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Forespar 253 Series Marelon Mushroom Head Thru-Hull Fitting
$15.96 - $35.96
Forespar 253 Series Marelon Mushroom Head Thru-Hull Fitting Item # 865871
Description
Features:
- Forespar Marelon® mushroom head thru-hull with hose barb connection
- Suitable for use 6" or more above the waterline
- Less than 6" requires a seacock
- Marelon fittings are popular with many top quality boat builders worldwide
- Marelon® is a proprietary formulation of polymer composite compounds using composite reinforced polymer and additives to produce a superior marine-grade product
- Designed for use above and below the waterline
- Complete freedom from corrosion
- High strength
- UV Stabilized
- Will not freeze or become brittle with age or temperature extremes
- U.L. and A.B.Y.C. approved
- Marelon fittings can be installed using the same techniques and materials as bronze fittings
Minimum Physical Properties Required for Approval are:
- Tensile Strength: 10,900 PSI / 75 mPa
- Flexural Modulus: 500,000 PSI / 3480 mPa
Note:
- Forespar threaded plumbing fittings, like most true marine plumbing fittings, use NPSM threads (National Standard Free-Fitting Straight Mechanical Pipe Thread). NPT (National Pipe Threads) are tapered, NPSM Threads are parallel. The two types are not designed to work together.
- Value by test to ASTM D638 (American Society of Testing & Materials)
- Value by test to ASTM D790 (American Society of Testing & Materials)
Part Numbers for Forespar 253 Series Marelon Mushroom Head Thru-Hull Fitting
Reviews
Rated 5 out of
5
by
PaulM from
Marelon thru hull, by Forespar
253 series, 2", for engine's wet exhaust on sailboat. Incredibly strong and durable: I am relocating the thru hull and had to remove it. I actually used a two speed winch to pull off the stiff hose, using a choking line, at a frankly very scary tension, deforming the fitting, sideways perhaps 20 degrees. After removing the hose I used a two-foot-long channel lock plier to grab the fitting at the barb/threaded portion to unscrew it from the nut, which was glued to the hull with the 5200 I foolishly used ~11-years prior. You can imagine what it took to break the fitting free: appeared to ruin the threads, etc. I pried the nut off with a long screwdriver. The entire fitting, including nut, actually survived to the extent that in a third-world it could have been reused. Amazing. Yep, I am now a believer of Marelon over bronze. Never thought I'd say that, but given the rarity of proper silicon bronze, I'd choose this unless the pedigree of the bronze equivalent can be certified. The other thru hull fittings (original to the boat in 1977, before Marelon was available) looked identical, but shattered like cheap plastic. Good thing they were above the wl (the mfr used proper bronze below wl). So, don't EVER accept a white fitting that does not say Marelon, including on brand-new boats, unless there is zero chance of flooding if it breaks off; these would have shattered if virtually anything of significant mass whacked them.
Date published: 2025-04-23
Rated 5 out of
5
by
Antoine from
Easy to install , looks great
Good looking and easy to install. Hopefully it will last.
Date published: 2024-08-03