Transducer mounting

[csm]

The PO of our X mounted a transducer under the cooler box using silicone. The transducer and power cord connectors are decomposed and need replacement. It seems the transducer is over the ballast tank, and I'd think that location would give poor readings. I'd like to stay away from a transom mount, but the ballast tank presents a problem; has anyone tried mounting a transducer forward of the ballast tank? Any other suggestions/tip are appreciated.
thanks,
Chris

[puggsy]

Try mounting the transducer in a piece of open ended PVC pipe...siliconed direct onto the inside fibreglass hull. and filled with cheap vegetable oil...A "wet" box. Angle cut the end of the pipe so that it is 90 degrees to the water. this compensates for the sloping hull form. After mounting the transducer, seal the oil in with a lid. And all the cabling. Have a top up hole and bung in the lid.. mount the pipe to either port or stbd. of the ballast section. Not on top. You will stll get a good signal but just a little bit off to one side...The signal goes from the trans. through the oil, then the hull, then the water and comes back from the bottom...a good reading...It is necessary to use oil as it does not develop air bubbles like water would...when a sounder reads a fish, it is in fact reading the fishes air bladder. All air must be eliminated. puggsy

[Nick]

I, like Puggsy, also mounted mine in a PVC pipe attached to the hull abeam of the ballast channel under the rear berth. I use water in the pipe and have had no problems with air bubbles. A potential problem with mounting too far forward is that when motoring the bow lifts out of the water and you will lose your reading.
Cheers Nick

[irayone]

Mounted on the transom just left of the swim step at the edge of the transom hull.

[csm]

I like the stand pipe idea. Even when healed over, you're shooting straight down; self leveling. Thanks for the replies.
Chris

[NiceAft]

Puggsy & Nick,

Can you give a bit more information on this technique? What do you believe to be the best I.D. of the P.V.C. pipe? How tall should the pipe be?

Chris said:

I like the stand pipe idea. Even when healed over, you're shooting straight down; self leveling.

Does the transducer self level? Again, how wide is this pipe?

Ray

[csm]

Ray, I may have read more into Puggys and Nick's post than they intended, but I'm thinking a pipe with sufficent ID to allow the xducer to move around, would tend to let it self level. Maybe a small piece of foam on top of the xducer would also help.
Chris

[Nick]

I used a 4 inch diameter pipe . The transducer is bolted to the wall of the pipe and the bolts are sealed to make the chamber waterproof. I hadn't thought about making it a pivoting attachment. I am not sure how the transponder works but I was under the impression it sends out a signal across a 30 degree arc so it doesn't matter that the boat is heeling.
Cheers Nick

[NiceAft]

Thanks Nick, that helps. Do you have any other tips on this idea?

Ray

[LOUIS B HOLUB]

Chris...I placed my transducer on the floor, under the galley sink. The transducer is against the ballast tank wall, and it's flat on the floor, secured with a generous amount of silicone (no bubbles !). It works very well, and is an easy installation.
I got this idea from a dealer installation on my prev. boat, a 1992 26-S, which had the transducer on the floor in the storage compartment (rear of the boat). It worked well also.

My fish finder, depth readings, work very well for my "X" -- and I mention the installation above since theyre so easily done, and reading displays have been very good.

Happy Sailing.

[Russ]

Silicone works great. I've installed a couple that way. Just get the bubbles out.
My dealer installed it on the transom which works well with the chart plotter to get water temps, but otherwise I'd simply use silicone. Cut out the bottom of a bowl (like a butter container) and fill it with silicone where you are installing it then squish the transducer in and you are good to go. If it doesn't work, a knife to the silicone can remove it.

[paj637]

Don't forget about the wax ring trick. My depth transducer has been mounted in wax for almost three years now. No melt or mess in south GA summers. I put in in as a temporary install and have had no need to relocate it or glue it down differently.

[puggsy]

In answer to NiceAft and CSM, the pipe needs to be about 6 inch diameter to accommodate the transducer...mounted on the side of the pipe which of course is upright. The transducer is usually manufactured , mounted to a fitting that usually screws or bolts onto the lower transom. And with instructions as to the correct way to face...the bullet shaped transducer always points forward. And usually the fitting has a toothed swivel to get the sender unit level. In the PVC pipe, it is mounted the same. It does not have to swivel to compensate with the movement of the boat. An initial setting is all that is needed.
Using water in the pipe can cause problems by sloshing and developing air bubbles. And it can evaporate. Cheap vegetable oil is more effective. Also the trans. can be mounted so that the sender unit is some inches away from the hull and not sealed directly against it. And it gives you the option of easily removing it for repair, replacement with a more modern trans or to on sell...Things that are hard to do if it fixed direcly to the hull...and there is no guarantee that you have got out ALL the air bubbles...the oil bath solves that. Hope this helps. Puggsy.

[Rick Westlake]

The transducer of my new Lowrance 527iGPS would need a 6-inch diameter pipe - I considered this, but chose against it.

I tried out the transducer in the very back of the cooler compartment of my - it's inboard of the ballast tank, and actually tucked under the coaming for the head door. The day I tried it, I found the PO's Plastimo water bladder had sprung a leak, so there was enough fresh water in that part of the bilge to partly immerse the transducer. It works beautifully there.

After I dried out the bilge, I used epoxy (as specified by Lowrance) to secure the transducer in place. I pulled the cable through the bilge, outboard of the ballast tanks and back to the transom, then led it up through the cable-duct into the pedestal. Used a clamshell vent for the power and transducer cables, and spiral-wrapped them together to the plugs on the plotter unit. (I installed that on a big RAM mount, whose base is on the port side of the top of the pedestal.)

I used a 4 inch diameter pipe . The transducer is bolted to the wall of the pipe and the bolts are sealed to make the chamber waterproof. I hadn't thought about making it a pivoting attachment. I am not sure how the transponder works but I was under the impression it sends out a signal across a 30 degree arc so it doesn't matter that the boat is heeling.
Cheers Nick

Nick is correct about the 30-degree arc; and on the X at least, the difference between "square to the bottom" and "true vertical" is maybe about 6 degrees of arc. That's about half a percent difference from true vertical - can you say "negligible"?

[csm]

Rick Westlake wrote:

I tried out the transducer in the very back of the cooler compartment of my

. I'm glad to hear that location worked for you as that is where my PO mounted one. I was assuming that was over the ballast tank; guess I need to study the ballast and bilge layup a bit closer. I'm no expert on transducer design, or how the signals are sent and processed, but intuition tells me that the transmitted cone should be kept as square to the water surface as possible. If I were a betting man, I'd bet the depth finder uses some sort of averaging function or "prioritizes" a much smaller degree cone to detect depth. If anyone knows how all that works, I'd really like to hear from you. Fish finders have always been somewhat of a mystery to me.