Lewmar Retro Fit Hatch Stay in practice

The retro-fit stay kit PN # 360918999 is a replacement option if your original strut or friction hinges (eg Rollstop/Superhatch) are no longer working, missing parts or just plain broken.


Originally developed for use on motor boats where slamming can create forces for which friction based supports may prove inadequate.


One key constraint is that at best the strut will allow 90 degree opening, but no more.


It's also designed to mount through the acrylic at its upper end which can be both a challenging DIY job (though less so with a fine bladed multitool) and stressful on heavier models where the action of the strut will put the acrylic/frame seal in tension in the locality of the attachment point.


3 Fitting Lengths

I have to admit that when I first researched this I was expecting three different models to support the three lengths quoted in literature, but in practice there is only one, with the customer expected to cut the support rod to fit. Three attachment holes are pre-drilled, though in practice the customer could drill their own hole and cut to suit.


The maximum length centre to centre (excluding the acrylic attachment) is 467mm. If using the acrylic attachment this adds 20mm to the underside of the acrylic. The stainless tube length is 383mm uncut and the handle body length is 100mm. The lower end of the tube is turned over to ensure it will not exit the top of the handle body but it can pass freely through the bottom.

Lewmar recommend two struts for Size 70 and above (~680x680mm overall) and one for smaller sizes. The handle locks by twisting the handle body. The tube is 10mm OD with a 1mm wall thickness, I presume 316 Stainless.


The photo to the right shows the strut in the fully extended position on a large Canpa hatch, if attached to base and frame, rather than through the acrylic. That's Tim holding the lid.


Mounting considerations


The tube holes are 5mm (M5) diameter. The handle base has a recessed mount with a 10mm hole, with the recess having a depth of 6mm and a diameter of 14.5 diameter. In the fasteners pack there is a plastic insert which fits in the recess and provides a M5 mounting hole. The back of this is slanted, presumably to fit the curve of the frame at the lower mounting point.


The centreline of the tube is offset approximately 20mm from the inner face of the handle attachment point, meaning that to be parallel in operation this must be accounted for.



Our View


The handle grips well so I doubt this will give trouble. The bottom mount could probably be drilled out to accept an M6 fastener, more common on older hatches. Mounting through the acrylic is relatively easy to fit with the correct tools, but be aware that when drilling acrylic it is best to use bits which are slightly dulled, particularly for the stage where you break through the other side. New/sharp bits may chip the surface when exiting the lower surface.


It's worth noting that sealed hatches (ie those using sealant around an acrylic sitting onto the frame) are sealed with sealant and not bonded with adhesive (please don't use adhesive) and as a result may suffer from the tension resulting from a through acrylic mount. Note that the Ocean, which has a friction lever mounted through the acrylic is also supported by an alloy extension from the frame for this reason. These issues are significantly reduced for hatches which use rubber seals encapsulated within the frame (eg Lewmar Low and Medium profile) where acrylic mounting is the best option.


If considering this for a traditional, heavier hatch, the better approach would probably be to not mount in the acrylic and manufacture a spacer which allows the tube to be fastened to the lid frame directly, but held off such that the tube is kept parallel in operation. Find a friend with a 3D printer or lathe and you're in business.


Alternatively, be aware when original spares are unavailable and love what you have.


Pack contents

  • Strut

  • Acrylic mount (3 pieces including top gasket)

  • Fastener pack

  • Instructions

Image to right shows acrylic mount components.








The fastener pack is designed for Lewmar hatches, but includes;

  • 1 x M5 25mm crossed pan head machine screw

  • 1 x M5 16mm hex cone head machine screw

  • 2 x M4 16mm crossed countersunk machine screws (for acrylic fitting)

  • 1 x M5 washer

  • 1 x M5 nut

  • 1 x M5 captive nut

  • Plastic insert for handle fixing with M5 hole

Image to right shows fastener pack contents







Price


RRP is £60 including VAT



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