hi i'm paul brodie we're back in my shop like last time i'm on this side of the
camera there's a man behind the camera his name is mitch i think you've heard of him before
today we're back on the tiger cub we sort of veered off to aermacchi and excelsior but we're
back on the cub we're going to be welding up an exhaust fin here
this has four broken fins to be honest the part of me wanted to practice prior to making the video
but i resisted that urge so that you get to see what happens now have i welded fins before yes
i found this what what happens on the fins is you put a piece of copper down there you see
how it's wedge shape because a fin is wedge shape it has to be because it's a cars thing you need
a draft angle of two degrees because otherwise you can't get it out of the mold so i know i did this
before because i found this and i'm thinking you know what what did i do way back when and i think
it was a english cylinder head that's all i can remember it was that long ago so you can see how
like this is this one's so large that it must have been a much larger head with larger fins
and it looks like okay so when you weld it it starts out like that that's the copper
because the aluminum isn't going to stick to the copper you can see where i've put this
in and i've welded back to about here and then something else happened here because
i've i've made a radius and it looks like i've also done some welding here so
that's all i can remember and that how long ago that was maybe 15 20 years i don't know
i have a toaster oven i wanted to put this into the toaster oven to make it nice and warm for the
welding do you think i can find my toaster oven it's hiding on me i must have looked for over an
hour i don't know so i'm gonna have to heat it up with oxyacetylene that was not my plan but
the toaster oven is missing i looked around here and what i might have to do is to add a couple
shims under here to to make this up to the right height this see i got these two shims each one
is about 18 20 foul so when i put those together it raises this up just a little bit you see that
now no maybe i just need one shin but over on the other side i know i need some shims because
because the head this head has inconsistencies in the fins so you make it so that it fits
how you want it to can you see that how that's going to go like that
see look i got a little bit of a gap looks like i got a little bit of a gap right there but i
know i'm going to do some filing anyways so all right so we'll get the tig welders set up
i don't have any mail to open today sorry about that still waiting for fork seals for the cub but
we just keep moving on so i'll get my my big torch out we'll heat it up we'll go to the tig i've got
my big torch i bought this when i was 17. it's a number four tip i've got on there pretty big
i've got my really good gloves on
so
that's one rod gun
i want you to see what happened i was welding and i couldn't stop the ark
look what happened i got the wire under the pedal so it won't switch off
there now it switches off so i'm like what the heck is going on with my pedal
because it was just it was welding on its own and then i had to pull it away which is
which is bad technique if you're wondering about the amperage i'm
using i got my welder set at 45 amps and that seems to be working pretty good
so we'll just continue here
so
i think we're good i did not dab the tungsten once i'm quite a little bit proud of that
so you can see how the copper goes black and the aluminum will not stick to the copper at all
that came out pretty easy so there's the you can see all the welding going across there
it can get used again that's no problem that seemed to work pretty well
and
it looks like it's raised up a bit
can you see how it's raised up no it's raised up that way i think what we'll do is to heat it
up and we'll we'll use the oxy acetylene torch and then we'll we'll bend it down
i don't have to heat up the whole head again i just i'm just heating up the fin
because i just want the fin to bend
see that see it ben
that looks good to me good what i need to do now do you see this hole do you see
how this hole isn't round it's not a round hole so i need to set it up in the middle
you see what i made here i took some cold rolled half inch cold roll and i i machined it so it just
fits in there what i'm going to do now i'm i'm going to clamp down this this piece of aluminum
it's half inch i'm going to use an end mill and make a half inch hole through here this is half
inch so this is going to go into the hole it's going to locate the center of the hole
and then in the top i've got a a boring mill set up and i can bore that and then i'll take an
end mill and i'll do a little bit of facing here then i'll do some filing
and then basically the fin repair is done so there's a couple steps we have to go through here
so we've got the head head located on the dowel pin and we're holding on on both sides of the head
don't want to do it too tight it's just the casting but
do you need a little bit of pressure there okay we'll try that
it worked out nicely in the metal cut quite well
in case i didn't mention it the welding rod that i use is a 53-56 i asked a couple
friends one suggested 53-56 and someone else suggested 40-43 or 40-47 that's a softer rod but
i've had good success with 50-53 so i thought i'd try it seem to work okay
okay let's do some filing
mitch is getting warm in here again this always happens with the filing
how thick is a fin 106 105
95 132 so okay i might have to shut the layer
so
ah
what i need to do is to is to round the fin a bit
because it doesn't it doesn't come square like that
this makes it look more authentic
wow
okay so what i'm doing is i'm smoothing out the top
this is one of the last steps is to get the file marks out
oh i got one little low spot there but whatever can you see right there i've got
one little low spot there i'm not going to go and fix that that's too much work most people
would probably never notice that i noticed things like that but the rest of the fin
looks good so i'm happy with that thank you for watching thank you for buying us coffee
coffee really keeps us going at this channel and we'll see you next week thanks take care
you