Timothy,
I don’t have a clue about whether the gap between panels does any harm or not. I just know that Roger Taylor has covered thousands of miles in his Mingming II. The gaps between the four lower panels are clearly visible in that rig (the upper section appears to be in one piece? ). Mingming II seems to perform all right, as most boats with cambered sails do.

However, lack of floor space is not an excuse for using separate panels.  One will anyway need floor space for lofting one full panel, and with that space available, one can also do the sewing. If done right, just about all sewing is done along an edge, so there is no need for rolling up big bundles of canvas to pass it under the sewing machine. Making my 35sqm sail for my Ingeborg in my crowded, little living-room shouldn’t be possible, but it worked well. Sewing was no problem at all. It was more a question of getting the lofting right and accurate. Measure twice  -  cut once!
Good luck!

Arne

    

Anonymous wrote:

Yes I have tried separate panels tied and laced individually to bamboo battens, and very soon decided that it was a good idea to  rather fill the gap with sailcloth.

Convenience in handling of smaller pieces of sail loses relevance once a performance comparison is made with one offering a 'cleaner' flow over the filled area.

Well that depends on how you connect the panels... it is possible to do it very smoothly and even without any gaps. If you are using bamboo, then by it's very nature the joining is likely to be gappy and probably uneven. Aluminium is a much more suitable material for battens in most western countries..

Anonymous wrote:

Anonymous wrote:

Has anyone tried leaving the panels separate and just lacing across the batten? Especially with chambered panels. 

Sure, I've made five sails like that to date and I'm using the method for LCB's main. However it's a lot more work and I see little point in doing it unless the sail is to big to handle in the space you have.

Work space is what got me thinking about this.  

Anonymous wrote:

Anonymous wrote:

Has anyone tried leaving the panels separate and just lacing across the batten? Especially with chambered panels. 

see: this thread

It is quite long but discuses it both theoretically and practically (someone has tried it or is in the process of doing so)

I had just found this! Thanks

Anonymous wrote:

But then I always wonder at the way an aircraft wing separates on landing and takeoff. The big gaps in the aerofoil does not seem to detract from the lift characteristics of the foil, maybe it even helps? But that is a different type of separation to what we are talking about.

Thanks David, 

This is kind of what I was thinking about. Each chambered panel being its own little sail, all working together.

I'm making a 10 sqm  sail for a small (~4m) boat. I may experiment and find out.