cutting fiberglass for speaker opening - need suggestions, ideas

wish2fish

Active Member
Dec 19, 2006
4,278
Locust Creek, Ohio River mm 433
Boat Info
2003 220BR
Engines
5.0 MPI
I am upgrading the original Panasonics to JL M770's. I will need to enlarge the original speaker opening out to approximately where the screw holes are in the picture below. With the vinyl surrounding the area it looks like it will be difficult to use a jig saw to cut the opening. Do you have any ideas as to how to cut this fiberglass? Also, are there any suggestions to keep the fiberglass from flying everywhere?

speakeropening.jpg
 
Air saw from Harbor Freight, Works very well and cuts a fine line. Only about 30.00 with blades, Use a metal cutting blade and it will cut a fine line. Can run off of a small compresser...
 
Another option is a rotozip. They use drill bit type blades.
 
Rotozip or dremel
get a clear bag you can see through and tape it around the area with the tool inside and it will catch the debris.
 
I usually set my shop vac below a job like that, keeps the bits and dust down.
 
I have done the same thing increasing the diameter of my speaker openings. I used a dremmel with a 1/2" bit by 1" long. If you keep equal pressure and go around the opening numerous times it does a pretty good job.
 
Dremel small cutting bit.
 
Do you have a router and a jig saw? If you can make a guide out of a thin piece of plywood, you can cut use your jig saw to cut the plywood to mimick the outside diameter to match your new speakers. Make holes in the plywood where the new mounting screws are. Then cut the inside hole to the diameter of the new cutout you want to make + the distance between your router collet and the blade. Screw the new plywood in the place you want the speakers to be and make sure the mouting holes are in the proper permanent location. Route the inside diameter and you'll have a nice clean hole. If you have a router with a 1 1/2" dia vacuum attachment all the better.
Best of luck.
 
Do you have a router and a jig saw? If you can make a guide out of a thin piece of plywood, you can cut use your jig saw to cut the plywood to mimick the outside diameter to match your new speakers. Make holes in the plywood where the new mounting screws are. Then cut the inside hole to the diameter of the new cutout you want to make + the distance between your router collet and the blade. Screw the new plywood in the place you want the speakers to be and make sure the mouting holes are in the proper permanent location. Route the inside diameter and you'll have a nice clean hole. If you have a router with a 1 1/2" dia vacuum attachment all the better.
Best of luck.

I like the way you think Todd. I will be using this router tip in the very near future. :thumbsup: :thumbsup:

regards, Ken
 
If I may so, a rotozip is the right tool. Hands down. I've cut 12 holes now in my last 2 boats. Some from scratch with a pilot hole. The great thing about a rotozip with the right bit is it cuts just easy enough not to wear you out but not like butter so it's VERY controllable. You can make a perfect cut along the a line. Also, put a bunch of thick masking tape over the area to be cut to prevent chipping. It will work like a charm. Good luck.
 
When I changed speakers I had to enlarge the opening a bit (not as much as yours) and I used a sanding drum on a drill. Was a bit slow and messy but controllable. The vacuum is a good idea!
 
If I may so, a rotozip is the right tool. Hands down. I've cut 12 holes now in my last 2 boats. Some from scratch with a pilot hole. The great thing about a rotozip with the right bit is it cuts just easy enough not to wear you out but not like butter so it's VERY controllable. You can make a perfect cut along the a line. Also, put a bunch of thick masking tape over the area to be cut to prevent chipping. It will work like a charm. Good luck.

:thumbsup:....gotta agree here. I've also used a jigsaw and glass blade but in close quarters, a rotozip is the tool. Had to buy one just for this purpose and love it.
 
I purchased a router base for my dremel tool along with roto-zip bits and it works great, fits in places a full size roto-zip won't.
 

Forum statistics

Threads
112,950
Messages
1,422,861
Members
60,932
Latest member
juliediane
Back
Top