Transducer flap fell out. Common problem?

[Reefmagnet]

So I've been swapping the log out for the dummy plug and vice versa on the Airmar DST800 triducer as supplied by just about every instrument manufacturer (we have Simrad IS20) for the last 15 months or so since I installed it. Last trip out, the wife volunteered to prep the boat for sailing while I attended to some shore side matters. Lo and behold, at the end of our weekend of adventure, I pull the triducer and notice something's not quite right. Oh yes, that's what it was - the three foot high spout of water coming out of the through hull. Although it was kind of like that movie cliche where the guy opens the door, sees the monster, closes the door and then after a few seconds realises what he's just seen so opens the door again and then the mayhem ensues. I pull the blank - again - and... whoooosh... all this water sprays up in the air. Replace the blank, take a big breath, pull the blank and stick my finger in the hole feeling for the flap. Yep, it's gone.

Now my first thoughts were that the wife jammed the triducer in or mistreated it in someway that caused the flap to depart. After a few lukewarm words, we figured that she hadn't forced it or felt it jam when she inserted it. The only thing that I could see is that she had put the arrow about 30 degrees off centre from forwards and I had loosened this off and rotated it so the arrow faced directly forwards (as it's supposed to) when I'd done the double check on my return.

It seems that these transducers may be a bit delicate when it comes to the flap. Anyone else had issues with them? Not happy about the rush of water that now enters with the changeover but there's nothing to really be damaged by it, but it is annoying.

[GordMay]

“... THE VALVE IS NOT A WATERTIGHT SEAL!
The multisensor incorporates a self-closing valve which minimizes the flow of water into the boat when the insert is removed. The curved flap valve is activated by both a spring and water pressure. Water pushes the flap valve upward to block the opening, so there is no gush of water into the boat. Always install the insert or the blanking plug secured with the cap nut and safety wire for a watertight seal...
... NOTE: In the very unlikely event that the valve breaks, replace the
housing the next time the boat is hauled...”
More ➥ http://www.airmartechnology.com/uplo.../17-435-01.pdf

[Reefmagnet]

May not have been a watertight seal Gord, but without it, it lets a heck of a lot more water in the boat. And unless I have a dud, I'm not buying the "unlikely event" bit either! Our previous boat had 42mm flapless through hulls which weren't as deep and the log swap for the blank was interesting with that one, too. I'm just a bit suspect that flap may be a bit fragile.

[sharpey]

Yep. Mine broke soon after installing also. Known problem apparently, but clearly not enough of an issue for us to get any compensation or recognition. Clearly a weak design.

[hellosailor]

Look at it this way: Your boat has come to love and trust you SO much, it ditched the training wheels.


Without that flap, it will now be lighter and faster, with a shoaler draft, too.

[a64pilot]

I leave my paddle wheel sensor in all the time, pulled it once to clean it and re-install it.
I've never pulled my depth transducer. Both are painted with bottom paint too, and work fine.

[ramblinrod]

Originally Posted by Reefmagnet

So I've been swapping the log out for the dummy plug and vice versa on the Airmar DST800 triducer as supplied by just about every instrument manufacturer (we have Simrad IS20) for the last 15 months or so since I installed it. Last trip out, the wife volunteered to prep the boat for sailing while I attended to some shore side matters. Lo and behold, at the end of our weekend of adventure, I pull the triducer and notice something's not quite right. Oh yes, that's what it was - the three foot high spout of water coming out of the through hull. Although it was kind of like that movie cliche where the guy opens the door, sees the monster, closes the door and then after a few seconds realises what he's just seen so opens the door again and then the mayhem ensues. I pull the blank - again - and... whoooosh... all this water sprays up in the air. Replace the blank, take a big breath, pull the blank and stick my finger in the hole feeling for the flap. Yep, it's gone.

Now my first thoughts were that the wife jammed the triducer in or mistreated it in someway that caused the flap to depart. After a few lukewarm words, we figured that she hadn't forced it or felt it jam when she inserted it. The only thing that I could see is that she had put the arrow about 30 degrees off centre from forwards and I had loosened this off and rotated it so the arrow faced directly forwards (as it's supposed to) when I'd done the double check on my return.

It seems that these transducers may be a bit delicate when it comes to the flap. Anyone else had issues with them? Not happy about the rush of water that now enters with the changeover but there's nothing to really be damaged by it, but it is annoying.

The flapper valve is not as robust as we all may wish.


Question: Why are you removing it so often? As long s you use the boat once every couple weeks, it shouldn't foul up.


I only recommend removing the xdcr or plug, prior to haul out or launch, only if the slings happen to ride in that area, and would damage the wheel.


Only make the swap while the boat is in the slings, so if there is a problem getting the or the dummy plug in, it can be immediately lifted before the boat sinks.


If the wheel fouls while in the water, dive the boat when you get a chance and clean it off, or wait till next haul out. (Only a seriously campaigned race boat should consider risking losing the boat over a malfunctioning knotmeter.)


Rod Brandon

[hellosailor]

Moored in a bay off LI Sound in brackish water, we learned to pull it after any day of racing, because in between Sunday and Saturday morning, critters would grow in there, even with bottom paint. And if you're racing, and the difference between 5.8 knots and 5.5 knots makes a difference to you, like, whether you are hitting your polars or not, then that paddlewheel has to come out every time.


If there's nothing growing on and under your boat, you are probably anchored in anoxic toxic waters, like NY Harbor was in the 1960's before the terados and other critters came back thick enough to start eating the pilings holding up the waterfront highways and docks. Good for sailors, not so much for fishing or swimming.

[Reefmagnet]

Not sure the "leave it in" approach works too well when moored beside a reef, inside the Great Barrier Reef, inside the tropics. Plus, the amount of times the unit is removed and replaced really shouldn't be a factor as long as it isn't abused. It's less than twice per month x2 on average.

For interests sake, here's a what a piece of nylon rope looks like after a 6 month soak (that's an eye splice at the top)...

[Davidasailor]

We have the same model transducer. The flaps fell out while I was with the dealer having him demo how to replace the plug. It was only about 6 months old at the time and the first time it was swapped. Now waiting for the dealer to come back and replace the housing before spring launching.


Sent from my iPhone using Cruisers Sailing Forum

[Drakenkade]

I just bought the dst800 and I haven't even launched and the flapper fell out ..
Seriously weak design...

[Oceanride007]

Happened to me also, heres what I did at the next hard stand, I'd previously ordered a replacement. But on inspection found it easier to replace the little spindle and retainer. Also best to have a catcher arrangement, the items are slippery.