Spindrift 11N progress and problems

[Garry]

My Spindrift 11, Nesting version, is all formed up and the forward section is filletted and taped inside. I'm starting the filletting and taping of the aft section this evening.

The plywood pieces formed wonderfully after unfolding the butterfly and then stitching up the side seams. The transom and the forward bulkhead dropped in easily. But the center (nesting) bulkhead looked wrong when I dropped it in.

There was a 2" gap at the bottom! The shape of the plywood panels looked so perfect, it couldn't be off that much. Maybe I should have set the center bulkhead in place as I stitched the side seams and then pulled the panels to the bulkhead. I even turned the shell over and stood on the bottom panels. They were surprisingly strong already with just the wire stitching but they finally collapsed and formed a dish-shaped buckle against the short bulkhead.

[Steve Day]

Now I find out. I guess I should have called earlier. I found this same problem, but forged on ahead and sucked everything up to the nesting bulkheads. It really isn't too bad, but you can definitely see the "dish" in the hull on my boat. Now I'm wondering if the performance will be affected appreciably. :oops:

No use crying over spilt milk. I'm in too far to consider any changes now.

Garry, That is a nice looking boat. Maybe we will get together one of these days and be able to see if there is an appreciable difference in our Spindrifts.

Steve

[Designer]

Steve,

That problem with the bulkhead was only on the S11N and it came about when I upgraded that plan recently. You are building a S10N, and I checked the plan before writing this, your plan measurements are correct.

If your keel line is not completely fair, it may be because you did not draw the center seam completely tight, or your CL measurements/cutting were slightly off. The trouble with the centerline is that any errors are multiplied X 2, for instance if one of your measurements was 1/8" off and matched the other bottom to the first bottom then your CL would be off by 1/4".

There is an old saying in the boatbuilding business, "let the batten be the boss". When you have wired up the boat, if there are any hollows or bumps they should be tweaked/adjusted out. Such as: if it dishes at the bulkhead, ease it away until it is sweet; if there is a bump just behind the bulkhead let the wires go and run a jigsaw up and down the seam to ease it out a bit and then re-tie it.

This is, of course, academic to you at this point, but it may be helpful to others who have not yet reached your point.

You asked how it will affect your boat's performance. Probably not much. We've seen boats come out all sorts of ways - (within reason) and they still seem to perform fine. I wouldn't worry.

[Steve Day]

Thanks for the good words, Graham. I was extremely careful about the measurements when I cut and sanded to get the final line on the hull and thought I was doing OK. However, I did not get a batten against the hull until I was fitting the keel. That was when I spotted the "dish." It isn't too deep (less than 1/4"), so I'm not too worried about it. It will stand up to the "20-foot test."

Your words are good advice to boatbuilders that are cutting out and getting ready to "go 3D." I know that I will pay a lot more attention to this when I build another boat.

Steve

[Garry]

Hey Steve,

Building one of these dinghys gets you daydreaming about bigger projects doesn't it?

Dave Gerr writes about a nice 28 foot power cruiser in his book "The Nature of Boats." Maybe when sail cruising gets too much for me, I'll have the steam left to build one those.

Garry

[Greg Luckett]

I keep thinking about building and sailing the Princess 26. Someday