A lot of the lanyards I use now are spliced by melting the ends of the nylon cord and making a butt joint with them.
You melt them just about the same as if you were doing a flame whipping and then just shove them together end to end.
I usually roll the joint between wet finger tips before it hardens just to smooth it out.
You end up with a short hard joint about the same diameter as your cord.

No question that people have often been successful with improvised signal mirrors, though one's chances are greatly enhanced by being well practiced in the technique. I've practiced a lot with improvised signal mirror aiming methods.

The "somewhat lessened accuracy" was determined independently by the Yanks and the Brits to be more than a factor of four in tests that were far more thorough and scientific than I've had the resources to duplicate {Tests detailed in my prior post.}

The beam of sunlight is very narrow, and the average passerby is inattentive, and not really looking for you in the first place.

I figure I'm going to be lucky to get them to respond to the first half-dozen flashes they do see. I'm not inclined to give myself a handicap unnecessarily when the AMK Rescue Flash mirror in my neck pouch cost under $10 and weighs 0.7 oz.

CASE STUDY I

One of the authors of "The Complete Walker IV" learned the hard way that getting people's attention with an improvised signal mirror can be harder than you like, even in the very favorable circumstance that they are: looking for you, expect you to be using a signal mirror, and are in the neighborhood for a long time.

On pages 706-708 of that book, the author describes his experience in trying to get the attention of an airdrop plane with the pre-arranged signal: a 2" diameter mirror pointed using the "thumb" method taught him by the pilot, a former Air Force survival instructor. He practiced before the trip until he thought he had the technique down pat.

The plane arrived overhead, and started circling 2 miles away. There were at least two observers on the plane expecting and looking for his mirror flash. He signaled for a full hour without success. He finally got their attention with a smoke plume as they flew over him heading back to base.

He now carries a dedicated signal mirror.

CASE STUDY II

I interviewed by email one survivor who was finally successful in flashing a helicopter with a plain camp mirror, a gambit he was aware of because he was a dedicated reader of the survival articles in Backpacker magazine. He had been unsuccessfully flashing passing planes for days.

He asked me to recommend a signal mirror.

My everyday targets are made from retroreflective tape, which works fine at 100 meters, but that's closer than I'd prefer, considering that SAR practice counts on seeing mirror flashes at 5 mile range.

One thing that is superb for a signal mirror practice target is an optical corner cube. At a range of 0.5 miles, the return from a 1.5" diameter corner cube is bright enough to "burn through" the fireball from a retroreflective aimer and let you know you hit the target. I wouldn't try signaling that cube at a range of less than 1/4 mile - too much like looking directly into the sun.

Without a "fireball" in the way (e.g., foresight or rearsight aiming) the return from the cube is visible at much longer range. I saw the return from the 2"x3" stainless steel mirror from a cube I'd mounted 3 miles away. I figure this approach drops off with at least the 4th power of distance, but even so, an array of 16 such cubes should work fine at 5 mile range (I tried it at 11.1 miles - no joy).

Alas, optical corner cubes are generally pricy, but occasionally you can get deals on Ebay. I've seen do-it-yourself plans for making a corner reflector from 3 mirror tiles, but I haven't tried that approach.

In a way, corner cubes and other retroreflective targets are too easy - after you hit them once, the feedback helps you hit them again. They are good for initial familiarization and drill, though.

For scoring, a spotter or video camera is better. At middling ranges (e.g., 1-10 miles) a star filter on the video camera makes it easier to analyze the video results later.

Two instructors and two groups, at range, is ideal.
For long range mirror signaling as part of On Target activity, we use cell phones and amateur radios for coordination.

You make a very persuasive case. I suppose I could shoehorn an extra 0.7 oz into my pack.....

I'd like to emphasize that you need to practice on a distant target such that you can't see the reflection hitting the background and guide it onto the target. Otherwise you are not really using the aiming system.

As mentioned before, a retro-reflective target such as special tape, automobile tail lights, bike reflectors or road signs work well for this.

My mirror is a Vietnam-era glass job w/o retrorelective mesh. From as stationary platform I can hit a stationary target very easily. A moving target would be more difficuly. From a moving platform, it would be very tough.

So, what features or capabilities would the ultimate signal mirror have? If you could have it all, what would you have in a signal mirror?

e.g. would some kind of telescope functionality be usefull? Even something like a 4x optic might increase the accuracy of your signalling. Not saying that's possible, but just to kick off some wild and crazy thoughts.

Case Study III - another real-life example where mirror signaling accuracy was not so great ...

An article in a US Coast Guard Auxillary publication from Oct 2009
(October 2009 issue of "Northwind", page 10, downloadable here)
http://resource.d11nuscgaux.info/northwin/2009/09OctNW_Web_View.pdf)

reported on their search-and-rescue exercise (p. 10, per protocol on bottom of p. 9), where one group was in a boat, and another in a search plane. The group on the boat were to signal to the plane via signal mirror. The plane spotted the boat by its markings, and made two passes. To quote the article:

"Only one mirror flash was observed during this approach, even though the sun angle was good for signaling"

Only one flash? With the people on the boat healthy, not in distress, expecting the plane in a narrow time frame, the plane expecting a flash from the boat, and two passes?

Not so good. No indication of the type of signal mirror used, but I'm thinking the boat team needed all the advantages they could get.

On the other hand....

We were helivacing an injured hiker from the Santa Catalina Mts., just north of Tucson, employing a Air Force bird from Davis-Monathan AFB (which lies within Tucson). As the sun rose, they asked for a mirror flash. I obliged, "painting" Tucson in the general area of D-M AFB, because I had no knowledge of their precise location. Sky conditions were moderately hazy, and they were at least ten miles distant.

They received flashes and had a fix on their objective before liftoff. It is always a good idea to make it as easy as possible for the helicopter pilot.

In most of our usage of signal mirrors, we did not know the specific location of our target. Painting was SOP....

I'm not worthy ... I'm not worthy *bowing and grovelling in Wayne and Garth fashion to the mirror master rafowell*

Seriously though (and this is a serious topic after all) I am seeing a lot of mention of 2" x 3" signalling mirrors. IIRC Doug Ritter stated that the reflectivity of the mirror is a function of its size. That said, I certainly hope everyone's dedicated signal mirror is larger than a 2x3. Granted it is extremely small, light and easy to carry but given a choice I would opt for a larger 3" x 5" or possibly a 4" x 6" for my main dedicated signalling mirror in a larger kit or pack. Or even in a pocket. I thought the smaller 2x3 was supposed to be a backup to your larger mirror but it appears that several people have turned it into their dedicated main signaling mirror. Not criticizing or belittling anyone here. Just want to make sure everyone is giving serious consideration to their signalling devices. I'm not an expert by any means just my opinion based on what I've read and learned thus far, mixed with a little common sense and stirred frequently over high heat ...

In terms of glass mirrors, a 2x3" mirror will be a lot less fragile than a 4x6" mirror. With plastic mirrors, a 4x6" will tend to warp a fair bit more. And, the more compact your mirror, the more likely you are to have it with you when you need it, i.e. a 4x6" isn't exactly pocketable.

We had been talking about aiming devices.

If you cant hit the target, it doesn't matter how big your mirror is. Even when painting an area, being able to accurately aim the device will increase the the probability of hitting a target in the area in a given amount of time (i.e. you will be more able to systematically scan the area). Same with scanning the horizon.