Rear Window drilling, etc ( 5 hrs )
Completed Step 4 in Sect 38-03 by tapping for 6-32 screws in Roll Bar. First drilled #36 holes through plexiglass and Roll Bar. Vans instructs to tap next, but I removed the plexiglass (after trying one). Since plexiglass gets drilled w/ larger #27 drill immediately as clearance hole, seems risky to tap the plexiglass. Had no trouble aligning the tap without plexiglass. Used Boelube on tap. Drilled remaining holes w/ #36 bit (dulled for plastic) - and deburred/chamfered each hole at top and bottom (advice on VAF forums to reduce cracking risk). Kept plexiglass warm with halogen lights, a few degrees above 83 deg shop temp. Then proceeded with Step 8 final drill w/ #27 bit (screw clearance holes). No cracks. Still have about 24 holes to final drill...then machine countersink for flat head screws or dimpled skins.
 |
| tapping w/o plexiglass window |
 |
| close up of tapped hole on Roll Bar |
 |
| warming plexiglass during final drilling to #27 size |
 |
example hole chamfered. Next add
machine countersink for flat head screw |
