380: Thruhull questions

[CruiserAD]

Hi again

Quite a few questions around the L380 (2004) im looking to buy. It still has the original thruhulls and valves (seacocks?) and I wonder if I have to renew them all together?

Does anybody know if they are real bronze or the cheap brass stuff one shouldn't use in saltwater for longer times?

I thought one should place the valve immediately on the thruhull but in most cases there is an elbow between the thruhull and the valve. If put the valve on the thruhull and then the elbow after that I probably will run into problems because the assembly protrudes further into the boat and might not fit?

Has anybody experienced any problems in this area or actually an idea for improvement?

If I change i tend to favor the marelon type fittings, but I'm not sure if they will fit since the seem bigger then the ones currently installed. Any arguments against that or any experiences or suggestions which ones are fitting best?

Thanks and best regards

Jan

[Cotemar]

Marelon type fittings will need a bigger thu-hole drilled if your using the heavy duty Marelon 93 Series Ball Valve / Mushroom Thru-Hull Fitting.

May want to consider the titanium-thru-hulls

Thru-Hulls - Titanium
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[a64pilot]

I guess you wouldn't have to worry about the Ti de-zincing would you, ever?
I assume its nearly impervious to stray current corrosion?

[Privilege]

Why are you thinking of changing the valves? If they are not corroded and turn freely, they'll be good for years to come.

[Training Wheels]

Interesting! Wonder how hard it it to cut the stem, if you need to shorten it ?

[a64pilot]

Originally Posted by Privilege

Why are you thinking of changing the valves? If they are not corroded and turn freely, they'll be good for years to come.

I think it's because some of the French built boats don't use bronze?

[CruiserAD]

Yes it's because the brass/bronze thing and the elbows being between the ocean and the valve ;-)

[Cotemar]

Originally Posted by a64pilot

I think it's because some of the French built boats don't use bronze?

Bronze is good.

The Brass ones they used are BAD

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[Sid at SailAway]

Originally Posted by Privilege

Why are you thinking of changing the valves? If they are not corroded and turn freely, they'll be good for years to come.

Those thru hulls and valves are now 13 years old. When we bought our Lagoon 410 the thru hulls and valves were 11 years old. After hauling and survey everything seemed fine. A few weeks later when we were ready to start our cruise, I went through the boat to exercise and relocate all the thru hulls. The first one I opened, which happened to be an 1-1/4", snapped off in my hand! It had broken at the nipple between the elbow and the valve. The cross section of the nipple looked like Swiss cheese.

During survey all the thru hulls "looked" ok. We had to re-haul the boat and replace all the thru hulls. As a test, when we were hauled, I grabbed each one and with a little more force then normal managed to snap off six more! They all had the same Swiss cheese cross section. This could have been a disaster on the cruise with thru hulls in this condition. None of them showed any outside corrosion. The problem was, and maybe still is, is that Lagoon mixed bronze valves with brass fittings causing the internal corrosion.

My advice, change all of them for cheap insurance and peace of mind. Just don't mix brass and bronze...

[Dockhead]

Originally Posted by Sid at SailAway

Those thru hulls and valves are now 13 years old. When we bought our Lagoon 410 the thru hulls and valves were 11 years old. After hauling and survey everything seemed fine. A few weeks later when we were ready to start our cruise, I went through the boat to exercise and relocate all the thru hulls. The first one I opened, which happened to be an 1-1/4", snapped off in my hand! It had broken at the nipple between the elbow and the valve. The cross section of the nipple looked like Swiss cheese.

During survey all the thru hulls "looked" ok. We had to re-haul the boat and replace all the thru hulls. As a test, when we were hauled, I grabbed each one and with a little more force then normal managed to snap off six more! They all had the same Swiss cheese cross section. This could have been a disaster on the cruise with thru hulls in this condition. None of them showed any outside corrosion. The problem was, and maybe still is, is that Lagoon mixed bronze valves with brass fittings causing the internal corrosion.

My advice, change all of them for cheap insurance and peace of mind. Just don't mix brass and bronze...

That's the crux of the issue! If you could see the corrosion happening, it would not be such a problem!! But often corroded underwater hardware looks just fine from the outside, and the first sign you have that there is a problem, is when your floorboards start floating. You CANNOT rely on inspection, to protect you from inferior underwater hardware.


Through hulls and ball valves should be quality, with no brass in them. Bronze ball valves often have brass valve stems and USUALLY have brass balls (chrome plated). This is no good. Do your homework when you buy new ones. Marelon and titanium are also good, and less risk that you'll get an odd bit of brass mixed in.

[CruiserAD]

Thanks to all the reponses - this forum rocks!!

I had "hoped" that they where all bronze but I did not really believe it and Sid's experience with his L410 confirmed my concerns about Lagoons choice of material Especially the elbow thing makes me nervous. I will most definitely have to them!
One more thing on the to do list...

[gspeak]

Originally Posted by CruiserAD

Thanks to all the reponses - this forum rocks!!

I had "hoped" that they where all bronze but I did not really believe it and Sid's experience with his L410 confirmed my concerns about Lagoons choice of material Especially the elbow thing makes me nervous. I will most definitely have to them!
One more thing on the to do list...

We have a same year (2004) L380 #241. We replaced the elbows & ball valves last year with the Trudesign (composite fibre reinforced). These are certified marine fittings.

You will have trouble fitting the valves directly to the through hulls because of space constraints. Especially as the replacement fittings are much larger than the standard ones.

The reason I replaced was mostly because half of the OME ball valves (appeared to be chrome plaited brass) no longer closed, & like you I was concerned about the material used.

Even though I had bought the Trudesign through hulls as well, when I removed all the valves & elbows I found that the through hulls appeared to be bronze & showed no signs of corrosion inside & out. I stress tested them all with a fair amount of force.

I would definitely replace the valves & elbows. The correct Trudesign fittings screwed straight on. I used both a small amount of thread tape & Sikaflex 291i as recommended.



Hope this helps.

Dave

[tuskie]

Originally Posted by gspeak

We have a same year (2004) L380 #241. We replaced the elbows & ball valves last year with the Trudesign (composite fibre reinforced). These are certified marine fittings.

I second Dave's recommendation, and if changing the through hull fittings, the Trudesign load bearing collars are an excellent product.

Load Bearing Collars | TRUDESIGN


They take the load off the through hull in a similar manner to flanged sea cocks, reducing the chance of a break off if there is a side load impacting on the fittings.

BTW, it's nice to see Lagoons still floating with 14 year old through-hull fittings. This is despite the CF Sages who predict that they will corrode off in 5 years.

[Dockhead]

Originally Posted by tuskie

. . . This is despite the CF Sages who predict that they will corrode off in 5 years.. .

I'm not sure that anyone predicted that the carpy brass through hulls used on some GB boatswill "corrode off" in 5 years. The point is that they can corrode and crumble in 5 years, or even less. See post #9 above.

So some boats might continue floating with them. Does that make anyone feel better about them? I hope not. "Might" continue floating does not fulfill the design criteria for a through hull, in my opinion.

[gspeak]

In post #9 Sid is a little confusing when describing what actually broke. The reference throughout is to "thruhulls" & yet he says "It had broken at the nipple between the elbow and the valve". This is not the through hull in my language. It is in the fittings after the actual "through hull" or skin fitting. See my photo. He then makes reference to corrosion caused by using brass & bronze adjacent, the elbow & the valve.

As I said, in my case, I found the actual "through hull" to be intact & apparently bronze. I also said that it was wise to replace the elbow & valve which appeared to be chrome plated brass & half of my valves wouldn't close. That is why I replaced all mine.

I'm just reporting what I found. I replaced what I found to be suspect. The "through hulls" were fine. I still have the Trudesign through hulls & will check again at the next haul out & replace if necessary.

But yes, my Lagoon was still floating after 14 years despite all of this.

Dave