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Mike G
04-05-2010, 01:50 PM
I am about to take on the task of wiring my tower speakers and I have a question about drilling through the gel coat. It seems that from the posts I have read everyone has removed the tower and drilled from the top side. I have access to the base of the tower from underneath - are there any issues with drilling from underneath as opposed to removing the tower and drillling topside?

kaneboats
04-05-2010, 01:53 PM
Never tried it but I know the SOP is to lay a piece of tape and then drill (in reverse) through the gelcoat and then forward through the glass. I imagine going from the back side has the potential to cause a crack or chip in the gel coat.

sandm
04-05-2010, 02:10 PM
I, too, have not done the underside, but having done the topside and I'd do that again every time when possible as I know that it does work as kane has described..

guess if it works, use it :)

Razzman
04-05-2010, 02:13 PM
The fault with that is that when you break through the gelcoat on top it will more than likely crack the gel and cause spider cracks to eminate outwards from the hole over time. Granted removing the tower is a pain but well worth doing it correctly in the long run.

If it were mine i would dril a very small pilot hole from underneath then unbolt it and just move it slightly to allow drilling. Reverse drill the hole until through the gel then forward, then countersink to prevent cracks.

Mike G
04-05-2010, 02:37 PM
Thanks for all of the feedback. This is obviously the first time I have had to drill into the gelcoat of a boat and I don't want to screw it up.

mmandley
04-05-2010, 03:55 PM
Are you refering to drilling from the tower foot into the boat for your cubby area? I did this on my boat and i drilled from the inside threw the boat into the center of the front foot on my tower.

Mine has a plate on the inside, heavly reinforced with a 1inch fiberglass or some material, then the hull, and the tower front foot is bolted right at that spot. It also has a pre cut hole in the center of all the mounting bolts in that plate. Id post some pics but im not at home this week. I might have some old pics of my amps and how i wired the tower.

If this is the place you are talking about then yes you can drill threw it. I ran my drill in reverse the whole way threw it though. Drilling in forward from the back will absolutly thrash the gell coating. Think of what a drill bit does when you drill threw wood on the back side. It generaly blows out.

I measured a ton of times. Then i took a very small bit and drilled a pilot whole in forward, it was a very very small bit, i wanted to double check my drill location so if i missed my tower leg i only had a tiny hole to fix. Then i progressivly got bigger and bigger till i reaced a 1/2 hole.

The hardest part of drilling threw the bottom of the boat up into the tower leg is the angle. You have to drill it straight up or you realy risk missing the tower foot. This area of the boat is incredably thick. Once i fished the live threw there and pulled speaker wire it was a long task. The speaker wire didnt want to make the bend into the hole i drilled and it took a lont time. I finaly got it and it created a truly seamly wire effect that matched the factory side for the nav light on the top of the tower.

If you have questions ro want to see some pics Pm me

Mike G
04-05-2010, 05:39 PM
mmandley,
that is exactly where I am tring to drill. I am not real sure about the plate but I think mine is the same as what you are referring to on your boat. Unfortunately I keep my boat in storage near the lake which is about an hour away so I am going to make a trip this weekend to check on her and see what I have. I may get back with you next week for some pics as that may really help.

Mikey
04-05-2010, 07:53 PM
As a plumber,when we drill fibreglass or acrylic tubs and showers we always drill from the finished side. If you don't as mentioned above it will blow out and splinter at the very least. Unless you have a area with lots of coverage i wouldn't recommend doing it.Also the bit backwards to start also helps,as does a Sharp bit pushing and or rocking bit around gently.

Suprahunter
04-05-2010, 09:03 PM
You have to countersink the hole as Razzman said or you will most likely get spider cracks. There is a lot of strain on that part of the hull. When I installed my tower the directions specifically said to counter sink the holes.

http://i303.photobucket.com/albums/nn127/suprahunter/SupraPicture013.jpg

http://i303.photobucket.com/albums/nn127/suprahunter/SupraPicture019.jpg

mmandley
04-05-2010, 11:46 PM
Mikey and Suprahunter i agree with you both 100% you should drill from the Gel Coat side and counter sink holes.

The front legs of the tower are actualy not under that much stress when pulling a boarder. The Rear legs are taking the brint of the force.

As i said before if you use small bits and progresivly get bigger you wont have any issues.

I can say i have drilled about 13 new holes in my boat in the gell coat. I have seen exactly what happens when you drill, cut, heat, sand and file gel coat on these boats. As long as your going small and getting bigger, going in reverse so the bit doesnt bite into the gell you can go threw from the back side and not cause splinter cracks.

Its never recomended but it is possible. Taking the tower off is the best option but it wasnt and isnt always an option for everyone. I can also tell you stereo shops Do Not remove your tower when they run speaker wires as a normal practise. They drill it from the inside out and i would bet money they dont step up the bits from small to large.

Suprahunter
04-06-2010, 10:57 AM
Keep in mind there are side forces on the tower legs especially when you load the racks with boards and the tower with speakers and lights. Gel is very brittle by countersinking it takes the strain off the gel.

Mike G
04-06-2010, 03:24 PM
I have managed to round up a few guys to help me remove the tower so it looks like I will be able to drill from the topside. Would you still recommend starting with a small bit and getting progressivley larger?

kaneboats
04-06-2010, 03:44 PM
Absolutely, for two reasons. First, you want to get that pilot hole in exactly the right spot and it's way easier with the small bit. Second, you can carefully go through the gel coat with the progressively larger bits, being careful not to allow any chipping. Good luck!

cab13367
04-06-2010, 04:23 PM
Absolutely, for two reasons. First, you want to get that pilot hole in exactly the right spot and it's way easier with the small bit. Second, you can carefully go through the gel coat with the progressively larger bits, being careful not to allow any chipping. Good luck!

Mike G,

Below is a link of my install that I think you will find helpful. Definitely remove the tower and drill from the topside as everyone else has said. Besides being better for the gelcoat, it will be much easier to run the speaker cable thru the tower leg with it removed. I made the mistake of not drilling a big enough hole (was only installing two speakers at the time) so I am going to have to go through this again since I've added two more tower speakers. I would suggest drilling a small pilot hole, then one size in the middle, then the final size. Use a sharp bit and drill in reverse. Most people say to drill in reverse until u get thru the gelcoat, then drill in forward. But I just drill in reverse all the way thru just to be safe since it doesn't take that long.

Hope that helps.

Al

http://www.moomba.com/msgboard/showthread.php?t=5467&highlight=tower+speaker+install

Razzman
04-06-2010, 04:26 PM
A new forstner bit will make an extremly clean hole in reverse or forward and make short work of it. That's what i use for all hull drillings.

Mike G
04-07-2010, 01:53 PM
Thanks for everyone's input - I do not feel nearly as nervous as I did a few days ago!

viking
04-10-2010, 04:23 PM
A new forstner bit will make an extremly clean hole in reverse or forward and make short work of it. That's what i use for all hull drillings.

I need to drill about a 1" hole for my speaker wire connector. Was thinking about buying a forstner bit for the job. Planning on taping off and running in reverse based on all feedback I've ready.

Thanks guys (and gals)!

kaneboats
04-11-2010, 02:37 AM
You're welcome!!! :) Not from me, but from all of them who truly have the expertise. Hope it works. Drill safe!!

mmandley
04-11-2010, 12:31 PM
Forester bit, are those the masonairy bits? Or the spade bits with the point in the middle you would use for making holes in wood normally? I am sure i know this bit just cant place the name with a picture of the bit in my mind LOL.

viking
04-11-2010, 12:35 PM
Here's a quick pic of 1.
Also wondering if you need to continue to drill up in size from small to get to the hole size you want if you are using one of these? I wouldn't think so? Past members have posted that you start with a small bit and work up? I would imagine that is if you are using a standard bit right??

mmandley
04-11-2010, 12:42 PM
Ahh ok yea i know those bits just didn't know the correct name of them.

Only time i do a step up bit is when im worried about placement and or drilling from the inside out.

2007 Outback V
04-11-2010, 02:03 PM
Here's a quick pic of 1.
Also wondering if you need to continue to drill up in size from small to get to the hole size you want if you are using one of these? I wouldn't think so? Past members have posted that you start with a small bit and work up? I would imagine that is if you are using a standard bit right??

Viking - learn from my mistake. When using a forstner bit, drill a very small pilot hole to double check placement and it's a guide for the forstner bit. Next, with forstner bit and drill in reverse, go full bore with the drill, no holding back. If you slowly drill to make sure things are going ok or you are not using enough pressure (not extreme sweat producing pressure, but good firm pressure), the bit may start to skate around and make an nasty oblong hole. Use firm pressure with drill going full bore, you will get a beatiful hole. Trust me, I know!!!

Hope that helps.

viking
04-11-2010, 02:58 PM
Viking - learn from my mistake. When using a forstner bit, drill a very small pilot hole to double check placement and it's a guide for the forstner bit. Next, with forstner bit and drill in reverse, go full bore with the drill, no holding back. If you slowly drill to make sure things are going ok or you are not using enough pressure (not extreme sweat producing pressure, but good firm pressure), the bit may start to skate around and make an nasty oblong hole. Use firm pressure with drill going full bore, you will get a beatiful hole. Trust me, I know!!!

Hope that helps.

Thanks OutbackV!
I'll do that! Going to buy the bit today. What are you guys doing then when getting to the carpet? Just cutting it out with razor blade?

mmandley
04-11-2010, 04:04 PM
If you referring to drilling the carpet. Drill right threw it. Most of it is glued and wont fray and tear like normal carpet. You can use a razor and get it cut out of the way first if you like.