Cutting holes in fiberglass

Thinking about adding some cup holders and got a VHF radio to install. Got any tips / suggestions for cutting holes in fiberglass? I’m pretty handy, got plently of tools - routers, dremels, jig saw, hole saws… just need to know the best method. All my work has been in wood…

2008 Sea Fox 197 CC
2008 Suzuki 140

I installed two stereo speakers in center console on old boat not really any problems. I used a jig saw drew my pattern drilled a hole and taped off surrounding area to keep from getting scratched begin cutting. Apply a little resin on bare spots.

Have you thought of the suction cup products made for your cup holders?

Really wanting to go with the flush mount stainless in the rail.

2008 Sea Fox 197 CC
2008 Suzuki 140

Dealer went down today to bring boat up from Florida. It already has two stainless holders on top of console. It’s a nice touch.

Yeah, I think so too. The wife lays out on the deck a good bit and is always complaining that she doesn’t have a cup holder so I wanted to add a couple up there and 2 in the back close to my jump seats…

2008 Sea Fox 197 CC
2008 Suzuki 140

I have cut into mine for stereo speakers, flush mount display, horn… It is not much different than wood, but will chip. Just use the rule. Measure twice, cut once.
I will be adding cup holders to mine soon.

Fishb8 (Fish Bait)

CharlestonFishing.com College Football Parlay Tournament “college football guru.”

23 Sea Hunt “My Last Boat V”

If you can’t stand behind our soldiers, try standing in front of them.

Oh and for cup holders, there are 2 kinds. with drain tube and without. If is drains, just think about where will it drain. Cold drinks sweat a bunch in this heat.

Fishb8 (Fish Bait)

CharlestonFishing.com College Football Parlay Tournament “college football guru.”

23 Sea Hunt “My Last Boat V”

If you can’t stand behind our soldiers, try standing in front of them.

yeah, just talked about the drain issue a few minutes ago… I’m a little, for lack of a better word, scared to do this. I know I can get my measurement right, I build furniture and cabinets as a hobby, but I’ve got zero experience with fiberglass and nothing to practice on. Don’t want to have to look at something every weekend that I screwed up…

2008 Sea Fox 197 CC
2008 Suzuki 140

Its not hard at all. I use a jig saw and drill plenty of large holes in it so that the blade will turn sharp. Take your time and measure TWICE. I also use the blue painters tape around the surface so that it does not scratch.

Sea Hunt 202
Yam 150

A hole saw for your drill will give you the most acurate cut for the cup holders. Just make sure your bottom clearance where you’ll be drilling. You can adjust the centering drill bit to be just past the hole saw itself so when you drill through the fiberglass it will minimize the penetrating depth of the drilling process.

74 Sea Ray 240
05 Mercruiser 496/375
Bravo 1

Ditto on the blue painters tape or masking tape. If you use a hole saw or a jig saw, tape the area to be cut and do your layout on the tape. I’ve found it helps with chipping.

Bob Van Gundy
Marine Designs,Inc.
Custom Aluminum Fabrication
803-727-4069

quote:
Originally posted by Happy Bob

Ditto on the blue painters tape or masking tape. If you use a hole saw or a jig saw, tape the area to be cut and do your layout on the tape. I’ve found it helps with chipping.

Bob Van Gundy
Marine Designs,Inc.
Custom Aluminum Fabrication
803-727-4069


That is correct, NEVER drill or cut without taping out around the area very good with green/blue masking tape

Sea Pro 210cc
Yamaha 200 4 Stroke
Dodge 1500 4x4 HEMI

I used a dremmel tool that worked fine. Just wear a dust mask and eye protection.

186CC Key West 115 Yamaha

quote:
Originally posted by tmb5894

I used a dremmel tool that worked fine. Just wear a dust mask and eye protection.</font id=“size4”></font id=“red”>
186CC Key West 115 Yamaha


Very good advice. I assumed that you would take proper safety measures. Fiberglass dust is nasty stuff</font id=“size5”></font id=“red”>.

Bob Van Gundy
Marine Designs,Inc.
Custom Aluminum Fabrication
803-727-4069

I taped off the console when I did my 4212. I used the sawzall for the big cut then we used a jigsaw for the small corners. Just take your time and be proud of your work.

No one knows if YOU are THE village IDIOT or not until YOU open your mouth and speak!!!

The only advise I can give is when you drill, run the drill in reverse till you get through the gel coat. I usually upsize my bit by 1 size too for the gel coat, but I’m not sure it really makes a difference. I have never had gel coat chip using this method.

I have found the easiest way to cut holes is with a dremmel tool using a zip blade or bit. The bit looks like a drill bit except it cuts on the side. You stab it in like a drill bit and when it is through; you just use the side of the bit and follow the line. Zip bits cost about a buck apiece at Lowes and last forever doing fiberglass. And they don’t chip the gelcoat as you cut. Good luck with the project.

Eat mor trout.

If you have to drill any holes for screws going in from the gelcoat side, use an over-sized drill 1st to start the ‘V’ into the gelcoat, then finish w/ the correct smaller sized drill bit for the rest of the hole. This bevels the entry, another way to avoid chipping.

Thanks for all the tips… I’m looking forward to getting started. If only I could decide which VHF antennae to use…

2008 Sea Fox 197 CC
2008 Suzuki 140