hey good afternoon youtube got a bit of a different project today got a couple of
these bronze ingots they weigh about 20 pounds maybe nine kilograms something like that i don't
know if these are silicon bronze or aluminum bronze anyway a neighbor does some metal casting
in his garage and he's picked up a bunch of these ingots the problem is his crucible is only big
enough to hold roughly half of one of these he had been cutting these in half on an abrasive chop saw
but it takes a long time and then you waste a lot of material because you've got that thick abrasive
blade with the chop saw you've got to sit there for 10 minutes trying to saw through this stuff
and it's supposedly fairly hard to cut i did take a test cut here on my little band saw
a bi-metal blade does cut it okay so i did some reading on some home metalworking and home casting
forums and people were talking about cutting these and they recommended a bi-metal blade
is one thing this coarse tooth blade as you can get as slow a speed as you can get
and as heavy a down pressure as you can get and lots of cooling and lubrication
because this stuff apparently is fairly hard to cut that's my regular bi-metal blade that i use
for most metal it's a 10-14 variable tooth blade the coarsest one i could find that fits my
saw is this bad boy i found this one on mcmaster carr it's the coarsest bi-metal blade they have
four to six tooth per inch so anti-vibration anyway i got to put this in the saw and then i've
got to slow the saw speed down i'm running my 7 by 12 band saw on the highest speed
i haven't run it on the low speed before so i'll show you how you change the speed on one of these
okay we got the blade in the saw and now what i've got to do is slow it down so i've been running
i think 255 feet per minute or 78 meters per minute so what i need to do is bump it up to the
small motor pulley and then the large drive pulley yeah so they loosen up the pulleys there's two
nuts right down there you can see one right there at the light and then there's one on the other
side of the motor and then over here is a sort of a jack screw there's a jam nut there and you
loosen the jam nut wind the bolt out and then you can tap this slide in and then that loosens up the
tension on the pulley so let's see if we can get over here i might need to loosen it up a bit more
let's see yeah there we go i was on the home machinists forum
and one guy was recommending something as close to 80 feet per minute for machining
this assuming it's the red bronze i can go down to 90 so i guess i i will go as slow as i can here
get up there
up there yeah i didn't think i've ever run this saw this slow
there we go that's the low speed right there so this should be 90 feet per minute or 27 meters
per minute then you just have to tension the belt back up okay i think it's time to give this a try
this blade is really slow so we've got the coolant running let's see what happens here well
i'm going to put the ingot with the fat side up i guess it doesn't quite hold down there
okay so i think holding this thing is the hardest part so what i did was i took a small scrap of
aluminum that i had left over had to cut a little bit off of there and then i just machined down
enough so it was just the height of the ingot laid over on its side the thing isn't quite square so
you can't get enough gripping force on there to hold it so i think that's that's in there
pretty good it's not going to twist lower this by hand and we'll see what happens here there we go
looks like it's cutting pretty good
though
whoa that's a big hunk of metal there whoo boy that's a nice cut yeah that's the way to do it huh
look nice and cool yeah these these ingots aren't square
or straight or parallel or anything but yeah there we go took about four minutes little piece of
metal so i just cut it off and then machined it down until it was just the height of the
ingot that way i can back up the far side of the jaw because like i say those parts really
aren't square or they're very irregular so yeah there's one i think it's about
the same height then i just got to slide this in and then find my halfway mark there
okay got that one in the ingots a little bit different size so
my center mark was off but let's give this one a try
release the down feed
yep there's another 10 pounds like ripples from the casting i guess
so i had to go through a few forum threads and different forums and finally found somebody that
seemed to have a good idea what they were talking about they gave specifics on the
the blade the coolant the down feed the cutting speed but yeah that seems to be a pretty good
setup for that run it really slow really hard down feed lots of coolant and then you got to
get it clamped in there because there's a lot of force on that part anyway i gotta get a hold of
my neighbor and tell him i finally cut his parts that he's left him here for a couple of weeks and
haven't had time to tear the saw apart and reconfigure it so i figured might as well do
that now and give it a test and yeah it seems to cut really nice it doesn't bind up the saw blade i
know when i cut aluminum one of the problems with aluminum is it'll gum up in the teeth and then
jam the saw blade and trip the circuit breaker so then you've got to unjam the blade clean it
out wait for the circuit breaker to cool down then you can reset it and it takes a lot of babysitting
this cut takes like four minutes so i can just start it go do something for three minutes come
back and catch the piece when it falls off no babysitting involved because i i think he says
he has like eight or ten of these ingots that he picked up so since i can cut them i i might tell
them to bring over the other ones and we'll cut them while i have the saw set up okay youtube
neighbor brought over the rest of his ingots he had uh i think 10 20 pound ingots there yeah i
mentioned it was silicon bronze anyway he had 10 of them plus the two i cut before so that's 12
240 pounds of bronze i always find it interesting to think back you know four or five six thousand
years ago bronze age that was the go-to metal that you used for your pots and pans and cooking and
weapons axes swords knives everything was bronze you know a piece of steel like that was incredibly
expensive i mean iron wasn't even a thing and then you had iron age and then at that point
your steel was you know a high-priced commodity and then even 200 years ago a piece of aluminum
like that was a precious metal you know they put aluminum on the cap of the washington monument
because it was a precious metal and now you buy aluminum foil and beverages in aluminum cans and
just toss them out or you know put them out for recycling or this used to be your everyday go-to
metal collected all the cuttings there's a little bit of steel and aluminum in there but uh yeah
there's a good half pound of uh shavings in there from cutting all that one thing i did notice was
after cutting 12 of these the first first few i did took four or five minutes per cut the last
ones were taking way longer maybe 15 or 20 minutes you can see here's the earlier cuts you got pretty
coarse marks there and they're a lot finer on this side so it was just cutting a lot slower
that blade probably would be getting pretty dull after that many more so yeah to cut bronze like
that you probably need a new blade that was a bi-metal blade four to six tooth per inch
variable pitch and yeah 12 12 cuts and it's it's definitely slowing down so hopefully it'll still
work for aluminum and plastic that i cut because that was like a 50 plus dollar blade and it made
made 12 cuts and it's already slowing down a bit he showed me his website he does a lot of
this work for galleries but he has a really nice website so i'll show you some of that
at the end of the video here just take a look at some of his pieces
you