Changing Transducers

[lehighsail]

I was reading the thread about painting the thru hull transducers and stopped at KappyKaplan's post. He doesn't paint his because he pulls them if not using the boat.
I watched a few videos and saw how they can be pulled without the boat sinking within 15 seconds. I looked at mine in the forward berth and there is a blank for each one.
My questions are;
1. Is there a special technique for changing them out?
2. How much water does come in when I change each one out if done quickly?
3. If you do this every week, how do you deal with the water that does come in?
ShopVac?
4. Is the amount of water that comes in be dependent on the depth of water the boat is
sitting in? (I know all these questions may be kind of a self explanatory, so this
one is to start the 'duh' comments, LOL).

Thanks.

 

[Davidasailor26]

I've swapped ours out a couple of times. Our thru hull has a flap that deploys when the plug is out which reduces the water flow. When the flap is working there is an initial burst of water that comes up a couple inches, then it subsides to a slower flow. If all goes smoothly the exchange can be done without leaking more water than a towel can absorb. We did have the flap fail once. That was more exciting, but still not more than a few gallons of water - easily handled by the bilge pump, and a sponge to dry up.

 

[Ron20324]

The depth transducer is probably a bigger diameter than the speed, so more water might come in. I leave the depth TH in all year. The speed one will clog with algae and mud shrimp in a week, so I take it out between weekly cruises in the warmer weather. Lube the rubber rings- I use KY. Have the dummy plug in one hand. You should have a locking ring screwed on the TH. The transducer will probably not just pop out, especially if it has been in for a long time. With the ring loosened all the way, rock the trans back and forth to make sure it is free to move a bit, though there is a keyway to align the transducers into the THs. . Then continue B&F and start to pull it up. Be ready with the dummy in the other hand, just above the TH. If you do this quickly and correctly, you might get a pint of water. Make sure you are holding the proper dummy for the transducer you are pulling. I get the wrong one and get more water ingress. I don't recall if the depth has an alignment tab, but the speed does, and probably an arrow that should point forward.

It's not a problem, and something a skipper should be able to do. When my club chartered in the BVI, the speed did not work. I knew how to pull the impeller and clean it, so was the hero of the day.

 

[Calif. Ted]

1. Make sure speed transducer is pointed forward, there's a diamond shaped arrow on it.
2. Less than a pint ?
3. It'll drain to the bilge
4. No, Theoretically dependent on how deep the thru hull is but you wouldn't be able to detect a difference, 1/2 psi per foot of depth.
Depth transducer not removable in some, and why would you ?
I used to paint paddlewheel with transducer paint but it didn't seem to slow growth enough to warrant the effort.

 

[LeslieTroyer]

1. Is there a special technique for changing them out?
Unscrew the paddle wheel/transducer then wiggle and pull it out with right hand. And put plug in with leaf
2. How much water does come in when I change each one out if done quickly?
A pint or two
3. If you do this every week, how do you deal with the water that does come in?
Sponge
4. Is the amount of water that comes in be dependent on the depth of water the boat is
sitting in?
No it depends on if there is a flapper and depth below the waterline. Mine doesn't have a flapper

The only depth transducer I know of is the one that has the paddle wheel/temp/depth all in one unit or just a paddle wheel. The retainer ring is on the top of the transducer do not undo the retainer down by the hull

Les

 

[chuckwayne]

I just leave the depth trans in, but do pull the speed - and what's above is correct. However, if you have raymarine (st-60) gauges, the depth doesn't have the rubber flap. Speed does, but it gets stiff if it's been folded in for a while and is slow to respond.

 

[Scott B]

I pull mine fall and replace in spring in the water. Depth is larger so will let in more water. There is a sudden surge of water when you pull but just pull and stick in the plug. I mop up with a couple of microfibre rags and only takes couple of minutes. Very little water actually gets in, it's just the surge that throws you off. Not nearly enough to even worry about.

 

[seadaddler]

I just was dealing with my transducer and as said don't remove depth because they don't usually have a flapper
and not all transducers speed or depth have a flapper ask me how I know and if have a flapper very little water and if no flapper too much water comes in and I stop taking speed mine out.
The other thing is if has not been removed long time they do get stuck and may get damaged or broken if too much force used ask how I know and just had mine both on hard and changed the housing and one day later the new housing with flapper the flapper broke off.
Don't mess with removing transducer when in water if you have never removed them before and wait until out of the water,if you have a diver come to the boat and he can use the old type red plunger to the opening while you try removing transducer and hope nothing goes wrong.
Sorry but messing with things that let water in to sink your boat should not be played with unless on land so it won't stop floating and have seen too many sunk boats.
Nick

 

[Ron20324]

You should remove the speed impeller, lest the haulout lift run their straps over it. It happens. Also, I'd say most skippers pull their transducers, even if to give it a coat of transducer paint. It's not a big deal. Keep a towel handy to make a dam to prevent water from running through the bilge.

 

[David in Sandusky]

We haven't pulled our depth transducer for 18 years, and continue to have accurate depth readings. I'm trying to understand the value of pulling the transducer. (I did it once while the boat was on the hard, out of curiosity, but see no reason to do it again.

 

[DougM]

I pull the speed trnsducer frequently because the paddlewheel seems to be a good home for zebra mussel babies. I just put a towel in the area around the through hull. When I make the swap between the paddlewheel and dummy plug I barely get enough water in to have to wring out the towel. Its a little scary the first time, but after that, no big deal.

I am of the mind that one never paints the depth transducer. In fact the documentation states that. It might just be a CYA thing, but who knows,

 

[seadaddler]

The depth transducer doesn't need to be pulled and have never ever removed it but yes the speed transducer
should be pulled as often as needed and usually do pull it if not using it for a week or 2 but I do like to pull my tri temp/speed/depth often just to keep the paddle wheel clean,yes I also have a separate depth transducer that was suppose to also do sonar but has not been working and glad I have my tri transducer for backup depth.
If going to remove the speed transducer yes have the plug and towel ready and just unscrew and easily pull up and out and quick put in plug and also make sure the plug is clean and I put vaselene on it and add some vaselene on the speed transducer and arrow should point forward.
Nick

 

[SG]

Lehighsail: What type of instruments do you have? You then can determine if there's a "flapper". Aside from that...

The only thing I'd add is that the reasons to pull your depth sensor is i) to keep it from locking-up (so if you need to service or check-it, you can without hauling the boat; and, ii) it avoids the problems which SOMETIMES occur if you paint over the depth sensor.

I've found that putting antifouling gear on boat speed transducer is a recipe for problems. We pull the transducer whenever we're not on the boat except in northern waters.

 

[LeslieTroyer]

The only reason I pull my depth transducer because it also houses the speed paddle wheel that gets gummed up occasionally.

 

[lehighsail]

I have the Raymarine ST60 Depth and Speed. I don't recall seeing any flappers near the interior of the transducers.

Also, what would be the best choice for lubricating the transducers before putting them back into the hull? KY Jelly, Vaseline, Superlube or some type of non water soluble grease?

What would be an appropriate way to treat the paddle to prevent build-up? Thanks.

 

[Ron20324]

I use the KY. It gives me an excuse for having it on the boat.

 

[Scott B]

I have the Raymarine ST60 Depth and Speed. I don't recall seeing any flappers near the interior of the transducers.

I have the same, ST60 and Airmar transducers.
Speed transducer has a flap part way down the hole, but can only see when the boat is out of the water. Depth does not have the flap.

 

[SG]

I would use a non-petroleum based teflon lubricant on your transducers (that would include SuperLube). I really don't like petroleum based lubricants on neopreme or rubber or the like.

I'd save the KY Jelly for more usually advertised uses. ;^)))

https://www.ispot.tv/ad/Al_Q/k-y-intense-symphony​

[Unless it's changed, I've always associated KY jelly with a prostate examine, so I'd hardly find it stimulating :^))).
Seriously, if it's like Vasoline (which is also "petroleum jelly"), I wouldn't be using it on my BOAT's o-rings. However during the aforementioned doctors' examines, I was compelled to utter "Ohhhhh!" :^))).]

 

[lehighsail]

I have the KY left over from when I pulled the new sanitation hose from the head to the holding tank.
I will save it. BTW SG, does your doctor ever send you flowers the next day? Thanks guys.

 

[LeslieTroyer]

If I felt o ring grease was necessary I'd use a silicon based grease I use on the housings of underwater camera. I think for the most part the water is there in sufficient quantity that additional lube is unnecessary.