Thru Hull Boat Fittings

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90 degree Thru Hull Connectors
90 degree Thru Hull Connectors
Features: Molded of rugged high-impact plastic. Will not corrode, discolor or contribute to electrolysis. Features finished head, single pass around …
Starting at: $2.64
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List price: $4.29
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Thru Hull Straight Fitting
Thru Hull Straight Fitting
High impact. White, corrosion proof nylon thru-hull fitting. For use above water-line only.
Starting at: $1.98
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List price: $2.19
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Seachoice 90° Thru-Hull Connectors
Seachoice 90° Thru-Hull Connectors
90 Degree - One Nut Application Designed for use with one back nut, unlike old style 90 degree thru-hull with both front and back nut. Made of hi- …
Starting at: $6.86
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List price: $9.45
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Brite Plate Chrome Plated Fittings
Brite Plate Chrome Plated Fittings
The look of stainless but with the price of plastic. Strong plating process strengthens parts. Five step metal bonding process. Won't flake, chip or …
Starting at: $4.99
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List price: $6.69
In stock

T-H Marine Extra Longthru-Hull Fitting
T-H Marine Extra Longthru-Hull Fitting
50 plugs per pack Hose I.D.: 1 1/2" Length: 6" Maximum hull thickness: 3 1/2" Flange diameter: 2 7/8" Installation hole diameter: 1 7/8" - 2"
Your price: $6.69
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List price: $11.09
In stock

Seachoice Thru-Hull Connections
Seachoice Thru-Hull Connections
Features: "Chrome Plated Plastic" Use in place of Stainless Steel thru-hulls.
Starting at: $5.20
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List price: $6.15
In stock

Seachoice Straight Thru-Hull Connectors
Seachoice Straight Thru-Hull Connectors
Features: Molded plastic with broad flange. Per ABYC "Safety Standards for Small Craft Not recommended for use below the waterline. Technical Info …
Starting at: $3.20
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List price: $4.15
In stock

Attwood Thru-Hull With Strainer
Attwood Thru-Hull With Strainer
Features: Prevents debris from entering and clogging the aerator pump. Strainer attaches to threads that extend beyond external retaining nut. Tough …
Starting at: $6.68
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List price: $8.69
In stock

THRU HULL W/SS COVER-1 1/2 90 - Seachoice
Your price: $12.33
List price: $21.45
In stock

THRU-HULL CONN-WHT 11/2 X90DEG - Seachoice
THRU-HULL CONN-WHT 11/2 X90DEG - Seachoice
Designed for use with one back nut unlike old style 90" thru-hull with both front and back nut. Made of hi-impact white plastic. Designed for easier …
Your price: $7.47
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List price: $10.45
In stock

Stainless Steel Nylon Thru-Hull Connectors
Stainless Steel Nylon Thru-Hull Connectors
316 stainless steel/nylon barbed thru-hulls. Available in straight or 90°.
Starting at: $6.73
List price: $9.39
In stock

THRU HULL 3/4" BLACK - Marpac
THRU HULL 3/4" BLACK - Marpac
* Molded plastic * Note: These thru-hulls for hose are not recommended for use below the waterline
Your price: $3.47
List price: $4.33
In stock

THRU HULL WHITE 3/4" - Marpac
Starting at: $3.28
List price: $4.09
In stock

NYLN/SS THRU HULL 1-1/8" - Marpac
NYLN/SS THRU HULL 1-1/8" - Marpac
* All nylon thru-hull with stainless steel outside cover
Your price: $7.98
List price: $9.98
In stock

SS THRU HULL HOSE 1-1/8" - Marpac
SS THRU HULL HOSE 1-1/8" - Marpac
* Stainless steel * Includes stainless steel nut. The thread length is 2-1/4 inches.
Your price: $22.38
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List price: $27.98
In stock

Brite Plate Chrome Plated Thru Hull Fitting, 90°, 3/4", 5/8" Hull - T-H Marine Supply
Brite Plate Chrome Plated Thru Hull Fitting, 90°, 3/4", 5/8" Hull - T-H Marine Supply
Brite Plate™ Chrome Plate-3/4" Thru Hull-90 Degree The look of stainless but with the price of plastic. Strong plating process strengthens …
Your price: $5.56
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List price: $7.09
In stock

3/4" White Thru Hull Connector, 1-1/4"Hull - T-H Marine Supply
3/4" White Thru Hull Connector, 1-1/4"Hull - T-H Marine Supply
Hose I.D.: 3/4" Length: 3 1/4" Maximum hull thickness: 1 1/4" Flange diameter: 1 3/4" Installation hole diameter: 1 1/16" All T-H Marine Thru-Hull …
Your price: $1.86
List price: $3.89
In stock

90&Deg; Thru-Hull Fittings (Rule)
90&Deg; Thru-Hull Fittings (Rule)
High impact molded plastic. Will not rust, corrode or discolor.
Starting at: $6.95
List price: $10.99
In stock

Flange Nuts (Conbraco / Apollo)
Flange Nuts (Conbraco / Apollo)
Cast bronze for thru hull connectors. Made in U.S.A. NOT TO BE USED IN POTABLE WATER SYSTEMS.
Starting at: $4.83
List price: $7.59
In stock

Thru-Hull Connector (Perko)
Thru-Hull Connector (Perko)
Molded white plastic with broad flange. For use with hose. Not recommended for use below waterline.
Starting at: $2.16
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List price: $5.69
In stock

Thru-Hull Connection (Perko)
Thru-Hull Connection (Perko)
Features: Cast Bronze Flange is machined to fit hull and grooved to retain bedding compound. Neck is threaded approx. 3/8" from flange.
Starting at: $17.93
List price: $33.69
In stock

Pipework Systems (Whale Water Systems)
Pipework Systems (Whale Water Systems)
15mm Equal Straight Adapter
Starting at: $0.76
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List price: $0.99
In stock

Hose Barb Connectors (Brass Fittings)
Hose Barb Connectors (Brass Fittings)
White nylon. FDA approved.
Starting at: $0.37
List price: $0.99
In stock

Thru-Hull Connector (Perko)
Thru-Hull Connector (Perko)
Molded white plastic with narrow flange. For use with hose.
Starting at: $5.06
List price: $6.49
In stock

Screw-In Overflow Drain Tube (T-H Marine)
Screw-In Overflow Drain Tube (T-H Marine)
High Quality UV and Chemical Resistant Virgin Polypro, Color: Black Stud Sized to fit all Marine hose 90 degree features finished head and pass …
Starting at: $5.99
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List price: $7.59
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Thru-Hull Connectors (Conbraco / Apollo)
Thru-Hull Connectors (Conbraco / Apollo)
Features: Cast bronze with machine finish. Deep caulk area for watertight seal.
Starting at: $8.74
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List price: $19.89
In stock

Stainless/Bronze Thru-Hull 90&Deg; (Groco)
Starting at: $21.76
List price: $37.00
In stock

Stainless Steel Thru-Hulls (Attwood Marine)
Stainless Steel Thru-Hulls (Attwood Marine)
Cast from #316 stainless steel. A channel under the flange holds a bead of sealant. All models have wrench flats or an end notch. Designed for …
Starting at: $14.83
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List price: $22.39
In stock

Thru-Hull Connector (Attwood Marine)
Thru-Hull Connector (Attwood Marine)
Molded of rugged plastic. Will not rust, corrode, discolor or contribute to electrolysis. Design eliminates hull streaking and allows …
Starting at: $3.74
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List price: $5.29
In stock

Stainless Steel Thru-Hull (Groco)
Stainless Steel Thru-Hull (Groco)
Includes locknut. Stainless Steel.
Starting at: $15.28
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List price: $22.00
In stock

Bronze Extra Long Thru-Hull Fittings (Groco)
Bronze Extra Long Thru-Hull Fittings (Groco)
Extra long through hull for installations where hull thickness dictates the use of longer fitting. Locknut has bonding connection. NOT TO BE USED IN …
Starting at: $26.39
List price: $38.00
In stock

Stainless Steel Thru Hull With Hose End (Buck Algonquin)
Starting at: $30.77
List price: $43.59
In stock

47 results 1 of 2 pages
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Thru Hull Fittings How-To's

Thru Hull Threads (Video)
A video demonstration on threads thru the hull presented by Forespar. ... read more



Video Transcript

And now for the exciting topic of threads on thru hulls.

On a marine thru hull- first of all a thru hull is just that. It is the fitting that goes through the hull and is secured or fastened on the inside with a nut or with a flanged valve called a seacock which replaces that nut.

It’s also important to note here that marine thru hulls all have parallel threads. No matter if they are US thread, BSB, or buttress- they are all parallel threaded. This is because no one ever knows the hull thickness that they are going to be installed on, so a taper would cause problems as the thru hull threads need to be cut to length for a given seacock installation or a valve installation.

This also means that the true marine seacocks or valves are also female parallel threaded to accept the thru hull. Non marine fittings and valves usually have NPT or nationally piped taper thread. This type is generally used in irrigation or house plumbing and should never be used below waterline. This is true of tail pipes and elbows on top of the valve as well. These connections must be sound and leak free. There is also more important information on threads on our website, forespar.com

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Why Marelon Plumbing Parts? (Video)
A video presentation on why Marelon plumbing parts are the best for your boat repairs ... read more



Video Transcript

Hi. I’m Wes Gary. I’ve built boats and I’ve been around sail and power boating for most my life. I’ve had my own plastics business for over 25 years and I’ve built a 55 foot slew. I know polymer composites very well.

I’m here today to talk about Forespars line of Marelon marine plumbing fittings. I know that Marelon is not just a plastic but an engineered carbon fiber and glass re-enforced composite polymer, ideally formulated for marine use. You go to your local boating supply store and you will notice that there are several plastic plumbing choices available. Marelon, however, is the only plastic to meet the rigorous marine UL test. Its also ISO certified and Marelon also meets the ABYC standards for above and below the waterline. These are the same tests that bronze or stainless steel parts have to pass too. I mention this because some of you may have seen Marelon fittings in stores and thought ot yourselves… ehhh… it’s a plastic and bronze has been the material of choice for boats in the past. Well think again.

What’s your boat made of? What about the hoses that are going to the valves? Well, if you accept those materials below the waterline, why not a valve that’s made from truly 21st century carbon fiber reinforced polymer composite.

There are other reasons as well. Marelon wil never corrode. Because it’s not made of anything metallic, it’s never subject to the cancer ravages of electrolysis. You don’t have to bond Marelon so you don’t have the additional copper bonding wires and you don’t’ have the additional potential corrosion of those as well, so all that goes away.

Marelon is also very lightweight. A typical bronze 1 1/2” seacock weighs about 10 pounds. A comparable Marelon 1 1/2” seacock weighs less than 2 pounds. Think about how more efficient you are going to be and how much more beer you can carry.

As you walk down the plumbing isle of your favorite marine hardware store, and you see the plastic stuff on the shelf, remember that all plastics are not created equal. Marelon is about as close as you can get to the material that your boat is made of in a precision melded, marine approved, polymer composite. It’s time to step out of the Bronze Age.

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