Building a Balloon in 22 Days

Today was the first day on the project without a significant mishap or other source of frustration. As a result, much progress was made. But there is less to write about.

The replacement fabric arrived via overnight freight from Noah Lamport. A lovely sky blue.

Together, Kevin and I cut out panels 6, 7, 8, and 9. We plan to cut the last four panels tomorrow. At that point, we’ll have completed the cutting for all of the envelope except the mouth (Nomex) and parachute top. We’ll fold up the cutting table which will allow more room for the ever-growing piles of fabric.

Kevin’s been sewing up a storm. His routine is to sew until the wee hours of the morning (i.e. 2:30 AM or so) He’s now got all of the gores completed from panel 2 thru panel 6.

I’ll post pictures tomorrow of the progress.

It seems that a great fabric crisis of 2006 has been averted. As a result of a fair bit of persuasion and persistence, the fabric vendor (Noah Lamport) says they’ll ship replacement fabric via overnight freight at their cost as well as pay for ground freight return of the wrong stuff. We’ll see tomorrow if they follow through.

In addition to leaning on the fabric folks, Kevin spent much of his day as purchasing manager. The load tape has now been ordered (from Bally Ribbon Mills) and lots of other component choices have been made. Kevin went so far as to order top grade, shuttle loomed webbing for the load tape. Most folks don’t even bother with the difference between shuttle loomed and needle loomed load tapes. But Kevin said he’d promised his Mother that he wouldn’t cut corners. So he got the good stuff.

As for the sewing, that’s coming along as well. Kevin was up late into yesterday night and started work at 11 or so this morning. At this point, nearly all of the panels 3,4,5 have been sewn together.

This evening we cut panel #2 which is the bottom-most nylon panel and the last one made of the green fabric. It’s a “half height” panel that will be joined with a half height panel 1 made of Nomex for the mouth of the balloon.

Half height panels are trickier to lay out since the usual system doesn’t work. There’s a fair bit of head-scratching and improvisational measurement technique involved. Kevin’s first attempt at cutting panel #2 ended in a disgrace that could lead to deep chagrin were his High School geometry teacher ever to learn of it.

Fortunately on the second attempt, Kevin and I played geometry back-and-forth with lots of double-checking. There were at least three serious errors made by one or the other of us during the layout that were (fortunately) caught in time. The strain of these mental gymnastics even lead us to butt heads (a rare event for two such ardently affable persons as ourselves.) Nonetheless, in the end, we managed (or at least we think we managed) to cut the panel out correctly. (I’ll believe it only when the sewing’s done.)

Although, even with our focused attention, we managed to cut out 14 panels rather than the required 12. Better two extra than two short.

This evening I left Kevin making registration marks along the edge of the panel.

With luck, somewhere between California and Massachusetts there is a roll of sky blue fabric winging it’s way Eastward. If so, we’ll be cuttin’ blue in earnest tomorrow. Keep your fingers crossed.

After two trips to the sewing machine store, the double-needle machine is back in working order. The nice man at the sewing machine store is very good at fixing broken sewing machines.

And how did the machine get broken you may ask? Well, it seems that your humble author, while changing the needles in the machine managed to install the new needles backwards. This is a bad thing to do. It makes the machine very grumpy. The truly annoying part of the story is that I know that it’s a really bad thing to do and managed to do it anyway. (My children make fun of me for doing things like this. So please don’t tell them.) But it’s all better now and except for spending a good chunk of the day in the car and a slight nick in my wallet, there are no lasting consequences.

We managed to finish cutting the third set of trapezoid panels. Only 10 more sets to go.

The good news is that the rest of the fabric, both baby blue and navy blue, arrived today. The bad news is that the baby blue is the wrong stuff. The vendor sent uncoated fabric rather than coated fabric. Uncoated fabric is more porous than the coated stuff. This leads to higher fuel consumption during flight as the hot air slowly seeps through zillions of tiny holes between the threads in the fabric. Not the end of the world, but a significant (and aggravating) additional cost over time.

Kevin is now mulling his options in terms of getting replacement fabric. The decision is complicated by the tight time table for this project. Given shipping time from the vendor, there is some chance that he’ll run out of things to sew before the replacement fabric arrives. (Stress? What stress?)

The other bad (if less bad) news is that the navy blue weighs a bit more than advertised. This too needs to be discussed with the vendor.

But in the end, it was a good day. When I went home this evening, Kevin was busily sewing away. Last evening he as dead in the water.

The entire day today was lost in the black hole of sewing machine adjustment.

I have a very spiffy nearly-new Juki double-needle machine. When I bought it, I had the nice man at the sewing machine store take a sample of my thread and fabric and set the machine up. I then took the machine to my shop, essentially left the settings alone, and happily sewed a mile or so of seams for my blimp without any significant difficulty.

But Kevin’s fabric is much lighter weight than mine (1.1 oz per square yard as compared to my 1.9 oz.) As a result, there was a fair bit of puckering of the fabric along the seam. The bottom threads were also being pulled up through the stitch.

Well, I said to myself, I know how to fix this. I’ll just reduce the top thread tension. This was the road to hell. A fiddle here, another fiddle there, and by the end of the day, neither of us could get the dang machine to sew more than a few inches of stitching without having the top thread tear or otherwise jam the mechanism. We both wanted to cry.

I am told that this sort of thing is par for the course. Sewing machine technology has not changed much in nearly 100 years. I have an old Singer machine from the beginning of the last century. It looks remarkably similar to the brand new machine I purchased last year.

Industrial sewing shops almost always have full-time mechanics to fiddle with their machines. Balloon repairs shops, which don’t usually have such people, often have many more sewing machines than people. Each machine is set up for a particular configuration (e.g. white thread on relatively heavy fabric vs black thread on relatively heavy fabric, etc.) and great pains are taken to avoid changing the settings once the mechanical house of cards is in place.

So, we’re off to the sewing machine store at the crack of dawn tomorrow to have the nice man there set up the machine properly. We’ll leave it alone after that. Really we will.

Although my shop is essentially complete, there’s always a bit of messing about to do when starting a new project. We spent the first part of the day setting up a roughly 15 by 6.5 foot cutting table. My cutting tables consists of modular table units. Each unit is a 30″x80″ hollow core door as the tabletop on top of a set of folding legs (purchased from the ever-so-useful McMaster-Carr Company — www.mcmaster.com) I can put spacing blocks between the tables to get a more precise size. Then I put down a layer of 1/8″ masonite to make a nice even work surface.

We then unrolled some fabric (It’s “ground cover” green.) and had great fun destroying bits of it on a pair purpose built fabric testers that I have. The fabric tested out with a tensile strength of around 40 lbs/inch. The tear strength is beween 5 and 6 lbs. This is quite adequate, particularly for the bottom part of the balloon.

Kevin (with some help from your humble author) then cut out the first two set of trapezoids for the bottom of the balloon.

In the evening, Kevin practiced sewing “French seams”. He’d done a fair bit of it last year when putting together a model balloon. But the fabric for this project is much lighter weight than the material on the model.

Kevin is not using a seam folder. I don’t have one (It didn’t make sense for the complicated seams on my blimp.) We’ve also heard very mixed things about the effectiveness of folders. Some folks swear by them as the greatest thing since sliced bread. Others tell tales of woe about spending seemingly endless amounts of time fiddling with the folders and never getting them set up right — in particular when using a folder on lightweight fabric.

Kevin called earlier this week to say that he’s decided to build his balloon this month. The first roll of fabric arrived yesterday. It’s 1.1 oz uncoated from Westmark, the same folks that I get my fabric from.

I’m off to the airport to pick him up.