Cutting through interior fiberglass for speaker mount

[Canyon Lake Tige]

I am relocating a 6” cab speaker from under my dash, to make room for a new 12” sub. I am relocating it to a section of cosmetic fiberglass on the interior cab of the boat (Interior isle way fiberglass). I want to know if there are any tricks or gotcha’s I need to look out for when cutting through interior fiberglass?

Any special blade or tool I need?
Will the fiberglass splinter around the edge of the hole?

Also, has anyone built a sealed sub box for the compartment under (Actually in front or behind) the dash of the Z1 to house a 12” sub? If so, what dimensions did you use?

[chadster2]

I'd like to know this too.
I did see a great pic of wood screws going through the gel coat hanging out an inch or two into the water.

[Jeff T]

I used a hole saw bit. I believe it was a 5in or 5.5in, I can't remember. It looks like the one in the link below, but bigger. Its been a few years. Get a new one so the teeth are sharp. I covered the area to be cut out with masking tape. I drilled a small pilot hole. Then I ran the hole bit in reverse to score through the gelled or painted surface. Once it was scored through the tape and paint, I ran forward and cut the hole out. I then took a VERY fine sandpaper (1500-2K grit) and wet sanded the inside rim of the hole. This process will keep the gel from chipping while drilling and afterwards as well.

http://www.lowes.com/pd_296745-28303...aw$identifier=

I didn't have any issues. You can do some searching too. I know there are some posts out there.

[chpthril]

Hole-saw works great as well as a Roto-zip. You will want to drill pilot holes for the speaker's mounting screws.

What sub are you installing and what kinda power will you be giving it.

[Micah]

I used a rotozip and it worked good. Make sure and where a long sleeve shirt and gloves. I also had a vaccum sucking up the dust as I cut the fiberglass.

[Iwndr]

I used a 4" holesaw for my pullout heater vent. Drill a pilot hole, Tape the area with painters tape, Start the hole saw guide bit in the pilot hole and when the hole saw makes contact with the tape/fiberglass run the drill in reverse to start your groove through the gel coat, switch to forward and use light pressure to finish the hole. Check your measurements at least 3 times!

[Iwndr]

I used a hole saw bit. I believe it was a 5in or 5.5in, I can't remember. It looks like the one in the link below, but bigger. Its been a few years. Get a new one so the teeth are sharp. I covered the area to be cut out with masking tape. I drilled a small pilot hole. Then I ran the hole bit in reverse to score through the gelled or painted surface. Once it was scored through the tape and paint, I ran forward and cut the hole out. I then took a VERY fine sandpaper (1500-2K grit) and wet sanded the inside rim of the hole. This process will keep the gel from chipping while drilling and afterwards as well.

http://www.lowes.com/pd_296745-28303...aw$identifier=

I didn't have any issues. You can do some searching too. I know there are some posts out there.

I should have read Jeff's completely

[Domsz06]

I used a hole saw bit. I believe it was a 5in or 5.5in, I can't remember. It looks like the one in the link below, but bigger. Its been a few years. Get a new one so the teeth are sharp. I covered the area to be cut out with masking tape. I drilled a small pilot hole. Then I ran the hole bit in reverse to score through the gelled or painted surface. Once it was scored through the tape and paint, I ran forward and cut the hole out. I then took a VERY fine sandpaper (1500-2K grit) and wet sanded the inside rim of the hole. This process will keep the gel from chipping while drilling and afterwards as well.

http://www.lowes.com/pd_296745-28303...aw$identifier=

I didn't have any issues. You can do some searching too. I know there are some posts out there.

i did exactly as he did for all my holes I drilled in my boat for speakers, ballast system and wires.

works great!

[Canyon Lake Tige]

GREAT...Thank you for all the advise.

[Canyon Lake Tige]

WS12-2 SUB and a ARC AMP Bridged to 500watts.

[Canyon Lake Tige]

Has anyone built a sealed box for a 12" sub for under drivers dash compartment on a Z1? If so, please share design.

Thank you,

[goose69]

I had a box rhino lined and it didn't sound good. I removed it and filled the compartment with 12 orange lifejacket and it sounds awesome (12" kicker comp.)

[chpthril]

Has anyone built a sealed box for a 12" sub for under drivers dash compartment on a Z1? If so, please share design.

Thank you,

All you need is a 1.0 cu/ft enclosure. What I would suggest is mock it up out of cardboard to see what dimensions fit the best.

www.the12volt.com has a great box volume calculator. Just plug in your dimensions and board thickness, and it will spit out the volume.

[Canyon Lake Tige]

Since the door to get in under the dash is not very big, I guess the trick is to make something that will fit in the opening or assemble in the compartment.