Transducer Grease Mount

[dsafety]

I went out fishing today, (Saturday). I will leave the fish report to some of the guys who actually caught fish today. All I was able to reel in were some greenies and a seagull. I did see several nice WSB landed. Most were caught on squid. To the jerks in the power boat that grinned as the drifted over my lines and got everything tangled up on their motor, #@%!! *&#. Why do some people behave so badly?

Anyway, even though I was skunked again, the day was not a total loss. As some may know, I have been playing around with another method of mounting a transducer in a yak. The wet mount works very well but some people have not been able to get the well to stick to their boats and others have not been able to make the unit completely water tight. For those people, (and maybe many others), I would like to introduce another option which I will call the “Grease Mount”.

I cannot take credit for this idea. I had read about it somewhere and thought that it might be a worth trying. My biggest concern was that the grease might melt when the yak is stored or transported upside down and exposed to the hot sun.

Recently, Humminbird released their version of this type of a mount. They sent me a kit to try out on the condition that I would send them a copy of my report. Well, Humminbird, I have some good news and some bad news.

The Humminbird kit costs about $30. It consists of a plastic bracket, some grease, an adhesive backing with primer and apiece of Velcro. You can see a photo of what comes in the kit here. http://store.humminbird.com/products...cac4337f6d8ce6

I am sure that all of this stuff cost less than a buck, not including packaging. Talk about a healthy mark-up. I’m just glad this company is not selling hammers and toilet seats to the US Government.

I followed the detailed installation instructions which included scuffing and cleaning the area where the bracket was to be installed; painting this area with the supplied primer; attaching the adhesive backing to the bracket and finally pressing the bracket on to the prepared hull plastic. They recommended letting everything sit for 24 hours, which I did.

The next day, I squeezed the grease into the well created by the bracket and set the transducer in place. The instructions said to rock the transducer back and forth a few times to squeeze out any air bubbles that might have formed. The bad news is that within seconds I noticed a bunch of green grease flowing out from the bottom of the supposedly attached bracket. The adhesive failed miserably.

This was a total adhesive failure. The adhesive backing had two bonding surfaces, to the bracket and to the kayak. Both failed. I attempted to reach someone at Humminbird to report this problem but never received a response. My recommendations… don’t waste your money on this product.

Although the H-Bird product did not work, I felt that a grease mount might still be worth trying so I modified things a bit. I cleaned all the grease from the bottom of my kayak, sanded the plastic again and installed the H-bird bracket with good old Goop. It bonded perfectly.

Next I needed to find some grease. It seemed to me that some sort of high-temp grease would resist melting so I bought a can of marine grease at Pep Boys. I took a glob of this grease, smeared it on a piece of tin-foil, turned the foil upside down and put it in the oven at 400 degrees, (I put another piece of foil under the one with the grease to catch any drippings.). Good news, even after baking for an hour there were no drips. The oven stunk like grease and my wife got pissed but the test worked.

I smeared about ¼” of the grease on the transducer, set it in the bracket and pressed it to the kayak shell. I then took some Velcro and fastened the transducer to the bracket so it would stay in tight contact with the hull. Not including the curing time for the Goop, the entire installation took about two minutes.

Today was the field test. More good news and bad news. The good news is that I could tell no difference in the fish finder performance between the grease mount and the wet mount methods. There was one exception. The water temperature reading, while I was out fishing, hovered in the 80 to 90 degree range. I think this is because the transducer was taking the reading from the inside of the yak, not the water below. With the wet mount, the water in the well probably acts as a thermal buffer so the reading will be closer to what it is supposed to be.

For those who want to give this method a try, you should be able to make your own “bracket” quite easily. Find a half inch thick piece of some flexible material that will not be affected by the grease. Some light weight closed cell foam or a heavier type of rubber will probably work. Trace the shape of your transducer on to this material and cut the shape out with a knife or jig saw. I am sure that your cut-out shape can be fairly rough.

Glue the bracket to the hull with Goop. You should add a couple of anchor points to the bracket so you can attach a piece of bungee or Velcro to hold the transducer tightly to the hull.

As for the grease, I have no idea if one kind of grease will work better than another. The Marine Grease that I used seems to work fine. The container I bought is probably a lifetime supply so if someone wants a tablespoon or two, PM me and you can come by my place in Encinitas and pick some up.

I should stress that I have only been out once using this transducer mount method. Problems or other issues may surface down the road. If anyone else gives this a try, please post your results.

One final observation. I commend H-Bird for coming up with their kayak mount kit. It is an acknowledgement of the fact that yakfishing is a rapidly growing sport. I only wish that they had tested the adhesive a little better. Charging $30 for this kit is a bit over the top. If I were running things at H-Bird, I would include the plastic bracket at no additional charge with every new fish finder. They could even include a little grease. The installation instructions should recommend that the customer use customer-supplied Goop or some similar adhesive. They should also provide the specifications for the type of grease that is recommended for this kind of installation.

Until next time.

Bob