Replacing in-hull transducer

[Chillaxintoo]

I would like to be able to test the original transducer to see if it is actually bad or do I just have a wiring or bonding issue. I think I'm probably just going to be buying a new trans though.

[rjames]

Since it uses a standard plug you could find another depth finder that uses the same plug and try it. If I recall, I purchased a new digital depth here Standard Communications D41 Tracker Back-Mount Boat Depth Sounder / Finder Gauge | Great Lakes Skipper for $60 and figured that price was cheap, since the going rate for a mechanic is over $100 an hour, and my time is worth something, and now have a spare depth gauge, which will probably be out of stock before too long. I also dropped the new transducer over the side of the boat, to make sure it worked, before running the new cable through the boat.

[Chillaxintoo]

I already bought that exact same part from GLS. I installed it last summer only to get the -- on the display. That's why I'm hoping to be able to test my existing Trans before I go out and purchase a new one. If I just need to rebond it to the hull, or refill a fluid reservoir, I'd rather do that than buy a whole new unit at this time.

[codingparadox]

Sorry to bring this thread back from the dead, but did you guys end up finding any simple puck replacement? Investigating options, and the transom mount isn't ideal for our boats since there's no good place to run the cable through that's not below the waterline, so contemplating just replacing the stock one. Also, is the stock one mounted off center, or is it down the centerline somehow? The bottom of of my 2800 has no flat section at all, the center rib of the boat is a V the whole way down, so curious how they even did the stock one.

[codingparadox]

I researched a bunch more last night, and this looks like a great option for us:
https://buy.garmin.com/en-US/US/p/530269#box

Just wondering where the stock one is since that's presumably a calculated good location for an in-hull transducer like this.

[codingparadox]

Okay, I went out and hand-pumped the last inch and a half of water out of the bilge (I really need to go re-seal everything on the outside of this boat -- bilge keeps getting rainwater in it...) and lo and behold, right to the left of the aft bilge pump, a little puck transducer appeared! I've ordered the Garmin GT15M-IH and I'll try installing it a little further fore from the existing one and leave the existing one in place for now as a backup, just never switch it on. Can't wait for the long weekend installing a radar, a chartplotter, and a transducer...

[speedcat]

Originally Posted by codingparadox

Okay, I went out and hand-pumped the last inch and a half of water out of the bilge (I really need to go re-seal everything on the outside of this boat -- bilge keeps getting rainwater in it...) and lo and behold, right to the left of the aft bilge pump, a little puck transducer appeared! I've ordered the Garmin GT15M-IH and I'll try installing it a little further fore from the existing one and leave the existing one in place for now as a backup, just never switch it on. Can't wait for the long weekend installing a radar, a chartplotter, and a transducer...

Hey, I'm probably gonna have to do something similar for my Maxum 2400 SCR. How did this turn out? Did you use the Garmin GT15M-IH?

[codingparadox]

Yup, worked great! Just 4200 the **** out of everything and really let it fully dry before doing filling it up.

[speedcat]

thanks! I may go with the other puck design as I am pretty sure i have a flat spot in the ER in front of the motor. https://buy.garmin.com/en-US/US/p/573584

[speedcat]

Originally Posted by codingparadox

Yup, worked great! Just 4200 the **** out of everything and really let it fully dry before doing filling it up.

So I understand, the transducer will read through 4200 (assuming no bubbles in application, etc)?

[codingparadox]

I just 4200'd around the edge for the offset mount block thingy, not all the way down the center. Just use a ton so it doesn't leak the coolant out of it.

[speedcat]

OK but I would be installing the puck style direct mount to the hull, not using a offset block or tank. It's a different style by Garmin, see linky above. So I think my transducer unit will need to read right through whatever sealant I use. I just need to know if I should use something like 4200 or Boat Life's Life Calk.

EDIT: OK I found the Garmin instructions:
https://static.garmin.com/pumac/GT8H...uctions_EN.pdf

[shrew]

There are two types of transducers:

Through-hull tranducers

Shoot Through-Hull transducers

They are not interchangeable. If you don't want to drill a hole, buy a shoot-through transducer that supports your display. If you have a through hull already just replace it with the same.

[shrew]

Originally Posted by speedcat

OK but I would be installing the puck style direct mount to the hull, not using a offset block or tank. It's a different style by Garmin, see linky above. So I think my transducer unit will need to read right through whatever sealant I use. I just need to know if I should use something like 4200 or Boat Life's Life Calk.

EDIT: OK I found the Garmin instructions:
https://static.garmin.com/pumac/GT8H...uctions_EN.pdf

This is a Shoot-Through model transducer, which I don't believe will work with your boat:

-> The transducer should be mounted over solid fiberglass, with no dead air space or coring in the boat hull.

This would be fine provided the hull isn't foam or balsa cored. I know it's not foam cored. I don't think the hull is balsa cored.

[speedcat]

I installed the Garmin in hull transducer using West System 105 & 205. It's working great! It even keeps depth at 30MPH.

Followed Garmin instructions. Sanded the area with 80 grit. There are definitely areas in that hull that must have cavities or something, but tested right next to the old puck and it seemed good; installed there.

​​​​​​​Thanks all for the advice.