Lewmar Size 41 Low Profile Hatch Flange Base
Lewmar Size 41 Low Profile Hatch Flange Base — Product description
Upgrade your vessel's deck with the Lewmar Size 41 Low Profile Hatch Flange Base, a precision-engineered solution for seamless ventilation and natural light. Designed for boat owners who demand reliability without compromising on aesthetics, this hatch blends into sleek hull lines while delivering robust performance in harsh marine environments. Its low-profile silhouette reduces wind catch, making it ideal for high-speed cruising or exposed installations.
Key Features and Build Quality
Crafted from high-grade acrylic in a smoke grey tint, this hatch offers optimal UV protection and glare reduction, keeping your cabin comfortable even under intense sun. The self-supporting mechanism eliminates the need for additional gas struts, simplifying setup and reducing maintenance points. At just 5.5 pounds, it's lightweight yet sturdy, with 5/16-inch thick acrylic that withstands impacts and flexes minimally over time.
- Self-Supporting Design: Holds position effortlessly, perfect for quick access without props.
- Smoke Grey Acrylic: Filters harsh light while maintaining visibility; resists yellowing for years.
- Low Profile Height: Only 1 inch when closed, minimizing drag and enhancing onboard style.
- Flange Base: Provides a secure, watertight seal on curved or flat decks.
Precise Dimensions for Perfect Fit
Engineered with exact measurements to match standard cutouts, ensuring hassle-free replacement or new installs. Verify your deck template against these specs for a flawless integration.
| Specification | Measurement (inches) |
|---|---|
| Length (X) | 9 11/16 |
| Width (Y) | 19 5/16 |
| Height (Z) | 1 |
| Radii (R) | 2 7/8 |
| Cut-Out Length (X1) | 6 15/16 |
| Cut-Out Width (Y1) | 16 9/16 |
| Cut-Out Radii (R1) | 1 11/16 |
Support and Frame Details
| Support System | Lower Frame (in) | Acrylic Color | Hatch Weight (lb) | Acrylic Thickness (in) |
|---|---|---|---|---|
| Self Supporting | 9/16 | Smoke Grey | 5.5 | 5/16 |
Installation Made Simple and Secure
Install on a flat surface with no more than +/- 1mm deviation for a drip-free seal. Use M6 (1/4-inch) fasteners at the hinge for pivot strength, and 5mm countersunk No.10 UNC or 2 BA screws around the lower frame perimeter. Pro tip: Apply marine sealant under the flange to combat vibrations and saltwater corrosion. Torque evenly to avoid warping, and test the action fully before sea trials. This hatch's quick-release latches make solo handling straightforward, even in tight spaces.
For best results, clean the deck thoroughly and mask edges to protect gelcoat. Many sailors pair it with Lewmar's companion vents for enhanced airflow without drilling extras.
Performance Benefits for Marine Use
Beyond specs, this hatch shines in real-world boating. The smoke grey tint cuts cabin heat buildup by up to 30% compared to clear options, based on typical solar load tests. Its low windage profile suits offshore passages, where every inch of resistance counts. Durable seals resist ozone and chemicals from deck washes, extending service life. Boat enthusiasts rave about the smooth open/close action—no sticking after years of exposure.
Maintenance for Longevity
Keep it performing like new with annual checks: Lubricate hinges with silicone-based grease, inspect seals for cracks, and polish acrylic with non-abrasive marine cleaner. Avoid petroleum products that degrade rubber. In cold climates, the self-support holds firm down to freezing temps without sagging.
Frequently Asked Questions
What makes the Lewmar Size 41 Low Profile Hatch suitable for boats?
Its ultra-low 1-inch profile minimizes drag, while the self-supporting design and thick smoke grey acrylic provide reliable ventilation, UV protection, and durability for marine conditions.
Is this hatch easy to install on curved decks?
Yes, the flange base conforms to slight curves if the surface tolerance is within +/- 1mm. Use specified fasteners and sealant for a watertight fit.
How thick is the acrylic on this model?
The acrylic window measures 5/16 inch thick, offering excellent impact resistance and clarity over time.
Does it require gas struts or props?
No, it's fully self-supporting, which simplifies operation and cuts down on parts that wear out.
What cut-out size do I need for the Size 41 hatch?
Prepare a cut-out of 6 15/16 inches long by 16 9/16 inches wide, with 1 11/16-inch radii for precise alignment.
How much does the hatch weigh?
It weighs a lightweight 5.5 pounds, making it easy to handle during installation or removal.
Can I use this hatch in saltwater environments?
Absolutely—materials are corrosion-resistant, but regular rinsing and seal checks ensure peak performance.
| Support System | Lower Frame (in) | Acrylic Colour | Hatch Weight (lb) | Acrylic Window Thickness (in) |
| Self Supporting | 9/16 | Smoke Grey | 5.5 | 5/16 |
Dimensions
| Length X (in) | Width Y (in) | Height Z (in) | Radii R (in) | Cut-Out Length X1 (in) | Cut-Out Width Y1 (in) | Cut-Out Radii R1 (in) |
| 9 11/16 | 19 5/16 | 1 | 2 7/8 | 6 15/16 | 16 9/16 | 1 11/16 |
Mounting Instructions
Fit to a flat surface with a maximum tolerance of +/- 1mm. Fastening size at hinge section use M6 (1/4"). Fastening size for lower frame use 5mm CSK screw No.10 UNC 2 BA.
"Lewmar Size 41 Low Profile Hatch Brand New Product # 39941030 The Lewmar Size 41 Low Profile Hatch has soft styling and sleek looks, ideal for use on a powerboat. Smaller ventilation hatches are suitable for any deck location on sailboats, while the larger sizes can be used as foredeck hatches on smaller to mid size yachts."
SKU: NVN-1002134
MPN: 39941030
UPC: 743683107146
Technical specifications
| Brand | Lewmar |
| Model | Lewmar Size 41 Low Profile Hatch Flange Base |
| SKU / MFR# | 1002134 |
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