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boknows 09-04-2013 09:36 PM

thru hulls - scared - need help
I am wanting to put a gps, chartplotter, fish finder combo in my boat but from what I hear the hull is to thick. I have a 45 foot boat and the old owner claims it is 3/4 inches thick. Is it possible to drill half way thru so that the thickess is less than 5/8 (which is what is the max thickness that garmin said it would work thru)? any help is much appreciated.


HUGOSALT 09-04-2013 11:12 PM

Re: thru hulls - scared - need help
One would think there would already be a transducer installed in a
boat that size already.
If not try to sound out different thinner locations in hull, maybe up forward.
Can/has been done but must be solid location which could
be hard to tell before drilling.
Cautionary tale...few years back in the boatyard on a quiet Sunday early in the spring heard strange noise coming from inside a nearby
boat, was one of the local marine electronics installers half laughing
half crying...he was replacing an old transducer in just such a install
as you propose. Seems hull was drilled a bit to much as when he
went to remove the old transducer that was siliconed/epoxied? in
place out came the transducer and the very thin part of the hull
it was attached to...leaving a a nice hole in the hull...very scary
thinking of what might have been had it decided to give way
one night when boat fell off a wave!
A proper thru hull might be less scary I think!

krazzz 09-04-2013 11:24 PM

Re: thru hulls - scared - need help
You should be able to do that. How about drilling a small test hole to check thickness? They also make long sending units to accommodate hulls that are on the thicker side. 3/4" seems excessively thick to me and not very likely.

PaulinVictoria 09-04-2013 11:46 PM

Re: thru hulls - scared - need help
Install it on the inside, or drill a hole and install it on the outside. Don't try and drill part way through a hull, you have no idea just how much you will weaken it.

kunkwriter 09-05-2013 12:00 AM

Re: thru hulls - scared - need help
You may want to try it without doing anything but cleaning the area first. I put an inhull transducer, garmin, on a 1973, 36 foot sailboat, that was very thick and it worked fine. This was two years ago. I sanded the area clean and used antifreeze as the liquid inside the casing, but had no problems. If that doesn't work, then you have to figure where to go from there. Good luck.

MikeOReilly 09-05-2013 12:10 AM

The transducer is likely made by Airmar. They make lots. I'm sure you could find a long shaft alternative that would allow a proper installation.

copacabana 09-05-2013 07:05 AM

Re: thru hulls - scared - need help
What transducer does the chartplotter/fishfinder come with? Is it the kind that is meant to be mounted on the transom of a small boat? If yes, you should be able to mount it inside the hull and it will read through your hull (providing it isn't a cored hull). You can do a simple test by getting some children's modelling clay (plasticine) and making a little "pool" in the location you want to install the transducer. Fill the pool with water and let the transducer sit in the water. If you get a good signal, you're ready to install it permanently. If you don't get a signal, first make sure the transducer is angled to shoot straight down (and not angled to shoot off to the side) or try another location in the hull. Once you find a good location, it's simply a matter of cleaning and drying the spot and fixing the transducer in place with a big gob of silicone sealant. Be sure there are no bubbles in the silicone. If, for whatever reason, you want to move or remove the transducer, it is easy to cut it out of the silicone with an razor knife. You may find you installed it in a place that has some turbulence when underway and thus doesn't give you a good signal. If so, move it to another place. Ahead of the keel should be fine. Post a pic of the transducer if you can.

zeehag 09-05-2013 08:35 AM

Re: thru hulls - scared - need help
28 Attachment(s)
my garmin transducer reads nicely thru my 2 inch thick hull when planted in a well of oil. try ti you will like it. no need to make holes in boat hull just for a transducer.

i have 2 depth sounders--one forward and one aft..aft is thru hull fitted, and forward is set into oil perfect and is accurate.

boknows 09-05-2013 09:51 AM

Re: thru hulls - scared - need help
Great info guys. This place is such a good resource. I will try it before I drill. I was nervous so that means I have good instincts or good end stinks. lol Thanks

zeehag 09-05-2013 10:08 AM

Re: thru hulls - scared - need help
28 Attachment(s)
i am not aguy but i will take the thanks---make the well deep and only cover the transducer end so it doesnt come dry in a case of extreme heel....
have fun--it does work.

i used a piece of pvc pipe glued to hull interior and filled with about 2 inches of oil---cooking oil--extra virgin olive wont come out unless i knock down.

omg you got help from a female...omg run fast--rodlmao

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