Chromed Canopy Turn-Button Fastener – Brass Base & Catch

The fastener (code 03975), often referred to as a “turn-button” or common-sense fastener, is a traditional locking device for boat canvas. It consists of two main parts: a flat base with screw holes and a movable winged tab (turn button) in the center that can rotate. When the tab is in the open (vertical or upright) position, it allows the canvas to be placed or removed; when it is rotated into the closed (horizontal) position, it clamps down on the canvas and locks it in place.

Design & Mechanism: This fastener is crafted from brass with a chrome-plated finish, ensuring both durability and resistance to corrosion. The central tab operates on a spring mechanism – when you turn it, it presses down on the canvas under tension. Typically, the open position has the tab aligned vertically (or at 90° to the base), and the locked position has it horizontal against the base. The quarter-turn action is easy to perform, even with gloves on or in rough conditions, providing a tactile and visual indication of locked/unlocked status.

Installation: The fastener mounts with two screws (usually spaced about 20 mm apart) onto a solid surface – for example, a cabin doorway frame, a hatch coaming, or the side of a console. Once installed, there is a small gap under the tab where the canvas (with a corresponding eyelet) will fit. In our system, this is achieved with the female clip 03974 installed on the canvas – its knob and rim essentially act as the “catch” that the turn button will secure. To use, you line up the canvas eyelet over the turn-button post while the tab is open, then rotate the tab flat – it slides over the edge of the eyelet and locks it down, preventing the fabric from coming off until you rotate it back.

Usage: This type of fastener is preferred in situations where the cover needs to be held very securely and not come undone on its own. Example: canvas cabin doors (the fabric flap that closes the companionway) often use these turn-locks on the inside; they keep the flap shut tight even under wind pressure. Also, on “dodgers” or windshield canvas sections, this fastener is used because it won’t accidentally unsnap – a deliberate quarter-turn is required to release it, offering a safety advantage over regular snaps.

Security and Advantages: Compared to common snaps, the turn-button provides a higher level of security. The canvas cannot be simply yanked free – the tab must be rotated first, which means the cover is far less likely to come loose due to wind or vibration. The chrome-plated brass construction ensures the mechanism’s longevity – the spring element is protected and the material won’t rust. Even after years of use, maintenance is minimal (perhaps a drop of lubricant or WD-40 on the pivot if it ever becomes stiff). The two-screw base spreads out any stress, and the hardware stays firmly attached to the boat.

Integration with Canvas System: As mentioned, this fastener should be used in conjunction with a matching canvas eyelet. EVAL’s female clip 03974 serves that purpose – it’s the part installed on the canvas that the turn-button grabs onto. If your canvas already has common-sense grommets, they will likely fit as this fastener follows the industry standard sizing. In case you are refitting an older cover – this fastener can directly replace the old ones, since the screw spacing and function are universal for this style.

By using this fastener (03975), you add a reliable locking mechanism to your boat’s canvas that is easy to operate (with just your fingers or using the auxiliary key 03999 if needed) and that keeps everything firmly in place even under harsh conditions. It’s the finishing touch for a well-secured boat – a small piece of hardware that offers big peace of mind, ensuring that your cover or enclosure won’t flap open or be carried off by the wind until you choose to release it.