up. Then I used some UHMW tape about 1" wide over the top of it; then some masking tape over top that. (That shows me when I'm about to hit the UHMW and allows for aggressive sanding.) The UHMW is very tough. When you're done sanding down to the UHMW, then you peel it off, then sand down to that 'fine line' masking tape - very carefully. Very carefully. Then when you're down to the fine line masking tape and start scratching it up with the 220, you'll know not to go any further.
If you need any more info or help, I can talk almost any time on the phone. Just PM me your phone number.
Cliff, Chase, BC
No hole tip up
Working on wiring