Experiments in skint blacksmithing

[ForgeCorvus]

Can I butt in here?
I trained as a Smith and I've messed about with blades of all sizes and for all sorts of uses over the years.

Heat treatment not only hardens and tempers your work, it also has the affect of removing previous stresses that are in the metal (even more so as you're planning on using 'found' stock rather then new stock)

The current plan that I have in my head is to cut it out with a grinder, then grind in the bevels on a belt sander.
Ideally keeping it cool enough to not lose the hardening that's already on it, then immerse the cutting edge in water to keep it cool while I anneal the tang and the spine with a torch.

Reckon that'll work or do you think I'll need to heat treat and temper it?
I think I'll end up with a fairly brittle edge, but I'm hoping that some time in the oven should help with that just to take the edge off the hardening, files are obviously a little too hard to become knives without some work.

There will be a few problems with this.
First off, by having a fixed waterline you'll have a fixed point of transition between the hot and the cold/cool parts. This will probably give you a weak point (I was taught to always keep a tool moving when quenching)
Secondly, if the back is free to expand and the edge is not you could distort the blade

You'd do better with a full heat treatment, its not hard to do as long as you can heat the whole blade to 'Cherry-Red' (or 'Non-Magnetic' which is pretty much the same thing) and can then accurately heat to the correct Temper Colour (several different ways to do that, I can talk you through them if you want)

This might also be useful

[shocker]

Thank god !! Someone who actually KNOWS what they are talking about, not just thinks they do...like me

[Jamesey1981]

Think I'll wait until I can get my hands on some firebricks and make a mini forge before I do it then, I've wanted a forge for ages anyway, not going to be doing anything as impressive as you forgecorvus, but I reckon I can knock up a few small things like pot hooks, and I've wanted to make a squirrel cooker for ages!
Will be a lot easier to work the metal then since I can anneal it first and won't be trying to grind through something that's already hardened without heating it up.

[shocker]

Forge, can you do a new thread to run us through this ? Jamesy is just starting, Im out of practice and have a stroke since I learned this years ago so we would both benefit from some info. Im sure it would be of interest to others too...please ?

[shocker]

Oh, I recently saw a smith heating just the cutting edge of an axe, this is what gave me idea about hardening an edge and keeping the rest flexible. Is this due to the relative thickness of an axe to a blade, the type of metal or what ?

New thread ! New thread !

[Jamesey1981]

Oh, I recently saw a smith heating just the cutting edge of an axe, this is what gave me idea about hardening an edge and keeping the rest flexible. Is this due to the relative thickness of an axe to a blade, the type of metal or what ?

New thread ! New thread !

From reading what forgecorvus said I think the problem would be down to the sudden change where the waterline is, if you were to heat just one part of a blade then the heat would conduct into the parts that aren't being directly heated, making the differential more gradual, that makes sense to me but I'm obviously not speaking from experience.

[shocker]

Jamesey, I think thats it.

I know my knowledge has been shown to be a bit patchy but I do know that you can make a simple coal forge from an old steel wheel rim or brake drum, using just about any thing including home made bellows to pump air up the tuyere, the air supply that comes up from underneath the coals.

I will try and find the name of the breeze block I used and still use as a brazing hearth. They can be sawn with an old wood saw into slabs and stacked as needed, very versatile. You could make a simple furnace with a calor propane torch on a hose that way. The blocks are not concrete, they are super light and make of a consistant ash like substance, somewhat like pumice. THERMALITE maybe ?

Something like that should take care of heating for anneal and temper.

PS Forgey- please do us a new thread on making blades from files/HSS and the like, I dont have the reference books anymore, most of the info online is BS and my memory is crocked

[Jamesey1981]

I'm planning a brake drum forge one day, I have a whacking great brake drum set aside from my old van, but to start with I'm going to get some of the insulating fire bricks and use a torch, doing a bit of research they seem to be the ones that people are using, and they look soft enough to drill, one guy was cutting them with a normal holesaw, looks to do the job for a small project and it'll be more convenient than a coal fired forge, doubt it would get hot enough for forge welding though so depending on how well I take to blacksmithing I'll probably need to upgrade.

I used to have a load of firebricks, but these were left over from when an old mate of mine was renewing his brazing oven in his factory, so they were crazy heavy and I don't have anything that would drill them, they were so heavy in fact that I didn't need to cement the barbecue that I built out of them together! Didn't do the suspension on the Renault 5 I drove back then any good either!

[shocker]

I think this subject has real legs

[Jamesey1981]

My neighbours are going to think I'm even more mad though, we had a new lot of students move into the house next door a while ago, and the day after they moved in myself and a mate had a roadkill fallow deer hanging from my apple tree while we were taking it apart!