Anti fouling paint over a depth gauge transducer

[landonshaw]

When you paint with anti fowlant, do you cover the depth gauge transducer or leave it uncovered?

[s/v Jedi]

Originally Posted by landonshaw

When you paint with anti fowlant, do you cover the depth gauge transducer or leave it uncovered?

Nah, I just take the feathers off and grill them crispy

[landonshaw]

I agree, but what for anti foulant?

[fstbttms]

Originally Posted by landonshaw

When you paint with anti fowlant, do you cover the depth gauge transducer or leave it uncovered?

Do not paint the depth sounder transducer.

[Neo]

They sell an antifouling paint designed for the plastic transducers. I think West Marine sells it. Comes in a little 4 ounce container with a brush under the cap.

[Jim Cate]

Originally Posted by fstbttms

Do not paint the depth sounder transducer.

I'm curious... why not? I've painted all of my transducers since I first had one in about 1978... didn't seem to hurt them, and did a fair job of keeping them clean. Heavy growth does reduce effectiveness IME, and usually not being where fstbttms works means that I have to clean them myself. OK in the tropics, not so OK here in Tassie!

Cheers,

Jim

PS The so called transducer antifouling is not very effective IME. I just use whatever paint I'm putting on the bottom.

[s/v Jedi]

The reason for not painting them is that the solvents in the paint may attack the materials that the transducer is made of.

I first paint it with transducer paint, then a second layer of regular anti-fouling paint.

In the tropics you easily get away without paint, as you can take a brush to clean transducers, prop etc. weekly while snorkeling. I also take the transducer out when not sailing, although that takes away the water temperature reading on the network.

[Jim Cate]

Originally Posted by s/v Jedi

The reason for not painting them is that the solvents in the paint may attack the materials that the transducer is made of.

I

Yep, that is what lots of folks keep telling me... but our current pair (Interphase sonar and Standard Horizon depth) have been thus treated for the past 11 years and show no degradation of surfaces or performance.

I guess they could fall apart next week, but I kinda doubt it!

Jim

[s/v Jedi]

Originally Posted by Jim Cate

Yep, that is what lots of folks keep telling me... but our current pair (Interphase sonar and Standard Horizon depth) have been thus treated for the past 11 years and show no degradation of surfaces or performance.

I guess they could fall apart next week, but I kinda doubt it!

Jim

Yes, I imagine that most of not all transducers are resistant now, but I did have an old B&G transducer that developed crazy cracks without anything obvious causing that...

[Pete7]

Absolutely, just slap some paint on. If I didn't then in a month I would have an underwater eco system growing on it. Those trasnducers will work through 1/2" of GRP so a little paint isn't going to make much difference. the tricky one is the speed transducer which is easy to clog up with paint, or if you don't tube worms and barnacles grow freely on them. We use the blanking plug when the boat isn't in use to solve this.

Pete

Originally Posted by Jim Cate

I'm curious... why not? I've painted all of my transducers since I first had one in about 1978... didn't seem to hurt them, and did a fair job of keeping them clean. Heavy growth does reduce effectiveness IME, and usually not being where fstbttms works means that I have to clean them myself. OK in the tropics, not so OK here in Tassie!

Cheers,

Jim

PS The so called transducer antifouling is not very effective IME. I just use whatever paint I'm putting on the bottom.

[noelex 77]

It would be nice to find a definitive answer.

People seem convinced that terrible, or not a problem, with no middle ground. The concern is that some solvents may attack the plastic.

Wandering around boatyards most are painted with conventional antifouling paint without any obvious adverse effects.

[a64pilot]

Stupid question, but why thru hull transducers? Why not use one that shoots through the hull?

[Pete7]

Originally Posted by a64pilot

Stupid question, but why thru hull transducers? Why not use one that shoots through the hull?

Well for depth that is what the boat was built with 25 years ago so I replaced like for like, the best spot has 20mm of solid GRP which might be challenging for a through hull. So the cost effective answer was replace the old Stowe sender with a new Raymarine one.

Same for speed, fitted a new paddle wheel when the old ones became unreliable.

[noelex 77]

Originally Posted by a64pilot

Stupid question, but why thru hull transducers? Why not use one that shoots through the hull?

A transducer firing through the hull is often a good option. It removes the need to drill another hole, but this cannot be used on metal, wood or cored fibreglass.

Even on solid fibreglass it does slightly reduce the sensitivity and quality of the depth reading.

[GordMay]

According to Airmar:

“Use water based anti-fouling paint only. Never use ketone-based paint, since ketones can attack many plastics possibly damaging the transducer. We recommend brands such as MDR, Woolsey, Pettit, and Sea Hawk.”

➥ Airmar FAQ - What anti-fouling paint should I use on my transducer?