NASA skin fitting

ghostlymoron

ghostlymoron

Well-Known Member
Joined
9 Apr 2005
Messages
9,889
Location
Shropshire
Visit site
A speaker at our club last night described how his NASA log skin fitting became detached when crossing some turbulent water. The external flange broke off leaving a 2"dia hole in his bow and he was lucky to save his boat. That is why NASA installation instructions say glass the fitting in on the inside.
I've never done that in the past but will be checking mine today to check the installation is adequate and I urge readers to do the same.
The speaker's topic was cruising the west coast of Ireland in a 25 footer which was very entertaining.
 
ghostlymoron said:
A speaker at our club last night described how his NASA log skin fitting became detached when crossing some turbulent water. The external flange broke off leaving a 2"dia hole in his bow and he was lucky to save his boat.
Click to expand...

Out of interest, had it been sealed with Sikaflex?
 
Was going to fit the duet unit to mine, even bought it but then read reports it's not very good anyways especially if your boat takes the ground as the unit can fill with mud, so didn't bother and sold it. I have the garmin echomap 50s so this does depth plus gps speed over ground so more accurate anyways. Still got the nasa wind unit to fit though.
 
pvb said:
Out of interest, had it been sealed with Sikaflex?
Click to expand...

I agree with pvb that this is the critical question. It seems that the plastic used by Nasa for these fittings is susceptible to stress-corrosion cracking, hence the warnings they issue about using solvent-free silicone sealants and glassing the fitting in. The combination of a solvent based sealant and a little overtightening can be fatal.
 
I fitted a duet on my first boat. I found it very good depth wise but the log twiddler tended to seize up after a year and no amount of cleaning/ polishing would get it to perform for long. I found the only solution was to fit a new one. The display is very clear and the digit size ideal.
Tammany said:
Was going to fit the duet unit to mine, even bought it but then read reports it's not very good anyways especially if your boat takes the ground as the unit can fill with mud, so didn't bother and sold it. I have the garmin echomap 50s so this does depth plus gps speed over ground so more accurate anyways. Still got the nasa wind unit to fit though.
Click to expand...
 
Tammany said:
Was going to fit the duet unit to mine, even bought it but then read reports it's not very good anyways especially if your boat takes the ground as the unit can fill with mud, so didn't bother and sold it. I have the garmin echomap 50s so this does depth plus gps speed over ground so more accurate anyways. Still got the nasa wind unit to fit though.
Click to expand...

In the name of all that's Holy, don't bother with the wind thing, their very worst product !

See countless comments from myself and lots of others...
 
MIne was glassed in as recommended but somehow it developed a leak. Fortunately I had lifted out to do something else and I only discovered the leak when wishing to store something under the floor. 5" water the full length of the hull.
When I removed the through hull log to glass over the hole I found that the flange had a crack at its base around about 2/3 the circumference of the unit. Not far from falling off altogether. I also found it very quickly clogged the rotor with barnacles so rarely worked for long after cleaning.
When I lifted out I had already planned to take out the old log and glass over the hole as I thought a thin bit of flimsy plastic is not good enough in a critical situation. The boat could well have gone down but for the timing of my lift out!
 
I was given a Clipper Wind job as a present, so felt obliged to fit it; I wouldn't want it myself, I can tell where the wind is coming from and how frightened I am.

It lasted 11 months, and the bloke argued about the guarantee !

That was years ago and I understand their customer service is very good nowadays - well I expect they get enough practice.

Fool that I am, I bought another to fill the hole on the bulkhead; that lasted 5 months, I gave up and didn't bother complaining.

If you look at the thing, with a needle spindle instead of proper bearings for the anemometer ( the cups for which are non - U/V resistant ) it hasn't got a hope in hell.

The golden rule with NASA kit is ' OK as long as no moving parts ' - true, their depthsounders are spiffing.

A great shame, with a little more effort they could dominate the market...
 
have had a NASA skin fitting crack and 'weep' on a previous boat. That, and the log impeller's penchant for weeding/fouling with barnacles led me to having the fitting removed and glassed up on two boats.

Sure it means I can't measure the distance run but I'm confident that the integrity of my hull is less compromised as a result.

I've always found NASA Marine a very good company to deal with and have found all of their other kit works great. Just a shame they can't make this skin fitting in DZR or bronze.
 
parsifal said:
The fact that they recommend glassing in the transducer housing seems like an admission that it is unreliable.
Click to expand...

Maybe, but remember that their customer service is apparently very helpful! Although I doubt that they pay the cost of getting the boat in and out of the water.
 
I stop buying anything to do with NASA 20 plus years ago , after a purchased a steering compass which steamed up ,
After sending it in for repair I was told I had to pay for it had the compass got steamed up because I had fitted it in the cockpit and it only meant to be fitted in side the boat , not sure how one can steer in the cockpit , when the compasses is inside , never brought any of their stuff again and never will .
 
This exact subject keeps coming up regularly.
Nasa installation instructions clearly state that it should be glassed in, there's even a diagram showing how to do it.
When I first fitted mine I thought I was much cleverer than Nasa so I didn't bother with the glassfibre.
It snapped off. Entirely my responsibility, not Nasa's.
They were very helpful, the new fitting came very quickly and was glassed in.
If you look at a broken one there is not much meat at the junction of the flange and the tube, so glass them in.
 
You must log in or register to reply here.

Share this page

Top