Drilling Fiberglass

[JIMOCO]

I am about to begin drilling for the hood latches and windshield wipers. Does anyone have any tips on drilling through fibreglass? I have never done it before and do not want to crack or chip the gel coat.

[billjr212]

i don't recall having any issues with this, but you can put down a piece of painters tape first. This helps with making clear markings for measurements anyway.

[Ray]

I used step bits like these38632. There were some jigs for the wiper holes floating around for a while. You might want to see if you can locate them. Last time I heard of them was over on the other forum. See reply #8 here: http://www.ffcars.com/forums/17-factory-five-roadsters/242969-i-need-wiper-hole-jig.html

Start slow and remember, fibreglass can be repaired.....

Ray

[JIMOCO]

Thanks Ray. I like the step bits for the hood latches but the wipers use a drilling guide and the step bit will not fit. Any thoughts there?

[Ray]

Thanks Ray. I like the step bits for the hood latches but the wipers use a drilling guide and the step bit will not fit. Any thoughts there?

You might try these with the jig: 38633

Ray

[grluisi150]

For larger holes (1") cover area with painters tape drill pilot hole just before the outer cutting edge touches the tape reverse the drill to score the gel coat, then run the drill in forward to complete the hole. Old boatyard trick.

[JIMOCO]

These are great suggestions. I will give them a try in the coming days. Thank you.

[MPTech]

Thanks Ray. I like the step bits for the hood latches but the wipers use a drilling guide and the step bit will not fit. Any thoughts there?

The drill-bit you need won't fit the drill guide either! The hole needs to be enlarged. I skipped the drill guide altogether. Marked when the holes for the wipers needed to be, drilled a pilot, enlarged it with larger bits and began opening it up for the required angle, then moved to a dremel sanding drum to finish the job. Check the fitment often and it worked like a charm. (you can you the guide as a starter, but be very careful drilling on the angle. you'll still need to open it open further).

Get used to drilling fiberglass and cutting it! (it's really not hard)
Good luck!

[Buzz Skyline]

The main thing, in my experience, is don't use a brand new and sharp bit. They tend to bite in and rip through/chip. I always use a slightly older, broken-in bit. I've even dulled them, when all I have is new ones around.

[JIMOCO]

I greatly appreciate all of the advice. I will be drilling tonight and will let you know my results. Thank you!

[Jeff Kleiner]

What Mark said RE: wipers. I make an initial hole near the center then work out to the edges of the jig opening from below with a Dremel (you could do the same with a round file). I also agree that the step bits work well for things like hood latches, etc. but you'll still need an initial small pilot. BTW, don't forget that the hood handles get a larger hole on top than on the bottom (I do the underside holes just large enough for the square shaft to pass through).

Jeff

[68GT500MAN]

For any hole over 1/2" I use a hole saw. I found that they do a great job, are easy to control, and it is fun to throw around the "washer".
Doug

[Jim Schenck]

I usually run the drill backwards, at least until it is through the gel-coat. The bigger diameter the bit the more this helps.

[JIMOCO]

After considering all of the recommendations I used a step bit to cut the hood latch holes, a cut off bit on my Dremel to cut the opening for the scoop and I used the jig provided for the wipers and took a 5/8ths bit, started backward until I pierced the gel coat and then forward through the hole. In all situations I used painters tape over the area to be drilled or cut. Everything came out great. the last holes to cut are for the defrosters. Now that I have some experience, I feal more comforatble about the cuts.

Thank you all for your great suggestions.
Jim