Transducer issues

 At the last "Storming at Del Valle, while stuffing my kayak with camping gear, I, at some time popped my transducer up off the hull. (It was siliconed in place) Probably when I shoved my sleeping bag into front hatch.  Anyhow, had to fish blind that weekend. Well, I've since fixed that problem.  I took a few pictures of the new install, but haven't moved them from camera yet. 
  I choose to try the wet install this time.  I got some nice 2" thick dense close cell foam, (White) was used for packaging protection that came in on our tool were installing in Fremont.  I cut a 6 or 7" square, then marked the  hull where it'll sit, then sanded the area, wiped it down with IPA (Alcohol not India pale Ale) The transfered the hull contour onto one side of the foam, then proceeded to cut, sand remove foam until it conformed to the hull.  Once that was completed, I traced the transducer shape and cut it out.  I made the tranny opening a little small to hole the tranny in place.
Next came the gooey part.  I opened up the tip of my silicon tube and goobered a nice think layer all around the edged, and around the transducer opening, then maneuvering the foam into position just behind the sail mast tube, (Trying to not get any silicon on the hull other than where it's intended to be, was marginally successful in doing that) once the goobered up foam piece was placed I smushed it into position.
  I had trouble finding any kind of weight I could use to apply downward force to the foam, so I just pressed it with my hand over half hour period.
  Let it sit for the week before I continued.  When I continued, I poured water into the cavity and waited maybe an hour then checked behind and in front for signs of water (leaking) no water was felt!   Placed the transducer into the water displacing almost most of it, and the transducer was still covered with the water! DONE!

I'll post pictures later.

That sounds like the same install I did on mine, I had a hard time finding a pool noodle that was big enough to hold a garmin skimmer type transducer so I went with a knee pad of closed cell foam and siliconed it to the hull and with  a smaller cut out to hold the sensor I filled  the pocket with water and now can fish all day with no probems at all

How about piks???

  sorry for the delay in the pictures.  Been busy with house chores.

What the transducer looked like when I inspected why it wasn't working.

Where the transducer was located with silicon.

My foam block cut to size aprox, 6" X 7" marked with the hull contour to remove.

Foam block cut and shaped to form to hull. ready to be glued in.

Glued in, using the same silicon that was used to glue the transducer in previously.

 Side shot, transducer cut out and it holds water! The tranny cut out with the transducer inside only needs about 4 to 5 tablespoons of water to cover the transducer!

Nice idea!

It seems this is what Sharky and I are about to embark on, to re-install a fish-finder on a scupper pro. Previously the fish-finder malfunctioned due to air bubbles that inadvertently where trapped in the glue after attempting a conventional install. Clearly, the "wet install" would eliminate this possibility, while offering more portability to the fish finder by making the entire assembly removable.

I have two questions however:

1) How can one determine a foam sample is "closed cell"?

2) How did you transfer the hull contour?

Thanks!

Open cell is like a sponge, you can breath air through it.  Closed cell is water tight, and wont soak up water like a sponge.  I like to use pool noodle. But there are other cheaper/free alternatives too.

Matching your puck to the hull shouldn't be an issue unless the foam is so dense it wont bend.  For the slightly U shaped hull i just shaved off the sides a little and when gluing in I put a brick on it and make sure the entire bottom is in contact with the hull. 

Try not to cover the puck hole with the weight, leave some breather space, or the glue wont cure very fast.

Another tip, draw a N/S line down the center of the puck before you mount it.  I tried eyeballing it, but in the end I mounted my last one a lil' crooked.

I did the same install on my Hobie Revo directly behind the mast mount.  It's a little difficult to pour water in the opening because the mast mount kind of blocks the access but it has worked well.  I can still throw stuff in the front hatch without being concerned that I'll hit the transponder since the mast mount blocks the mounting block.  I cut up an old Morey Boogie board instead of the pool noodle so that I could get get a big enough piece to hold the transponder.  It holds water all day and the screen provides a nice clean image.  The only down side is the temperature readings are way off.  I think the only way to get correct water temperature reading is to externally mount the transponder.

On Hobies you just need to be sure to mount it far enough forward that you don't have bubbles being generated under it from the mirage drive.  On my Outback I put it in front of the mast and never have issues with bubbles, or stowing gear.

If you work at a 'computer' company that uses hardware (like servers) they will have tons on foam you can use. It may be odd shaped but you can usually find a piece that will do the trick. Or look in the back (garbage area) of a best buy or fry's its all over the place. I use little blocks of it to float hook removers, pliers, etc.

 

  B.  sorry for the late reply, I missed your post back when you did it some how.  The way I transferred the contour was to use cardboard or poster paper, something thicker than paper and then hold one edge to the hull, eyeball where to cut, then cut it, compare and cut until the cardboard matched the contour.  I then traced that to the foam.  It didn't need to be exact as I was going to (and did) use a lot of silicon to glue the foam in place.

  Hopefully you got you installation done and it's working.

 

On my Outback I put it in front of the mast and never have issues with bubbles, or stowing gear.

Ditto on the Revo.