Bumminbird blues (transducer issues)

Got a new kayak this year and spent ALOT of time rigging it up.  I use a humminbird 587ciHD.  I can't say I've ever really loved it, but it's worked and the cost to switch has been prohibitive.

Anyway, I've always used the gooped transducer method and it's worked fine.  So I went with that.  First trial on a lake a few weeks ago I got very weak soundings.  Second time out, no soundings.  I assumed the transducer was busted, so I replaced it (huge pain).  I water tested the transducer in a bucket before mounting and verified it worked (also water tested the original transducer, and it worked as well).  Gooped the new one in.  Tried in a lake the next day, strong soundings.  Problem solved, right?  Wrong. Took it out to Neah Bay last weekend and started off with very weak soundings.  Then after a couple hours, no soundings.  Same deal.  Sucks to be bottomfishing without a sounder (charts and waypoints saved me).

I am thinking it has something to do with the gooped mount because it seems the transducers work fine when not gooped in.  Maybe?  I'm doing it the way I've always done it.  Put a huge bead on the hull, pressed the transducer all the way down and weighted it so it wouldn't float up.  So, no idea what's going on there.

So, I put this question to the experts.  Any ideas???  Here are some possible solutions I'm considering:

0.  Continue gooping until you get it right.  Experience more heartbreak on the water.

1.  I noticed the OB '15 has a lowrance-ready panel on the bottom.  Try to jam the bumminbird transducer in there?  I'm assuming that wouldn't need goop or anything.

2.  Wet mount?  I was thinking maybe sawing a nalgene bottle in half and sanding cut end to the form of the hull.  Goop the seams inside and outside, fill with water, etc.  If I cut it just right the lid could keep the transducer flush against the hull.  If not, shim it a bit. 

3.  Just get a lowrance?  I'd really rather not do this as I use the same FF for my boat and kayak.  I'd have to change the boat out too.  And I have the fish-n-chip chart for the humminbird.  I really don't want to have to spend hundreds and hundreds more.

Have you considered a tranducer arm?  I think there are a few on this board that use one of the various arms from RAM.

http://www.rammount.com/products/kayak/transducer

Is the bottom of the transducer rounded more than the round shape of the hull where you are trying to mount it? If so, the goop method should work. What I feel that your problem is is you may be using too much goop. I have found that with that method it is actually better to use less. When you use more than is necessary you get big air pockets because the goop tightens as is cures over time. One decent to small-ish bead down the middle of the 'ducer is all you need, then duct tape it down and let it the kayak rest right-side up on the floor for about a day.

Using a foam block with the shape of your transducer cut out is an awesome way to go. Make the cutout for the transducer snug so it holds the transducer. Cut the bottom of the foam block so it fits the contour of the hull. Goop the hell out of the bottom of the foam block and spread some goop on the inside edges of the 'ducer cutout once the block is fixed into place and the goop has set but try not to get any in the cutout where the business spot will be. Fill the cutout with water to test and if it doesn't leak you're good to go.

Your ducer should fit into the Lowrance ready mount on the 2015 OB and that's what I would recommend you go with. I modified things a bit so my hummingbird ducer would fit and it did, so yours should fit.

Finally, I've settled on using the RAM transducer arm that Brian mentioned. It's noisy, slows me down a tad, catches weeds and is a pain in other ways, but the return I get is worth the trouble, no question.

Hopefully this helps. I've used all of these methods at some point in the past and they all have their pros and con's. It mainly boils down to personal preference IMO.

Excellent - great ideas guys, thanks.  I'm going to try the lowrance mount first, and if for some reason that doesn't work I'm going to get a transducer arm.

rawk - I think you might be right though, I might have been using too much goop.

also, what humminbird do you have and are you happy with it?

Also rawk, which transducer arm did you get?

I think the fishing gods are trying to tell you to give it a break so we can have some fish too.

The Hobies come with a Lowrance transducer bracket for the transducer pocket, but for a couple bucks you can buy transducer brackets for other brands of fish finder.  When I mounted my Humminbird transducer in the pocket on my Revolution, I was in a hurry, and I cobbled together the bracket shown below.  But it would be way easier to buy the Hobie bracket for a Humminbird transducer.



I have been real happy with the performance of my fish finder with the transducer in the transducer pocket.  The only issue I worry about is getting sand or mud in the pocket, piled up on top of the pocket cover, which could impair the performance of the fish finder.  It's a good idea to hose out the transducer pocket periodically.

Rory,  order the humminbird adapter kit for the Lowrance ready,  and be thankful you have really long arms,  not sure how the outback is,  but reaching the revo 16 wiring hole hurts,  physically hurts.

I've been using the 798ci SI HD for over a year now and I am really happy with it. I had to warranty the head unit once but I am pretty sure it was my own fault. I wasn't being very careful with it in the surf. I would say my only gripe about it are the pins and pin connections - they don't give me a lot of confidence they will last.  I am using the same transducer arm that Brian posted a link to.

Rory,  order the humminbird adapter kit for the Lowrance ready,  and be thankful you have really long arms,  not sure how the outback is,  but reaching the revo 16 wiring hole hurts,  physically hurts.

This is a good point - it is a royal pain in the ass to run the wires through the hole in the tank well and screw the nut on while reaching through the middle hatch. To solve this and other mounting limitations I cut out a hole and mounted a hatch in the tank well of my revo.

I would say my only gripe about it are the pins and pin connections - they don't give me a lot of confidence they will last.

Slather the pins and pin connection with dialectric grease, which you can buy at auto supply stores.  I have had two different Humminbird transducers start malfunctioning, and was able to fix the problem both times by applying dialectric grease.

OK, glad I posted.  Stoked there is an adapter for the lowrance plate!  Thanks fellas!

I would say my only gripe about it are the pins and pin connections - they don't give me a lot of confidence they will last.

Slather the pins and pin connection with dialectric grease, which you can buy at auto supply stores.  I have had two different Humminbird transducers start malfunctioning, and was able to fix the problem both times by applying dialectric grease.

I've been doing that as long as I've been using a sonar unit on a kayak.  Even with that treatment, I still feel as though they won't last as long as I think they should.

I would say my only gripe about it are the pins and pin connections - they don't give me a lot of confidence they will last.

Slather the pins and pin connection with dialectric grease, which you can buy at auto supply stores.  I have had two different Humminbird transducers start malfunctioning, and was able to fix the problem both times by applying dialectric grease.

I've been doing that as long as I've been using a sonar unit on a kayak.  Even with that treatment, I still feel as though they won't last as long as I think they should.

Yeah I have had some problems, and I keep them greased.  Another problem is they don't fit snug in their socket and a hard bump can cause a shutoff.  I have had to ever-so-slightly and gently bend them out to keep a good contact.