Non-Yamaha Related...Advice For Cutting Fiberglass

[Jason2tpa]

Pictured below is my console, and inside the red circle you'll see a hole cut thru the fiberglass. This hole is 1" in diameter. I need to widen the diameter to minimum 1.5". A spade bit was originally used. I'd rather not use a spade bit this time around since the tip wouldn't have a surface to spin on axis. Doing so without a surface is a dicey task and I prefer to not crack the console. Thought of using a powerful drimel saw, but I don't have one. Any other suggestions?

[99yam40]

hole saw.
just have to find a way to put a piece of wood under there so the saw has a center point for the bit
why would anyone use a spade bit on fiberglass

[panasonic]

Jason, take something round of the right diameter. With a fine tip sharpie trace around it to give yourself a nice line to follow.

Take your cordless drill and with a 1/8" bit drill a series of holes around the circle as close together as possible, staying inside the line.Leave about a 1/8" between the holes.

Go to home Depot and get a 1/8" spiral pin router bit. You will find them next to the dremels. P/N 561. Get Two of them.

You can use this pin router bit in your cordless drill you don't need the dremel tool.

Run you drill on high speed, take your time and let router bit do the cutting and cut each little section away between each hole.These little bits are for cutting sideways unlike a drill bit. So in the hole and cut sideways to the next.

Here's the kicker...they are small and fragile, so not to much side pressure and use the fat part of the bit...not the tip. Take you're time and don't push to hard, two hands on the drill. It won't be fast but it will get the job done.

Finish hole with a half round file to the line.

Make sure all wiring is out of the way before drilling...lol

Good Luck.

https://www.dremel.com/en_US/product...se-cutting-bit

[oldmako69]

As mentioned, hole saw hole saw hole saw.

[ausnoelm]

Done the same thing many times, as mentioned, just attach a piece of scrap timber across hole from behind, use hole saw, fit gauge, go boating.

[mesias_yam]

Fill up the existing hole with a piece of wood, cut it level with the surface and go at it with a hole saw of the needed diameter. This method will even let you off set the new hole.

[cleddau1]

Cut some thin plywood to exactly fit over the entire horizontal surface that has the hole. Mark on the vertical surfaces of the console so you know where the hole is. Firmly gorilla tape the ply over the surface, the vertical part of the console will help to lock the ply in position. Once you are confident you know where the centre of the hole is, use a hole saw through the ply. If you can get at the underside of the console first drill a small pilot hole through the ply thus accurately identifying the hole centre. Good Luck!

[Jason2tpa]

hole saw.
just have to find a way to put a piece of wood under there so the saw has a center point for the bit
why would anyone use a spade bit on fiberglass

Did this ^^^ with thin length of wood. Broke through it first go. Doubled the wood. Worked second time.