You want to be careful with high speeds, since the top is fiberglass in resin, and the resin can melt if you get it too hot.  Also, standard metal bits can tear it up a little.  I have good luck with a brad point bit, available at most good hardware stores and home centers.  Be careful when you go through that it does not break out on the other side.  I prefer to go part way through, and when the brad point starts to poke out the other side, stop and finish the hole from the other side.

Bill
  ----- Original Message ----- 
  From: Steve Gough 
  To: vanagon@GERRY.VANAGON.COM 
  Sent: Wednesday, June 13, 2001 4:43 PM
  Subject: Drilling the Westy poptop

  Dear List,

  I'm mounting some stuff, including a solar panel, to the
  top of my '86 Westy, and need to do some drilling.

  Have never drilled fiberglass before.  I'm guessing I should
  use a nice sharp bit and go slowly at high rotational speed.  
  Any other things I should know?

  TKA,  Steve

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