Transducer attachment

[erbster]

Hi folks,

I want to fit an oil tube for my NASA depth transducer, currently attached with silicone.
I can get a kit from NASA, but I have a piece of domestic waste pipe which is a good fit for the transducer and would seem to be an ideal alternative. Will an inexpensive fibreglass kit like this: http://www.ebay.co.uk/itm/Fibreglas..._Body_Shop_Supplies_Paint&hash=item20d60c7da1 stick to the plastic waste pipe? Or should I not such a cheapskate and buy the NASA kit? (The main advantage would seem to be the included lid, but this would mean disentangling the cable, to fit it; the NASA man suggested cutting the lid in half to fit around the cable in situ)

What does the committee think?

 

[superheat6k]

Use the cheap kit, but coat the resin well up the outside of the tube and above the intended oil level, and use several layers, i would also extend the glass matt right up as well. This way the tube is just providing an inner guide, so adhesion is less critical. Once mounted pour in a small qty of mixed resin to provide a level base for the transducer to sit against.

Simple engine oil or vegetable oil should suffice. Avoid anything aggressive like ATF.

 

[ghostlymoron]

My nasa depth trunsducer is just epoxied to the hull but i used plastic pipe and oil on a previous boat. Bought a pipe cap on previous installation, drilled it and fitted extra nut so it dangled in the tube. If its not a new installation you'd need to re-thread the cable.

 

[erbster]

My nasa depth trunsducer is just epoxied to the hull but i used plastic pipe and oil on a previous boat. Bought a pipe cap on previous installation, drilled it and fitted extra nut so it dangled in the tube. If its not a new installation you'd need to re-thread the cable.

I'm not brave enough to just epoxy the transducer to the hull.
And I'm too lazy to clip off all those cable ties to recover the plug end of the cable, so I could thread it through a cap.

Was therefore thinking of plugging the pipe without using a kosher fitting.

Superheat6k: does the transducer *need* a flat base? I've cut the pipe at an angle so that it is vertical when mounted. As long as there's oil filling any void, I thought that was ok?

Transducer currently stuck on with bathroom mastic, but does not work reliably- keeps saying "out" at embarrassing moments. NASA told me this was because the mastic is too soft and is not transparent to ultrasound, therefore a lot of signal is lost, which makes the transducer less sensitive. Sounds plausible.

 

[ghostlymoron]

the transducer does not need a flat base. it can dangle in the tube so doesn't touch the base. if you use a tube of similar ID to the transducer,it won't rattle around much.
if you don't want to re-thread the cable, you can cut a cable sized slot in the pipe cap.

Edit. Is your cutter based at Porth Madog. I think I saw one there last year being rigged by the yacht club.

 

[erbster]

Edit. Is your cutter based at Porth Madog. I think I saw one there last year being rigged by the yacht club.

That was our boat you saw, but it's not based at Porth Madog. We spent Mid Feb - Mid Apr there last year. Nice club.