Logo
FULL SITE MENU

Adhesive required to mount a transducer

W

William01

Advanced Contributor
Looking for suggestions for a suitable adhesive to “reglue” my transducer preferably a product I can obtain at an auto parts store. I have a fibreglass hull, the transducer mounts inside the hull. Any suggestions greatly appreciated.
 
About half a million results on Google, but I can't recommend anything since I've never mounted one that way. Why are you mounting it that way? Just curious. Now that I think about it, my brother has his mounted that way. It's completely encapsulated in some type of epoxy.
 
Thanks for the reply. I Googled it also but was getting a bunch of different product suggestions. The Hull Truth boating forum had quite the debate on the topic. General consensus is two part epoxy slow cure.
 
Any good epoxy will be fine...the trick is to make sure there is no air between the puck and the hull...playdough makes a cheap damn is you need one...the only drawback to this approach is if you need to use it in "deep" water - the hull adds an extra level of attenuation...if it was good before, you should have any problem.

make sure both surfaces are clean...
 
makomark said:
Any good epoxy will be fine...the trick is to make sure there is no air between the puck and the hull...playdough makes a cheap damn is you need one...the only drawback to this approach is if you need to use it in "deep" water - the hull adds an extra level of attenuation...if it was good before, you should have any problem.

make sure both surfaces are clean...
Click to expand...
Thanks, mostly as a reminder for the kids and grandkids to tilt the engine up when it alarms.
 
Most on-hull depth finder brands come with Epoxy- it really doesn't matter since it's not supposed to be subjected to any forces that would knock it off of the hull.

Buy the stuff from Ace Hardware with the mixing tube on it (because Ace is all over and the price isn't bad) but be prepared to push hard because it's not always easy. Scrape the old Epoxy off and wipe the hull with Acetone. If the hull is bare fiberglass (not gelcoated), sand it smooth before mounting the transducer.

One thing I want to mention- if the original transducer was installed by the boat manufacturer or dealer, don't assume it was in the best location. They may, but as a boat owner, I don't recommend 'taking their word for it'.

When I worked for boat dealers, I tried to meet the boat owners at the lake, so I could put some water in the bilge and move the transducer to various places- the water is a good coupler (no air voids) and it's easy to see where the puck isn't reading accurately. Once the best location has been found, it's just a matter of thoroughly drying the hull, washing it with denatured alcohol to remove the last of the moisture and installing the puck.

With bare fiberglass, I also recommend smoothing it and giving it a coat of resin, just to make sure the surface is smooth. Another method is to use bilge paint, so it's sealed. Filthy bilges are a pet peeve of mine, from years of working on other peoples' boats which have had years of oil, gasoline and other stuff left on the bottom. That stuff makes mounting a transducer nearly impossible, too.
 
jimn said:
Most on-hull depth finder brands come with Epoxy- it really doesn't matter since it's not supposed to be subjected to any forces that would knock it off of the hull.

Buy the stuff from Ace Hardware with the mixing tube on it (because Ace is all over and the price isn't bad) but be prepared to push hard because it's not always easy. Scrape the old Epoxy off and wipe the hull with Acetone. If the hull is bare fiberglass (not gelcoated), sand it smooth before mounting the transducer.

One thing I want to mention- if the original transducer was installed by the boat manufacturer or dealer, don't assume it was in the best location. They may, but as a boat owner, I don't recommend 'taking their word for it'.

When I worked for boat dealers, I tried to meet the boat owners at the lake, so I could put some water in the bilge and move the transducer to various places- the water is a good coupler (no air voids) and it's easy to see where the puck isn't reading accurately. Once the best location has been found, it's just a matter of thoroughly drying the hull, washing it with denatured alcohol to remove the last of the moisture and installing the puck.

With bare fiberglass, I also recommend smoothing it and giving it a coat of resin, just to make sure the surface is smooth. Another method is to use bilge paint, so it's sealed. Filthy bilges are a pet peeve of mine, from years of working on other peoples' boats which have had years of oil, gasoline and other stuff left on the bottom. That stuff makes mounting a transducer nearly impossible, too.
Click to expand...
Thanks for the detailed reply.

The fiberglass has a smooth finish on it, makes wiping down the bilge easier. I’m ASSUMING it’s resin It appears to be thicker than gelcoat. Was going to give it a sanding with 120 grit and use your suggestion and wipe with acetone.

The transducer has to go in the same spot, the original installer left about 6” of wire to work with and to complicate the whole process I’m dealing with a “super structure” to support the tow bar. My wife looked at the tight hole and laughed, offered me a pail of lard.

Going to be one of those jobs that should only take 10 minutes but I know better. I’ll get my upper body in that enclosed space and be sniffing acetone and epoxy. Jim Stafford’s song Wildwood Weed comes to mind.
 
William01 said:
Thanks for the detailed reply.

The fiberglass has a smooth finish on it, makes wiping down the bilge easier. I’m ASSUMING it’s resin It appears to be thicker than gelcoat. Was going to give it a sanding with 120 grit and use your suggestion and wipe with acetone.

The transducer has to go in the same spot, the original installer left about 6” of wire to work with and to complicate the whole process I’m dealing with a “super structure” to support the tow bar. My wife looked at the tight hole and laughed, offered me a pail of lard.

Going to be one of those jobs that should only take 10 minutes but I know better. I’ll get my upper body in that enclosed space and be sniffing acetone and epoxy. Jim Stafford’s song Wildwood Weed comes to mind.
Click to expand...
What color is the bilge? If it's yellow-ish or green, it hasn't been painted, but that doesn't mean it can't be cleaned well enough for the Epoxy to stick well enough.

You could turn the bilge blower on, to remove the fumes.

I forgot to add- I would wipe the bottom of the puck with Acetone, too- I saw several that dislodged because the surface was too smooth and had no 'tooth' for the Epoxy to hold onto.

You're not splicing the cable, are you?
 
Bilge is a grey colour with bits of blue splashed in. Could be painted, it’s kevlar reinforced so the sticker says.

Outboard, no fan/blower. Was thinking of putting the shop vacuum hose and run it as a blower. Room is tight.

I’m going to sand the bottom of the puck holder, there is a bit of the previous adhesive stuck on.

Not spicing the cable, it’s tied into the wiring loom nicely and wiring loom is attached well above the bilge.
 
William01 said:
Bilge is a grey colour with bits of blue splashed in. Could be painted, it’s kevlar reinforced so the sticker says.

Outboard, no fan/blower. Was thinking of putting the shop vacuum hose and run it as a blower. Room is tight.

I’m going to sand the bottom of the puck holder, there is a bit of the previous adhesive stuck on.

Not spicing the cable, it’s tied into the wiring loom nicely and wiring loom is attached well above the bilge.
Click to expand...
If you flick the edge of the old Epoxy, you may find that it peels off- I used to do that when a puck came off and then, I would wipe it with Acetone or Lacquer thinner to make it stick better.

To me, it's important to make sure the puck stays put- if it fails, the bad one can be biffed off with a dead blow mallet and damaging it wouldn't matter- I would hesitate to do that to a working transducer, but I doubt it would cause a problem since it's 'potted' in Epoxy.
 
Turns out I don’t have pure acetone at the cabin, must be at home. I do have fingernail polish remover with acetone. See photo for ingredients. I do have paint thinner and varsol. Would they work?
IMG_6291.jpeg
 
I'd suggest not using the nail polish remover...water never helps with epoxies...out of your other two choices, I'd use the varsol unless you know what is in the paint thinner....
 
Anything that is a pure solvent should work, as long as it's not oily. I use Acetone and Lacquer thinner because it can soften the plastic and doesn't leave a residue that can prevent the Epoxy sticking.
 
Back
Top