Monday, December 22, 2008

Let's try this again... shall we

Ok so I screwed up the 1st set of chain stays by cutting them to short... it was kind of fate anyway because the 1st set wasn't as high quality as I want. So I ordered the correct flux to use with my bronze rods and below are the pictures of my brazing steps.
By the way I also just bought an oxy/acetylene set up on craigslist that was a great deal and it is so much easier to use than the MAP gas setup.


All fitted up and ready for flux...

Getting ready to braze...

Wow that went so much better than the last time, I couldn't see that there was a bubble and not enough bronz in the joint so I needed to go back and dump a little more bronz in there.


Ah much better, I built much more of a filet inside the joint and this thing is solid!


These are presoak brazed...
















After about 30 minutes of soaking... almost clean.


This is after about 15 minutes of filing and sanding... looks pretty good




I am especially proud of this joint, there are no voids, no extra bronz anywhere and once I sanded it down it looks great.






So this is basically the finished joint, I will finish it after I have done the seat stays and brazed it into the BB.
I realized I haven't put any pictures of the cleaned up front triangle yet so I will post some those tomorrow.
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1 comment:

Unknown said...

Great photos Mark, keep it coming!
Craig

December 22, 2008 at 7:46 PM

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The lessons I am learning are amazing and really fun to work out...

The pictures below are the work I did last night, finished grinding the bottom bracket sockets.
Notched out the seat stays to fit the drop outs...
And the big big moment... doing my 1st miter on the seat tube (Tim calls this one the most forgiving miter and he is right)

I think that many of the lessons and techniques I have learned from wood working are carrying over into metal working very nicely.

bottom bracket, right side done (before finshing sanding)

bottom bracket, right side done (before finshing sanding)
the left socket is just starting to get ground, notice how thin the walls of the right socket have gotten. there is a lesson there and you will see in following pics!

grinding with a stone

grinding with a stone
it took a while with this stone but with the tight corners I had to use it because I only have one small sand paper bit left

ooh ahhh... a little sparks flyin

ooh ahhh... a little sparks flyin
That lesson I spoke of earlier is happening in this pic...

Ahhh... oh DOH!

Ahhh... oh DOH!
is that blueing? Yup that is the lesson that I learned on this socket. the grinding stone heats the metal very fast and as that wall gt thinner it started blueing. Bad, bad, bad! so I will have to sand and reshape that wall a little because I even got some chipping around the blue.

Chain stays with the drop outs notched in...

Chain stays with the drop outs notched in...
So this one was a little scary because I wasn't sure if I would get them straight and true... it ended up ok but I can do better.

Notching wasn't to hard but keeping everything even was hard

Notching wasn't to hard but keeping everything even was hard
I decided to try the bevel sides on the notch, I think I can do better so I may do the stays again?

The big moment... my first miter!

The big moment... my first miter!
I should have taken some before during and after shots but this went pretty fast actually. this is the ruff cut, I rounded it out better and got rid of that hump on the back wall

A little different angle... check out my home made tube holder... works like a charm!

A little different angle... check out my home made tube holder... works like a charm!
I am so proud of the wood block tube holder... now I just have to make the other sizes

A quick fit test...

A quick fit test...
Not bad forthe 1st miter and fit check... I only need to file the inside edges to match the bevel of the inside of the BB

Nother fit check after some finishing

Nother fit check after some finishing
still need to angle the inside of the edges then it is done and ready for finihsing before brazing. I also still need to finish the socket wall to clean up any uneven edges or tooling marks