Removing a Through Hull Transducer

[catalanc]

Hello all,
I have a Catalina 22 MK II and there is presently a non-functional in hull (shoot through) transducer glued (epoxy?) in the forward compartment. The glue feels soft.

I need to remove it and want to replace it with a new shoot through transducer. Anyone have any suggestions on the best way to do this? Razor blade? Putty knife? Oscillating tool with scraping blade?
carlos

 

[chuckwayne]

It's probably a caulk like 5200. get a length of monofilament - I use 50lb test- wrap one end on a dowel, then the other end, so the dowels are about a foot apart. use this tool like a tree saw to carefully cut between the hull and the sender.get some debonder (the name brand), and spray the caulk - really wet it down.wait 15-30 minutes, then try wedging a putty knife in between the hull and sender. you may have to respray and repeat. With luck, the bond will yield and you can pull the sender off the hull without damage.

 

[Ted]

If you have, or can borrow a oscillating tool like the Fein Multimaster, it will make quick work of removing the transducer. Use a fine tooth blade of the appropriate shape that will allow access to the transducer. The problem with using a debonding product to soften the caulking or adhesive is that you won't be able to wet the area toward the center of the transducer unless you make many many attempts at this process. Eventually it will work but will take a long time.

 

[dlochner]

The oscillating tool is a good choice. A challenge with putting the new transducer in the same place will be removing all of the old caulk. It may be easier to just mount the new transducer in a new location.

 

[jssailem]

It may be easier to just mount the new transducer in a new location.

That is what I found my previous owner did. Now I am dealing with clean up.

Carlos. What is not functioning? The transducer or the display of the signal. I recently took an old transducer that was glued to the hull and it now transmits depth numbers to my ( SeaTalkNG - NMEA2000 compatible) backbone for play back on my new MFD display.

 

[NYSail]

Or simply get a new transducer (if in fact that is what is broke) and matching hull fitting and just break the entire
Old transducer and hull fitting off and start from scratch. If the old one was glued in they
May have removed the original internal rubber baffle that slows the flow
Of water when removed to clean. Nice
New and clean! Good luck!

 

[dlochner]

Some in-hull transducers are a like a hockey puck that glues directly to the hull. Newer ones have a fitting that is glued to the hull and is filled with antifreeze, the transducer then attaches to the fitting. Like this Airmar in-hull transducer: Airmar

Airmar makes most of the transducers that are on the market. If you need to replace just the transducer they may be able to help you choose the correct one.

 

[catalanc]

Thanks for all the replies. To address the responses; there may be room in the area to simply install the new puck and leave the old one, but the old one is in the optimal spot so I would rather remove it. I really like the idea of a monofilament, but not sure it will be strong enough. Nevertheless, that will be my first try. I have an oscillating tool and scraping blade so I will try that next. A "real" blade really scares me. While it will probably work great, I fear sending the thing through the hull! Finally, removing the old caulk/epoxy will be the real chore, I think. Time will tell.
Thanks again for all the suggestions, and I'll post the results.
cec

 

[jibes138]

The oscillating tool works great for cleaning up the residue and prepping the surface. Use the half moon carbide grit blade to get all the residue off then a sanding triangle to final prep.

 

[LakeShark]

Just an FYI that you likely already know but once you get the old one out use plumbers putty or wax (toilet ring) to bed the new transducer. They work great on our boats and should the transducer ever need to be moved, replaced, or upgraded it makes it so much easier. I highly recommend it just make sure there is no air bubbles in the putty / wax when you push it down.

 

[catalanc]

Just an FYI that you likely already know but once you get the old one out use plumbers putty or wax (toilet ring) to bed the new transducer. They work great on our boats and should the transducer ever need to be moved, replaced, or upgraded it makes it so much easier. I highly recommend it just make sure there is no air bubbles in the putty / wax when you push it down.

Lake Shark.
I have have not heard of this and sounds like a really interesting idea! So either putty or a toilet ring, mold into a patty and press the transducer into it? Almost sounds too simple ...

 

[jssailem]

You can test it by submerging the transducer in water in a plastic bag and laying it against the hull..

 

[LakeShark]

Lake Shark.
I have have not heard of this and sounds like a really interesting idea! So either putty or a toilet ring, mold into a patty and press the transducer into it? Almost sounds too simple ...

It works great! I did it on my 87 model and put the transducer just behind the water tank under the V berth and still in front of the wing keel. Make the putty / wax into a ball and flatten it a bit then place the transducer where you want it and press down allowing the excess to ooze out. Takes all of 5 min at best. I prefer the putty as it is easier to handle and work with than the wax but the choice is yours. I learned this trick from the C22 board on this forum and from the Tech Manual. If you don't already have a Tech Manual from the Catalina 22 association I highly recommend it as well as it is well worth the cost and can easily be downloaded to a phone, tablet, or computer for easy access.

Recient thread on the subject: https://forums.sailboatowners.com/index.php?threads/transom-mount-in-hull-thru-hull.186392/

Tech Manual can be purchased through: https://catalina22.org/ (it's not the Catalina Direct manual but is full of tips on everything for a C22)

 

[markwbird]

I just knocked mine out with a hammer. Remove the retainer collar and hammer it out from the inside.

 

[dlochner]

I just knocked mine out with a hammer. Remove the retainer collar and hammer it out from the inside.

That works for a through hull, but not for an in hull transducer. The in hull transducers shoot through the hull, there is no hole. These work well for boats that have a solid glass hull, not so well with wood boats or boats with a cored hull.

 

[jibes138]

A toilet bowl wax ring can be softened up by heating it making it very pliable. Don't overdue it and melt it but mild heat makes a huge difference. Stick it in the sun in a hot car, or heat it in an aluminum pan on a grill, etc.

 

[BlowMeAway]

Following @Crazy Dave Condon and @Kermit advisement and expertise, I test fitted my transducer with water filled ziplock bag, found an excellent reading spot under port settee, cleaned the fiberglass with some acetone, kneaded a full (9 oz.) jar of plumbers putty, smacked down a dollop of the stuff, squished in the transducer with slight side to side rocking motion, formed a filet along side walls of the transducer, turned on chart plotter...works great and reads accurately based on correlation to my handheld depth gauge. No muss, no fuss!

 

[catalanc]

UPDATE: I used the plumbers putty approach and it works great. I affixed it in the bow storage compartment. Reads accurately, according to a dock-mate and I really like the idea that I can easily remove it and replace it in the future. Thumbs up from me!

 

[jssailem]

Plumbers putty is a good temporary solution. Problem is “It drys out” once out of the sealed plastic container.
Once you have found a good location you need to look at using materials that are more permanent.

 

[catalanc]

Plumbers putty is a good temporary solution. Problem is “It drys out” once out of the sealed plastic container.
Once you have found a good location you need to look at using materials that are more permanent.

OK, makes sense. It has only been installed for few months so perhaps it will go bad before too long. I have some slow cure epoxy in hand so will deal with it when it occurs. Thanks for the advice.
cec