Plastic thruhull and Sika-291i

[Bowdrie]

Originally Posted by Matt Johnson

The plastic thru hulls can be permanently bonded in place with polyester or epoxy (this is shown in the instructions) Since they typically need to be grounded off to replace anyway, it doesn't add too much more to the job if bonded in place. That at least eliminates your fear of them moving if the valve is removed.

True enough.
A similar argument can be made that if the Groco adaptor is mounted on a G10 or self-made fiberglass pad, (not the one you get from Groco,) with a good sealant, and the pad itself is bonded/glassed to a fiberglass hull, one can have an operable system even without a thru hull.
In any event, the Groco system allows not only the valve to be changed, but the thru hull can also be changed with but little effort and no drama.
The adaptor becomes a "part of the boat" and cares little what kind of thru hull or valve you screw into it from the outside or on to it from the inside.
It's a system that does not depend upon the thru hull for strength and integrity.
If you section a thru hull, either plastic or metal, you'll see just how little real "meat" there is under the thread depth.

[s/v Jedi]

Originally Posted by Bowdrie

True enough.
A similar argument can be made that if the Groco adaptor is mounted on a G10 or self-made fiberglass pad, (not the one you get from Groco,) with a good sealant, and the pad itself is bonded/glassed to a fiberglass hull, one can have an operable system even without a thru hull.
In any event, the Groco system allows not only the valve to be changed, but the thru hull can also be changed with but little effort and no drama.
The adaptor becomes a "part of the boat" and cares little what kind of thru hull or valve you screw into it from the outside or on to it from the inside.
It's a system that does not depend upon the thru hull for strength and integrity.
If you section a thru hull, either plastic or metal, you'll see just how little real "meat" there is under the thread depth.

Yes it is a great design. I don’t understand why not everyone is using them as the price is good to imo

[Celestialsailor]

Originally Posted by Franziska

I'm in Europe and could not care less about ABYC [emoji2957]

Originally Posted by Pete7

Absolutely, what's more they are only an advisory organisation for one country on the planet. Nor do I agree with their advice, which is just what it is.

Watched a couple of YT videos a while back on gas installations. The viewers comments really tore into the ABYC.

There are tens of thousands of yachts with mushroom through hulls and ball valves referred to as seacocks if you like, doing sterling service as are ours. Glued in with a good seal of sika

I believe they are also responsible for the color coded duplex wire of red and yellow instead of red and black.

[sailingharry]

Originally Posted by Celestialsailor

I believe they are also responsible for the color coded duplex wire of red and yellow instead of red and black.

I assume your comment is meant as an enthusiastic endorsement of ABYC? This is such a brilliant step forward in wiring safety, it's stunning that marine equipment still come with black wires for ground....er, I mean, black for hot... er, I forget, which is the one I shouldn't touch? It's still not completely easy to find, but I try hard to use yellow wherever possible, and at the very least put yellow heat shrink near the end of every black (where in this sentence, black means ground) wire I install.

[sailingharry]

I read upthread about the trudesign fittings. It's actually on my mind right now. I want to replace my existing little holding tank vents (up near the rail) with a 3/4" through hull. I also have something like 4 factory white plastic through hulls down near the water line.


Plastic, in general, has a bad reputation. But not all "plastic" is the same. Some are Nylon, some are Polypropylene, Forespar is something else, and TruDesign is "resin." Forespar is only available in black, no thanks (I'll go stainless first).


So, first, how is TruDesign in the sun? They are about double (triple?) cheap ones, but at $20 each for the size I need, it's irrelevant (and if the price reflects the quality, even better).


And if not TruDesign, what plastics are good in the sun?


Thanks for the insight.

[Celestialsailor]

Originally Posted by sailingharry

I assume your comment is meant as an enthusiastic endorsement of ABYC? This is such a brilliant step forward in wiring safety, it's stunning that marine equipment still come with black wires for ground....er, I mean, black for hot... er, I forget, which is the one I shouldn't touch? It's still not completely easy to find, but I try hard to use yellow wherever possible, and at the very least put yellow heat shrink near the end of every black (where in this sentence, black means ground) wire I install.

Oh sure...after 90+ years of DC black being negative and red being positive it's so easy to forget and hey yellow as negative?...ya, that makes sense. How do you manage to tie your shoes?

[Pete7]

Originally Posted by Celestialsailor

I believe they are also responsible for the color coded duplex wire of red and yellow instead of red and black.

A major advancement in marine safety I'm sure

[s/v Jedi]

Originally Posted by sailingharry

I read upthread about the trudesign fittings. It's actually on my mind right now. I want to replace my existing little holding tank vents (up near the rail) with a 3/4" through hull. I also have something like 4 factory white plastic through hulls down near the water line.

Plastic, in general, has a bad reputation. But not all "plastic" is the same. Some are Nylon, some are Polypropylene, Forespar is something else, and TruDesign is "resin." Forespar is only available in black, no thanks (I'll go stainless first).

So, first, how is TruDesign in the sun? They are about double (triple?) cheap ones, but at $20 each for the size I need, it's irrelevant (and if the price reflects the quality, even better).

And if not TruDesign, what plastics are good in the sun?

Thanks for the insight.

For thru hull fittings above the waterline I use the Forespar fittings. The material they use is Marelon and this is a fiber reinforced plastic just like Trudesign uses. It is available in black and in white and paint will not stick to it for long.

I have some fittings just above waterline, like the discharge from the A/C cooling loop and I use those cheap not good for much Forespar flanged seacocks for that. I even have one of those under the waterline for a long term test, right next to a bronze Groco flanged adapter. Both still work like new and are more than 10 years old.

Originally Posted by Pete7

A major advancement in marine safety I'm sure

The problem is that in the US, black is L1 and red is L2 in AC wiring so 240V. I remember Holland used red and black as well 100 years ago because I found that in old wiring.

[Pete7]

Originally Posted by s/v Jedi

The problem is that in the US, black is L1 and red is L2 in AC wiring so 240V. I remember Holland used red and black as well 100 years ago because I found that in old wiring.

Raymarine still use red and black. I thought the red/black colour scheme quite sensible, not sure about the latest blue/brown/green-yellow for AC circuits.

The US system is really confusing for a European. Wrong frequency, voltage, two live wires and no fuses in plugs. That really needs sorting out, perhaps they should have stayed in the Empire I mean, they can't even have a kettle, I feel for them.

Pete

[Bowdrie]

I've found the European system of Blue/Brown to be quite intuitive for DC.
Brown - = Earth/Dirt = Ground.
Blue + = Sky = Above Ground
If you want to have some fun, do some electrical work on an old wooden Chris-Craft, where every wire in the boat is black.
Over time the little number tags come off and then it provides additional fun.

[team karst]

Except that its wrong. Brown is not earthed and in dc is pos.

[Bowdrie]

Originally Posted by team karst

Except that its wrong. Brown is not earthed and in dc is pos.

Ok, sorry, thanks for correcting me.
Now I'll have some ammo to use on the guy that sold me the fans that were made in Europe.

[team karst]

Ha. My german hella fans use zip cord. Black, and black with white stripe. [emoji848]

[osprey877]

One issue not mentioned is the problem that most mushroom thru hulls are a straight thread, whereas most ball valves have a tapered pipe thread. Combining the two is a recipe for disaster.

[s/v Jedi]

Originally Posted by osprey877

One issue not mentioned is the problem that most mushroom thru hulls are a straight thread, whereas most ball valves have a tapered pipe thread. Combining the two is a recipe for disaster.

Indeed a problem for those who screw a ball valve onto a thru-hull fitting. The flanged adapter from Groco solves this as it has the right thread for each.