New Transducer Delema

[FourPoints]

I want to add a wind instrument, and replace my old SR Mariner knot indicator and log with a matching instrument.

The thruhull size for my current transducers is 2 1/8", the thruhull for the new transducer I am looking at is 42mm (1.65").

My current thruhulls need to be rebed or replaced as they have worked slightly loose over the years and started to (slightly) leak this year.

My delima is this, Do I:

A) Rebed the current thruhulls and just leave the dummy plugs installed (est 2 hours of work), and install the new transducers somewhere else

B) Glass over the old holes, sand and fair everything smooth (est 2 days of work), and install the new transducers in the same place as the old ones?

with A I have 2 holes in the hull that are no longer needed, but just as watertight and safe as they ever were, but have the new transducers in a less ideal position, for reasonably little effort.

with B I have no unnecessary holes in the boat, and the transducers in the ideal spot, but with a lot of extra effort and cost.

Thoughts?

 

[Chris Patterson]

B...hands down. You know why.

 

[Calif. Ted]

That's how you tell right from wrong isn't it ? Which requires the most effort? But I think you may be underestimating the effort required to mount them elsewhere. I'd look at using the existing holes as easier.
A real clever guy might be able to figure a way to epoxy in a sleeve or reducer of some type for a quicker method.

 

[Rick D]

I did B. (rather I had it done)

 

[Chris Patterson]

Yeah, there is no way that I would just drill elsewhere. As you said, they're already in the optimum place. Man, that hole can be fixed blindfolded. If it's a tapered thruhull, the work is already done. If it's straight, just grind a bevel from the outside, (or the inside if you like, I just like the idea of a plug patch wedging itself upwards with the "pressure"). A quart of West epoxy and 205 hardener, pre cut round pieces of woven roving, and mat to alternate the layers, and from the inside start laying the glue and glass to it. It can be easily done in two applications, as I thing that one throw at it may be too thick, given your exothermic reactions. You can actually use duct tape for your outside mold, because West will not stick to it worth a d***. I've done this too many times, seriously. It's the easiest patch you'll ever put in! Redrill, Remount. Sail.

 

[Ted]

"B" you'll never regret doing a project the correct way.

 

[FourPoints]

B...hands down. You know why.

sigh, you are right, I do... I guess I was hoping to hear a lot of "don't worry about it" posts to get away with saving the extra work / expense in the spring, but in the end I would only be delaying the inevitable...

guess I will just suck it up and patch it properly!

 

[Don12364]

If your present transducers can be taken out of their thru hull fittings, would it be possible to make up a sleeve to take up the difference in diameter? Its about 1/4" all round.
Alternatively to cut off the existing ones level with the top of the nut on the inside and fit the new thru hulls into the existing fitting.
Then again, the makers of the new smaller fittings will have come against this many times before and might have either an adaptor or a larger thru hull to fit in your existing holes.
Ask!

 

[FourPoints]

Then again, the makers of the new smaller fittings will have come against this many times before and might have either an adaptor or a larger thru hull to fit in your existing holes.
Ask!

I did ask, and so has the sole importer of them to the US. The response was (and while I am paraphrasing, I'm not making this up) "They are a european (Brittish) company and the people over there are more handy than us Americans, and are they fine dealing with the different sizes and coming up with their own solutions, so why should they change their transducer size to appease us lazy Americans"

This is what I'm looking at for speed and backup depth sounder http://www.nasamarine.com/proddetail.php?prod=Clipper_Duet

It's NMEA 0183 so I can hook it into the chart plotter if i want.

 

[redhead78]

four points, I have found wf myself, and I suspect most people are the same, when I am faced with these kinds of more or less quality issues, be it a boat or house project, I first ask myself , then fully knowing what I should do I turn to others to try again to hear it will be ok, follow your gut, it was probably first anyhow. An old timer carpenter told me, usually when you do it the faster easy way, you end up doing it again, so its actually easier and faster, to do it right the first time....Red

 

[ifmdalvey]

What about checking all the other manufacturers options to see if any produce a transducer that will fit directly into the present fitting?

 

[FourPoints]

What about checking all the other manufacturers options to see if any produce a transducer that will fit directly into the present fitting?

SR Mariner used a 2 1/8" hole, the "standard" is 2", NASA Marine uses a smaller than standard, 1.6" hole, so regardless of what unit I pick, the hole will be too large...

Plus NASA Marine units are 50-75% cheaper than garmin, raymarine, or similar. They are known as a no-frills simple WYSIWYG, yet very reliable unit.

 

[Don12364]

Another Thought

AFAIK no instrument manufacturer makes their own transducers. Bye and large they all buy them in from Airmar. This leads to considerable commonality between all the instruments.
Also it is very rare for a transducer to go bad.
So - have you thought of trying the new instruments with the existing depth and log transducers?

BTW:- On Saturday, and on your behalf, I e-mailed Alan Mullery, MD/owner of NASA Instruments and asked if he made, or knew of, a spacer to bulk up his 42mm transducers to the size of the Raymarine ones.
With luck I will receive a reply early next week.

Regds Donalex.

 

[FourPoints]

AFAIK no instrument manufacturer makes their own transducers. Bye and large they all buy them in from Airmar. This leads to considerable commonality between all the instruments.
Also it is very rare for a transducer to go bad.
So - have you thought of trying the new instruments with the existing depth and log transducers?

BTW:- On Saturday, and on your behalf, I e-mailed Alan Mullery, MD/owner of NASA Instruments and asked if he made, or knew of, a spacer to bulk up his 42mm transducers to the size of the Raymarine ones.
With luck I will receive a reply early next week.

Regds Donalex.

You are correct that arimar makes the transducers for Garmin and raymarine among others, I am pretty sure that SR Mariner (my old instruments) and NASA Marin actually make their own, hence the non standard size of each.

As for emailing the president, thank you. I spoke with the guy that handles all the US imports and he said he has discussed this many times with them, and they were not interested in conforming to the 2" standard (see previous post for explanation). After that conversation I didn't feel like it was worth the effort to contact NASA Marine directly.

I would love to purchase a standard arimar transducer and attach it to these displays, but I have no idea if that would work.

 

[Bill Roosa]

C: pull the transducers, tape a piece of heavy paper over the outside to make a dam, fill the holes with epoxy filler from the inside, drill out the new holes to the correct size.
the size of the holes does not present a structural problem so glassing it all over and starting from scratch is not required. Be sure to check the core for water intrusion. it is probably solid glass so there should not be an issue but best to give it a look since you are there.

 

[gettinthere]

Find out the frequency in hz of the existing transducer. If it matches any of the inputs of the new displays you are considering, you're golden.

As an example, my old Standard Horizon was the same freq as new Raymarine ST 60. Took a bit of rewiring, no big deal, and all works perfectly.

Ask Airmar, they may know which stuff matches which. Or ask Mr Helpful at the old manufacturer

 

[Don12364]

Correspondence with NASA HQ

For what it's worth NASA say that Raymarine are the ones with the non standard size transducers.
See below for my e-mail exchange with NASA in the UK.
Rgds,

On 08/12/2012 10:04, Don Alexander wrote:

Hi all at Stevenage,
Is there a fitting that will allow the installation of your 42mm diameter log and sounder transducers into the 2" diameter holes left by Raymarine's removable transducers?
Or perhaps a sleeve that will take up the approx 6mm all round difference?
I don't fancy having to re-glass the original holes and then drilling them out to 42mm again.

Kind regards,

Don Alexander
Hi Don,

Alas there are no sleeves or adaptors. If only there had been a size standard for transducers, we adopted a standard plumbing size (as did B&G and Plastimo) but everyone else's are different. Its probably best to leave the original transducers in/or glass over the old holes entirely and make new holes for the the new log transducer.

Regards,


--
NASA MARINE
Boulton Road
Stevenage
Herts
SG1 4QG
www.nasamarine.com

 

[FourPoints]

For what it's worth NASA say that Raymarine are the ones with the non standard size transducers.
See below for my e-mail exchange with NASA in the UK.
Rgds,

About what I was expecting, although the comment about B&G being the same size is interesting.

Thanks for checking in with him, even though the answer won't help make this project any easier...

 

[LloydB]

Why can't you C) Rebed the current thruhulls and just drill out the dummy plugs for the new transducers (est 2.3 hours of work)?

 

[FourPoints]

Why can't you C) Rebed the current thruhulls and just drill out the dummy plugs for the new transducers (est 2.3 hours of work)?

hmm, for the new sounder that actually may be a perfect solution! They suggest a through the hull install with the sounder bed in epoxy. I could just drop the new sounder into the dummy plug and fill with epoxy.

As for the speed transducer, I'll have to think about if I really want to trust the dummy plug integrety after it's been drilled out.