Interphase Transducer Pains

[silverp40]

Have an old Interphase forward looking depth sounder whose transducer is a real pain!
When hauled out, I paint it 7-10 coats of non-copper, water base TD paint but barnacles eventually get through the paint. The transducer has a thin rubber like (silicone?) cover and barnacles keep damaging it when they get stuck to it. I think that if the cover is perforated, the unit is shot. I'm on my 2nd transducer in 6 years and this one is not working now. 3rd unit?

If anyone has experience with these units, any help in protecting the transducer would be really appreciated!

[Roy M]

Call Interphase at 831-477-4944. Talk to Charles. They are a great company, in my experience. I have an SE200C. You have a serious barnacle issue.

[silverp40]

They are a good company but are owned by Garmin as of late so all their good guys (Cory) are at Garmin. None of them can tell me though, what to do about keeping barnacles off.

In desperation, I added a small bit of b5200 caulking to take place of the original rubber "skin". The unit worked for a bit but then quit altogether. I think it is because of the caulking (about 1mm coat only) but I think that without it, water would get inside the unit...

[Roy M]

I lightly sanded my two transducers and brushed on some epoxy, then lightly sanded again and used copper bottom paint. I suspect you have other problems. What model unit are you using, and how old is it (and the newest transducer)?

[Jim Cate]

FWIW,

I have used the same ablative paint (Altex 3000) on the transducer as on the bottom for the past 9 years, and nothing bad has happened so far. Still on original transducer, seems to work as well as ever.

Cheers,

Jim

[silverp40]

Great info here...the unit is a 1999, probably one of their first generation units. I replaced the TD in 2007 but little by little it seems that the darn barnies kept eating away at the skin.

Jim, did you scuff and coat your with epoxy first before painting with copper/tin paint? Does the unit work normally with the ablative paint?

Roy, does your unit function normally after receiving the "treatment"?

Thanks mucho
Ovi

[Roy M]

ALL transducers I have ever had got a coat of regular bottom paint, atop a thin coat of SANDED epoxy. I have seen this practice hundreds of times in boatyards, over the years. All worked fine. P.S.: Get an SE200, preferably C. They are great.

These are pics of the installation of my Raymarine 50/200 fishfinder transducer, near the SC200C. I used Z-Spar Splash Zone epoxy putty for the fairing blocks. It is like working with clay. Just keep it wet and you can work it to the point it needs little sanding. I use this stuff a lot underwater.

The black hemispheric units are the port and starboard scanning sonar transducers. They got "scuff sanded" with 120 grit, then coated with West System, scuffed again, then primed and bottom painted, just like everything else underwater (except the shaft and prop which were treated with PropSpeed).

[Jim Cate]

Originally Posted by silverp40

Great info here...the unit is a 1999, probably one of their first generation units. I replaced the TD in 2007 but little by little it seems that the darn barnies kept eating away at the skin.

Jim, did you scuff and coat your with epoxy first before painting with copper/tin paint? Does the unit work normally with the ablative paint?

Roy, does your unit function normally after receiving the "treatment"?

Thanks mucho
Ovi

G'Day Ovi,

No, I just painted the stuff on! On my previous boat I installed one in 1996. Used the water based transducer paint a couple of times but found that it had essentially zero antifouling properties. Switched to regular paint (whatever I was using elsewhere) and never noted any difficulties. Didn't notice any change in performance, either. But, I don't notice much difference when the AF dies and the transducer gets fouled, so who knows... maybe I am jsut not very observant! AFAIK that transducer is still working for her current owner.

Cheers,

Jim

[silverp40]

Quote

Used the water based transducer paint a couple of times but found that it had essentially zero antifouling properties.

I agree with you now, will not use the TD waterbase paint any more.

Thanks also to Roy for the details, I will certainly antifoul it over the epoxy undercoat. The Splash zone epoxy sounds like a wonderful product!

I wish I could get the newer model, but the old TD is only $140 now (used to be about $700) and my display unit still works fine. So, will probably install another older TD and keep it properly painted!

Thanks to you both
Ovi