Through hull transducer

[PNWPederson]

I have a 1970 Grand Banks woody that I will be upgrading my electronics on. I will be pulling the boat soon for bottom paint and wanted to have a new transducer in my possession prior to paint so that I can replace the old one. The old transducer goes to a Raymarine ST60 Tridata display. I'm not at the boat and won't be able to get to the boat for a couple of weeks or so, otherwise I would measure the old transducer, so I was hoping I could get some guidance on what transducer I should get and the what size opening it is. Here's a couple of pictures of the hull where the transducer and the speed paddlewheel are located. I will be going with Raymarine electronics.

 

[Tim]

I have a 1970 Grand Banks woody that I will be upgrading my electronics on. I will be pulling the boat soon for bottom paint and wanted to have a new transducer in my possession prior to paint so that I can replace the old one. The old transducer goes to a Raymarine ST60 Tridata display. I'm not at the boat and won't be able to get to the boat for a couple of weeks or so, otherwise I would measure the old transducer, so I was hoping I could get some guidance on what transducer I should get and the what size opening it is. Here's a couple of pictures of the hull where the transducer and the speed paddlewheel are located. I will be going with Raymarine electronics.

View attachment 162330View attachment 162331

I have a 1970 Grand Banks woody that I will be upgrading my electronics on. I will be pulling the boat soon for bottom paint and wanted to have a new transducer in my possession prior to paint so that I can replace the old one. The old transducer goes to a Raymarine ST60 Tridata display. I'm not at the boat and won't be able to get to the boat for a couple of weeks or so, otherwise I would measure the old transducer, so I was hoping I could get some guidance on what transducer I should get and the what size opening it is. Here's a couple of pictures of the hull where the transducer and the speed paddlewheel are located. I will be going with Raymarine electronics.

View attachment 162330View attachment 162331

Check the specs on your Raymarine unit. It should tell you the compatible transducers. Most likely an Airmar unit which made the Tridata transducer. Exact choice depends on if plugging directly in or networking N2k.

 

[PNWPederson]

I was thinking, (every now and then it happens), but can the internals of a transducer be replaced without replacing the entire unit?

Looking at the lower picture, the transducer looks like a standard through hull transducer with faring. Here's a picture of what it looks like from in the boat.

That looks to me to be a bronze through hull. Can I buy a different transducer, just the plastic portion, and replace the internals without putting in a new through hull faring and bronze transducer housing as bronze seems to be what raises the price quite a bit. Am I wrong with this line of thinking?

 

[tiltrider1]

Yes, if you get lucky. I bought an Airmar DSR-810 transducer as I wanted my depth to be on the NMEA 2000 network. I had intended to replace an old out of commission transducer. As it turned out the old transducer was the exact same size as the new one so all I needed to do was pull out the plug and insert the new transducer.

 

[High Wire]

If you KNOW the depth finder that you are going to install, call AIRMAR. They make the TDs for almost every manufacturer. The top skinny one will need a whole new TD. The bottom one may get by with a replacement center core. Personally I would replace the whole TD with similar sized units. You might be able to reuse the fairing blocks if they are in good condition.

 

[PNWPederson]

If you KNOW the depth finder that you are going to install, call AIRMAR. They make the TDs for almost every manufacturer. The top skinny one will need a whole new TD. The bottom one may get by with a replacement center core. Personally I would replace the whole TD with similar sized units. You might be able to reuse the fairing blocks if they are in good condition.

Thanks High Wire. I've sent a message to AIRMAR.

 

[PNWPederson]

An update on the transducer. I contacted AIRMAR and they say it's an old B744V. I can replace the speed and temp, but not the depth. It is recommended that I replace the entire unit, including the fairing block.

While I was in the engine compartment, I saw another transducer on the other side that I had not seen before. Due to time, weather and work, I haven't spent any time in the engine compartment going through things.

Well, this transducer is a flush mount like the image below. I went through the photos of the haul out last October and there it was. I missed it. A question for the smart people here, how easy or difficult is it to remove this type of transducer and put in a new one? I don't need an expensive transducer and this type of through hull seems to be more cost effective than the style with a fairing block.

 

[Comodave]

It isn’t too difficult to replace it. It will likely be bedded with 5200 which is tough to remove. I use heat on the 5200. If that doesn’t work the I use a grinder and cut the transducer off on the inside. Then you can grind off the outside, just don’t go too far and grind the fiberglass. Then use heat and a putty knife to clean off any residue of the 5200.

As to the fairing blocks they make tilted array transducers so you don’t need a fairing block. Just mount the transducer flush and the array looks straight down. I don’t know if they make tilted array transducers with the speed sensor or not.

 

[tiltrider1]

Take a grinder and carefully cut a giant X across the bottom. Don’t cut into the glass. Then take a chisel pound in between the transducer and the hull. The transducer lip will curl up and pop off. Once the lip is pealed off there won’t be enough adhesive left to prevent you from just pushing the remainder of the transducer out.

 

[PNWPederson]

Thanks for the advice. One thing of note is that this is a wood hull boat.

 

[Comodave]

Still same procedure but instead of fiberglass insert wood.