Making a mast base plate adapter for the Beaufort

Beaufort - side view
Beaufort – side view

At the writing of this article, I have installed SeaDog sails on three different kayaks. Each installation has been different due to differing circumstances. Each installation, while requiring some extra work, has been reasonably easy and straight forward. In this article I will concentrate on making an adapter for the mast baseplate on a Skimkayaks Beaufort.

Vortex and Whisper with Instaled with SeaDog Sails
Vortex and Whisper installed with SeaDog sails
Mast baseplate on the Guillemot expedition single
The deck of “Whisper”, a Guillemot expedition single has a very large radii curve. So I screwed the mast base-plate “as is”, with only a thin 4mm EPDM foam strip between the deck and base-plate. Thus far it has been enough. deck is strong and no water ingress has been observed.

 

The Deck of the Vortex has a slight ridge, which more or less requires an adapter, if the baseplate is to be installed on the centerline. Here I fashioned a clunky looking adapter from a scrap piece of HDPE. A quick and dirty solution which has worked thus far. To ensure against water ingress I put a blob of (Black)SikaFlex polyurethane based sealant/adhesive between the adapter and deck when installing the whole set.
The deck of the  Tiderace Vortex has a slight ridge, which more or less requires an adapter, if the base-plate is to be installed on the centerline of the deck. Here I fashioned a clunky looking adapter from a scrap piece of  white HDPE. A quick and dirty solution which has worked thus far. To ensure against water ingress I put a blob of (Black )SikaFlex polyurethane based sealant/adhesive between the adapter and deck when installing the whole set. The purpose of the sikaflex sealant is to seal, rather than attach The two m4 SS thru-bolts do the job of attaching.  Also under the deck I made the opposite shape from a similar sized HDPE block. Thus hoping that mast pressure will be spread out on an larger area.. somewhat anyways.. SO far All seems to be working nicely.

The Beaufort however, with its negative groove (or gutter)  running down the center of the deck is the most demanding installation thus far. The negative groove will require an adapter  for the mast base plate.  The flat bottom of the plate needs to be mated with the bottom of the groove. Otherwise this may cause pressure ridges onto the deck groove which may later cause cracking. Also the mast base plate needs to be slightly higher to allow  enough counterclockwise rotation of the mast attachment piece!

Mast baseplate sitting at the intended location on the deck of the Beaufort... See the problem? mating a flat bottom against a concave surface..
Mast base-plate sitting at the intended location on the deck of the Beaufort… See the problem? mating a flat bottom against a concave surface..

 

I had some balsa/WesternRedCedar scrap blocks leftover, which I decided to use in thie project. Initially I made two test prototypes which are in their very rough form here. Mast balse plate to give idea of shape
I had some balsa/Western Red Cedar scrap blocks leftover, which I decided to use in this project. Initially I made two test prototypes which are in their very rough form here. Orange mast base plate to give idea of shape.
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After a rough pencilled in outline, some imagination, the actual shaping of the balsa/WRC pieces was fairly easy and quick work with a carving knife and a sanding block.
After rough shaping the topside of the adapter block I still needed to shape the mating surface, ie. bottom surface of the adapter.
After rough shaping the topside of the adapter block I still needed to shape the mating surface, ie. bottom surface of the adapter.
In order to get te best fit with minimal effort, I used the deck gunnel as a shaping form , by putting 120 grit sandpaper on it and sanding the adapter block bottom to the corresponding shape.
In order to get te best fit with minimal effort, I used the deck groove/gutter as a shaping form , by putting 150 grit sandpaper on it and sanding the adapter block bottom to the corresponding shape.
After Sanding the block sits nicely in the groove.
After sanding, the block sits nicely in the groove.
While I was at it, I made prototype#3, more of a teardrop shape. No practical purpose, more aesthetic if anything.
While I was at it, I made prototype #3, more of a teardrop shape. No practical purpose, more aesthetic if anything.
After the final shaping of the balsa/WRC plugs, I vacuum bagged them. 1 layer CarbonFiber + 1 layer of carbon/glassfiber combo in epoxy. Being prototype work the workmanship is a bit rough. Operative term being here "quick and dirty. Later several layers of varnish to close the pinholes visible in this picture.
After the final shaping of the balsa/WRC plugs, I vacuum bagged them. 1 layer CarbonFiber + 1 layer of carbon/glassfiber combo in epoxy. Being prototype work the workmanship is a bit rough. Operative term being here “quick and dirty… Later several layers of varnish, to close the pinholes visible in this picture.
The undersides of prototype #1 and #3. The grooves purpose is to let water run pass under the adapter down the groove and not cause a "dam" onto the deck.. yes..I know it might be splitting hairs... ;)
The undersides of prototype #1 and #3. The grooves purpose is to let water run pass under the adapter down the deckgroove and not cause a “dam” onto the deck.. yes..I know it might be splitting hairs… 😉
Prototype#1 setting on deck prior ot installation.. Looks ok.
Prototype#1 setting on deck prior to installation.. Looks ok.
Prototype #3 looks good on the deck. I think this is the one I will go with!
Prototype #3 looks good on the deck. I think this is the one I will go with!

More about the actual installation process of the mast will follow…

Author: paaso.fi

A wee bit touched on the head! Something , anything and pretty much everything that has to do with sea-kayaking has my undivided attention, adoration and possibly worse.. ;)