new nasa depth transducer - mounted in hull with sika

[UK-WOOZY]

it isnt working, i encapsulated it in sikaflex could that be why? too much sika? i have it in the original oil tube from the previous transducer

thanks

 

[VicS]

it isnt working, i encapsulated it in sikaflex could that be why? too much sika? i have it in the original oil tube from the previous transducer

thanks

Too much Sikaflex between the transducer and the hull perhaps or air trapped between them, ?????????????

 

[pvb]

I wouldn't use Sikaflex anywhere near Nasa plastic!

 

[dunkelly]

interestingly i am having a similar problem with nasa depth but without sikaflex . had the instrument checked by nasa who said worked perfectly in their test rig . on mine instrument reads 1.1 mtrs and flashes out . occasionally it has read slightly deeper but unreliable to say the least have changed medium in tube to veggy oil as suggested by nasa but nothing changes. Am about to give up and fit a raymarine unit . would be interested if you get yours working

 

[dunkelly]

if you hav'n't already read the previous threads on nasa instruments . a lot of very useful thoughts in the posts

 

[VicS]

interestingly i am having a similar problem with nasa depth but without sikaflex . had the instrument checked by nasa who said worked perfectly in their test rig . on mine instrument reads 1.1 mtrs and flashes out . occasionally it has read slightly deeper but unreliable to say the least have changed medium in tube to veggy oil as suggested by nasa but nothing changes. Am about to give up and fit a raymarine unit . would be interested if you get yours working

B4 you finally give up on it try different locations for the transducer. Stick it down with blob of Blu tack or chewing gum ensuring no trapped air. Its just possible you have it positioned over a bit of a void in the grp

Also check the connection with the instrument and the cable for damage.... but I expect you've already done the simple checks .

 

[dunkelly]

yes have done most things suggested , although the unit has been checked i am wondering if as in a previous post there may still be a fault with the display . hav'n't tried re-positioning though so will do that first . was also going to try the depth transducer in a tube of water as per nasa test

 

[yerffoeg]

I mounted the transducer oil bath on the hull with epoxy. The NASA transducer it too tight a fit to the mounting tube provided, therefore I cut and created a side channel to allow air out, and the oil in under the transducer face. The inability to get oil under the transducer face may be the cause of your problem.

I use any cooking oil I can lay my hands on and replenish once a year.

The NASA depth sounder has always given sterling service over the past 10 years ( wish I could say the same for the speedo/log).

 

[PaulRainbow]

Transducers should not be stuck down with Sikaflex, silicone or anything similar. Slow drying epoxy is the correct stuff. Rather than oil, some of which can go rancid, antifreeze works fine and last forever. It used to be what Airmar recommended, but the changed the recommendation to food grade anti freeze , as the car stuff is toxic to aquatic life. Just dont tip it in the sea :encouragement:

 

[BabaYaga]

Transducers should not be stuck down with Sikaflex, silicone or anything similar.

Depth transducer set in Sikaflex, has worked fine since 1993.
Maybe I have just been lucky.
Not Nasa though, but Autohelm (probably Airmar).

 

[dunkelly]

how much oil do you put in the reservoir . enough just for the face to touch it or up to the top when completely pushed home ?

 

[agurney]

yes have done most things suggested , although the unit has been checked i am wondering if as in a previous post there may still be a fault with the display . hav'n't tried re-positioning though so will do that first . was also going to try the depth transducer in a tube of water as per nasa test

No need for a tube, just put it in a poly bag with some water and try various locations.You'll hear an audible 'tick' if the system's working - no ticking and your problem's elsewhere. Having identified a suitable spot my preference is to fix it with a blob of silicone sealant. The last one is still working after about ten years, but will be easy to remove if I want to upgrade.

 

[dunkelly]

hi tried this and low and behold got a proper reading . the tube was installed sometime before i bought the boat and i always assumed it was working before i got it but maybe not . however not sure what to do now . will talk to nasa tomorrow and get some suggestions .

 

[VicS]

Transducers should not be stuck down with Sikaflex, silicone or anything similar. Slow drying epoxy is the correct stuff. Rather than oil, some of which can go rancid, antifreeze works fine and last forever. It used to be what Airmar recommended, but the changed the recommendation to food grade anti freeze , as the car stuff is toxic to aquatic life. Just dont tip it in the sea :encouragement:

Although ethane diol is very toxic to mammals it is not considered harmful to aquatic life.

 

[PaulRainbow]

Although ethane diol is very toxic to mammals it is not considered harmful to aquatic life.

Are you really so damn sad that you have nothing better to do than pick through posts ?

have you considered getting a real life, rather than your cyber existence ?

 

[UK-WOOZY]

turned out the transducer plug had come out from the display when we put the ply panel back over the back of the instruments.... seems to be working perfect with the sika now. not once has it shown 'out' either

 

[ghostlymoron]

That's very harsh Paul. I don't think Vic posts more than you do and I find many of his replies interesting (as I do yours).

Are you really so damn sad that you have nothing better to do than pick through posts ?

have you considered getting a real life, rather than your cyber existence ?

 

[Spirit (of Glenans)]

interestingly i am having a similar problem with nasa depth but without sikaflex . had the instrument checked by nasa who said worked perfectly in their test rig . on mine instrument reads 1.1 mtrs and flashes out . occasionally it has read slightly deeper but unreliable to say the least have changed medium in tube to veggy oil as suggested by nasa but nothing changes. Am about to give up and fit a raymarine unit . would be interested if you get yours working

Castor oil is the recommended medium; it doesn't go rancid, unlike veg oil.

 

[dunkelly]

just like to add .although my problem not yet completely resolved the guys at nasa marine are very helpful

 

[rgarside]

Castor oil is the recommended medium; it doesn't go rancid, unlike veg oil.

Like other vegetable oils, castor oil can go rancid. Airmar recommend propylene glycol as the coupling liquid [propylene glycol is less toxic than the more common ethylene glycol]. Any liquid should work in the short term, the recommended fluids reduce the risk of freezing, deterioration, etc in the longer term.