Thru Hull Scupper AISI 316 Stainless Steel 1 1/4"

Function and technical context

The thru-hull (also called thru hull or emptying thru-hull) is the structural element that passes through the hull of the boat to allow the passage of fluids between the inside and outside of the boat, whether in bilge circuits, deck drain, seawater intake or gray water outlet. Made of AISI 316 stainless steel, it offers superior resistance to marine corrosion compared to AISI 304 steel, being the recommended material for submerged applications or in permanent contact with salt water. With a nominal measurement of 1 1/4" and reference dimensions A 85 mm, B 120 mm and C 89 mm, this thru-hull is installed sealed with polyurethane or epoxy putty, guaranteeing the tightness of the hull at the point of penetration. A thru-hull in poor condition, with cracks, galvanic corrosion or deteriorated joints, represents a direct risk of water entry and, in the worst case, the sinking of the boat.

When to replace this part?

The most common symptoms that indicate the need to replace a thru-hull include the appearance of rust or corrosion stains around the fitting, visible microcracks in the body of the thru-hull, water leaks from the sealing point or difficulty in operating the associated bottom valve. It is recommended to visually inspect all thru-hulls at each docking or seasonal maintenance, checking the state of the sealing, the integrity of the material and the absence of pitting due to galvanic corrosion. Replacing a thru-hull preventively during a grounding has a minimal cost compared to an emergency repair in the water or the consequences of a water leak while underway.

Compatibility table