How to store leaders and tippet so they last

Three fish in a row, in the last hour of an August evening. None of them big. The tippet parts a foot above the fly on an ordinary hookset, then does it again, then a third time.

So you check the knot. The knot is fine. You run the rod tip through your fingers looking for a nick, find nothing, decide the hook must have been dull, and drive home annoyed with the fish.

The next morning you open a fresh spool out of the closet. Same brand, same size. You fish it for a month and the problem never comes back.

Here is the part that stings. The spool that failed never saw an hour of direct sun. It rode behind the seat of a hot truck all summer, in a dark zip pocket, alongside the sunscreen — which is exactly where the standard storage advice tells you to keep it.

The dark part of the checklist did its job perfectly. Something else in that pocket spent the strength, and the testing is fairly clear about what.

If it wasn't the sun, what wrecked it?

• Light is the least of it. Polyamide netting held under lab sun equal to 2,700 hours of daylight came out with 0.36% loss from simulated sunlight.
• Weather is the expensive part. The same family of nylon left outdoors on a hot roof held 74.23% of strength after 90 days. Buried dark and damp in soil for the same period, it held 88.41%.
• A cover pays. Working nets of identical nylon with identical service broke at 4.81 kgf covered versus 4.21 uncovered.
• Nylon drinks the room. It takes up to 8% moisture at saturation and around 2% at ordinary indoor humidity, swelling slightly as it goes.
• Fluorocarbon doesn't. The polymer sold as fluoro absorbs 0.03% of its weight in water.

All of that is about what a spool sits next to and how warm it gets, not how dark the drawer is. So before anything moves, it helps to know what you own and where it has been living.

What should I check before I move anything?

Go and find all of it. The spare leaders in the pack, the tippet spools on the lanyard, the half-used ones in the drawer, and whatever has been rattling around in the door pocket of the car since spring. Put it on a table together, because you cannot judge any of it while it is scattered across three bags.

Then note three things for each spool. What the material is — nylon and fluorocarbon age on completely different clocks, and the packet will tell you which you have. Where it has been sitting, and for how long. And what has been sitting with it: sunscreen, insect repellent, floatant, a leaky bottle of anything.

If you are not certain which of those spools is leader and which is tippet, straighten that out first, because they do different jobs and they do not wear out at the same rate.

Most of that pile is probably fine. The rest of it is a matter of where it goes tonight, and in what order.

How should I store leaders and tippet?

This is a ten-minute job once, and then it is a habit.

• 1. Get it out of the vehicle today. Not on Saturday. In the rooftop test, nylon was already down to 89.46% after eight days outdoors, and the loss ran in a straight line with time from there — no plateau, no grace period. A closed vehicle in summer is a hotter box than that roof. The damage is cumulative, and it does not reset when you carry the pack back inside.
• 2. Break up the pocket. Sunscreen, insect repellent and floatant do not share a pocket with spools again. Netting held at room temperature, in the dark, gave up 10.09% to detergent contact, and petroleum solvent took 6.475% off it. That is ten times what the light chamber managed. Chemicals go in their own outside pocket or a zip bag, and hands get wiped before you handle tippet.
• 3. Pick cool over dark. A cupboard inside the house beats a dark shed or a garage that bakes in July. Shops that flag heat in car trunks as the overlooked factor have the priority right. A hot glovebox is worse than a windowsill in a cold room.
• 4. Put something over it. A drawer, a lidded box, a zip bag, an old wallet. That is the tarpaulin finding above, and it costs nothing — the covered nets and the uncovered ones had done the same work in the same water.
• 5. Keep the room dry rather than damp. Nylon never stops trading moisture with the air around it, so a basement floor or a boat locker keeps it soft and slightly swollen the whole time. A bedroom closet is a better room than the garage.
• 6. Date the spools. Marker on the rim, month and year you first pulled line off it. Age is the one thing you cannot see in nylon, so write it down while you still know it.
• 7. Store leaders loose, not crushed. Coiled in a wallet or a bag, not folded flat under a water bottle. A leader that comes out with hard kinks in it is also a leader that lands in a heap instead of straightening.
• 8. Rotate the sizes you actually fish. The two spools you use every trip earn a fresh replacement; the odd sizes you touch twice a year need dating more than they need replacing.

Every one of those puts heat, chemistry and damp ahead of light, which is the reverse of the three words printed on most storage advice.

So is "cool, dry, dark" just wrong?

It is not wrong. It is mis-ordered, and the last word is doing most of the talking on most pages. Cool is doing the work. Dry matters continuously, because nylon keeps trading moisture with the room the entire time it sits there. Dark, tested on its own, barely showed up at all.

The other thing worth knowing is how much of what you will read is asserted rather than measured. One widely copied guide states 20% loss from six months sun with no test behind it. Shops disagree with each other by an order of magnitude: one puts monofilament at six months to a year, another says nylon holds up for several years under proper storage. Both are describing real experience. The gap between them is the storage, which is the same point behind the advice that storage conditions beat printed dates.

And "inspect it, throw it out if it looks bad" is not a test. Nylon that has lost a tenth of its strength looks exactly like nylon that has not. It is not cloudy, it is not chalky, it does not feel different between your fingers. The only place the difference shows up is on a fish, which is the one place you cannot afford it.

If looking at it tells you nothing, the question becomes how you decide a spool is finished before it decides for you.

How do I tell when a spool is done?

Compare, do not inspect. Pull an arm's length off the suspect spool and an arm's length off a new one in the same size. Wrap each end around a pencil or a dowel rather than a bare finger, and pull them steadily, one after the other. You are not measuring anything. You are ranking two pieces of line. If the old one goes first, and goes easily, it is done.

Do it at the kitchen table on a Thursday, not standing in the water with fish rising.

Commercial net testing puts an actual line under this: the material counts as unserviceable at 50% original strength. You cannot measure that at home, but it is a reminder that the decision is about strength and never about appearance. As a working default, replace tippet every two years, and sooner for anything that spent a summer in a vehicle.

A spool that fails the comparison is not rubbish. It is the best knot-practice material you own, because you can break it on purpose and learn what a bad blood knot feels like before it costs you anything.

That handles the spool in your hand. The awkward cases are the sealed packets, the leader still on the reel, and the freezer.

The version you can do tonight

Walk out to the vehicle and bring the pack inside. Take the sunscreen and the insect repellent out of the pocket with the spools in it and put them somewhere else. Write the month and year on the rim of each spool with a marker. Then put the lot in a drawer in the coolest room in the house, with something over it.

That is the whole job, and it costs nothing. The dark part sorts itself out on the way.

What about the freezer, sealed packets and the reel?

Does the freezer actually help? Some anglers do keep spare leaders in one, and cold is the direction you want. It will not hurt sealed nylon. It is also not necessary if the cupboard is cool and nothing chemical is touching the spools, and you have to let packets warm up before opening them or you are handling condensation.

Do sealed packets of pre-made leaders last longer? The packet slows moisture exchange, but it does nothing about heat. A sealed leader that spent August in a vehicle is still a leader that spent August in a vehicle.

What about the leader left on the reel between trips? That one has been in the water, in the sun, and through hands with sunscreen on them. Treat it as the oldest piece of nylon you own rather than the one that is ready to go.

Does fluorocarbon need all this? Heat and chemical contact still apply to it. The moisture problem is the one it mostly dodges, which is why a fluoro spool can outlive a nylon one bought the same day.