All tacked up with no place to go.

...And then there were two.

Tube Prep - The OCD Stuff

So now I've got a bunch of holes in my tubes, thanks to some ridiculous notion that it might provide some potential future benefit.  That means it's time to put it all back together in the jig, and start welding it up, right?  Well, that would be one option.  But there's that nagging little voice in my head, convincing me it would be irresponsible to put this car together with tubes that have so much crap inside of them.

First up is getting rid of that nasty burr on the inside edge of each hole.

Now I could stop there, but why half-ass it?  I'm not going to be satisfied until I've made a complete ass of myself.  So I stuff a half sheet of paper towel in the end of the tube and use my highly specialized multipurpose tool to swab it through like cleaning the barrel of a rifle.

Most of the grime comes out with the first swabbing.

And the second swabbing leaving it clean as a whistle.  Come to think of it, whistles get pretty gross...Hopefully cleaner than a whistle.

Then it's just a quick wipe down on the outside with Acetone, bevel all of the edges on the grinding wheel, final smoothing around all of the edges with the wire wheel, and putting it all back together in the jig as shown below in the picture that is not-at-all* the same picture used in my previous post.

My only thought for next time is swabbing the tubes before drilling the holes, rather than after deburring them.  I'm not exactly the most skilled with a deburring tool, such that even with the big bits of burr gone there can still be just a little bit left poking up that can snag the paper towel a bit.

* "exactly"

Tube Prep - The Boring Stuff

"Anything worth doing, is worth overdoing." - (Sir) Mick Jagger  

So, it turns out I might be going a little overboard with tube prep.  I start out with my jig board, that has now been expanded to accommodate the full length of the outboard cockpit sides. 

Notice the 'flat pack' of tubes all cut to the correct length and angle, looking like they're in a police lineup. 

Each number corresponds to a numbered location on the build table. They are also cataloged in an excel spreadsheet, including their raw stock length, for the purpose of maximizing tube cuts and minimizing odd length excess.  It also might come in handy for future reference.  The full set of tubes are then temporarily mocked up in the jig, where the edges of each tube intersection are marked with a Sharpie.

At each tube intersection where one tube dead ends into another, a hole is drilled.  The end result is that the entire chassis will be one continuous interconnected volume.

One theory is that this improves the finish weld, as the heated (expanding) air has a means of escape other than past the weld arc and puddle.  The other, more important aspect to me is that, should I choose to do so, I will be able to pour the rust inhibiting compound of my choice inside the chassis, rotate it a few times to get into every tube, then carefully drain it back out again.  This would be all but guaranteed to have some 'pools' that would never be fully drained out, and will certainly add a little weight, but could also help the chassis longevity...Or could end up being little more than some quality time spent with my drill.  Hence the quote from the great philosopher, Sir Jagger.

More overdoing it to come...

First Article Welding

Wow…Looking back on my build log, I didn’t realize that I hadn’t updated it with any of my activities in as long as it has been.  Over the past couple of months since my last update, I have not been simply been idle.  While progress is almost never as fast as I would like, it is still happening.   It never ceases to amaze me how quickly time slips away. 

That’s not to say that all of my time has been productively moving the project forward by any means either.  As SWEETA (She Who Enables Every Thing Automotive) will readily attest, I am constantly researching various aspects of exciting and interesting (to me) ideas.  The theory behind this is to gain an understanding of the idea to the point of identifying the obstacles or shortcomings, and devising a method for overcoming them.  However, frequently this obsession gets in the way of making other physical accomplishments as well.  Some of the research does end up being for ideas ultimately related to this car, but are not really of concern for quite some time to come.  The irony being that much of the time taken for the research now, subsequently pushes my actual timeframe to use the information gleaned even further out.  Beyond that I often become totally obsessed with unconventional ideas for a period of time, completely unrelated to completing this project whatsoever.  These will typically last anywhere from a couple of days to a few weeks.  The most frequently recurring of these relapses are the ones that are most likely to be attempted as future projects…Provided I can stop researching them for long enough to finish this project first.  

Meanwhile, back at the ranch, when we last left the project I was just getting ready to add blocks to jig the tubes in place prior to welding.  These blocks are not built into the table itself, but rather are all on a separate sheet of (cull) MDF that can be stored separately without taking the jig blocks off.   Following that was tube prep for the first attempt at executing my planned method for building the chassis sides.  This would serve to prove out a host of ideas and methods I’m attempting, be they successful or not.  More specific details will follow in subsequent entries over the next few days.

 

Once my first article was tacked together, I then focused on improving my welding skills until I could regularly run a bead that wouldn’t make me afraid to drive the car.  I did decide to abandon my attempts at perfecting the ‘weave’ welding technique for now, which produces the stack-of-dimes look, in favor of sticking with the structurally equivalent but less attractive ‘stringer’ welds.  I’d like to be able to say that the time saved was making up for the time I spent researching and gave me more time to work on the car, but there is no amount of time saved that can make up for the time I spend researching…And the reality is more likely that the time saved, just gave me more time to research.

With my welding skills turned all the way up to ‘adequate’ it was time to finish weld as much as possible on the first article piece, to see how badly it would potato-chip.  As it turns out, almost not at all!

 

WARNING!

After numerous unsatisfactory attempts to make adjustments to the settings of both ‘welders’ in the garage, the machine and myself, I needed a new piece of scrap to continue my slightly frustrating efforts at producing a consistently ‘good’ weld. I grabbed a drop off tube, cleaned the oily residue off of it, and ran the first weld bead. After finishing the weld, the glass on my auto-darkening helmet allowed me to once again see things other than sparks and molten metal. The first thing to catch my eye is the wisp of smoke twisting up from my steel work piece. Instantaneously my mind transports me just a minute or two back in time, as I was preparing the piece of tube. Instead of cleaning it off with acetone, as I normally would, I casually grabbed the can of brake cleaner that happened to be within arm’s reach. I sprayed the metal down and gave it a quick wipe with a paper towel, before setting it up on the table to begin my welding…Returning to the present, panic immediately sets in. Was the brake cleaner fully dried? Is that the normal smell from welding?? What’s that tingle in my lung?!?...

Now some people are acutely aware of the huge safety violation I just made, but others might be quite surprised to learn the potential severity of such seemingly insignificant actions. Either way, we all need the occasional reminder of how even brief instants of carelessness are capable of changing our lives forever. Even though the previous sequence of events happened over the course of only a second or two, before thinking clearly again and realizing I was completely safe, it is still worth bringing up for anybody that that actually reads through this build.

The problem arises when chlorinated hydrocarbons are exposed to oxygen and UV radiation or high temperatures. Even a few residual drops of chlorinated brake cleaner not fully dried off of a part can react to form Phosgene gas. While not a name heard much today, it is the chemical weapon from the trenches of WWI believed to be responsible for more deaths than any other…Not exactly something you want to be breathing in ANY quantity.

I thought I only kept non-chlorinated brake cleaner on hand, but it had been so long since using it last that I wasn’t completely certain. Thankfully I was able to quickly verify it and calm myself, since it is only the chlorinated type that has this extremely dangerous reaction. In some places, like California, I don’t think you can even get chlorinated brake cleaner anymore. Regardless, welding is a pretty intense process capable of numerous health and safety concerns. So you need to be conscious of everything you do around the welding too. Thus I can’t recommend strongly enough that it is best to ALWAYS make sure you’re using a solvent that does not have a variant capable of accidentally releasing a Schedule 3 chemical weapon in your garage. That way you’ll never even have a reason to question yourself.

While I'm cutting the second set of inboard and outboard chassis side tubes, I decided that this would be a good time to introduce a surprising 'tool' that has become invaluable to me...

That's right.  It's an every day, ordinary, and FREE paint stirring stick from your local hardware store.  This one has even been used previously for painting, so as to not be accused of any illicit procurement methods...Although with as much as we spend there, the least they can do would be to contribute a few pristine sticks to the cause.  It turns out that while the typical 4x6 horizontal bandsaw has an angle finder to help get it close and reduce the amount of time spent grinding the tube to the exact angle you wanted, it's not terribly accurate.  In an effort to reduce rework, I have been using the paint sticks primarily as follows:

First I have carefully measured and planned out my tubes on my work surface, and calculated the necessary cut angles involved.  I set the band saw as close as possible to the desired angle and cut the paint stick.

After cutting the paint stick, I can carefully lay it over the plan for the tube end being cut next, and make any adjustments necessary.  If there is a mating tube that has already been cut, I will hold their mating surfaces together and see just how close the angle naturally sits to the plan.  I only proceed once this looks to be almost perfect.

At this point, if I'm not just copying existing tubes, I should also have markings on the tube to indicate the length of either the long or short side of the angled cut, illustrated by the slightly difficult to see vertical line on the tube in the photo above.  Then all you have to do is line the appropriate corner of the paint stick up with the correct edge of the measured line, and then copy the angled edge of the paint stick on to the tube with a Sharpie.  With this line in place, and the bandsaw angle set, the tube can be cut.  Thu far this method has allowed me to cut nearly every tube to the exact desired length and angle on the first try, with no grinding required.

I'm sure that there are other ways of accomplishing the same end result, and this probably isn't even the easiest, but it has worked for me.  It also doesn't work quite as easy once we leave the 2D world and enter the 3D world, but it has already more than paid for itself in saved time, reduced effort, and improved quality.

Eating an elephant...One tube at a time.

As is typically the case, the first side took the longest to get the angles and lengths all spot on for fitment.

With having gotten the hang of getting the angle right on the steel, and using mostly the same shapes again, cutting the tubes for the second side went much more quickly...Of course, having fewer tubes didn't hurt either.

I will be duplicating both of these again for the other half of the cockpit...In other words I'm going to be smart (i.e. lazy) and transfer the patterns over via the magic of Sharpie.  

Some people may notice the lack of 'proper' triangulation.  This was done intentionally, as I have decided to sacrifice the more ideal loading for two reasons.  First is the ability to fully tack all of the tubes in place before final welding any of the seams together.  I can't say for certain if this will be useful in helping prevent weld distortion or anything like that, but it's all part of the experiment.  The other reason is that it provides better welding access for my MIG nozzle to all seams.  Any tube intersection that would have been less than 45 degrees, now has a 0.5" gap and a greater than 90 degree angle.  To compensate for any loss in strength or rigidity, there will be 3-sided gussets made from sections of tube with one side sliced off that will be welded into each of these nodes...Which you'll be seeing more of later.