My Goop didn't harden

This is probably just a case of old goop or the wrong stuff. I gooped my transducer down with atwood marine silicone I bought from walmart. It was unopened but probably has been sitting on the walmart shelf for 8 months at least. Anyway Its been drying for 3 days indoors. I thought it was good to go, I reach in and grab the transducer to make sure its solid and straight and the thing pops right out, silicone still wet like it came out of the tube 10 minutes ago.

I can't seem to locate the stuff that says "marine goop" on the tube. I can find different brands of marine grade silicone though at west marine. So what do you guys recommend?

"So, what do you guys recommend?"

A Pfizer product?

Did you close the hatch while it was drying? I use the foam puck and water model.

True

"So, what do you guys recommend?"

A Pfizer product?

Did you close the hatch while it was drying? I use the foam puck and water model.

True

Yeah the hatches have been more or less closed. I know the center hatch has been open a lot. The end hatches have been cracked open at least and the drain plug is out.

I will add that the goop that was exposed to the air and the stuff that oozed out dried. It was mainly the stuff under the transducer that didn't dry. The only thing that tipped me off was that it seemed to mysteriously move since last night when I took the tape off.

Marine silicon is not Marine Goop!

The reason I used Goop on the first gooped down transducer ever (I love saying that) was because the 3M 4200 that I used didn't cure.

I had some plain old Goop in my glove box and stuck it on with a quarter-sized dollop of that. It's been stuck for going on 13 years or so and is still stuck. I would not worry about Marine Goop vs. all the other Goops. They all set fast and stay stuck.

You also don't want a thick layer of whatever stickum you use between the transducer and the hull. A quarter sized dollop will do it and even then, you want to squish most it out when you set it. That makes for the closest couple between the hull and the transducer (and the water for that matter). The thin layer and letting it cure will also insure that you don't get any bubbles in the goop that will wreck your signal.

Guessing the outer exposed area of the silicon was somewhat dry, almost like an "outer crust" but the inner portion was not ?

Guessing the outer exposed area of the goop was somewhat dry, almost like an "outer crust" but the inner portion was not ?

No, it was just like it was fresh out the tube under the transducer. The stuff around the edges that oozed out was cured fully.

+1 on the Goop, I use Marine Goop. Its just really tough stuff!

The only bad thing about Goop is that its chock full of toluene, a pretty nasty substance you don't want to be breathing in.

The dose makes the poison, so wearing latex or nitrile gloves and Gooping outside will limit your exposure and also give you a chance you move around the Goop with your fingers without getting it all over your hand.

 

yes,  that area that was directly exposed to air starts drying, sealing out air from continuing to get to the mass underneath.   Most any mild smelling adhesive like silicon will act much the same way and take an extensive amount of time to dry or cure throughout.   Strong smelling adhesives like Marine Goop use a highly evaporative solvent as a base for their liquid form and dry / cure much faster

+2 on actual goop. I had the same experience with some cheaper stuff.

Fishermans Marine Supply sold me some epoxy to fix my transducer in. Never had a problem with a two part epoxy from not hardening. I'm going to test the depth finder on Friday while I fish Springers on the Willi. I'll give you an update if all works well or not.

I used two part epoxy after roughing the surface with sandpaper.  Haven't had a problem with it.  Hope I never have to take it off!

Fred Meyer always has Marine Goop. Look around caulking.

If you can't find marine goop plumbers goop works fine. I think they're all pretty much the same formula.

Epoxy works and its whats recommended by the FF manufactures, BUT they assume you're mounting it in a fiberglass hull. Our boats are made of HDPE plastic and it flexes. Most epoxy does not flex as much as our boats and will pop off relatively easily. That's why I tried the 4200 and Goop in the first place.  An exception to that would be G-flex epoxy that will stick that sucker down forever if the surface is properly prepared.

All that said, I don't use any adhesive at all anymore. My transducer is held in place with a section of pool noodle under my seat pressing it against the hull. The temperature is a couple of degrees off (but consistent), but the FF signal is just fine. An added benenfit is that its removable so you can move it from boat to boat.

You might want give that a shot or any of the "transducer in a puddle" mounts that don't require you to stick it down permanently. If you don't like it, you could always go back and glue it hard.

I had some old tubes of silicon seal (bought a case) that failed to cure even in the warm open air.  I assumed they had degraded, and tossed them out.  Now I only buy what I need for the particular project.