Epoxy Transducer Install DYI
 

There is a school of thought that an internal transducer installation using epoxy instead of the usual silicone based Goop makes for better fish finder performance. This is due to epoxy's harder set, which makes for more signals transmitted outside the hull and better reception. Also, the use of 30 minute or longer epoxy allows air bubbles to escape better than Goop, which is more viscous.
That said, here is how I did it. First, select a polyethylene compatible epoxy. I hear Devcon Polywelder does well, but personally, I recommend Marinetex Flexset. It is rated for PE and starboard and is recommended for PE transducer installations.
http://www.marinetex.com/marinetexflexset.html
http://i12.photobucket.com/albums/a2...23/flexSet.jpg

Flexset has some special instructions -

How to bond a transducer to a polyethylene hull (as in a kayak): -Product: Marine-Tex FlexSet
-Materials: Solvent for cleaning transducer's bonding surface, 80-100 grit sandpaper, propane torch with spreader
-Conditions: Minimum 65˚F temperature, 48 hours to fully cure
-Read instructions on packaging. Prep bonding surface of transducer with solvent and sanding. Prep polyethylene by using the 'flame-treatment' method. There is a one hour window to bond the materials after flame treating the polyethylene. Apply epoxy to the surface of the transducer's bonding surface and attach to hull. Use mechanical means to support contact between the transducer and the hull while the epoxy cures. Let the application sit for the full cure time.

Scuff the area with fine grit sand paper, as well as the transducer. Clean the area with paper towel and some alcohol. Most kayak have a release agent on the hull. Cleaning the bond site is very important.
Since we are using long set time epoxy, it will flow. Construct a dam to keep the epoxy from going all over the inside of your kayak. I used a small section of a disposable water bottle.
http://i12.photobucket.com/albums/a2...3/IMGP5349.jpg
adhere it to where you want the tx
http://i12.photobucket.com/albums/a2...3/IMGP5350.jpg
seal up any leaks that may occur with little pieces of masking tape
http://i12.photobucket.com/albums/a2...3/IMGP5351.jpg
then level the kayak hull. this is an important step but accurate leveling is not crucial. the long set time will cause the epoxy to settle at level. I used some pencils and tape to do the job on my saw horses. you can level the kayak earlier to chose a level spot for the tx too.
http://i12.photobucket.com/albums/a2...3/IMGP5354.jpg
mix up the epoxy in a small cup to assist pouring in hard to reach areas. this is another advantage to long set time epoxy. you get more working time. be sure to mix it up thoroughly. this has a direct effect on the bond.
http://i12.photobucket.com/albums/a2...3/IMGP5356.jpg
pour the epoxy into the well you created. drop the transducer by putting one side down, and slow leveling it. this will allow air to escape as you put it in. the epoxy will act as a lubricant and will cause the tx to slide. dont worry, center the tx and hold it with tape. you dont see it here, but i centered it later and taped it in place. you will need a small weight to put pressure on the tx. this will allow it to dig into the epoxy and press out any air in the installation.
http://i12.photobucket.com/albums/a2...3/IMGP5357.jpg
leave the installation for at least 3 hours, overnight if possible. if you are not confident with your own skills, you local kayak shop should be able to do this for you.
thats it. hope that helps.

i'll be testing the performance next week. if there is any difference, and anyone is interested, i'll post a report.

/bing

p.s.

MORE ON FLAME TREATING

http://www.marinetex.com/marinetexfl...rections-59554

Directions for bonding polyethylene using flame treating:

1. Fit a propane torch with flame spreader.

2. Following the operating cautions of the propane torch, ignite the flame.

3. Observe the flame in a darkened room, noting the primary (bright blue) and secondary (faint yellow) portions of the flame (see drawing).

4. Adjust the flame so that the primary flame is contained within the spreader, and the secondary flame is 1-1/2" beyond the spreader (see drawing).

5. Treat the polyethylene to be bonded with the tip of the secondary flame by passing it over the polyethylene in 5 gentle strokes. Total exposure to the flame should be 2-3 seconds (.5 second per stroke.) This light exposure should not deform or melt the polyethylene in any way.

6. Test the polyethylene for bond readiness by wetting it with water. If the water runs off immediately, the treatment was not effective. If the water sheets on the surface, the surface is ready for bonding. If unsure, compare the water's action on the treated area with the untreated area.

7. Bond joints per the above directions within 1 hour after flame treating. Always prepare test bonds to be certain that flame treating is effective with your material.

Bitchin idea with the water bottle. I like reading about peoples creativity with this stuff. Definitely post a report if you notice a difference between the epoxy vs. goop.
Thanks!

I've used both and Epoxy does give a better signal than Marine Goop.
It needs to cure for a long time to bond properly. I used an 8 hour slow cure epoxy and left it to cure for 3 days.

I wish I would have read this a few days ago, I just installed a humminbird 525 with marine goop in my yak. better than nothing, and proven to work. Now I just need luck! I used my kids play doh to make a base barrier. whatever works!

i like it. very creative. but im assuming with this method the transducer becomes very permanent? because i know with goop you can pry up the transducer if there was ever a need to ei; replacing it due to corrosion, bent prong, selling the yak.

yes, it is permanent. before anyone epoxies their tx, they will have to determine if they want the tx for later use. replacements are about 50 bucks.

/bing