Cutting/drlling holes in Fiberglass

[longjess]

I need to mount a bilge pump switch on the dash of my center console. It is Fiberglass. Any suggestions or potential problems to consider when drilling or cutting into Fiberglass?

 

[Beernutz]

Re: Cutting/drlling holes in Fiberglass

A Rotozip works great. Sears sells their brand for about half the price with more accessories.<br />Sabersaw blades don't last very long.<br />Countersink the screw holes to prevent chunks of gelcoat from popping out around them when you start to run the screws in.<br />That's about it, except for your choice of sealant.

 

[epresutti]

Re: Cutting/drlling holes in Fiberglass

LongJess,<br /><br />Where gloves and eye protection. If you are drilling circular holes, use a hole saw (drill attached) and back up the glass you are cutting with a piece of wood, so you don't splinter out the back. If the hole is to big for a hole saw you can use a Jig saw. Use masking tape on the finish side to reduce splintering and scuffing of the surface. Once the hole is cut you might want to sand the edges smooth.<br /><br />How thick is the glass?<br />Does it have a core and what material is it?<br />How big of a whole do you need?<br /><br />If it is a three position toggle (I have one from Attwood for my bildge pump), you will need a square hole. You can use a drill for a pilot and then use a Jigsaw. I wound up using a sawzall with a fine blade because of other "things in the way". I have a lot of experience with a sawzall and am able to control it nicely. I don't suggest using one unless you are really sure of what you are doing.<br /><br />Of course you can always drill a hole big enough for a hacksaw blade and use it.<br /><br />Good Luck.<br /><br />Safe boating to all.<br /><br />Cheers.<br /><br />emp.

 

[epresutti]

Re: Cutting/drlling holes in Fiberglass

Beernutz,<br /><br />Didn't even think of the RotoZip, I might just go get one now!<br /><br />Thanks.<br /><br />Safe boating to all.<br /><br />Cheers.<br /><br />emp.

 

[longjess]

Re: Cutting/drlling holes in Fiberglass

The switch I plan to mount is a 3 way Attwood and its probably 1/2" by 1", square. the dash board is maybe 1/4 to 3/8".

 

[longjess]

Re: Cutting/drlling holes in Fiberglass

The switch I plan to mount is a 3 way Attwood and its probably 1/2" by 1", square. the dash board is maybe 1/4 to 3/8".

 

[epresutti]

Re: Cutting/drlling holes in Fiberglass

Longjess,<br /><br />I would go with BeerNutz suggestion on the rotozip. Make sure you dont make the hole to big, the mouting screws are pretty tight to the perimiter of the switch. Actually, does the switch have a sticky back on the face plate. I think mine did, it didn't stick very well, so I drilled holes through the plate, used marine calk in the hole and used round head screws that were 1/2".<br /><br />Good luck.<br /><br />Safe boating to all.<br /><br />Cheers.<br /><br />emp.

 

[oldboat1]

Re: Cutting/drlling holes in Fiberglass

If it's the three-way switch with the fuse, I recommend making a cardboard template for the opening. A rotozip works well for 3/8 or 1/2 inch thickness. Don't drill the screw holes until you mark them from the actual switch plate (i.e., don't mark drill holes with the template. The actual fit might be off a bit.)

 

[crab bait]

Re: Cutting/drlling holes in Fiberglass

i'd use for that small a square hole is a dremel tool... pretnear the same as as zip tool but i think alot more useable..an heck,,, you probably already have one .. if you don't ,,you should...

 

[Beernutz]

Re: Cutting/drlling holes in Fiberglass

Don't wanna beat it into the ground, but check out the Craftsman All-in One Cutting Tool. It has a 5 amp 2-speed motor, and comes with a plunge router base and circle cutting attachment in a plastic case. All that for $59.99.<br /><br />It's great for cutting holes for stereo, VHF, speakers, and inspection ports, etc. Handy around the house, too. You can cut thru material up to an inch thick, and 95% of the dust ends up on the outside of the cut, not inside your console. Work slowly. Fiberglass really heats up the bits or saw blades. Dremels are weak, but good for detail work like polishing, etc.<br /><br />That coutersinking trick really works. Leaves a nice bedding area to compress sealant around the screws, too.<br /><br />One more thing. Your screws are probably stainless steel. If the screws start to bind up when you're running them in, STOP. Drill the hole a little larger. Stainless has a nasty habit of wringing off rather suddenly, and it's tough to remove the jammed piece.

 

[StringBox]

Re: Cutting/drlling holes in Fiberglass

power cutting tools were too big to use when cutting<br />holes for new instruments in my dash. <br /><br />I traced the outline I wanted to cut on the dash with<br />a pencil. Then using a small drill bit, I drilled holes very close together around the outline. <br />I then took a larger drill bit, hit each whole again<br />to finish cutting out the shape. Sanded the rough spots down pretty close to level. Installed my instruments.

 

[Beernutz]

Re: Cutting/drlling holes in Fiberglass

If you can get an electric drill in there, a Rotozip (or equivalent) will also fit and do a better and faster job.