Tackle-tinkering time is coming fast. It is almost axiomatic that anglers extend the enjoyment of their sport through long winter evenings by tinkering with gear. Each year more of them are tying their own flies.

In spring and summer I frequently spend time with individuals and groups anxious to learn to throw a fly line or improve casting techniques. A question that I am hearing more and more is, 'Bob, what am I doing wrong that makes flies come apart when I cast them"?

The answer is simple. There is nothing a caster could do that would cause this. Starting the forward cast before the back one straightens sufficiently, may snap a fly off but not make one disintegrate.

It is kind of a fad now to assemble flies with no knots except the one that finishes the head. Some of the most prestigious concerns are turning out flies that depend on several turns of waxed thread alone to hold each operation in place. They are bound to come apart in service.

The only ways I know to be sure of obtaining durable flies is to buy from an individual tier in whom you have confidence or learn to make them yourself.

This is probably one reason for the revival of interest in learning the craft.

Here are some construction tips that will insure durable, neat flies.

General: First of all master the half-hitch. Learn to hold it in the desired position with a finger of one hand while pulling straight down to tighten with the other. Pulling straight down will help keep the material you are securing where you want it and on top of the hook.

Practice this until it is automatic. One or two wraps and a half-hitch will bulk up much less than several turns of thread.

Secure each operation with a half-hitch and a drop of cement.

Don't use waxed tying thread. Fly head cement won't penetrate wax. Old fashioned varnish will, but it dries much too slowly.

Modern tying threads are nylon and won't rot. Wax was used originally to prevent tying silk from rotting, not to hold material in place.

If you tie with a bobbin, don't let it hang and spin. it weakens the thread.

Clamp the hook in the vise with the point exposed. Burying it will often crack or break a properly tempered hook.

You can prevent the finished fly from twisting and sliding on the hook by first making a foundation of tying thread and cement. Coat the hook shank with tying cement, wrap with thread and half-hitch at the rear, then coat again with cement. Be sure to wrap up close to the eye to close any gap where the metal forming the eye turns back to the hook.

The only exception to this is when hair is to be spun for hollow hair bodies.

Tails: Dry flies almost always have tails. Wet flies and nymphs sometimes do not. Dry fly tails must be stiff and water-resistant. The others should be soft and water-absorbent.

Putting on a tail is usually the next operation after the thread base. Secure it on top and to the rear of the hook with a turn or two of thread, a half-hitch and a drop of cement. As a rule, dry fly tails should be as long as the hook and those on wet flies extend back of the hook only one body length.

Bodies: Tie all the body material strands on before any is wound. Secure them in the opposite sequence than they are to be wound. That is, what is to be wound last is tied on first.

For dubbing, wax a separate piece of thread, dub with fur, then tie on. By using different thread colors and allowing it to show through slightly, various body hues can be obtained and you won't get wax on the tying thread.

To wind ribbing or another feather through hackle without tying down fibers, wrap with a zigzag motion.

Make a fur or yarn body more fuzzy by combing with open scissors points. It's quicker than picking out with a needle.

When making hollow hair bodies, don't wind the hook full length with thread first. Only the part where the tail and the first clump are tied on needs a thread foundation. The rest should be left bare so the hair will spin around the hook as it is tied on.

It's easier to center a clipped hair body on the hook if you trim it square first, then round off the corners.

Removing fuzz from a strand of herl to make a quill body is probably easiest done with a large soft eraser such as artists use. Just lay it on a flat surface and erase the fuzz.

The neatest flat tinsel bodies are made by fastening at the front, winding to the rear, then forward again. Any kink where it is tied on is concealed by hackle and the return winding covers gaps. Coat liberally with clear fly cement. This holds it in place and slows tarnishing.

Tie material such as herl, quill stem, hair or feathers in by the tip. When they are wound forward, the body will be more full towards the front, which is what you want.

Winging: Quill section wings usually give beginners (and some veterans) fits. They are really quite easy. The secret is to first make a half-hitch exactly where you want the wings to be, then, holding the matched sections tightly between thumb and finger of one hand, place them on edge on top of the hook. Now, without releasing your grip at all, take a loop of thread over the wings with the other hand and pull straight down. The thread will pull down between your finger and thumb and compress the quill fibers without allowing them to separate.

Do this one more time, open your fingers to inspect and if everything is okay, secure them with a half-hitch and cement.

Leaving part of the center stem on each quill section will make it easier to tie them on without splitting but unless the material you are using is very short or too coarse, it shouldn't be necessary.

Many older brook trout patterns and some modern salmon flies call for stripes of contrasting color in the wings. This is done by "marrying" feather sections. Notice how a duck wing feather can be stroked back together if the feathers separate? The living bird does this with its beak. You put a multicolored wing together in the same way from sections of dyed feathers. Just be sure they are from the same bird family. For instance, it would be difficult to marry turkey and duck feathers.

Hackle: Palmer hackle, which is a feather or feathers wound the length of the body, is fastened in by its tip and spiraled forward. By doing this the legs that it simulates are longest at the front like a natural insect's. Tie it on where the rest of the body material is fastened. Since it is wound last, it should be tied on first.

Don't try to wind more than one feather at once. You will end up with loose hackle.

Feathers for shoulder hackle are prepared by stripping the fluffy fibers from the stem's base. Do this with a scissors, leaving a row of stubble on each side, rather than just pulling it off. The hackle is tied on by the butt and this helps the thread and cement get a good grip.

Hackle feathers are wound on edge but don't try to force this. Usually, after 1 turn or two, they wind edgewise of their own accord. If you find one that doesn't, discard it. If a feather insists on winding flat, every one from that chicken will.

Nymphs have stubby legs. Trimmed hackle looks natural on them. It is a good way to use up feathers too wide for flies you ordinarily tie. Trim it before winding.

Tying a hackle feather on with the concave side towards the hook will cause it to wind with its fibers sloping towards the rear. Concave side out will slant the fibers forward.