Depth Transducer in Oil

[ash2020]

I have a Garmin Fishfinder 240 which has completely stopped working. I located the transducer which is much larger than I expected, around 3" diameter. It is sitting in a tube of oil, bonded to the hull, as expected. However, the oil is more like treacle, very thick. I've always used something like the consistency of olive oil for other similar transducers. Does anyone have any experience of this? Thanks.

 

[Minerva]

I always just topped up the oil with whatever cooking oil we have on board whenever the sounder starts playing up.

Perhaps worth changing out the oil and see if it makes a difference.

 

[ash2020]

I always just topped up the oil with whatever cooking oil we have on board whenever the sounder starts playing up.

Perhaps worth changing out the oil and see if it makes a difference.

Thanks, yes I will do that but I just wondered what this thick gloopy stuff was.

 

[penfold]

The old man's fishfinder is attached to the inside of the hull with about half a tube of domestic bath/shower silicone; as long as the treacle doesn't have bubbles in it it should work.

 

[ash2020]

The old man's fishfinder is attached to the inside of the hull with about half a tube of domestic bath/shower silicone; as long as the treacle doesn't have bubbles in it it should work.

Oh really. In that case the unit is probably fu**ed.

 

[justanothersailboat]

Check the cabling and plug before junking it. I don't know this one in particular but depth transducers in general seem pretty sensitive to iffy connections. Never pass up the chance of an easy fix even if the chance is small

 

[ash2020]

Check the cabling and plug before junking it. I don't know this one in particular but depth transducers in general seem pretty sensitive to iffy connections. Never pass up the chance of an easy fix even if the chance is small

Thanks. Will certainly do that.

 

[Refueler]

Many are a co-ax plug that easily corrodes / gets iffy ...

The 'goop' in your tube may be congealed Castor Oil ..... Castor was the recc'd oil for tubes for decades ..... actually some brands still mention it.

 

[ash2020]

Many are a co-ax plug that easily corrodes / gets iffy ...

The 'goop' in your tube may be congealed Castor Oil ..... Castor was the recc'd oil for tubes for decades ..... actually some brands still mention it.

That's interesting, I hadn't thought of that. I will try a much lighter oil.

 

[doug748]

I have used water with a bit of anti freeze for several years. Clean to use and no problems so far.

 

[europe172]

Thanks, yes I will do that but I just wondered what this thick gloopy stuff was.

I believe mine was covered in the gell they use for ultrasound at the clinic

 

[Slowtack]

Try cleaning out the oil, degreasing the probe and container and embed the probe in silicone sealant...

 

[VicS]

I have a Garmin Fishfinder 240 which has completely stopped working. I located the transducer which is much larger than I expected, around 3" diameter. It is sitting in a tube of oil, bonded to the hull, as expected. However, the oil is more like treacle, very thick. I've always used something like the consistency of olive oil for other similar transducers. Does anyone have any experience of this? Thanks.

Traditionally castor oil was used.
It does not seem to deteriorate or become rancid like vegetable cooking oils.

 

[QBhoy]

Fitted countless transducers (mostly designed to be external transom mount types), inside the hull in bilge, just using a carefully applied blob of silicone. Even a blob of vasaline a few times too. The main thing is to make sure it’s going in a position that it’s going to work (by experimenting in a temporary blob of vasaline in various positions that aren’t affected by running gear or any aerated water flowing under the hull…and throughout the speed range) and also most importantly, that the medium you choose to mount and sit it in (silicone perhaps), is applied and has the transducer sat into, without introducing any air pockets or bubbles into it. These need a pure medium to sound through and absolutely without air. Best of luck.

 

[Refueler]

Fitted countless transducers (mostly designed to be external transom mount types), inside the hull in bilge, just using a carefully applied blob of silicone. Even a blob of vasaline a few times too. The main thing is to make sure it’s going in a position that it’s going to work (by experimenting in a temporary blob of vasaline in various positions that aren’t affected by running gear or any aerated water flowing under the hull…and throughout the speed range) and also most importantly, that the medium you choose to mount and sit it in (silicone perhaps), is applied and has the transducer sat into, without introducing any air pockets or bubbles into it. These need a pure medium to sound through and absolutely without air. Best of luck.

There are many ways to test where to site ....

Place transducer in a thin plastic bag of water ..... place - test .. move on ..

Large blob of Bluetac on transducer .... place - test ... move on ....

Silicon is fine - but can lead to transducer coming loose later .... the tube system avoids that IMHO.

But agreed - the important point is to have no air bubbles in the joint medium.

 

[Snowgoose-1]

I have always just water instead of oil . Top up each season . Transducer is in middle .

 

[KAM]

KY jelly is a lot cleaner.

 

[MikeCC]

Airmar/Garmin recommendation is to use neat antifreeze.

 

[Refueler]

Airmar/Garmin recommendation is to use neat antifreeze.

Neat A/F ... actually its a diluted blend of water and a product that contains large proportion of Glycol.

MEG (Mono Ethylene Glycol) as used is actually a poison .... so please wash affected areas if you get splashed.... eyes / mucus areas - seek medical help.

You may think I'm being over-reactive - but Glycol poisoning is not good - affects liver when ingested and Glycol can be absorbed through skin, but thats a slow process - washing will usually take care of that.

 

[Neil]

I've used a mineral baby oil ( think this was Airmar's original suggestion) in the past - no chance of oxidation resulting in gloopiness