Plastic Tranducers On A wooden Hull

donncha

donncha

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I am new to this forum but am a regular reader of Classic Boat and I would be very grateful for any help on this issue.

I bought a Raymarine ST40 Bidata(depth and Log) a while back and never installed it. It comes with plastic transducers as standard. I own a Falmouth Pilot and it had a wooden hull. Is it possible to use plastic transducers on a wooden hull? I know it is possible to buy bronze transducers, but they cost an arm and a leg and I would much prefer to make do with what I have if at all possible.

Thanks, Donncha
 
Not usually a problem, just fit 'em as you would a bronze one, I would make a guard block for the depth sounder transducer though.

PS. forgot me manners, welcome to the forum! /forums/images/graemlins/smile.gif
 
Thanks there are already ancient transducers in the boat so there is a guard block for the depth sounder one already. Good to know that I can use plastic ones.

By the way, the manual said that you had to use bronze transducers. But it shouldn't be a problem.
 
The last wooden boat I owned didn't have any electronics so I can't advise from my experience but I have seen it said on here, by them as knows, that there is a risk of the transducer being cracked if it is a tight fit in a wooden hull and the wood swells [which wood does when it's wet]. Therefore make it an easy fit in the hole and fill the gap with a flexible sealant.

I'm sure there has been a thread about this during the last year.
 
[ QUOTE ]
The last wooden boat I owned didn't have any electronics so I can't advise from my experience but I have seen it said on here, by them as knows, that there is a risk of the transducer being cracked if it is a tight fit in a wooden hull and the wood swells [which wood does when it's wet]. Therefore make it an easy fit in the hole and fill the gap with a flexible sealant.

I'm sure there has been a thread about this during the last year.

[/ QUOTE ]

If you install the tranny in an oak or Iroko block, and seal that block with epoxy before painting over it, it will be alright, but the point Ken made is a valid one, and maybe allow a bit of movement, via the application of a good sealing compound, one of the Sikaflex jobbies should do the trick, maybe 292? Though I suspect that you would bed it all down in that way anyway?
 
I have exactly the same kit installed in my plymouth hooker. Made the hole a bit loose, sealed it with sikaflex, and it's been fine. You do have to be aware though that the plastic transducers aren't as long as the bronze ones and you may have to take bit away from the inside of the plank to get the ring to screw on. Good luck!
 
You have a Plymouth Slapper!!.................erm sorry, Hooker /forums/images/graemlins/blush.gif /forums/images/graemlins/grin.gif

Lucky you! /forums/images/graemlins/cool.gif
 
Thanks very much for the replies. The planking is pitch pine and I think I will simply make a slightly larger hole and seal it in with sikaflex. As there are already holes there from the old ones it would probably be easier to do this then installing them in a hardwood block first.

Thanks again for the help.
 
ERm, you don't install it in a hardwood block first, you make the hard wood block to fit neatly around the transducer, and it should be boat shaped, ie. pointed at both ends, it's to protect the tranny in the event of you grounding or striking an underwater object, that would otherwise wipe away your tranny allowing water to enter the hull, the block should be fasten to the hull, with bolts through a backing plate.
 
These is already a block fitted for that purpose as there was transducers already in the boat.

Sorry but I thought that you meant by fitting the transducer in the block and then fitting the block in hole in the hull you would by-pass the problem of the flexing and contraction on the timber harming the transducer.
 
I have plastic transducers fitted in mahogany planking. When the boat is afloat it is more or less impossible to withdraw the paddlewheel for cleaning, I think this is because of the wood swelling and tightening the fitting, though not enough to fracture it. I plan to change to a bronze transducer when resources allow.
 
You all make valid points! You can fit a plastic transducer through wooden planking. It does need a fairing chock. This chock allows:
the transducer to be mounted vertical,
fits the curve of the hull,
protects the transducer,
reduces drag.

The important point is that if you do the nut up to tight, when the external fairing block, internal angled backing pad, both probably made from kiln dried timber, expand on immersion, you MAY stretch the threaded neck of the transducer enough to break it.

The solution is to use plenty of soft bedding, such as Arbomast Butyl Rubber, which stays soft, and to tighten the nut up gently, then undo half a turn. Give it to the end of the season untill you tighten it up just finger tight.
I have seen many transducer nuts which are as much as 2mm up of the internal pad after a winter ashore. If they were tightened up breakage would probably occur in a few days after launch.
I would only invest in a bronze transducer if it was passing through the stem.
 
[ QUOTE ]
You have a Plymouth Slapper!!.................erm sorry, Hooker /forums/images/graemlins/blush.gif /forums/images/graemlins/grin.gif


Very funny! most people add a joke about her owner! and the fact she's right by Plymouth Hoe.
 
[ QUOTE ]
[ QUOTE ]
You have a Plymouth Slapper!!.................erm sorry, Hooker /forums/images/graemlins/blush.gif /forums/images/graemlins/grin.gif


Very funny! most people add a joke about her owner! and the fact she's right by Plymouth Hoe.

[/ QUOTE ]

Apologies Ma-am, no offence intended, twas just a bit of frippery /forums/images/graemlins/smile.gif
 
Ta muchly, we are talking about that lovely old hooker that was at Del Quay. Yes?
 
Indeed - last summer. now in sutton harbour, plymouth. Sailed her down from solent in july. Almost finished - if that's not an impossibility with a wooden boat. When did you see her?
 
Summer 2006, I was in the yard, looking at another boat that was for sale. I was very took with your boat. How does she sail?
 
Well. She does need a jib up to stop her having weather helm, and she's well canvassed! Comfortable in a sea. Got caught out in a force 7 off plymouth in a beam sea. She handled herself with aplomb! Your location says the west country.... you're welcome to come sailing in the spring?
 
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