Best way to remove glued transducer?

I'm grabbing moments here and there to install my new FF/GPS and I'm now to the point where I need to remove my old glued transducer before I install the new one. I used the hobie install kit to put this one in -- my first one.  I put it in with the Marine Goop in the hobie kit. 

Right now I'm just gently working it loose with a putty knife.   

I'm going slowly because I am super cautious.  Is there a better way aside from using the putty knife ?

Dave     

I think that's a good method, Dave.  You don't want to nuke it!  If you hit some concrete-like sections you may have to hit the putty knife with a hammer.  There may be a strong solvent that would help, but that sounds potentially toxic and messy!

GL and have fun.   

  heat your putty knife,  it'll cut right through.

I did the same thing.  A putty knife and more time than it should have taken but it came out pretty clean.

Find some acetone (Nail Polish Remover) It will help loosen up the goop and it should pop right off.

GOT IT --It  just took some patience. 

Will sand the old spot to remove the last vestiges of the goop and to rough up the surface before I install the new one. 

I can see the air bubbles in the hardened goop now that I've got it out.

The new transducer is much larger.  I'm going to make another "transducer pad" out of foam rubber and basically just try to do the same kind of install. 

Going to have to drill one more hole for the power cable -- two cables for this one.

That's enough for today though. Time to cook dinner for "mama".   

After a couple of times using Goop and having bubbles form, then having to work in confined area getting the goop off (hair dryer heat helps), I just went with the foam donut gooped to the hull, filled with water.  The FF works just as well, and the foam donut hasn't leaked or lifted off in about 5 years or more since I put it on.  Just cut the foam donut a little bit smaller than the transducer so the TD wedges into it and holds the water in beneath it.  I often install it the night before on the garage floor, then lift the yak at an angle onto my car and drive to the launch- the water doesn't leak out. 

Did the same thing as F. T. & works great.  Transducers Dont work well with air bubbles like that.  I have the larger lowrance quad ducer installed.  Worked out great.

Bill

 

  Yes ,scrap the gluing of the transducer in method, as you saw, air bubbles did form!  Glue some foam in, make the foam deep enough to cover the transducer and fill with water.  Guaranteed there will be no air bubbles between the transducer and hull that way.  Fill transducer when you get to the water.  Bada bing ....... done!

  Ultrasonic pulses don't travel well through air, so air bubbles beneath the transducer will block or simply not pass through, causing false information on the FF screen.  Air bladders in fish are what generate the returns seen on FF screens.
  As you can imagine, it's always better to have the transducer in the water, but that's not always convenient or  practical in some situations.  So having a "Water bath" in the hull is the next best thing.

OK -- I'm convinced to try this because it makes sense, and seems easy enough.  I am now changing plans.  I can always pull it out and glue it if it doesn't work or I don't like it.   

Do you have some links to pictures?  I should be at this stage by the weekend.  (I am a professor and we're in finals, so I am in grading purgatory for the next few days.)

Any hints on the kind of foam rubber to buy?  I have some on hand but it seems too porous.  I think the real hint is to make it deep enough to cover the transducer with water when you fill it, as you pointed out.  Also thoroughly seal the foam rubber to the hull with goop.  This sounds easy enough -- I'm sure there are links here to pictures of such installs but if you have a link -- point me to it!

d   

I'm definitely more of a fan of the duct seal puck nowadays than the foam puck.  I think it works just as well.

Agreed, duct seal is the way to go but it can soften into a mess with hot summer temps (only applicable if you live in a blazing inferno like me).

The duct seal does work great, but it did stain the yellow plastic of my kayak permanently. I prefer something I can "undo" if I need to, although I don't care too much about aesthetics.

Do you have to do something special to make the duct seal adhere to the kayak...because the last dozen times I used duct seal, it leaked. And I had to add more water throughout the day, as it seeped through the duct seal into the hull of my yak. So I've just accepted the fact my Hobie will always have random water inside it...which is fine except when I need to go through mussel inspex!

The Humminbird kayak kits use some sort of grease to shoot through. It looks like petroleum jelly. Should have no problems with it leaking or trapping air bubbles.