Bottom Connector for Nesting Dinghy

[Garry]

Here is a pic of my bottom connector design that I will be using for my Spindrift nesting dinghy. The fasteners will be install once the final fairing and finish work is done.

I routed recesses for the plates and the space for the "hook" to go before I taped the nesting bulkhead seams so that they will lie flush. I plan to add some thickened epoxy to the taped edges to make the seam more streamlined.

I used this design years ago on my first nester and it worked very well. The forward section simply drops onto the stern section "hooks" and then the top is connected. I always put mine together in the water rather than wrestling with it on deck.

I will also upload a jpg drawing with the details. If it doesn't come thru clearly, email me for a full size version.

[attachment over 4 years old deleted by admin]

[Klaus]

Hi Garry, this design looks neat, do you have a pic of the two parts on their own? How does sand affect the un-nesting of your idea?

What I find annoying with the mortise type lock on my dinghy is that any sand that gets into it makes it rather difficult to un- nest.

On a cruise I never disassemble the dinghy, it gets towed complete. There's no room for it on the fore deck anyway. and, at 10' its big enough not to worry about flipping in the conditions I sail in.

So, after a few beach landings the sand gets in the join, it also gets into the dummy CB plug, it jams things solid and makes the removing of it a very trying job.

If you can convince me that your idea is 'sand proof' I might copy it next time my nester gets an overhaul.

Klaus

[Klaus]

Just spotted your drawing which makes the design crystal clear to my muddled mind. I also notice that you use two of these 'hooks'.

Is that really necessary? I would imagine a single 'hook' at the centreline would be easier to 'engage' and it would certainly be strong enough as there is no load on it once afloat as a whole dinghy.

Klaus

[Garry]

Hi Klaus,

You are probably right that one center connector would be enough. I went with two so that any stresses are carried mainly by the side panels and not stressing the bulkhead joints. Also, if I decide to use dinghy davits or just drag the dinghy up the beach etc.

I don't remember any problems with the connectors getting jammed. There is enough extra room for sand etc. to get flushed out. I would think marine growth would be the biggest problem. I would take the dinghy apart occasionally and clean the gunk out.

I don't know about the CB plug. Maybe a little extra room to let things work out?

I certainly don't want to convince you of anything. These are just my ideas offered for use at your own discretion. (But I think they will work out fine.)

[Steve Day]

Garry,

Your nesting brackets look pretty cool. However, I am subscribing to the KISS principle and will use Graham's original design of 5 machine bolts and wing nuts.

As far as the CB plug goes, I'm probably going to go with some sort of cap as opposed to the plug. My cap will probably extend down a couple of inches into the slot, but for now will not extend all the way down to the bottom of the boat.

Steve

[Klaus]

Steve, you are probably right, the CB plug does not have to close off all of the slot. Its just the way my mind works, it does not look right with just a cap, even if only the fish will notice it :wink: .

Klaus

[Garry]

I think it might be important to reduce hydrodynamic drag to have the CB plug come flush with the bottom of the boat.

Also, I have been thinking about Klaus' (if I remember correctly) story about a fountain of water coming up thru the trunk. A flush bottom profile would help keep from building up the pressure to do that.

In addition, I think that I will form a ridge on the side of the CB plug (and maybe the daggerboard also) just below where the PVC roller rests when the plug is in position. This is to provide more initial resistance against the plug coming up, but not enough to prevent pulling it out manually.

[Klaus]

Garry, the CB plug that popped out and provided the spectacular water fountain was closing up the slot at the bottom. I made it very light, from western red cedar wood and it was just a frame of about 1x1" pieces with no centre at all. There was a cap board of 4mm plywood that was held by a thin shock cord, cleated in a clam type cleat.

It was the cleat that let go of the shock cord, resulting in an easy water pressure push to expel the plug out through the top CB opening.

I now have a much more secure retaining method with two different cords holding the plug down. The plug is also much heavier but, alas had jammed up with sand.

It now has two shallow grooves routed all round the bottom part in the hope to trap the sand there and not at the tight fitting places.

I will see on my forthcoming cruise how successfull that idea was :wink:

I have also fitted alu half round strips at the keel line and on the two skegs as my dinghy had suffered epoxy abrasion by being dragged on the sand. After rowing 100m against a 20 knot breeze to the beach, one has little incentive to carefully lift the dinghy

Klaus

[Klaus]

Garry, the CB plug that popped out and provided the spectacular water fountain was closing up the slot at the bottom. I made it very light, from western red cedar wood and it was just a frame of about 1x1" pieces with no centre at all. There was a cap board of 4mm plywood that was held by a thin shock cord, cleated in a clam type cleat.

It was the cleat that let go of the shock cord, resulting in an easy water pressure push to expel the plug out through the top CB opening.

I now have a much more secure retaining method with two different cords holding the plug down. The plug is also much heavier but, alas had jammed up with sand.

It now has two shallow grooves routed all round the bottom part in the hope to trap the sand there and not at the tight fitting places.

I will see on my forthcoming cruise how successfull that idea was :wink:

I have also fitted alu half round strips at the keel line and on the two skegs as my dinghy had suffered epoxy abrasion by being dragged on the sand. After rowing 100m against a 20 knot breeze to the beach, one has little incentive to carefully lift the dinghy

Klaus

[Steve Day]

Klaus,

The aluminum strips on the bottom of the keel sound like a good idea. I suspect I will put some sort of rubrail strip on my keel too. Do you have additional skegs on your dinghy? If so, where?

I have been thinking about sand, and rocks up here in Nebraska, abrasion on my boat. Maybe an additional skeg out near the chine on the bottom would be a good idea. What has been your experience?

Thanks,

Steve

[Klaus]

Steve, I will soon know if the alu strips, fastened with countersunk ss screws will do the trick. The idea is they get bashed up first when dragging the dinghy up the beach.

My Cameleon dinghy is designed to have twin skegs on the aft section. They start about halfway along the aft section and increase to about 2 1/2" heigth. They are spaced about 16 - 18 " apart.

Twin aft skegs keep the dinghy upright on the hard, they seem to help it track in a straight line very well while towing or rowing. Even for sailing, for those last few feet to the beach when the board has to be raised.

Klaus

[Klaus]

I should add that there is no centre skeg at all on my dinghy.

Klaus