Islander 28' cored bottom?

[Gathhill]

I'm trying to replace depth sounder with a shoot thru the hull transducer. Manufacturer says it won't work with a cored hull. My Islander is a 1977. Does anyone know if it's solid below the water line or cored? Thanks.

 

[JoyRide28]

May we assume that pulling the boat and replacing the through hull transducer is not feasible?? I only ask because I replaced mine a couple seasons ago. With the boat out of the water it was a fast and easy (about two hours) job which will hopefully last for the next 20 or so years.

 

[MrBill_FLL]

Can you just try it and see? clay or silicone works to mount a puck if there are no air bubbles.



-sorry don't know the answer to your question...

 

[alexco38]

Wax Toilet sealing ring will do just fine.

 

[zeehag]

islander did not make cored hulls in 1970s. hand laid glass made in costa mesa cali.

 

[Gathhill]

Thanks Zee. That's what I was hoping for.
Frank

 

[Barnacle Bill]

I used to own an Islander 28 and will also confirm it is a solid fiberglass hull.

 

[Gathhill]

Thank you for your input everyone. I purchased the sounder with a "shoot thru the hull" transducer and after fooling with it for two days and trying to get the old transducer to read I'm about ready to throw the towel in.

 

[Barnacle Bill]

I don't know why you don't get a thru hull transducer. Drilling the exact size hole with a hole saw and installing it in your hull with a poly sulfide caulk like
Boat Life's Life Calk is easy and safe. Then you don't have to worry about shooting through the hull. If there is any air bubbles in the solid fiberglass lamination of the hull, that might cause problems, plus with the in hull variety you have to have a bubble-less mixture between the transducer and the fiberglass to get a good reading. Supposedly in hull transducers are supposed to be able to shoot through 1.5" of fiberglass if there is no core or bubbles.

 

[Merlin Clark]

You can find a sweet spot for the shoot through transducer by putting it in a bag of water on a wet spot (hull). Have someone hold it level and turn it on.
It will be helpful to know the water depth at that spot.
Even though the hull is solid it may have an air bubble or 3 in the layup.