New FF Install DONE ! (out with the old)

Thanks. Brilliant.  Gonna do it.

I can't take credit for this idea, but it does work really well for me. Not the cleanest or sexiest design, but it's foolproof and effective.

The duct seal/water bath method is awesome in cool environments, but if you ever fish in the valley heat (100+ degrees) that stuff will soften into a gooey mess.

I went with the foam block, cut slightly undersize to the transducer, GOOP the block down to the hull & let it cure for a couple days.  I applied enough goop to the bottom of this block to ensure it is watertight to the hull & weighted it down while it cured.  Once cured, put a few spoonfulls of water in the "well" of the block & stick the transducer in.  Works great.

I started with the duct seal, but the larger Lowrance HDI transducers require a block & a half of this stuff and I wasn't able to easily tell the water level so I yanked the duct seal & went to the foam block wet-bath method I mentioned above.

I used a tupperware dish for my water well.  I cut the bottom out of the tupperware, leaving a rim that could be glued down with RTV.  I cut a small hole in the lid and a notch from the lid edge to the hole for the transducer wire to go through.  Then I put the transducer in, filled with water, snapped on the lid and called it good.  That has worked for 2 years now and I never have to replace or refill with water. 

 

 The reason I've found, that gooping the transducer in fails is, directly related to the Ultrasonic pulses sent out by the transducer.  My very first transducer installation was by silicon.  I goobered a huge puddle of clear silicon down on the location, (Ensuring there were no air pockets in the glob), I choose to put the transducer, then mushed it down into the glob.  I let it sit undisturbed for about a week!  When the bead of silicon I mushed out around the transducer had cured, I felt it was good to go.  My FF worked as expected, great, for a short time.   I eventually  noticed I wasn't seeing anything on the display, pulled it up and found  way too air pockets caused by bubbles in the silicon bed!   I opted for a water bath after that.
   What happens is, The US pulses will cause cavitation within the goop, also, the transducer can heat up. Microscopic air bubbles form (Especially if the goop is not fully cured) and the U.S. pulses don't pass through air very well.  Any air pockets under the transducer will degrade it's function.
  This problem is not present with a water bath installation.  Air pockets  (Bubbles)cannot remain beneath the transducer (Float out)
 I'm glad you installation is working for you right now. 

Picked up some duct seal today $3.50 per pack at a local hardware store. Only if I can make up my mind on which ff to get...Lowrance HDI5 is the leader now, but I have till next May so slow coming.

I'm really happy with my Lowrance Mark-4. It's simple and it does everything I need.

Where did you get the caps for your connectors? I did a similar type setup with duct seal and I am 3/4 on positive trips.

One of the holes on connector has rusted over and I bought some crappy Lowrance caps for them but they suck.

Matt 

Dielectric Grease . 

Dielectric Grease . 

Ya I put some of that on there too....still have corrosion. Little frustrated with unit but I'll work it out.

Wow this thread came alive again.  Here four months later,  I oddly find myself back up in Humboldt County this weekend, fishing in the Lagoons -- the FF is still going strong -- working great.  Hopefully the bubbles won't appear.  I'm not sure I would do it differently on my current kayak, a hobie sport.  But I might do it differently with a different boat.  I've seen some interesting things.

I have had my current fishfinder transducer gooped in for 7 years without any problems. That said i need to upgrade so i just ordered a lowrance elite 5 hdi. I was planning to goop in the new transducer because i am afraid the water or transducer may fly around or pop out in surf launches if it is just floating around in there

Dielectric Grease . 

Ya I put some of that on there too....still have corrosion. Little frustrated with unit but I'll work it out.

That dielectric, along with regular freshwater cleaning/drying, should have prevented corrosion/rust completely.  Sorry to hear that!

I have had my current fishfinder transducer gooped in for 7 years without any problems. That said i need to upgrade so i just ordered a lowrance elite 5 hdi. I was planning to goop in the new transducer because i am afraid the water or transducer may fly around or pop out in surf launches if it is just floating around in there

Glad to hear the GOOP is working out for you.

I was also worried about the water sloshing around in the "bath", but haven't found it to be an issue whatsoever. I usually don't fill the "bath" until I'm past the breakers. I have my transducer mounted right under the center hatch of my Hobie, so it's easy to pop that open and dribble in a little water. I have never had the water leak out, or had any other issues with it on the water.