Speaker install

[ssichler]

As my wife can attest I'm not the handiest guy so any opinions or advice would be welcome on my plan for installing speakers.
I've been browsing around the forum and have bought one pair of the 6x9 JBL speakers and plan on installing them under the dinette and opposite by the galley on the port side as shown here link to Brian Engles' M stereo Mod

My stereo unit is installed above the mirror like this link On the opposite wall in the head a shore power cable runs from the top of the wall and down to the bottom where it goes into a hole under the forward dinette seat. I'm thinking I will enlarge the two holes and run speakers wires through the compartment. I don't think I can go under the liner by the ballast tank so the wire will have to run all the way back and around by the batteries to get over to the port side. I'll use plastic loop things to keep wires neat.

I have a wired remote similar to David Mellon's install which I'm thinking I will mount on the port side of the pod and then run wire down tie and then under the liner on the side back to the head wall and up.

I borrowed a friend's rotozip and read the the SC5 Sabercut bit is used to cut fiberglass. Anyone see in hole's in my plan besides the clean ones I hope to cut for the speakers?

Thanks,
Scott

[Scott]

Be afraid be very afraid. A rot-zip can get away from you pretty quick.

[Dimitri-2000X-Tampa]

I used my dremel with a drywall cutting bit on it. It was just about perfect, not too weak, not too powerful. One trick I didn't learn until about my second hole though is to turn on a vacuum cleaner and drag the nozzle right below the cutter, it sucks everything up and you have nothing left to clean up!

[Night Sailor]

Maybe too late for you. I've cut a lot of holes, but onlly when I couldn't think of any other solution. For mounting the stereo speakers I bought the models that have cabinets with mounting brackets. Two screws each, no big holes to cut out. That way I can move them or replace them without worrying bout fit and sizing.

[Frank C]

Scott,
FWIW, I used a rotoZip for mounting my new Autopilot (work-in-progress). But rather than trying to freehand it, I first used a 3.5" hole saw thru the way-back liner. Then I used the Zip-saw only to extend an ear below the hole for my mounting bracket. In the case of your speakers:

• I'd first measure the size of required main hole, (presumably about 5 inches?),
  and spend the bucks on appropriate hole saw at HD.
• It might be less costly to buy a hole saw kit in HD's Lighting department,
  intended for cutting recessed lighting into ceilings.
• Also, an earlier hint from this forum ... start the hole saw in reverse to score the gelcoat,
  then switch to forward for drilling the hole.
• Use the RZ to carve out the "speaker ears " along the 9-inch dimension.
• Finally another RZ hint ... when trying to cut straight lines thru fiberglass, it's lots easier to use a Dremel cut-off disk rather than the drywall bits. In fact, next time I need to cut dry wall, I might try a disk too ....

[ssichler]

Thanks for the tips here. Aya16 came by on Sunday to cut holes and only ended up making one below waterline porthole;) Thx Mike!

The new 6x9 speakers sound great. Now just have to get the rear plugs for exterior box speakers and remote installed in time for MDR BBQ so all you guys can enjoy my impressively loud collection of Rap music.

[Dimitri-2000X-Tampa]

Maybe your bit is dull Frank. Mine cut through the fiberglass almost like butter. And I think you have much better control cutting on the side of the bit. Actually, you can use a drill bit too. I find those cut-off disks to be a pita.. I can barely cut through one small bolt without them breaking off. Flex that sucker just a tiny bit and it breaks off. Don't know how you could possibly do 6.5 inch diameter speaker holes with those.

[Frank C]

Nah, I was referring to straight cuts only. For my autopilot I needed a keyhole. Cut the circle w/ a hole saw, then cutoff disk for the 3 straight cuts below the hole. I also managed to use the little cutoff disks to shorten the stainless shroud adjusters (must work to very close tolerances to avoid cutting into the shroud itself). You're right about the Dremel-style, thin disks but the fiberglass-reinforced disks are pretty darned good.
(results from the larger RotoZip cutoff disk (3" diam?) is like using a chainsaw versus a hacksaw)

Finally, I had to enlarge the aft dinette hatch so my Igloo 70 would fit through it. I used a jig saw but it made a complete mess. The little cutoff disks would have worked much cleaner cuts, in only a quarter the time. Same is true for enlarging the battery hatch to clear a couple of GP 29 batts. Roger makes that opening 12.5" and the bigger batts need only an inch larger to drop right in ... maybe next weekend.

[mike uk]

For cutting both thin and thick fibreglass. Ive used a Dremel with a tungsten carbide bit which goes through it like butter. The bit is just a normal "stick" shape and has a very fine cutting surface (similar to a knife sharpening "steel").

I agree with Dimitri regarding use of a vacuum and also suggest plenty of newspaper and sheets for masking. The fibreglass dust behaves as though it is magnetic.

I always get a good tight hold of the Dremel and wedge my elbows against something. Start in the middle, which will be scrap anyway, to get the feel. So far no disasters!

Mike

[mike uk]

For cutting both thin and thick fibreglass. Ive used a Dremel with a tungsten carbide bit which goes through it like butter. The bit is just a normal "stick" shape and has a very fine cutting surface (similar to a knife sharpening "steel").

I agree with Dimitri regarding use of a vacuum and also suggest plenty of newspaper and sheets for masking. The fibreglass dust behaves as though it is magnetic.

I always get a good tight hold of the Dremel and wedge my elbows against something. Start in the middle, which will be scrap anyway, to get the feel. So far no disasters!

Mike

[aya16]

Now that Scott has a glass bottom boat I have to reccomend the
roto zip again. But use the remote hand held extension to control it better.
It would have cut the 6x9's perfect if the lines were straighter...
as for the big 6x9 hole below the water line in the hull, should the plexi glass be 5200ed inside or outside of the hull?