I didn't expect that

[Dave 71]

A couple of weeks ago, I was shown how to remove the log transducer, put the bung in, clean it, and swap it back.

Today, after seeing 0.0 knots boat speed whilst bowling along at 5 or 6 knots, I decided to man up and make a hole in the bottom all by myself.

I took the transducer out and put the bung in with a satisfyingly small amount of water going into the bilge. I cleaned the log. Great, 50% successful.

I then spent the best part of 2 hours trying to get the bung out. It's stuck fast. I can get the female screw part/lid loose - at which point water starts coming in, slowly - but the bung won't shift. Two guys from the yard had a go, nope, it's stuck. I'm not 100% sure that the thread isn't somehow still binding when loose, but it loosens until it binds on the top (wider) part of the bung then goes tight and loose, whilst 'clicking' as you rotate it...

All I've been able to do is arrange a lift on Monday, but then what? My current thinking is that I try and push it up from underneath, or use a rubber mallet and a thin wooden bung or dowl and hammer it up, or cut the top off above the screw lid, remove the lid and hammer it down, and if that fails try and drill it out and somehow cut or grind away the bung (whilst saving the through hull.....)

Thoughts? Suggestions?

Have I invented a completely new boat problem?

I would leave it but the transducer is combined log and depth. Here in Essex I really don't want to be without the depth

 

[William_H]

Clearly you will have to destroy the plug to get it out. Unless you can fabricate some sort of socket or spanner to get real turning force on the cap. Yes being out of the water will be a lot safer than risking damage (leak) that can not easily be fixed. Presumably the scew on cap has got sand or cross thread that jambs up the thread.
Now no help to you at all but when I had a paddle wheel log now long ago but did constantly foul up I developed the art of removing the log and slapping one hand over the hole. I could free up the paddle one handed and slap it all back in again with minimum water ingress. ol'will

 

[Skylark]

My current thinking is that I try and push it up from underneath, or use a rubber mallet and a thin wooden bung or dowl and hammer it up

I don’t envy your situation but that’s what I’d try.

One of my last jobs before new season launch is to remove the bung and ensure that all components are throughly cleaned. I do not use lubricant when fitting as, depending upon what’s used, this can cause a jam.

 

[[70521]]

You need to go for a swim with a bit of wood and a hammer.

Making sure you have somebody in the cabin unscrew the bung and remove it as far as you can then place the bit of wood in the recess and tap with hammer. The bung should pop out.

 

[dankilb]

Don’t forget you can potentially save a bit of time/money by having the hard hold the boat in the slings with the waterline just below the offending skin fitting (depending on facilities). Similarly, some might feel comfortable trying more destructive methods while in the lift bay. If it works = great, job done. If it fails = full lift out anyway.

Saves the labour and faff of properly chocking the boat on the hard for one fitting.

 

[Refueler]

Sorry bit confused ....

Bung + Screw cap ??

My method based on being right handed.

Unscrew NEARLY all way the securing ring of transducer. Have tube blanking cap in RIGHT hand ready to screw on ..... unscrew tranducer with left and 'wiggle' it out ... slap on cap and screw.

To put back ... tranducer in right hand ready to push in to tube.

Never used a bung ....

Pal of mine years ago - had an old failed transducer he used to use as temp while cleaning ....

 

[Skylark]

Sorry bit confused ....

Bung + Screw cap ??

My method based on being right handed.

Unscrew NEARLY all way the securing ring of transducer. Have tube blanking cap in RIGHT hand ready to screw on ..... unscrew tranducer with left and 'wiggle' it out ... slap on cap and screw.

To put back ... tranducer in right hand ready to push in to tube.

Never used a bung ....

Pal of mine years ago - had an old failed transducer he used to use as temp while cleaning ....

A bung with screw cap is very common. Mine is Simrad. Exactly the same form as the transducer but has a flush fitting, blank end (no paddle wheel or depth transducer). Always fitted during haul-out and launch to avoid any risk of strops causing damage.

 

[Dave 71]

A bung with screw cap is very common. Mine is Simrad. Exactly the same form as the transducer but has a flush fitting, blank end (no paddle wheel or depth transducer). Always fitted during haul-out and launch to avoid any risk of strops causing damage.

Exactly this. The bung is a dummy version of the transducer. It is stuck fast. I don't know why it isn't simply a screw on cap. That would be so much easier. I wish I could 'just wriggle it out and slap the transducer back in' but all I can do is lift, try and hammer it from underneath and if that works, great, if not, onto the hard whilst I work out something else.

 

[Fr J Hackett]

Don’t forget you can potentially save a bit of time/money by having the hard hold the boat in the slings with the waterline just below the offending skin fitting (depending on facilities). Similarly, some might feel comfortable trying more destructive methods while in the lift bay. If it works = great, job done. If it fails = full lift out anyway.

Saves the labour and faff of properly chocking the boat on the hard for one fitting.

I doubt they will allow anyone to be in the boat to insert the log whilst it is in the slings.

 

[Dave 71]

I doubt they will allow anyone to be in the boat to insert the log whilst it is in the slings.

I wondered that too but they've told me I can......

 

[Fr J Hackett]

I would guess it's jammed somehow with the self closing flaps that most transducer housings have that sometimes work sometimes don't. Or there is some foreign object that has been pulled into the housing and jammed the plug. What you suggest of a lift and knock it upwards is the only practical and safe way because there is a small risk of damaging the tube which would then make it impossible to get a watertight seal with the log. In which case you are going to have to buy a new log and housing.

 

[Fr J Hackett]

I wondered that too but they've told me I can......

You are lucky.

 

[Dave 71]

I would guess it's jammed somehow with the self closing flaps that most transducer housings have that sometimes work sometimes don't. Or there is some foreign object that has been pulled into the housing and jammed the plug. What you suggest of a lift and knock it upwards is the only practical and safe way because there is a small risk of damaging the tube which would then make it impossible to get a watertight seal with the log. In which case you are going to have to buy a new log and housing.

Shouldn't need a new log, that's fine, just a case of getting the bung out without damaging the thru hull. Worst case I guess is a new hull fitting.

 

[Refueler]

OK ....

All the through hulls I've fitted have cap only ..... interesting.

Regarding hammer and knocking it out ...... I would suggest care - especially if plastic through hull tube - to be sure not to crack or break the outer flange from tube.

On board in slings ? Never been refused that in UK or out here in Latvia.

 

[Fr J Hackett]

Shouldn't need a new log, that's fine, just a case of getting the bung out without damaging the thru hull. Worst case I guess is a new hull fitting.

I don't think you will get a new hull fitting without buying a complete log which will almost certainly be an Airmar. I did say there is a small risk of damaging the fitting which would likely arise if it is jammed with a foreign object.

 

[Dave 71]

That would be deeply annoying. I can see the right sort of thing on line, albeit for Raymarine not B&G.
Airmar ST600, ST800 & ST900 Transducer Housings (echomasterdirect.co.uk)

so would be a case of making sure its the right thing.

 

[Dave 71]

Another question, in the event that I need to fit a new thru hull, I assume I would use a sealant on the outside, not just rely on screwing it together?

 

[Fr J Hackett]

I have always used a sealant maybe butyl tape is the current way. The Airmar are pretty common and universal across most of the leading manufacturers so in all probability the BG and Raymarine ones are the same.

 

[Draystone]

I came across someone with this problem a couple of years ago. The root cause was the o-rings which were either incorrectly fitted or the wrong size. When he did get the log out, the only damage was to the o-rings. Here's hoping.

 

[Fr J Hackett]

A quick thought, does it have a ring connected to it like the rings on keyrings to allow multiple keys? If it does you could try with some caution a variation on a slide hammer. Tie a piece of cord say 40 cm long to it and the other end to a hammer preferably one with a bit of weight. Then standing directly over the transducer use the hammer in reverse of its normal operating mode which will tighten the cord and apply a vertical force on the plug. Start softly and increase the force till you feel you shouldn't try any more. The dangers are that the ring will break ( no real problem) the plug will break in the housing potentially big problem.
Good luck.