Paneled Sails for RG65?

Are paneled sails worth it at this size? I ran a couple of typical plans through Sailcut and the amount of curvature at the seams was miniscule.



Hi Earl - I guess I would second that question.

I have just finished my first flat (single) panel and once on the mast (stuck into some soft earth in the front yard) they actually have a decent looking set to them in the light breeze we had.

I have some drafting vellum that I was going to try making a test set of paneled sails just to see if there was a measurable difference. Like you - when looking at the curvature in the individual panels, unless you lay a straightedge on the seam line - it is pretty hard to see much. Perhaps even that little bit would make a difference though.

Any sailmakers care to weigh in?

As my sails seem to come out better than my hulls, I made them panelled. But, I don’t think it’d be all that important.

I’ve often wondered if a flat sail made from rip-stop would stretch just enough to give a little camber. It should work in light to moderate winds, might add too much camber if the wind gets up. On a small sail like the RG65 there wouldn’t be that much stretch though.

I was wondering about the effect a flat or cambered sail set would have on the RG-65. Seeing that the difference will be very little, it will be much easier to make a set of sails for me as well as any other newbies.

At least with a single panel sail the repeatability is there. With a panelled sail of that size you might make one perfect sail but I would doubt the chances of duplicateing it.

I have made good experiences with panelled made by myself. I use UL-Mylar (appr. 25g/sqm) for both MicroMagic and RG-65 sails.
However, I know many good skippers in both classes using “flat” sails only. For my opinion in both cases the most important thing is, that the luff curvature meets the mast bend well. This can be controlled better with panelled sails, because flat sails need an extra amount of luff curvature to get the necessary camber.

On the other hand, there are several guys familiar with fluid dynamics, who say that in such small dimensions it makes no difference at all …

I am in the process of building sail set #1 - fortunately I didn’t get the numbers affixed. Grandson has decided he wants white jib/red main. Thus the jib in photo when done will be his dad’s who will have a red jib/white mainsail. Ahhh GrandKids - would do anything for them !

Anyway - I’m going with flat panel and will be able to dial in camber or no camber by outhaul and downhaul (Actually main halyard… more like uphaul)

Fabric is 1.5 oz. ripstop treated nylon. Corner patches are sticky-back Dacron and lettering/numbers/logo (not in photo) is hand-cut vinyl. I am thinking wire mast rings to attach main to mast. Forestay will run inside jib luff. Battens on both main and jib.

Still need to add mast crane (carbon tube probably) and trim mast length to class legal length.

really Nylon?

It is not a good choice! Nylon will not keep its shape when getting wet. Use Polyester spinnaker cloth instead or the so-called Ultra-Light Mylar.

It’s a treated finish. Water doesn’t affect it. Works for my multihulls, [see photo below of my 1 Meter trimaran] as well as a few of my other boats. Would love to be able to buy polyester, but it is getting pretty scarce. Many of the US fabric companies moved production to Asia and what is imported is more for clothing industry - ie - very soft hand and that’s the stuff that won’t hold shape.

… then good luck for you!
We made the experience, that even coated Nylon will absorb water from the edges. This leads to curling leeches.
Of course coated Nylon is much better than the conventional stuff, but as far as we have learned not good enough.

Polyester spinnaker cloth is here available from sailmakers (they often have small peaces left - pieces too small for big sails but large enough for our small sails) or from kite shops. In Germany polyester cloth is known by the kiters as ICAREX PC31

Isn’t Icarex something a bit more special, like polycarbonate coated polyester. It’s much more expensive than Mylar. has a nice collection of thin Mylar (left hand menu - LW Covering)

Martin - will save the web for future reference. Like Haegar’s suggestion for Icarex - if you do a Google search - you don’t get many “hits” on the product here in the states - so one must add the shipping costs from overseas on as well.


The site did give a “trade-name” that I can look for. I also am hitting up some aerospace suppliers for some specialty products. Have a batch of samples on thier way to home so I can actually see/feel products.

As an aside - woman in customer service decline recommendations - she had never heard of r/c sailboats !! :smiley:

Why not use Trispi for your sails? It is available from several RC sailing sources. It is also available in several weights. The stuff is expensive but not prohibitively so. Trispi is stable, waterproof, and is not subject to much if any stretch

I will argue in favor of the paneled sail, even on small ones. Yes the “broadseam” curves are miniscule, but if you want an effectively shaped sail those curves are necessary. A flat sail can be randomly shaped by luff, leech, and foot curves along with bending (or not) spars. To induce draft into a flat panelby that method, the fabric must be forced into a distorted condition. Subjected to tortured areas, the fabric will reward you with inconsistant shapes and duplication is an iffy prospect.

The use of sail blocks will solve the miniscule curve problem. The process of making sail blocks is well within the capabilities of many of the forum members. A simple 2 x 4 is the basic material. The narrow edge is cut to a radius usually somewhere between 54 and 72 inches. Then the block is faced across the wide surface with an angle of from 3 to 6 degrees. The blocks are used in identical pairs. Smaller curve radius and/or larger flat surface angles will yield more draft and visa versa. The best sails seem to have more draft, relative to chord, in the upper panels, which defies my intuition.

One of the blocks is sprayed with an adhesive such as 3M spray mount. That will hold one of the panels in place while the other is carefully positioned across the non sticky block. Dressmakers basting tape or similar double stick will join the panels nicely. Some but not all basting tape is water soluble so one must read the labels before buying it… But many of you guys already knew all that sail block stuff didn’t you.

I risk starting an argument by claiming that sails are more important than the boat if winning races is your game. That is a frequently demonstrated reality with full sized boats.

No argument - but an observation …

If what you say is true, then Footy’s like J Class all should have paneled sails. Additionally, there is a world of difference between Footys (and the RG65’s) sail areas of less than 300 sq. inches as opposed to a full size boat with sail areas of 190 sq. “Feet” or more in size.

Like the tall vs. short rigs and air velocities at surface versus 4 feet in the air versus 30 feet in the air, I guess on water performance will bear out if performance warrants the extra time. My first ones will be single panel strictly because of limited time factors. Perhaps my own hull #2 will allow me to spend more time building a panel sail to see if the difference does exist.

First project is to find a good, but inexpensive source of lightweight material for sails - be it Icarex, micron Mylar, Polyspan, or some other alternative where weight is more critical than in an IOM or similar.

Will see what my aerospace contact delivers as samples. Maybe a whole new product for consideration with real on-water experiences. :cool: