Thru Hull Transducer Install

Mar 23, 2011
30
Down East Yachts Downeaster 38 040 Milford, CT
Hi Maine,

I was wondering what you opinion is on the best way to seal up a through-hull depth transducer/fishfinder. I'm putting a Ray-B260 on Argyle this year. The last time I messed with below the waterline through-hulls, I used 3M 101 polysuflide to seal it up and that seemed to work great for the application. That stuff doesn't exist anymore, however.

Is there a good alternative to the 101? It seems you like the "Boat-Life" stuff when not using Butyl, topsides. Do they have a product that you use for sealing below the waterline?

In addition to the sealant, I'm curious about how to handle the fairing? The transducer comes with a fairing to help with drag and make installing on a deadrise easier. Do I just use sealant on the fairing just as I wold on the bronze through-hull.

Hull is solid glass, ~20-25 degree deadrise at the install location.

Thanks for any advice :)

-Argyle
 
Aug 19, 2013
32
oday 23 nockamixon
perfect timing, I'm at the point of deciding on keeping the old shoot thru or adding a true thru hull triducer. The thought worries me though, as I've read varied problems and issues with both thru hulls and paddle wheel sensors.
 
Oct 28, 2013
114
Catalina 30 1978 #980 Catalina 30 1978 #980 Mission beach, California
I would add my two cents for what it's worth, a couple months ago I asked a friend of mine who had a 38 foot Hans Christian which they cruised for two years. I asked Doug when you pull up to an anchorage how do you know whether or not it's rock or sand/mud. He said I'm not sure about that, never been asked that question. I told him on my fishing boat I have a furuno 582 L with a 1 KW transducer. I told him I could tell the difference between a hard bottom/rocky bottom, or a soft/Sandy bottom. With that said, the next transducer will be a through haul and at least 600 W maybe 1 KW transducer.

Of course she would have to have the machine to go along with this transducer, I'm a Furuno guy, so I would probably put the replacement for a 582 L that I have on my fishing skiff. The other Advantage to this, is if you got really hungry and had to have some fish or just wanted to catch some fish, for dinner let's say. Then you have a hot meter/machine that will give you more than depth, and also tell you the consistency of the bottom. Which is important when you want to drop the hook.

Don't beat me up on this, it's just my opinion. And I'm going to put a good air mar transducer the next time I haul out.

Kim a.k.a. guts
 

Waybad

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Nov 12, 2011
25
Skookum 34 34 Custom DesMoines
Boat Life has a polysulfide, which is what 3M 101 was. Which is replaced with fast cure 4000. I complained to the 3M rep. as Have used 101 for over 30 years. He insisted it was better. I am trying some out, but the jury is out. Boat Life polysulfide seem just a little bit thinner.
I glassed a 4 inch PVC coupling to the hull, cut to fit angle so transducer was pointing straight down. Mounted transducer in PVC screw in cap. filled with mineral oil. works great. Good luck. waybad
 
Jul 21, 2013
333
Searching for 1st sailing boat 27-28, 34-36 Channel Islands, Marina Del Rey
I would add my two cents for what it's worth, a couple months ago I asked a friend of mine who had a 38 foot Hans Christian which they cruised for two years. I asked Doug when you pull up to an anchorage how do you know whether or not it's rock or sand/mud. He said I'm not sure about that, never been asked that question. I told him on my fishing boat I have a furuno 582 L with a 1 KW transducer. I told him I could tell the difference between a hard bottom/rocky bottom, or a soft/Sandy bottom. With that said, the next transducer will be a through haul and at least 600 W maybe 1 KW transducer.

Of course she would have to have the machine to go along with this transducer, I'm a Furuno guy, so I would probably put the replacement for a 582 L that I have on my fishing skiff. The other Advantage to this, is if you got really hungry and had to have some fish or just wanted to catch some fish, for dinner let's say. Then you have a hot meter/machine that will give you more than depth, and also tell you the consistency of the bottom. Which is important when you want to drop the hook.

Don't beat me up on this, it's just my opinion. And I'm going to put a good air mar transducer the next time I haul out.

Kim a.k.a. guts
What model airmar do you have in mind?
 
Oct 28, 2013
114
Catalina 30 1978 #980 Catalina 30 1978 #980 Mission beach, California
What model airmar do you have in mind?

The one I used on my Boston Whaler Montauk was a Cams BR7 as I recall but that would be relevant to which machine you're using. The BR stands for bronze and the "7" is how long the shaft is coming up the transducer. This transducer goes with a Furuno FCV- 582 L

This transducer is shaped somewhat similar to a football in other words with a point front and back. You would need to use a fairing block that's where the long shaft on the transducer comes in to play.

All I'm trying to say is use a machine matched with a transducer that is capable of getting your good reading of the bottom.
 
Jan 22, 2008
53
Macgregor 21 MN
Those high wattage transducers pull some juice, don't they? I'm thinking sailboat, not powerboat. Otherwise, I think the fewer holes you have to put in the hull the better. If you want to check the bottom drop a proper lead line. The hole in the bottom will usually pull up something, unless it's rock, in which case you should be able to feel it bouncing off the bottom. Waybad's solution allows you to easily position the sensor vertically, as well. I guess the only through-hull sensor that makes sense to me (for a sailboat) is a tridata sensor which gives you speed, depth and temperature.
 
Dec 1, 2009
1
Hunter 30' Deux-Montagnes Montreal
video about speed transducer replacment

Hi Maine,

I was wondering what you opinion is on the best way to seal up a through-hull depth transducer/fishfinder. I'm putting a Ray-B260 on Argyle this year. The last time I messed with below the waterline through-hulls, I used 3M 101 polysuflide to seal it up and that seemed to work great for the application. That stuff doesn't exist anymore, however.

Is there a good alternative to the 101? It seems you like the "Boat-Life" stuff when not using Butyl, topsides. Do they have a product that you use for sealing below the waterline?

In addition to the sealant, I'm curious about how to handle the fairing? The transducer comes with a fairing to help with drag and make installing on a deadrise easier. Do I just use sealant on the fairing just as I wold on the bronze through-hull.

Hull is solid glass, ~20-25 degree deadrise at the install location.

Thanks for any advice :)

-Argyle
Can you give me the link to a video about how to changer a ST60 speed sensor on a fiberglass hull?
 
Mar 23, 2011
30
Down East Yachts Downeaster 38 040 Milford, CT
Waybad: The 3M rep was either outright lying or didn't know what he was talking about. The 3M 4200 or 4000 UV are not replacements for 101. They were all on the market at the same time, 101 was just discontinued for some reason, perhaps poor sales. 101 was a polysulfide while 4200 is a polyurethane like 5200 (just not as strong) and 4000UV is a poly-ether. The polysulfides don't bond as aggressively as the others and they typically stay much more flexible. That's why it was good for thru-hulls; as the hull flexes, the seal remains intact, but if you have to remove the thru-hull, it will still be possible without extensive effort.

I think I will go with Life-Caulk, it seems like it is most similar to to the 101.