Archive for November, 2011

Practice Lug #2

Posted: November 29, 2011 in Lugged Bicycle Frame Construction

Thanksgiving and the dry weather kept me busy getting miles in out on the road.  While I didn’t do any frame work I did manage to come out of the other side of Thanksgiving lighter than what I went into it.

Last night I did lug #2.  As you see from the picture below I over (under?) compensated in my attempt to control the silver better.  While things looked good during the process – less burnt up flux, less silver where I didn’t want it, etc. – after cleaning up the lug it became apparent that I didn’t use enough silver.  With hindsight the fact that I didn’t use nearly as much brazing rod as on the first attempt should have clued me in but I was so focused on being neat and tidy that it didn’t click.  In the image you’ll see an obvious lack of silver between the lug and tube.  I’m pretty sure I just need to re-flux the joint up and add some more silver so that will be an exercise in learning too.  However, in light of the realization that practice make perfect I’m going to order a couple more “cheapo” tubes today to utilize the remaining lugs from the “cheapo” lug set so I can have a couple more practice sessions before I start on the actual project.

Neat & tidy but not nearly as good a joint as the first one.

First Lug Work

Posted: November 21, 2011 in Lugged Bicycle Frame Construction

So after many days/weeks of deciding whether or not I could do this or if I was just flushing money down the toilet I got my ducks in a row and ordered my tubes and lugs and as noted in the previous post they showed up Friday.  Then I had to go and buy the rest of the stuff on the materials list.  Stuff like a vice and grinder, some threaded rod and angle steel, etc.  I had a little epiphany in that a cabinet Lazy Susan base just happens to be the same dimensions as the vice I bought.  The Lazy Susan base is rated at 500 lbs so I thought “Why not?”  It’s pretty cool being able to easily spin the vice around while brazing up a lug.  I don’t really feel like running power out to and insulating/sheetrocking the little detached garage that will eventually become my shop in the middle of winter so for now the enclosed back porch has become my shop.

When I bought all my tubes and lugs I ordered an extra tube and a cheapo set of stamped lugs for something to practice on.  Below are the results of my first actual lug work.

I used the “Tube Notcher “ program on Nova Cycles to get my miter right.

A nice miter

Here’s a dry fit of the head tube/top tube.  When it came to the actual brazing of this joint I left the head tube out because 1.) I wanted to be able examine the penetration of the silver through the lug and 2.) I didn’t have a head tube for that lug set.  The head tube in the image below is actually the down tube for the oversized tube set that I will make the actual frame out of.

If only it looked this good after the brazing.

Here are some shots after the brazing but before the clean up.

Now here are some shots after cleaning everything up.

Left Side

Ride Side

The right side is definitely cleaner than the left.

Top

You can also see that I got a little build up of silver at the point on the lug on the top of the top tube.

But here are the important shots – the inside of the lug.

Inside

Another inside shot

You’ll notice that the silver penetrated all the way through and around the lug.

So if I understand the concept correctly this would be a strong, acceptable joint.  The only issues would be the wasting of a little silver on the outside of the lug and the time wasted in filing/sanding to clean up the lug.

All in all I’m pretty pleased with the first attempt.  I still have some practice tubing and the seat/top tube lug from the cheapo lug set so I give it another go tonight (if I’m not too zonked from sitting on the trainer after work).

All the parts for my first frame just showed.  I can’t wait to get started but I’m going to have to reread my frame building book before Thanksgiving just to make sure my ducks are in a row.

Tubes and Lugs

They’re not in the picture but I ordered a set of cheapo stamped lugs and an extra tube so that I can do some practice joints.  I’ll be doing those this weekend so I will post pix with the results.

On the Way

Posted: November 16, 2011 in Uncategorized

So I just bought $500 dollars worth of tubes. lugs, and what-not from Nova Cycle Supply out of California.  The reason that the total was so high is that I bought an extra set of generic lugs and an extra tube so I can do a little actual lug brazing practice.  I also went with a Taylor Carbon Wishbone Seatstay kit.  I was told that I might be biting off more than I can chew going with the carbon stay but this is how I figure it:

Going with the carbon stay entails welding/brazing a connector tube to the seat tube and then bonding the wishbone to it and then bolting the other end of the stays to the drop-outs that are designed for such.

Going with the steel seat stays entails additional brazing – at the drop-outs, the seat lug, a stiffening bridge, and the cantilever mounts.  All areas that a noob such as myself may mis-align.

I think that the carbon stay option is going to be easier and look totally pimp too.  The one issue that arises in going this route is that the joint at the connector tube/seat tube won’t be strong enough if I do a fillet braze with silver solder but Brian up at Kelson Bikes in Ashton, ID said he would TIG the connector tube on for me and I’m hoping that since he incorporates carbon in some of his bikes he will help me out with bonding the stay to the connector tube.  I think I might probably smooth out his TIG bead with a little silver solder after the fact to keep the lugged “beadless” aesthetic going.

Hopefully I’ll have the tubes and stuff by this weekend.

Just sayin’…

Posted: November 15, 2011 in Uncategorized

I believe the two greatest inventions in the history of the world are STI shifters and the iPod Touch.

My First Brazing Attempt

Posted: November 13, 2011 in Uncategorized

So here are the results of my first brazing attempt – but before you see it I want to give you some background.  I’ve never brazed before in my life.  I took a TIG welding course at the local technical college about ten years ago but have never TIG’d since then.  I did work at a trailer manufacturer for a few weeks MIG welding right after I had finished the TIG course but my back couldn’t take moving the trailer parts around all day so that was short lived.  Armed with merely the knowledge gleaned from the frame building book and some internet instruction I turned to.

Quite a learning experience.  First off I couldn’t find any thin walled tubing locally so I ended up getting some 1″ OD mild steel that was almost 3mm thick – over twice as thick as the tubing I would eventually be using but I had to start somewhere.  After mitering and cleaning the tubing I fluxed everything up with Radnor Stay-Silv (white) erring on the side of too much.  Then getting the stupid little MAPP torch lit became an exercise in frustration but I finally figured it out.  I followed the instructions that came with the torch as to how to adjust the flame and what it should look like for what I wanted to do and I was sure the flame was too low but I proceeded.  Since I was doing a fillet braze instead of lugs I used the Safety-Silv 45 brazing rod instead of the S-S 56.  I had the mitered tube in the vice so that the other tube could balance on top of the miter.  After doing a little “tack” braze I switched the tubing around so that the non-mitered tube was in the vice and the mitered one was facing up.

The first thing that caused concern was that the flux immediately got covered in black soot when I applied the flame but I proceeded undaunted.  The flux was interesting in that I had invisioned it melting and getting really runny but with hindsight it’s pretty amazing stuff.  It never got runnier than honey and after having the heat on it long enough it starting acting as the book described – it got clear and then slightly greenish yellow.  At first I was a little apprehensive about having the torch so close but knowing that the tubing needed to start glowing (and that it was twice as thick as it should be) and that the flux started acting as described I pressed on – I was even able to move the flux around with the brazing rod just as the book described.  The rod finally started melting and at first it was clinging to only one of the tubes but by applying heat to the other tube I got it to flow over to it.  I’m not sure if this is the correct proceedure but I basically put the torch where I wanted the silver to flow to.   Since the set up was in a vice and I wasn’t sure how fast the tubing gets out of the proper heat range I decided not to use the pliers to turn the tube around so I could get at the other side of  the joint.  It was a little awkward but I was able to lean over and get the back side. 

When I was satisfied that I had a decent fittet all the way around the tubing I turned off the torch and went to Mc Donald’s to grab a burger while eveything cooled off.  Then I cleaned everything off and dressed the fillet up a little.  See the results below:

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…Anitidote or Sodium – I’m leaning toward Antidote Bikes.