through hole fittings

[EchoPilot1975]

I have an older boat, a 75 to be specific, and it has the original fittings on the exterior of the hull for all the through holes.

For the most part they need replacement badly and while I'm repainting it I figure this is the best time to get new ones. Since westerly parts are rare in the southeast US, I'm wondering what I should do for replacing them. Will I have to enlarge the holes for new fittings or will i have to fabricate new fittings entirely? If you have had experience with this or have found a good place to purchase these it would be welcomed to know.

[HopCar]

Is this what you're talking about?

Groco Bronze Thru-Hulls

[Gavala]

They're called 'skin fittings'.

Buy bronze ones if its within budget or stainless if possible as stainless contains no zinc / corrosion properties.

Brass is OK but are a serviceable item, whereas bronze far less so and stainless not at all.

[goboatingnow]

Originally Posted by Gavala

They're called 'skin fittings'.

Buy bronze ones if its within budget or stainless if possible as stainless contains no zinc / corrosion properties.

Brass is OK but are a serviceable item, whereas bronze far less so and stainless not at all.

Do not use stainless as an underwater skin fitting , bad stuff

Dave

[Gavala]

Originally Posted by goboatingnow

Do not use stainless as an underwater skin fitting , bad stuff

Dave

Why would you say that? Do you not understand the make up of metals and their various corrosion properties against seawater?

You may have nearly 8K posts but your knee jerk reply shows you have little knowledge in the properties of stainless steel whilst submersed in salt water. Its not just a 'pretty metal'.

[Sailmonkey]

Originally Posted by Gavala

Why would you say that? Do you not understand the make up of metals and their various corrosion properties against seawater?

You may have nearly 8K posts but your knee jerk reply shows you have little knowledge in the properties of stainless steel whilst submersed in salt water. Its not just a 'pretty metal'.

Stainless is not the preferred material for skin fittings. It suffers from crevice corrosion, and does not do well in an atmosphere devoid of oxygen.
Bronze is the preferred metal for this task.

[EchoPilot1975]

Yes some of them do look like that but there are three others that actually look like a tub drain as if to keep stuff out.

Currently there are no metal ones. They are all plastic fittings that are mounted on. Should I stay away from plastics?

[Gavala]

Originally Posted by Sailmonkey

Stainless is not the preferred material for skin fittings. It suffers from crevice corrosion, and does not do well in an atmosphere devoid of oxygen.
Bronze is the preferred metal for this task.

What a crock of crap. Let me say this before I exit this forum, crevice corrosion is a result of weld and not present on 'turned' fittings as stainless skin fittings are.

I was hoping you'd reply after googling this matter and mis interpreting the results.

As a chandlers supply manager up until last April I supplied many turned stainless fittings to high end customers, the most prevalent being Eric Claptons Vabene which is moored in Antigua.

He most likely didn't bother googling for the underwater properties of stainless steel and misinterpret wiki but took good advice from someone who is out there doing it rather than someone spending his days making 1.78 posts a day sat at a computer.

I bow out. You are almost laughable if I could surrender the energy.

[Sailmonkey]

This isn't Wikipedia


http://www.mcnallyinstitute.com/04-html/4-1.html

[Gavala]

Originally Posted by EchoPilot1975

Currently there are no metal ones. They are all plastic fittings that are mounted on. Should I stay away from plastics?

I would avoid plastic just because of fatigue. Go with the metal of your choice

[EchoPilot1975]

Originally Posted by Gavala

I would avoid plastic just because of fatigue. Go with the metal of your choice

Yea i was thinking that. I can't believe plastic was used in the first place.

[Sailmonkey]

Originally Posted by EchoPilot1975

Yea i was thinking that. I can't believe plastic was used in the first place.

I'd be willing to bet the plastic is Marelon, perfectly acceptable for a thru hull fitting, especially so if connected to a through bolted seacock.

[Gavala]

Originally Posted by Sailmonkey

This isn't Wikipedia


Corrosion, stainless steel

No, but it took some time finding a random sight that has no weight when it relates to 300 stainless and not 316!!!!

Come on.

I'm really struggling here to get through. Crevice corrosion is due to weld and the site you linked is for 300 stainless. Please.

[Gavala]

Originally Posted by EchoPilot1975

Yea i was thinking that. I can't believe plastic was used in the first place.

Just go with the metal of your choice. Plastic is ok but I prefer feedback through a spanner with metal skin fittings rather than wondering if I'm about to ride the thread of a plastic skin fitting.

[EchoPilot1975]

Originally Posted by Gavala

Just go with the metal of your choice. Plastic is ok but I prefer feedback through a spanner with metal skin fittings rather than wondering if I'm about to ride the thread of a plastic skin fitting.

Thats a really good point. Any metal, no matter what type, will be more durable then plastic.