16 here, just finished my first blade from an old coil spring

I'm 19 now but started at 15 with a fire brick forge on top of an old grill, so reading your post brought back some memories. Making the jump from hooks to a blade is a big deal and the fact that yours passes a hair-shaving test that early is genuinely rare. My first three knives all ended up as shop knives becuase the edges rolled the first time I hit anything hard with them.

One thing that helped me a lot was switching from quenching in water to plain canola oil warmed up a bit. Water was cracking everything I made from high carbon stock. I also learned to normalize a couple times before hardening, just heating to nonmagnetic and letting it air cool, and that took the warping out of my blades almost completly.

For the cord wrap, don't give up on it yet. I used to have the same problem untill I started wrapping over a layer of stretchy athletic tape on the tang, then finishing the wrap with a coat of super glue rubbed in with a rag. It soaks into the cord and locks everything down stiff. Looks clean too if you keep tension consistent while the glue is still wet.

What are you using for steel besides that spring? Around here the local leaf springs have been my go-to free stock but every one of them seems to behave a little differently at the anvil.

I'm 17 and did the brake drum thing too, except mine sits on a stand my uncle welded from scrap angle iron and I burn charcoal from the big bags at the farm store instead of coal. Cheaper around here and easier to find on a Saturday. Takes a bit more managing to keep the fire deep but it works fine for knives up to about four inches of blade.

On the handle, don't reach for epoxy yet. Soak your cord in shellac before you wrap it. Dip it, squeeze the excess off, wrap it tight while it's wet, and let it cure a day. Mine has never moved since and if you ever want to redo it the shellac softens with alcohol, unlike epoxy. Learned that from a guy at a hammer-in who makes tomahawk handles that way. Also, if your wrap keeps loosening, check where it goes past the tang. Wrapping over a flat section lets everything slide, so if you can peen or upset a little shoulder at the front of the tang the cord has something to push against. Good to hear from someone else my age actualy swinging a hammer. I mostly get funny looks from the older guys at meetings until they see what comes out of my fire.

My mom kicked me out of her kitchen too after the whole house smelled like burnt oil, so I grabbed a beat up toaster oven at a garage sale and it lives in the garage now. Nobody complains and the results came out the same. I also leaned on the magnet thing for months before I trusted my eye enough to work without it. Do you grind with hand files or do you have a belt sander anywhere? Files took me forever on my first few blades but a used one from a pawn shop changed everything for me.

Gotta push back on calling the hair-shave thing genuinely rare. A fresh edge off a fine stone will shave regardless of wheather the heat treat is good or mediocre, so it really only tells you the last few thousandths are sharp. Chopping through a board and still shaving after is the part that actually says something, and even then a rope or cardboard cutting test to dullness tells you way more about edge retention than one shave does. Not knocking the kid's blade, sounds like he did it right, just saying that test gets overhyped. I'd rather see how the edge looks after ten minutes of cutting than whether it pops one hair off an arm.

Chiming in on the spring steel side of things since that's mostly what I run too, going on 20 years of weekends at it. Coil springs are a mixed bag depending on what vehicle they came off, so what worked for one blade might not treat the next one the same. My fix has been to always temper choppers higher and longer than a kitchen knife would want. Mine get two one-hour cycles around 400 in the shop oven and the edges take sapwood abuse all day without chipping. A little softer on paper, but for a chopping tool I'd rather have it bend than break. Keep track of what each spring came from and how it behaved, that notebook pays off.