Transducer mounting

[handball]

I have just purchased a furuno model ls6100 with a airmar bronze thru hull transducer model # b744v witch has a speed paddle and temp sensor. the transducer requires a 2" hole for the main body and some other size hole to stop rotation, I asked airmar for the details but they directed me to an outfit called gem electronics in order to buy their high speed fairing part # 33-353-01.This fairing is made from a plastic, and costs about 70$, has anyone used it or do most make the block from wood to suit the 19 degree < on my sea ray bottom.what size is the second hole? and does a bolt fit the second hole and go thru the boat bottom?how does this plastic fairing cut? I would like to use my radial arm saw .<br />Thanks for the help<br />Bill

 

[snapperbait]

Re: Transducer mounting

I install quiet a few thru-hull transducers with both wood and plastic faring blocks, and I have to say that the plastic faring block is the way to go... Don't get me wrong, wood's ok but for a boat that stays in the water, there's just too many issues.. Teak is probably the best wood for that job, my opinion of course.. King Starboard or other plastic is another option as well... Might check with your local plastic supplier and make your own block..<br /><br />$70 bucks is about right, but expensive if you screw it up cutting it... (done that once... ONCE!) <br /><br />The anti-rotation bolt goes all the way thru and is usually a 3/8" hole.. The bolt usually goes thru the faring block and the bolt head is capped off with a little plug, nut and washer on the inside of the hull... Some transducers do have two stems and the manufacturer usually supplies a pattern for drilling the holes..<br /><br />The best tool i've found to make a clean cut is a bandsaw, especially if theres any slight curve in the hull where you mount the transducer.. Set the angle of the table and use a fence to make a straight cut.. As for cutting it with a radial arm saw, I could not say cause i never done it that way.. <br /><br />Don't be stingy with the sealant... Use it on the inside and the outside of the hull... Sand just enuff to rough up the surface of the hull and clean the area extreemly well with denatured alcohol or acetone... Use plenty of 3M 5200 sealant... You can always clean excess sealant off later, but ya can't add more later...<br /><br />Good luck..

 

[18rabbit]

Re: Transducer mounting

It’s going to be some work (not hard) to install but when you are done you are going to be so happy with that thru hull…and the LS6100. I believe your transducer allows you to pull the paddle wheel while the boat is in the water. Furuno should have supplied you with a ‘blank’ or plug that fits the 2-inch threaded bronze tube. This allows you to clean the paddle if you need to. If you are in water when you do this, you need nerves of steel and you will want to be very fast. Surprising little water gets in.<br /><br />Fwiw, Airmar is making an ultrasonic speed sensing transducer that fits in place of the paddle wheel. At some later date you can pull the paddle, insert the speed transducer and it should plug right into your LS6100, but check with Furuno first. Simrad tested the first generation of these new transducers but would not bless them due to erratic results. They’re telling me the second generation of speed sensing transducers is looking better and may get Simrad’s nod. Airmar has no mention of a 2nd generation on their website.<br /><br />Someone posted something in another thread about Gem being the retail outlet for Airmar. You might be able to get that fairing cheaper elsewhere. It is a common part.

 

[handball]

Re: Transducer mounting

Thanks for the replies snaperbait and rabbit.<br />The one question I have in mind for airmar is this rotation problem. If you look at the transducer the distance from the fwd area to the main 2" threaded part is much greater then it is to the aft point, if it was the other way around the unit would not have a tendicy to rotate, but t6hats the way they designed it. I will probably go with the plastic airmar fairing and will certinly use plenty of 5200 as you recommend.I tried a practice cut at about 19 degrees on the radial and it worked out o.k. as I do not have access to a bandsaw.Back in 1996 and 1997 my wife and I cruised to florida from n.y. and I wish I could be there now, the weather in the northeast is brutal.It was great wearing shorts this time of the year in fort pierce and the bahamas.We also spent a month in lake worth waiting for a window to cross the gulfstream, great memories.<br />Bill