The Scrimshaw Fleet

Fully rigged, glued to pallets of Sitka Spruce, protected by a coat of spar varnish applied with a Q-tip, the Scrimshaw Fleet sets sail for the Christmas Tree.

Protected by jelly jars, the tiny boats will be making whimsical voyages long after their builder has departed for Fiddler's Green.

-R.S.Hoover
-Dec 2007

the Nina, the Pinta and the Rancho Bernardo

Scrimshaw II

"What are you making for the kids this year?" my wife asked about a week ago at breakfast.

Total blank. I was cracking walnuts to eat with chunks of Korean pears; I'd forgotten all about making gifts for the grandkids. "Little boats," I lied. "In fact, I'm working on them right now."

I continued to crack walnuts with the blade of my pocket-knife while I told her about Duke Haliburton and how he'd persuaded King Charles of Spain to out-source the transportation between Mexico and the Philippines, back around 1665. She gave me a suspicious look.

"Seriously. Duke Haliburton convinced crazy King Charles that out-sourcing would save him a buncha money. Then the Duke hired some Chinese guys to sail back & forth between Manila and Acapulco..."

"Chinese guys?" Her eyebrow arched up the way it does when she's on to me.

"Sure. It was a lot cheaper than building a galleon..."

"I suppose these chinese guys used a Chris-Craft."

"Don't be silly." I crunched my way through a couple of chunks of Korean pear. "Chinese guys sail junks."

"So... you're making the kids Chinese junks?"

"Right!" Whew, that was a close one.

"Three of them?"

"That's how many Duke Haliburton hired. Cost him twenty pieces of eight a month, each. For which he charged King Charles something like a million dollars."

That got a smile. "Things haven't changed much." Then she gave me that look: "I don't suppose you remember the names of those Chinese junks."

"Ah... the Nina, the Pinta and... uh... the Rancho Bernardo."

At which point she said something rude.

-------------------------------------------------------------------------------

From that morning to this, I've added half an hour or so of Basic Boat Building to my breakfast schedule. As the little boats took shape my wife stopped making jokes about it.

Every kid knows walnut shells make perfect boats. In fairy tales. In real life they need some ballast, which I provided in the form of lead BB-shot, glued to the bilge before I started construction.

Small hull needs about eight BB's, bigger hulls can use up to twelve.

To make the decks I took a pair of scissors to some scraps of cardboard; the same stuff I've been using for gussets in my airplane rib experiments.

I made the sails out of a coffee filter, gluing on the battens. Straws from a whisk-broom provided the yards and booms; the battens are bristles from a defunct paint brush.

For masts I'd planned to use toothpicks but the only round ones we had were colored and the flat kind didn't look right, so I split some aircraft spruce with a razor-knife and turned the splinters into spars.

As you can see, the fleet isn't quite ready to get underway but they'll be sailing in formation under the tree by Christmas morning.

------------------------------------------------------------------------

Every sailor does this sort of thing. The generic term for it is scrimshaw, which I wrote about last Christmas.

Junks are a bit easier to model than other types of sailing vessels because they don't have much in the way of standing rigging, although their running rigging is wacky enough to confound Confuscius. Oddly enough, the junk rig is superior in almost every way to the square-rig, something no Westerner will accept until they've actually used one.

-Bob Hoover

VW - Volkswagens and Sex

You like sex, right?  (Come on, don't be shy.  Just nod your
head if you don't wanna say it.)  Okay!

So I guess that means you really enjoy changing those diapers,
right?  Mixing up the formula?  All those PTA meetings and
putting money aside for college...  You're really hot for all
that stuff, right?

No??!  Well... gee.  I mean, that's the whole IDEA behind sex.

Ah!  I see.  You want the fun but not the responsibilities.
Ummm... okay. It's your life.

Unfortunately... (you knew that was coming, right? :-)

Unfortunately, old Volkswagens have a lot in common with sex.
The sexy part is roaring around, lotsa noise & chrome, a really
kewl ride ... or for geezers like me, driving off to the ends
of the earth, hitting rocks with hammers, catching fish, getting
chased by bears & stuff like that.  It boils down to the same
thing:  Having fun. Getting down & dirty.  Like good sex.

But after you've had your fun you gotta face the
responsibilities -- the shitty diapers.  That's the maintenance
and tune-ups and clutch-jobs and doing the brakes and all those
other unkewl things that YOU gotta do soz you can keep on
having fun.

The reason I'm writing this is because a lot of folks out there
are in it strictly for the Fun & Games.  They want sex without
babies and a kewl ride without getting grease under their
fingernails.  The problem is, it don't work that way.  Not
unless you are stinking rich... in which case you wouldn't be
reading this anyway :-)  Most folks aren't rich but neither
are they dirt poor.  They let somebody else raise the baby...
and do the brake jobs.  But of course that gets expensive as
so you gotta scrimp here & there.  Never on the polish, of
course.  Or that ohsewkewl bud vase.  But you let a lot of
'unimportant' details slide, such as keeping your wheels
aligned or your shift linkage tight or whatever, firstly
because you yourself haven't any idea in the blue-eyed world
how to do such things.. and aren't about to learn since you're
only in it for the fun anyway, and secondly because you can't
afford to pay someone to do them because you've pissed away any
money you do happen to get on 'having fun'.

I hate to tell you this but you can't have it both ways.  Oh,
you can.  But not for long.  All those 'unimportant' things
start to pile and, eventually, so do you.  (Darwin was right
you know :-)

The point is, when it comes to Volkswagens you can't have your
fun without accepting the responsibility that goes with it.
Not if you want the fun to last.  How long will it last?
Statistically, based on the transfer of VW titles (ie, ownership)
here in California, about thirty months.  Two and a half
years. (*)  That's when all those 'unimportant' things finally
catch up to you and you sell your bug or bus to the next kiddie
waiting in line because you have neither the bread nor the
brains to fix it.

Over and over and over again.  That's the 'churn' that spells
survival for the VW-specific magazines and all those VW after-
market suppliers (who are becoming fewer each year, in case
you hadn't noticed).

Don't believe it?  Check the archives of this Newsgroup.(**)
Where are the kiddies of yesteryear?

So what's the answer?  It depends on the question :-)

Wanna earn up to $400,000 in 'hidden' income during your life?
Then keep your car forever. (ask Consumer's Union for the
article on this subject)  That's right; just keep repairing it
instead of throwing it away every couple of years.  Fuel, oil,
tires and maintenance accounts for only 7% of the cost of
owning a NEW car.(*)  The rest gets pissed away renting the
money to pay for the thing, which isn't worth what it cost
to begin with, for the insurance and taxes and license and
all that other crap the System demands you must have.
Average cost?  Almost a buck a mile for a full size sedan,
more for an SUV, less for a rice box.  (Sound too high?
Check with the AAA.  You're in for a surprise.)

Or you can buy an old bug or bus, fix it up and keep it that
way, you'll end up driving for about three cents a mile.
 (It doesn't have to be a Volkswagen... the Forever Car
Philosophy applies to any repairable vehicle.)

Of course, that kinda thing means buying tools instead of
those kewl chrome rims, and manuals instead of that bitchin'
bud vase and planning slightly farther ahead than where to
go for lunch... and the record shows most kiddies
don't have the Right Stuff to do that.  (Because it's not kewl,
of course :-)

Volkswagens and sex have a lot in common, when you think about it.
But so does divorce and Volkswagens.  The sad part is that the
record shows most VW owners are only interested in a joy ride
instead of a stable, long-term relationship.

-Bob Hoover

* -  The DMV data was for 1996.  Vehicle cost data was 2000.  This article first
appeared in 2002.
** - RAMVA

Cooking Airplane Ribs

Do any amount of travel, you gotta eat. Good trip, say up to Alaska or down through Central America, you’ll be gone thirty, forty days. That’s a lot of cooking. Even when you do your traveling by airplane, boon-docking old mining sites in the Mojave or whatever, you gotta eat, although going airborne, you generally do the cooking at home, rig it so’s you can eat it cold or just an aluminum-wrapped something you can lay on the coals of a fire.

If you write about your travels the facts of feeding yourself tend to creep into the typewriter so that pretty soon, thanks to blogs and Newsgroups and stuff like that, folks become aware of Bob’s Basic Biscuits, Beans a la Boom, Bajanese Salad and the other recipes - even cookies - that have made life away from home a bit more enjoyable and deserved mention because of it.

The point here is that most folks who drop by the shop are used to me putting down my tools to go check something in the oven, especially during the holidays when I shift into Pie-Making Mode. Which is what I was doing when The Visitor arrived, and why I carried the timer out to the shop as we went.

“Pies,” I said.

He nodded in understanding. “My wife said you had a good cookie recipe.”

We chatted about cooking while I replaced the stripped nut-plate on his spinner backing-plate, which was why he’d dropped by. While I worked he glanced around the shop but there wasn’t much to see. Major projects are on hold due to a lack of funds. To fill the time I’ve been doing some experiments with cardboard ribs and other such stuff. Actually, they’re not cardboard at all, they’re plain old-fashioned stick-ribs. But the gussets are made from heavy paper, like the stuff used to package a 12-pak of soda pop. Or the better stuff used to package a 12-pak of Colorado Kool-Aid. (This isn’t new, by the way. For the past several years I’ve posted occasional messages about alternative materials, including several recent articles posted to my blog.)

The ‘cardboard’ appellation came from a gentleman who took me to task for daring to even mention such a ‘stupid’ idea, unaware that paper or ‘fiber’ gussets had already been used by a pair of bicycle boys named Wright, a company called Aeronca, the late Paul MacCready and a few others dummies. Unfortunately, their work with paper gussets hasn’t made it onto the internet forcing all future dummies - like me - to conduct our own experiments. And to write about it so that when I fall screaming from the sky the NTSB can simply hit a button, peruse a few million words of gibberish and say: ‘Ah ha! When he made his casein glue he failed to properly neutralize the mixture!’ ( er... actually, the casein glue is another set of experiments. And if you read a bit farther down that page and you’ll see that my home-made casein glue worked jus’ fine, thanks... although I wouldn’t want to use it except in an emergency... such as living in a village in rural India... or being even poorer than I am.)

Among the many details no doubt included in the missing body of literature describing the use of fiber gussets is the fact they are hygroscopic, something I had to rediscover for myself. Unless treated, paper absorbs water. Since the ‘fibre’ I’m using is various grades of paper obtained by a series of dumpster dives, it too absorbs water. (My neighbors already have good reason to believe I’m crazier than a hoot owl in heat. When they found me fighting off the ‘possums to get at their garbage it produced only a few sighs of resignation and a request to put the lid back on when I was done.)

Since paper is hygroscopic that means some of my experiments have dealt with ways of waterproofing the stuff after the rib is assembled. So far, dilute varnish seems to be the best solution but the tricky bit was discovering I had to use at least two coats, the first being no more than 50% varnish. Of even more interest, at least to me, was determining the ideal moisture content for fiber gussets, and how to adjust it when the paper is too wet or too dry.

Which is why I shoved the repaired backing-plate into his hands and went scurrying into the house when the timer dinged. The pair of punkin’ pies were baking slowly to perfection on the top shelf but the cookie sheet of gussets cut from a Coors carton were done to a turn. The pies had to be baked; that’s what Thanksgiving is for, right? And it was just plain old fashioned common sense to slide a sheet of damp gussets in with them.

I come back out to the shop with the cookie sheet on high, put it gently on the bench and inspected the result. My nose told me the paper hadn’t been over-heated. By positioning the triangles of cardboard on the cookie sheet with their printed-side down I’ve found I can estimate their dryness by the amount of their curl. Ten minutes seemed to be just about perfect for that particular batch. And I may have said something to that effect as an aside, so the visitor wouldn’t feel slighted that I’d interrupted him by dashing off in mid-sentence. But when I turned his eyes were as wide as port-holes.

“Gussets,” I explained. He nodded then looked at his watch like he’d just discovered it lurking there on his wrist.

“For the ribs,” I waved toward the cardboard heat-box inside of which - and thus invisible to the normal eye - there was more than dozen ribs basking in seventy-degree warmth from a twenty-five watt light bulb.

“Right,” he says, edging toward the door. “Clare will probably want the recipe.” And with another mumble - glance at his watch he’s like, gone!

That’s when I figured out that he’s probably never read the posts about Chugger’s Rib and has no idea in the blue-eyed world that I’ve been searching for the Holy Grail. Or low-cost ways to build airplanes.

-R.S.Hoover
-21 Nov 2007

----------------------------------------------------------------------

I'm afraid the gussets made from Coors 'Long-necker' packaging material haven't worked out. Turns out, the printed side of the package is coated with a plastic film that prevents the dilute varnish from soaking into the paper.

Although the gussets are more than adequate when it comes to their dry strength, if you can't prevent them from absorbing moisture you'd be better off to stick with plywood.

I will continue the experiments using the packaging material for 'Sprite,' of which I'm accumulated a good supply. Its thickness is only 0.017" (The Coors stuff was 0.030") which is right on the ragged edge for dry compressive strength and it takes only a tad of moisture (a foggy night will do it) to cause the gusset to fold up under a load. But when given two dilute coats of varnish the 'Sprite' gussets have survived my 'soak-test' -- leaving sample, varnished, gusseted T-joints in a pan of water over night.

So it goes.

------------------------------------------------------

Although a broken rib can be repaired, these things started out as scrap lumber. The last couple of nights have dipped into the low 40's, cold for southern California, and we heat with wood. The failed experiments were used as kindling but to their credit, some of them put up a hell of a fight on their way into the firebox :-)

-R.S.Hoover
-24 Nov 2007

Year of the Blog

On 16 Nov 2006 I became a blogger by uploading ‘The World’s Ugliest Toolbox’

http://bobhooversblog.blogspot.com/2006/11/ugliest-toolbox.html

...in response to Google’s offer of free blogging space. Since then I’ve uploaded 264 others from a file of a thousand or so digitalized articles accumulated since about 1992. The material covers a broad range of interest and includes articles submitted for publication, successfully in a few cases but mostly rejected, especially so for the aviation-related material.

To provide this ‘free’ service Google attaches advertising to your material. When someone clicks on one of the ads, the advertiser pays Google, who shares a bit of the wealth with you. You are allowed to limit the number of ads and to block ads from companies you deem unsuitable. Of course, the more restrictions you impose on your site, the lower its potential income. And the thing has to generate SOME income or Google will simply kick you off.

Over the past year the blog has been visited 97,305 times. Those visitors clicked on 862 of the ads, for which Google paid me $292. That’s about 266 visitors a day and two clicks worth eighty cents, a tad shy of Minimum Wage even for a writer :-)

As soon as my blog appeared I got a few friendly jabs from fellow writers about getting rich through blogging. This message should lay their fears to rest :-) At the same time, a number of other folks asked if creating a blog was worth their time. I didn’t know. I said I would give it a year and tell them how things were going, which is what I’m doing here.

Over the course of the last year the blog has generated a fair number of comments, some of which I’ve posted. A lot of people have urged me to submit a particular article to various magazines, unaware that in most cases, I already have. If you want to see a particular type of article in your favorite magazine the person to talk to is the editor, not the writer.

Has the effort been worth-while? If you mean financially, no. But as a means of disseminating information, I think the blog has been a success.

-R.S.Hoover
-18 Nov 2007

Chugger's Rib - IV

Does everyone understand that the strength in the joints of the sticks in a rib is due to the gussets and not the contact between the sticks? If not, you need to put on your thinking cap and do a few experiments until you understand how a load in the sticks behaves when it encounters a joint. You don't need to build a rib to teach yourself what is going on its joints. Use whatever is handiest -- match-sticks, toothpicks or whatever -- to make a basic T-joint and then break it. Make one without a gusset, then one with a gusset. Then try replacing the gusset with a thread or a piece of toothpick.

When you do this you will see that as you put a load onto the leg of the T, one side of the gusset will see that load in tension whilst the other side sees it as compression.

There's a bunch of common-sense assumptions here; that the load is imposed in-line with the axis of the rib and so forth... that I won't bother to go into; the key point I want to get across is that both tension and compression are present.

If you've made a sample joint using thread in place of a gusset, when you broke it you will have seen that while the thread does okay in tension it's worthless when it comes to compression, proving the old saw that you can't push a rope :-)

Cardboard doesn't do very well in compression either, and that's really what this posting is about. In fact, the only reason my cardboard-gusseted rib is able to bear its designed load has more to do with the number of bays in the truss and the spacing of those bays relative to the intended load, in that the load at any given joint is low enough so that it does not cause buckling on the side of the gusset subjected to compression.

This wasn't by accident. As mentioned in a previous post I've been messing with ribs for a couple of years now and you may have noticed that I've not bothered to post the results of my early experiments. Which were pretty awful :-) But even failure is data of a sort and I eventually came up with a rib that should do the job, even though the gussets are nothing but 'cardboard.'

Of course, a four-bay rib is heavier than a three-bay rib, but I assumed at the outset that using low-cost, commonly available materials would impose a weight penalty.

A second purpose of the experiments was to discover just how big that penalty would be, since another design-constraint was that the bird had to be able to fly -- safely -- behind a converted Volkswagen engine. And despite the hype from the hucksters, no matter what the VW's displacement might be, it's maximum sustainable output is only about forty horsepower, about the same as the Continental A40.

So what is that weight penalty? About four-tenths of an ounce per rib; about three-quarters of a pound for the whole wing.

Keep in mind, the normal or unaccelerated load on the wing is less than seven pounds per square foot or about 30 lbs per rib, and about a third of that will appear in the plywood D-cell that makes up the leading edge, leaving about 20 lbs to be dealt with by the remainder of the rib.

-R.S.Hoover

(Photos and drawings to follow)

VW -- More on Air Filters

(written in 2002)

I've just finished reading the thread on air filters. If you haven't read it, you probably should. Marvelous stuff. Laughed my ass off.

Yes, there is a standard for automotive air filters. SAE J726 (or maybe 826... there's more than one).

Read the specs? Okay, here's pop quiz: Other than the Beta test (ie, ratio of particles that make it through a filter as compared to the number of particles which go into a filter), have you ever wondered how they arrive at those "efficiency" figures? Come on, think about it. No filter is 100% perfect for all sizes of particulate contaminant. So what are they comparing things to? What is the nearest thing they have to a perfect air filter?

Would you believe it's a multi-stage kinetic type filter, usually having a water-bath catchment... covered by a thin film of silicon or mineral oil to reduce evaporation?

Although we're talking laboratories here, the principle is the same as the oil bath air cleaner on your veedub. Not small, though; you can walk inside some of them. And except for HVAC applications they're almost always used with pre- and post-filtering, including electrostatic precipitators. (Anyone who has ever worked at a chip plant knows about this stuff. Even old sailors, like me because the government has its own chip plant, inside the fence at Ft. Geo. Meade, home of the world's longest indoor shooting gallery... and one of the cleanest 'clean rooms' on the planet.)

But the subject of comparison also applies to the air filters for cars and the point a lot of folks missed is the fact treated paper filters (ie, a non-kinetic labyrinth-type filter) are compared to an oil bath filter (which typically scores about 99.9%).

And those marvelous K&N filters? Last time I checked, they're compared to paper filters. (Go on; lookit up; K&N has a web site and is justifiably proud of their product, which works at least as well as a paper filter, so long as it receives the proper periodic maintenance and liberal doses of K&N's magic elixir.)

All of which means that clunky, old fashioned oil bath air filter on your bug or bus is still a hands-down winner... for anyone who cares to do a bit of reading :-)

As for all that 'flow-rate' stuff... Anyone care to take a WAG at the flow-rate for your 1600cc engine, roaring along at 3500 rpm? No? Howzabout a 2550cc big-bore stroker turning five grand? (Hint: Be prepared to be underwhelmed.) But bigger is always better, right? So more flow has gotta be good, right? Horseshit. The fact a particular filter can flow more air doesn't mean your engine can use it. Those counter-top ‘comparison’ units are just a sales ploy; a kind of IQ test for the technologically naive.

Read the specs. Flow is relative to the pressure differential and restriction. The bottom line is that your oil bath air cleaner does just fine, folks. Always has and always will, so long as you give it the maintenance it requires. For stock engines an oil bath air cleaner has no problem providing more air than the engine can use. (If you think about it for a minute you'll understand why that has to be so.) In fact, the stock oil bath air cleaner works just fine for engines up to about 2200 cc so long as they don't spin over 5000 rpm, a fact you can work out for yourself with nothing more exotic than a #2 yeller pencil and basic arithmetic. Working it out will also give some idea how much you'll have to shorten the service interval when you use an air filter designed for a small engine on a big one. And the service interval of any air filter is a critical factor in determining its practicality.

Indeed, the service interval is one of those things the tea-cozy crowd doesn’t like to talk about. As with any labyrinth-type filter, their effectiveness is a function of surface area. Under harsh conditions, where you might need to service an oil-bath air cleaner as often as once a day, you may need to wash & re-oil a gauze & window-screen air filter every few minutes... which is why you don’t see such filters used for real-world applications.

Don't take my word for any of this. After all, nobody is right all of the time :-) Think for yourself. Go look it up. Work it out. It's your ride and it's entirely up to you what kind of filter you use. You're the Mechanic-in-Charge, not me.

In fact, lemme repeat that: You are the Mechanic-in-Charge. Making the right choices is up to you. All I've done here is express an opinion, albeit one based on experience. In effect, I've described a particular path. The decision to explore it -- or not -- is yours.

The only reason I've bothered to say anything at all is because automotive engineering is not subject to the democratic process. Having a big mouth doesn't automatically make you a good singer, nor a loud voice a good speaker (although it helps :-) The fact someone posts a thousand messages a month does not mean the messages contain anything worth reading. Apply that logic to the fact all your buds are using gauze & tea strainers for air cleaners and you'll see it only means its a popular idea, not necessarily a good one. The task of determining the merit of something is up to you. And I'm not just taking cars here. Every person is capable of error. That fact extends to every organization as well because organizations are nothing more than collections of people. And if you think an individual can screw up, our personal faults pale by comparison to the outright evil of which groups are capable. (And yes, you can look this up too if you wish. Although since 9-11 I've got a hunch most folks can figure it out for themselves.)

The wiser course, in my opinion, is to always think for yourself, even if doing so sets you apart from the majority. Because when push comes to shove, it's your life. And your ride. Not theirs.

-Bob Hoover

PS -- Oil bath air cleaners fell into disuse for passenger cars because of economic factors, environmental issues and the shear size of the damn things.

The size issue had to do with their height. To work properly an oil bath air filter must have a certain minimum height. If you had a 'tall' engine yet wanted a low hood line you had to move the oil bath air filter over to the side, as Volkswagen did with the Karmann-Ghia, Hudson with their dual-carbed 'Hornet' and others. But doing so increases the parts count and complexity of the system and such things carry an inherent increase in maintenance cost. Which leads to...

The key economic factor in the demise of oil bath air cleaners in cars had to do with the time needed to properly maintain them. I can't remember the Flat Rate Manual for servicing an oil bath air cleaner but it was on the order of 0.5 m/hr. No big deal when making 'good money' meant a dollar an hour. But nowadays spending half an hour to clean an air filter would be economic suicide for a dealer paying his line mechanics $37.50 an hour plus full medical, dental and so forth. (What's it take to change a treated paper air filter? Maybe a minute... if you've never done it before. Less, for an experienced mechanic :-)

The environmental issues with regard to oil bath air filters wasn't so much the oil you poured out of the thing. Hell, recyclers will pay you for the stuff. What really sets a tree-hugger's hair on fire is seeing that drum of sandy sludge -- the scrapings out of the bottom of the oil pan -- accumulate over in the corner of the lubrication bay. A high percentage of the particulate matter found in the air above most roadways is toxic. And you've just concentrated 55 gallons of the stuff (and usually hauled it off to the local dump). The solvent-filled parts washer you ran it through was another E-ticket ride for tree-huggers. Not only did it generate its own quotient of sludge, in normal use it pumped a few pounds of hydrocarbon aerosols into the air every day. By the time you've shifted to a water-based high pressure detergent washer, or added a vapor recovery system to your solvent tank and negotiated a HazMat contractor to collect & dispose of the sludge, servicing an oil bath air cleaner has become a very pricey proposition.

There's plenty of justification for doing away with oil bath air cleaners. But their ability to clean the air wasn't one of them. Indeed, such filters remain a standard method for many industrial applications, as a bit of research will show. - rsh