my fly line came with a loop in the end and i was practicing casting and it cam undone. it looked like it was welded together and i was just wondering if there was anyway to fix it. also how long do you use a fly line before you replace it

It came undone? What brand of fly line is it? I replace my fly lines every 8-12 months. There are several options to creating a new loop in the end of your fly line. (Shrink Tubing) / (Cut the rest of the loop off and attach a piece of mono with a nail knot and just make a loop in the mono to attach your leaders to)(whipped loop)

Orvis. I wasnt using a leader so that might be part of it

If you are not fishing every day or every weekend, fly lines should last you several years, if you care for them properly. They need to be regularly cleaned (mild soap and warm water) and should be rinsed and dried if used in saltwater or a sandy river.

Do use a leader and yarn or fly (hook clipped) when you practice casting, otherwise you can crack the whip with your line and cause damage (like the loop problem you describe).

It pays to learn several methods of attaching leader to fly line. Try to nail knot a butt section of mono to the fly line, with a loop in the end. Or learn Dave Whitlock's knotless leader connection method.

I have had the same problem. Try doubling over the tip of the line forming a loop after cutting off the welded loop and tie 2 nail knots on top of the loop then glue it with some kind of waterproof glue. Any of the UV cure products out there work good, along with Goop, sally's hard as nails, or even plain old super glue. I have been using the loope mono or this for a few years it works pretty good

use braided loops (some folks here make 'em, but I buy mine) or nail knot a short piece of heavy mono with a perfection loop

When practice casting always use a leader. It doesn't have be fancy, a piece of mono will work. Casting the fly line by itself without a leader can damage the end of your line.

Loops on the end of the line are easy to replace as several folks have mentioned.

Rex

It happens. Every line I have ever owned has come undone; why even bother? I "fix" them now the moment I buy them buy tying two nail knots over the weld, then guerrilla glue + heat shrink tubing.

I'd learn a nail knot. You never know when you will need to put a loop on while fishing.

but...

I have been buying braided mono loops. If I had some braided mono, I would make them. But the store bought ones are okay. I lost one, but it wasn't due to the "single catch" failing. It just slipped off the end. I'm still alright with them. The other ones I have on have been through quite a bit.

So, nail knot or braided mono! and don't cast without a leader and yarn or something

I have never had a loop come undone even from the fierce fight of the smallest shrub to the largest tree. -- But as suggested when practice casting always use some sort of leader to prevent cracking the end of the fly line.

Those that have repaired with double nail knots and glue over the welded loops -- do you have problems with the tip of your line sinking?

Yes I have thats why I stick with the braided loop.

A little bit. It's a product of repeated failure and short patience. The endeavor leeches into all my hobbies, including hunting, in which case I switched over to .338 lapua

Not really, but you have to be careful. Too much glue means sink. I use no more than is needed, like a little dab on each knot.

Dang it! That ought to knock a whitetail down!

terrible hunters gotta do what we (I) gotta do