Thanks for reply, but, again: Does putting two battens in one pocket run the risk of doing damage to the pocket?

Specifically, at the luff end of the pocket. Because you can get only one batten into the batten pocket protector.

All three of the plastic lower batten pocket protectors on my stock sail have split, which looks to be increasing the sail's draft some.

The pocket will accomodate two battens, but not the plastic thing on the luff. The stiffening batten does not have to be full length either. Probably a good idea to tape the stiffener to the regular batten

I have some old TheMightyHobie18 battens. I will try 2 of those.

The company that makes those battens for Hobie, makes bigger ones and they are cheap compared to most battens. I will look for one that is about twice as stiff.

To answer the question about who makes stiffer battens, almost everyone that makes battens. They make battens for big boats that are wider and thicker. They are normally sold through sailmakers. The stiffest batten I know of are the carbon over aluminum honeycomb. They are sold under the black magic and other names. If you need something stiffer than that, you can order sheets of composite and cut then into strips with a table saw or laminate wood carbon.

I have not seen ratings for batten stiffness -- like the hardness rating on bolts and screws. Or for the diameter or thread size of bolts and screws -- like #10 oval head screws with 24 thread size.

There are variables in the making of things like this. If a rating system exists, I haven't seen it. Go ahead and give me the "you-dummy" if you find it...

The batten pocket protectors (80550005) used to replace the original (12480001) take up 1 5/8" battens.

Heh, just trying to steal the knowledge you've gained from experience...

I like the idea of taping the battens together...

Batten that are ready to go in a sail are classified by:
"Full battens are classified by their draft position and bend characteristics. The draft position is the fore and aft location of the maximum amount of bend at a given bend pressure. This measurement is given in a percentage of the batten's overall length, starting at the inboard end. The poundage it takes to reach this maximum draft position is the weight of the batten. For example, a batten would be classified as 56 inches long x 5/8 inches wide x 40% draft x 6.5 lbs." (from Ullman)

Blank stock is frequently classified by how many pounds hung from the middle of the batten it takes to deflect the center of a 40 inch batten tbd inches.

A sailor has different approuch. All he knows he needs a stiffer batten or softer batten and he just needs a way of comparing the battens he has. A sailor comparing battens, puts one end of the batten against the wall, connects a fish scale to the other end of the batten, then by pulling on the fish scale the sailor moves his end of the batten about 1/8 the total length of the batten closer to the end of the batten against the wall, and reads the scale. All you need is a fish scale and a tape measure to compare battens.

Hmmm. Thanks.