hey Jody here today I'm gonna build a knife out of a file I know this has been
done many times before but i have never seen it done the way I'm gonna do it now the
handle of a file is generally not hardened. I'm able to cut the handle with
this file so it's fairly soft. it softer than the cutting surface anyway but it's
still the same material type . it's still hardenedable . Files are made from things
like 1095 carbon steel and a lot of times they won't tell you exactly what's in it
sometimes it might have a little bit of chromium or a little vanadium or
something like that in it for hardenability . a simple way to test hardenability
easily is to make a quick puddle like wtih a tig arc. you know it reaches transition temperature
because it's melting and it's like filing a ball bearing right there that
file is just slipping over it and not cutting at all so it got a whole lot
harder and the reason that makes a difference for this video is I'm going
to build up a bronze handle using aluminum bronze and silicon bronze and
because it TIG brazing and not TIG welding I should be able to do this without
exceeding the transition temperature in the area that would make it brittle and
likely to snap between the handle and the cutting surface. I'm using alternating
current today because I find that really helps in not diluting any of the base
metal in with the with the aluminum bronze and incidentally this is the way
I repair a whole lot of cast iron parts too with a preheat. but TIG brazing with
aluminum bronze it's stronger than silicon bronze and when you use AC it
lets you wet a bead in without diluting hardly any base metal and on high carbon
steels and on cast iron that's a big deal
doing the same thing here just sped up and then I decided you know it's gonna
go a whole lot quicker with backing. I can just lay the heat to it and really
pour the metal to it without it sagging over the edges if I put it against a
piece of aluminum backing like this I'll show that right here see me just kind of
pushing rod in there I can go along it at a nice slow speed but I can feed a
whole lot of rod in there it traps are gone it doesn't let the bead sag
anywhere having that aluminum backing now if you use too thin of aluminum
it can easily melt the aluminum and kind of create a well it'll usually be
brittle and snap right off but you don't want that so here it's just sped up and
I'm able to just you know periodically wire wheel sand and whatnot to get a
good clean surface so that it flows and after I get a full layer of aluminum
bronze on this thing with AC I will switch to silicon bronze really just
mainly because I didn't have enough of either one to finish the job and I like
the idea of aluminum bronze for the first layer that little bit of aluminum
in aluminum bronze kind of retards hardening a little bit on that fusion
layer which is also a good thing on cast iron repairs but after I get the first
layer in and I run out of aluminum bronze that I'll just switch over to
silicon bronze and finish the job takes a lot of beads here and I'm
speeding this up a whole bunch and I'm rushing it a little bit you can see it's
getting red-hot here and there but a funny thing happens when you're doing
this because because of the bronze is so much more thermally conductive than the
steel even though it's red-hot it's still pulling heat out of the steel and
the Steel's not getting hot I can hold the steel on the end
no problem after even camping out for a long long time here building this up a
little more contouring putting it in a vise touching it up here and there and
it'll be ready to put the finger pieces on there are a lot of welding textbooks
and you can even find things online like on blacksmith forums that give you color
temperature and according to what I saw this is roughly where we're at here so I
only got a little bit over 800 even in that fusion area so it should be
slightly annealed maybe in that area but not hardened you may have heard me once
or twice talk about going to fabtech. At the last fabtech I got some samples of
these walter wheels enduro flex Alu flap discs they're designed for aluminum to not
load up with aluminum but they work great for bronze too
long as you keep it cool it gets pretty hot but they didn't load up at all they
took off a lot of material and left a good finish so once I got that roughed
out I'm cutting some finger pieces here out of
I believe this is inch and a quarter pipe just depends on how big your
fingers are making some marks there between them and then I cut some pieces
out so that it fit my fingers the spacing better and I'll get a few tack
welds on that using silicon bronze and then I mark the areas in between because
I don't want to have to fill in those big huge holes and possibly have voids
and pockets and have it want to build up pressure and have all kinds of pinholes
and stuff like that so I'm kind of just really quickly slamming a lot of metal
in there and I'm gonna grind it down I get to a point to where those little
areas are sort of filled up that's manageable there using a little spacer
piece to get things situated and centered up I get this whole thing
tacked up there's still a whole lot of thick brazing to do I want to put tick
braze everywhere on this thing because I want basically I don't want there to be
any steel showing or a very little steel showing I'm gonna sand it down I'm gonna
polish it all up hopefully be nice and shiny and pretty when I'm done and this
is sort of patterned after the trench knives of World War one and World War
two you see them all over the Internet some of them have skull breakers on the
end like this and whatnot but I'm just sort of patterning it after historical
pieces but then putting my own touch on it alternating heat here and there so
that things don't get overheated and just slamming a whole bunch of silicon
bronze in there I'm on DC now by the way
again using that Walther wheel getting things roughed out and I decided to go
ahead and tape the handle up and go ahead and work on the blade a little bit
here before I get a polish on the handle because I don't want to scratch it up
picked up these at this last fabtech to is called a Walther excavator it's a
ceramic hard rock and I saw a demo at fab tech where it really removed a lot
of material really quickly so I thought it'd be a good idea to hog the material
off basically using this thing it's working great and it's actually not
heating the piece up too much but I'm still stopping every every minute or so
and squirting water on this blade to keep it cool I don't want it to turn
blue I don't want lose hardness it's gonna lose a little
bit the next thing is to go to a 80 grit sanding disc with a backer pad on it and
I'm still trying to keep it cool still trying to you know keep things even and
only go in one direction here and it's it's coming along I'm getting pretty
close now so I decided to put this two in one wheel on there is this like
sanding pads sandwich between scotch-brite here on this it leaves a
good finish but still removes quite a bit of material so I'm working it down
I've heard that Windex helps in use quarter keeping things cool and also
keeping a wheel from loading up so they give it a try but it's coming along I'm
getting pretty close to being done these little things are abrasive cartridges we
used to call them tootsie rolls in the aerospace industry once I got all the
finger holes sanded out it's time to put a final polish on everything. you may
have seen a lot of Walter stuff in this video I'm trying to show them some love
because they did send me this polishing kit a year or two ago and it's a nice
one and I haven't really said thank you a whole lot so I'm using it here for
this video and that's my thank you it's working great though it's there's a
whole science to polishing and they've got it down pat with the different steps
you're using I'm just kind of winging it for this video getting a pretty good
polish on everything I don't really want a super mirror finish because I'm gonna
use this thing and if you get a super mirror finish that every little pitch
shows every little scratch shows I don't want that but I do want this