Marelon vs. Bronze

[thinredmohican]

I am in the process of replacing all thru hulls on my Irwin 28. Would the marelon be better to use beneath the waterline? Can I use bronze valves with marelon thru hulls? I greatly appreciate any feedback.

[thomasstone]

I just did the same thing. I never got an answer I was comfortable with so I used a bronze thru hull for my raw water intake with a bronze seacock( the bronze seacock was cheaper also). That is my only hole below the waterline and I felt more comfortable with the bronze than the marelon.On all of my cockpit drains/deck drains total of 8 I used the marelon drains these are all well above the water line and the marelon are cheaper than bronze as thru-hulls.
thomas

[thomasstone]

oh yeah I probally went the extra mile ,but my exhaust thru-hull is bronze also with a sea **** on it as well, that I turn off once I am out to sea on an extended passage.For regular day sailing I leave it open all the time. I do have a nice bend in my exhaust with a proper siphon break ,but when iwas putting in my engine I met an old salty who ruined his motor from water siphoning in . I figured I would double protect myself.
thomas

[Jeff_H]

I just sold a boat that had Marelon seacocks and through hulls and replaced it with a boat of virtually the same age with bronze seacocks. The Marelon still worked well and required minimal maintenance. Quite a few of the Bronze thru hulls and seacocks are shot and in need of replacement. For a 28 footer I would not hesitate to use the Marelon.

Jeff

[scnicklefritz]

Another consideration is what happens to the bronze thru hulls if the boat gets hit by lightning??

I''ve heard of metal thru hull fittings disintigrating from a strong lightning strike, as they provide a good path to the water.

If you weren''t on the boat if this happened, it could sink.

I suppose that and corrosion are the only real disadvantages to using bronze. Make sure the bronze is electrically connected to a sacraficial zinc and that should solve the corrocion problem.

[thomasstone]

Would you feel comfortable using a marelon sea-**** below the water? Also its probally alot easier to change down the road since they are impervious to corrsion.If you did use all bronze should you ground them all together ? I noticed when I was fighting to remove old sea-cocks thier appeared to be some sort of wire glassed in, I am assuming this was some sort of ground? I have heard very different opinons on this.
thomas

[thinredmohican]

I don''t feel uncomfortable using marelon below the waterline, should I? It seems that the marelon is up to the task. Corrosion free sounds good. The most economical way would be to use marelon thru hulls with bronze ball valves. Does this sound like a possibility?

[thomasstone]

I dont know, Im asking too. Either way you go I dont think trying to save a dollar in this situation is the way to go. For me holding the bronze sea-**** and marelon in my hand i felt the bronze was more solid. A marelon sea-**** could be superior, maybe some one will let us know?
thomas

[kimberlite]

i believe hinkley uses marelon seacocks ant through hulls.
eric

[fer@fer]

Hi Mohican,

Is your thrugh hull near the waterlin?. If you carry, marelon and get stucked on your thrugh hull, probably it couldn`t cope with your vesselīs weight. Moreover, heat melts marelon.

In any case, mu boat carried marelon for the last 8 years, and there were OK. I just changed them, because I thought there were old enough.

Mixing Marelon and bronze spherical valves is not recommende since both materials have disimilar rates of dilatation. However if you will only navigate in waters where it tempersature have a small amplitude, this will not be an issue.

Last, some guys recommend kicking your thru hull and valve after instalation with a ski boot. If it remains in place, means that it was ok.

Regards
Fernando