PiranhaMAX 170

[David, aka, "McScruff"]

This Humminbird model is what I'll be using in my canayak.
Thanks to Ken Sobanski for his generosity.
I'm mounting it as a through hull, with a puck transducer.
Any tips or tricks would be welcomed.

[dick tabbert]

I don't know if its still true but you use to be able to glass them on the inside of the boat as long as the boat made water contact where you glassed it in. Don't know if that's still true be but might be worth checking into.

[Leo Nguyen]

I have many friends with the P-Max 170 for their kayaks and float tubes. If you're shooting through the hull, temperature won't be accurate, and you already know about bubbles under transducer for the through hull. This is why they mounted either to the side as a detachable side-extension, underside as a permanent between the grooves, or the backside near/on the rudder assembly.

[Slip Sinker]

thanks David...

some fine memories with that device. i became so dependent on the fish finder i would not fish with out it. why not!... its your eyes under water. i remember preparing my boat at a crowded boat launch close to home. waiting in line to launch and looking in my rear view mirror and seeing an empty fish finder bracket. uhggg!!! back home and start all over again. i think i had almost 2 successful seasons with that device before i decided to move on. i hope you will find success with this device as i did on you new vessel!

ps be sure to read up on the dual cone feature of that transducer. nice

[David, aka, "McScruff"]

KEN: Thanks David...

Some fine memories with that device. I became so dependent on the fish finder I would not fish with out it. And why not!... it’s your eyes under water. I remember preparing my boat at a crowded boat launch close to home. Waiting in line to launch and looking in my rear view mirror and seeing an empty fish finder bracket. uhggg!!! All the way back home and start all over again. I think I had almost 2 successful seasons with that device before I decided to move on. I hope you will find success with this device as I did on your new vessel!

I think it must be very easy to become dependent on the FF. I can see it happening. I’m wondering if one might spend so much time peering at the screen… you forget to fish!

ps be sure to read up on the dual cone feature of that transducer. Nice

Okay, I’m a little fuzzy on the advantages of the dual beam. One is more focused than the other, I get that.

-        The higher frequency on the narrow one is better able to provide detail.

-        The lower freq of the other offers better bottom and structure detail.

But how do these things apply in the real world? And to what advantage?

DICK: “I don't know if it’s still true but you use to be able to glass them on the inside of the boat as long as the boat made water contact where you glassed it in. Don't know if that's still true be but might be worth checking into.”

Dick, it’s still true. What is needed is a hull that is free from voids or air pockets. I intend to glue the transducer to the inside of my hull. I have purchased a puck type transducer to facilitate this. The puck type has a flat, round face which should lay down on the flat hull interior with minimal adhesive between them. Closer to the hull is better!

The one drawback is, it won’t give an absolute reading on temperature. But, I have a remote thermometer I can use to check the temperature against, and so calculate an offset factor.

LEO: I have many friends with the P-Max 170 for their kayaks and float tubes. If you're shooting through the hull, temperature won't be accurate, and you already know about bubbles under transducer for the through hull.

I’m gonna go through-hull for a couple of reasons:

1. I like things tidy in and around my boat.
2. I DON’T like a lot of setup work at the launch.

I’ve already made a cushioned box for the battery; Velcro will be added so it is secure beneath the forward seat. The transducer will reside inside the vessel, beneath another seat – out of the way and free from damage. All I’ll need do is install a freshly charged battery at home, connect two cables to the control head at the launch point… and I’m golden.

[Leo Nguyen]

David, dual beams technology is great for a few reasons, and of course, depending on which dual beams/quad beams you're using. Low frequency can travel further, which is designed to give you broader detection. Part of the lower frequency is also designed to detect the outline of the structures. High frequency designed to penetrate, but much narrower, also designed to get proper soft-vs-hard bottom.

If you can use both and decipher the info, you can actually detect fishes in greater detection areas. Mine utilizes quad beams. Trust me, the deciphering is not fun. The information is phenomenal. Instead of 1ft wide for every 5ft depth (1-to-1 ratio, standard for most low to med end fishfinders) using single beam, I get 1ft wide for 1ft depth detection ratio. I get a massive detection and information underneath me. Running dual beams will increase the returned info from 1-for-5 to 1ft wide for 3ft depth. Still a great advantage.

Just an added warning for the through hull. If there is no proper contact between transducer and the hull, glued in place using marine epoxy and remove all air bubbles, the information report back to the fishfinder will be bad..really bad. You get false positive on temperature, false positive on structures, massive amount of noises displayed on the screen, and sometimes, information just get trashed altogether.

Just play with it first. Try the transducer without gluing it to the hull to see if it works well. If things work well, you got yourself an easy to set unit.

[David, aka, "McScruff"]

Well, Leo, I’ll have to do the best I can. I got the flat faced puck so I could use the thinnest layer of adhesive possible. In theory, at least, this will give me the closest surface contact of the transducer face to the hull. If I’m good, I could get the adhesive layer down to thousandths of an inch;  near-contact with the hull. Whether I’ll be that good or not will be seen.

But my research suggests that the problem with bubbles has to do with the application of excessive adhesive. Too much “goop,” in other words. This thick gloppy layer of goo exudes gasses during the cure phase and fills with bubbles. Slow cure epoxy is less prone to this, as are several of the silicone types.

So my idea is the thinnest layer possible, flat down on the hull, using the one least likely to off-gas: Silicone RTV.

But I will surely take your advice and test it out first.

[Leo Nguyen]

Good choice. Make sure to compensate for the initial surface depth down to 1ft to avoid noises display due to the silicon and hull. Otherwise, it might be golden.

[David, aka, "McScruff"]

Good tip: null the first foot of response!
See, it's ideas like that which make this such a great group idea

[David, aka, "McScruff"]

Leo,
Here's am pic of the transducer I'll be using.
Humminbird even refers to it as a "through hull" model.
Flat, circular face, non-directional.

[Leo Nguyen]

All transducer are through-hull, in-hull based. It's all about the amount of power being used by the transducer, and the shape to accommodate the mount. They're making too much money off us trying to scam us.

[David, aka, "McScruff"]

Well, yes - any transducer can be mounted inside the hull. I understand what you mean.

I'm sure Humminbird - and others - have a reason for producing accessory components....

Refinement, perhaps.

Response driven, perhaps

Make a little extra money, sure.

Im also thinking there is a reason why non-directional is good, and the round flat face can only help with transmitting the power into the water. Was it needed? Well, maybe not.

But thanks to Kens, generosity, I can afford to experiment with it.

[Leo Nguyen]

Here here.