Well I'm about to test fit a gp sport bumper. I was wondering, If i wanted to drill into it, is there anything i should place in the hole where i drilled? like some type of washer? or Could i just put the bolt right on top of the fiberglass?

 

Are you talking about a bolt or a screw? Considering the thickness of most automotive fiberglass you will need a washer on both sides and nut to back any bolt you put through it, it is not thick or strong enough to hold something just threaded into the FRP.

 

Yeah, so besides washers, should something be going inside the hole? like some type of small sleeve (perhaps made out of plastic) , so it won't crack the fiber glass?

 

No, you shouldn't need a sleeve as long as you are careful not to overtorque. Fiberglass will generally bend before it cracks, so when you see it start to bend, stop tightening.
In marine applications we put a little bead of 3M 5200 caulk around the shaft of each bolt (under the washer) before tightening it down to make it waterproof so depending on whats underneath you may want to use some silicone caulk if you want it waterproof. (Don't use 5200 because it's expensive and really hard to remove..(very adhesive) it's more for permanent applications)

 

Thanks mike for the quick replies =p