Sailrig mast step screwing in necessary???

Building a CLC canoe/ kayak sailrig with a 40 sq ft sail to be mounted on a MC 13.

On attaching the mast step to the cockpit floor is it absolutely necessary to screw it in through the bottom of the hull. The manual suggests this for the 70 sq ft sail for EXTRA MEASURES  but no info on the smaller sail attachment procedures.

I would just epoxy/cab o sil it to the floor and fillet around then drape two layers of four oz cloth epoxied over it. 
Just unnerving to drill through the hull and deal with wear and tear on those screws ongoingly. ??? Countersinking or using a plate would be necessary IMO. So more work, necessary or not ???

Thanks for any insight on this, PP

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RE: Sailrig mast step screwing in necessary???


I have never screwed the mast step onto any of my S&G boats, including my  18-ft schooner, and I have yet to have one tear out.

I totally agree with your concerns about the screws. They're stress concentrators and require holes in a perfectly good watertight shell. Why would anyone do that when they're permanently bonding the mast step anyway?

The trick is to make the mast step assembly very solid, thoroughly bed it to the floor and use great big fat fillets along the sides.  I used woodflour for the putty, no cab-o-sil, and did not glass the fillets.

On one boat the step was 4 layers of 3/4" marine ply, 4x4 inches with a 2" diameter hole bored dead center through the top 3 layers.

For the schooner, I built it up out of plywood and dimensional lumber. Here it is before the final fillets. The inside joints already had their fillets.

Glassing the fillets wouldn't hurt anything but I didn't find it necessary. Consider how hard you'd have to whack a properly constructed and bedded mast step with a sledge hammer to pop it off the floor. The mast and sail on a small boat will never develop that kind of force and even if it did, the mast step would probably break before the joint.

So, yeah, lose the screws. I'm building a sail rig for my WD12 and that step will not be screwed in.

Have fun,



RE: Sailrig mast step screwing in necessary???

   @ Laszlo Thanks I always ask myself WWLD? Now I know.

So the manual says four screws for good measure, I think the concern is the larger sail size 70 vs 40 sq ft. 

BTW see my other post on ama flanges. Will you be modifying in any way? I've already built the amas but considering laminating another 9 mm piece on the midship deck side and filleting to the deck. For "good measure"


RE: Sailrig mast step screwing in necessary???

For some reason, I decided not to screw the mast step on my Eastport Pram.  One day when sailing in 16 knots, I heard a loud crack in that general vicinity.  When I looked closely, the entire fillet delaminated.

RE: Sailrig mast step screwing in necessary???

   So one for one against, anyone want to break the tie?

@ Captain Skully. Did you glass cloth over it or just glue and fillet?

Also I stand corrected on my comment of no directions for smaller sails.

On plans sheet 8 part 3 number ten it does say " with a helper, securely install mast step with thickened epoxy and SCREWS" FWIW!


RE: Sailrig mast step screwing in necessary???

The mainsail on my schooner was 55 sq ft., the foremast had 56 sq. ft. with the foresail and jib, My sailing dinghy is 40 sq. ft. The Eastport Pram is 42 sq. ft. and the sailrig is 40. So they're all in the same ballpark with my gaff-rigged schooner being the outlier with about 20% more sail area per mast than the rest. I've had both boats out in excess of 25 kt winds and none of the unscrewed mast steps failed.

The step on the Eastport Pram looks a lot lighter than the steps that I used on my boats - less wood and thinner pieces. There's less surface area to bond to so there's more force per square inch. That could have had something to do with why the one on Scully's EP failed without screws.

The other possibility is a dry joint. The fact that it had delaminated instead of the wood breaking sort of hints at this.

Based on the relative sail areas and years of sailing them, I'll still stick with the no-screws approach.

No plans to modify the flanges at this point, though that may change when I get to that stage.



RE: Sailrig mast step screwing in necessary???

   On my EP I took piece of 1" mahogony and cut a square in the middle of it and epoxy and fillet to the floor. the mast fits in the square hole and eliminated any slop . Kinda like a mast cup. works perfect. the stock clc mast base is still there 

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