Hunter 240 transducer installation

Dan Hill · Sep 20, 2012

I installed mine under the rear birth right next to the bilge pump. The hull is about 5/8 of an inch thick. I never had any issues with it being aft. The difference between being forward at speed will make little difference if your about to run a ground. Just don't drill into your ballast tank

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onecoolair · Sep 20, 2012

You do not need to drill hole in boat....Just get your self a 80-100 dollar Humming Bird and some goop to stick the antenna puck to the inside of hull.
http://www.walmart.com/ip/Humminbird-HDR-650-Digital-Depth-Gauge/15213146?findingMethod=rr

marginal said:
Hello everybody,

I have to install a transducer for a sounder on a hunter 240. I think that the best place is in the bulkhead under the front berth. The bottom and hull seems quite straight... Your advises are welcomed ! Is the hull thick at this location ? Has anyone ever installed one at this location ? Elsewhere ?

Thanks to all !!!

Regards

Martin

Crazy Dave Condon · Sep 21, 2012

The advice nest to the bilge pump is the best way to go. Make sure the hole drilled is big enough for the transducer to go thru. There has been alot of discussion as to what sealant to use but this is a fitting that you do not want to move at all. Therefore, I suggest using 3M 5200. Liberally caulk the hole and the threads near the flat bottom of the transducer to insure a seal. Have someone then tighten the ring around the transducer inside without moving it. If the sealant oozes out, then you know it is sealed. Clean off with alcohol as it will not affect the transducer. DO NOT USE ACETONE ON ANY TRANSDUCER WHEN CLEANING UP. Let it sit for 7 days for the sealant to dry.

As the one who got Hunter to build water ballast sailboats and the top selling dealer of the 240, I know this boat too well. Any other style sounder or depth finder I will not recommend contrary to a few who will disagree with me. By the way, it is ok to bottom paint the transducer as the signals will go thru anti fouling paint with anti fouling paint only and again NEVER USE ACETONE BUT ONLY ALCOHOL TO CLEAN UP ON INSTALLATION.

As for knot meters, with the introduction of GPS, I would go that route that can read speed vs. standard knot meter which by the way you cannot paint the paddle wheel.

crazy dave condon

caverun · Sep 21, 2012

On my 240 the depth and speed transducers are aft, on either side of the bilge pump. Both are thru-hull installations, and have worked well. If you decide aft, keep in mind where the trailer bunks sit if it's not on the trailer when you drill.

Johann · Sep 21, 2012

Test it first

Test it first with some toilet wax... Just slap some on the 'ducer and smack it to the inside of the hull where you are considering installation. I did this on a 23.5 and a 336 and actually the wax hold the 'ducer in place very securly...

Ralph Johnstone · Sep 21, 2012

Absolutely ........................

Johann V said:
Test it first with some toilet wax... Just slap some on the 'ducer and smack it to the inside of the hull where you are considering installation. I did this on a 23.5 and a 336 and actually the wax hold the 'ducer in place very securly...

..................... DO NOT drill another hole in your boat below the water line. It makes for lots of work. It needs a haul out. It makes for sleepless nights.

You'll get all sorts of pros and cons but the only way to REALLY be sure this will work for you is to test it as Johann has said. If toilet wax doesn't give very good test results, try filling a resealable baggy with water and rest the transducer on the bag of water in the desired location. The one I tested worked as well as the final installation.

Speaking of final installations, the best way to go is to ooze out a big puddle of silicone sealant on the desired spot and then rest the transducer in it for a few days until it's dry. Keep the nozzle close to the floor so that the puddle has no air bubbles in it.

I suspect that any transducer will work using this method.

Crazy Dave Condon · Sep 23, 2012

Contrary to others, I installed many transduceres over 30 plus years as the largest small boat dealer in the country and I will stand by my conclusions as to what works well. Thru hull using alot of 3M 5200 for permanent sealing is the best and most accurate in the location of the 240 and 23.5. For many of you, it was I who got hunter to build my 23.5.

crazy dave condon

Dan Hill · Sep 23, 2012

Dave is spot on as usual about this model hunter. I installed both my speed and depth transducers for my st40 unit in that aft location just as Dave said with lots of 5200 and had excellent results. Some are scared to add more holes below the water line but if done right its a no brainer. Get the drill out and do it right! Your boat, your wallet. Good luck!

Crazy Dave Condon · Oct 9, 2012

Marginal;

If you want further imput, send me your phone number and a time to call advising which time zone you are in during the day. I know the boat better than others. You do not know my involvement.

Deucer · Oct 21, 2012

Dave,

Do you recommend drilling the hole a little large, filling with epoxy, then re-drilling the correct size hole? I read that keeps water out of the plys of the fiberglass.

Deucer

Crazy Dave Condon said:
The advice nest to the bilge pump is the best way to go. Make sure the hole drilled is big enough for the transducer to go thru. There has been alot of discussion as to what sealant to use but this is a fitting that you do not want to move at all. Therefore, I suggest using 3M 5200. Liberally caulk the hole and the threads near the flat bottom of the transducer to insure a seal. Have someone then tighten the ring around the transducer inside without moving it. If the sealant oozes out, then you know it is sealed. Clean off with alcohol as it will not affect the transducer. DO NOT USE ACETONE ON ANY TRANSDUCER WHEN CLEANING UP. Let it sit for 7 days for the sealant to dry.

As the one who got Hunter to build water ballast sailboats and the top selling dealer of the 240, I know this boat too well. Any other style sounder or depth finder I will not recommend contrary to a few who will disagree with me. By the way, it is ok to bottom paint the transducer as the signals will go thru anti fouling paint with anti fouling paint only and again NEVER USE ACETONE BUT ONLY ALCOHOL TO CLEAN UP ON INSTALLATION.

As for knot meters, with the introduction of GPS, I would go that route that can read speed vs. standard knot meter which by the way you cannot paint the paddle wheel.

crazy dave condon

Crazy Dave Condon · Oct 28, 2012

Generally you are drilling a two inch hole. Try to keep it in that range. What I use to do was to make sure about the transducer size and had many hole saws. If if did not go in snug, then buy a small router bit for the drill and go around even with the hole unitl it fits thru. Make sure you seal well with it oozing out and clean the excess. I suggest using 5200 and allow 7 day cure. You can generally paint anit fouling over the depth finder but make sure you never allow acetone on the head of the transducer as it will affect it. I suggest using alcohol to clean up with.