Depends on if it sits in the direct sun. If not hot hot melt glue would do it. Sitting in the direct sun in summer the glue may soften enough to let go. If it doesn't come right off when you want it to run a little mineral spirits under it and it will cause the glue to fail.

 

It’ll be below decks, out of the sun, but it will be in an engine compartment which is subject to some heat.

 

I’m planning to glue a fish finder transducer to the inside of my boat. Best practice seems to be to use epoxy since it cures hard and won’t impair signal transmission like a more rubbery material like silicone would. It’s also easier to get any bubbles out of epoxy.
But, I want to remove this thing in a year or two without grinding.


BTW, I already tested it by gooshing the transducer into a glob of toilet seal wax and it worked great!

This is a new one to me . . . in my world, the "transducer" is mounted on the outside of the hull to be under the waterline when fishing.
Personally, I would like to know more about the reasoning of mounting it "inside" the boat.
Is the boat wood, fiberglass, aluminum, plastic ??
The type of material for the boat (in my world) would determine which adhesive to use.
A photo of the transducer and where you want to mount it woud be interesting to see.

 

Another option might be velcro.

 

John, I was in the “same boat” as you (pun intended) until recently.

Apparantly, someone discovered that the transducer doesn’t care whether it’s on the inside or outside of a fiberglass hull as long as the hull is not cored. It’s apparently commonplace now for transducers to be simply glued to the inside of the hull and the signal shoots right through the hull, with minimal loss of accuracy. They even make transducers specifically designed to be mounted inside the hull.

So, not only is it easier - for anyone who’s squeamish about drilling a hole in the bottom of a boat, it’s probably a great relief.

When I get my longer term solution, I will in fact put in a thru-hull transducer; that’s why I want to be able to get this one out when it’s time is up.

 

Lots of spit-balls hitting the wall. Choose which one suits you the best.
Did you run this across the boating website yet? Seems like there would be more folks there that actually use what you have.

 

If not hot hot melt glue would do it.

Another option might be velcro.

Neither of these suggestions will allow the transducer to function as intended.
While hot melt glue will allow a sonar signal to pass through it, it is not an acoustically optimal coupling agent. The potential for trapped air bubbles and inconsistent acoustic properties means it could severely degrade signal quality and weaken the connection between the transducer and the target. For any application where signal integrity is critical, a purpose-built acoustic epoxy should be used instead.
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I’m planning to glue a fish finder transducer to the inside of my boat. Best practice seems to be to use epoxy since it cures hard and won’t impair signal transmission like a more rubbery material like silicone would. It’s also easier to get any bubbles out of epoxy.

You are 100% correct, in fact, the very best practice is to use acoustic epoxy such as; Vexilar A.C.E. transducer adhesive. A.C.E stands for Acoustically Conductive Epoxy.
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BTW, I already tested it by gooshing the transducer into a glob of toilet seal wax and it worked great!

It’ll be below decks, out of the sun, but it will be in an engine compartment which is subject to some heat.

It may possible to create a bracket to (A) hold the transducer in contact with the hull and (B) use the toilet seal wax to displace any air, allowing the sonar signal to pass thru smoothly.
The mounting bracket could possibly be attached to existing structure within the engine compartment?

 

E6000, Goop, or others like it. I use E6000 to fix canopies on my RC airplanes. You can work a monofilament line under it to cut it or a sharp knife. I think no need to slather the entire surface of the transducer???? Just some spots would be enough????? This family of glue has some flexibility.

Ken

 

Not sure how a flexible substance is going to allow the transducer to function as intended. Seems like the flex would adversely dampen the transducer signals.
What ever is used, has to have full contact with no air gaps or air bubbles.

 

Screws aren't an option?

 

Thanks for all these great ideas.

I’m thinking of a combination approach.

There’s no existing structure that I can mount a bracket to, but I could glue a block of wood or angle to the inside of the hull and mount the transducer bracket to that after bedding the transducer in a glob of wax. I’ve also heard of guys using Duct Seal.

There’s the added benefit of being able to remove the transducer in one piece when the time comes.

Also, the sealant or epoxy that holds the wood block to the hull needn’t be a big glob, just enough to hold the wood. A whack with a hammer should easily remove the wood block and leave behind very little residue.

I’m tellin’ ya - you guys are gold.

 

Fish - we want to see pictures of the FISH !!!

 

I'm surprised no one has mentioned the kraft paper ( brown paper bag ) and the glue joint will release with a butcher knife and a hammer . The paper thickness simply splits in half . First learned about this process in Jr High about 70 years ago just after Elmer's was invented . Test this on wood to see how simple it is . The small
table top I glued to the frame years ago and can be removed in seconds .

 

I’ve used the brown paper method for joining pieces that were later turned and separated.

But, this is bonding plastic to fiberglass in a wet environment, so the likely adhesive would be epoxy and I suspect paper might only server to strengthen it.

I did consider Titebond III but that couldn’t be made into a big blob.

 

I doubt there would need be a big blob . I seldom fully coat anything but do a spot glue .

 

In this case, a big blob is required. There must me no (air) gaps between the transducer and the inside of the hull. It’s no so much adhering the transducer as it is acoustically coupling it.

 

Something I've forgotten about is and used on my model glider plane when even a 1/4 ounce is too much added weight.

I've wrapped servos with GOOD masking tape then epoxied them in place. The tape allows the removal process to be fairly simple yet hold very well under some fairly high loads.

Would be easy to test with a couple of pieces of scrap wood to see if you like the bond or not.

Ken

 

RTV silicone