|... this... is a summary of some lessons learned by a newbie
builder with good shop skills but no prior sheet metal experience. It is primarily
presented for first time builders.
Carpenter screws. Harbor Freight sells low cost wood carpenter screws
(clamps). These clamps are very versatile and I prefer them over steel clamps
because they won't mar if used without shims. They also have a deep depth of reach
and can be opened easily. They are easily adjusted to fit over rib and bulkhead
flanges. The two sizes I use are two 12 inch and four 10 inch. The larger ones
also make excellent holding jigs while riveting light but unwieldy components like HS
spars, wing rear spars, etc.... Just clamp two to the spar and set them
vertically on the workbench while drilling or riveting. A couple of wraps of duct
tape around the center threads is a good idea to prevent chaffing. They're like a
second set of hands.
Swivel flush riveter
Avery sells a swivel flush riveter that is IMHO indispensable for a newbie riveter.
My HS skins were dinged in several places because the alignment of the rivet gun to
surface was off slightly. The swivel rivet tool would have prevented this. It is
very forgiving and a bargain.
Harbor Freight sells a touch up gun for $20 that works great on priming small
parts. If the cup is Teflon coated, I recommend soaking it in MEK and removing
the coating with steel wool or another abrasive. The Teflon tends to flake off and clog
the paint gun. The HVLP gun sold by Harbor Freight was discussed several months
ago. I bought one and believe it lives up to all expectations. The paint
savings is dramatic to someone used to conventional sprayers.
Pneumatic cleco gun
This item was purchased from Avery as sort of a nice-to-have tool half way through
drilling my wing skins. I now consider it an essential part of my tool bag. It
saves lots of time and helps prevent
fatigue from repetitive motion. In fact, I keep it in a holster, designed for drill
motors. With a my nail apron on to hold clecoes and the cleco gun in my belt
clecoing goes fast. I look a little foolish though; but who cares?
Avery sells a 1 inch wheel and mandrel that is outstanding for fast finishing of aluminum
edges. If there was ever a tool that minimizes metal fatigue cracks; this is
it. These tools work well in drill presses and on high speed die grinders; however,
they don't last as long on the die grinder but work twice as fast. After shaping the
part on a belt sander, it is passed through the scotchbrite wheel for a smooth
satin finish. I usually keep about five wheels on hand and two mandrels, one
for narrow edges like skins and the other for structural edges 1/8 inch or better. I
can't comment on the other wheel sizes but it seems other builders are satisfied with them
Bucking bars. There is nothing special about bucking bars. They are simply a
smooth and heavy surface to form the finished rivet. The manufactured bars are great
and several should be purchased but I recommend buying small pieces of scrap steel from a
scrap metal yard or welding shop. Expect to pay about $0.35 per pound for this
metal. Anything more, is a rip-off. These pieces can be shaped and smoothed
for the one or two rivets that can't be reached with a manufactured bucking bar.
The task of priming small parts can be a pain because they stick to flat surfaces after
painting. This became a non-problem by using a painting surface made from chicken
wire attached to a 2x2 wood frame. The chicken wire mesh size is 1 inch. The frame
can be any size. I use one approximately 3 ft x 7 ft laid across two
sawhorses. Really small parts can be impaled in the mesh while painting.
Because so little surface area actually touches the primed part, it dries fast and
leaving adhesion marks..
The manual recommends a plywood or similar surface while drilling stiffeners
to skins. I used aluminum backed insulation board on top of my
workbench. This insulation board is used in home construction. This IMHO is a
superior surface. It doesn't scratch. The drills easily penetrate it and the
clecoed skins can be lifted free when finished. The material is cheap too. Of
course, the underlying surface must be flat. None of my skins have any oil
canning. I highly recommend
it over plywood or particle board.
Carpet remnants are excellent for preventing scratches on bare skins. The handiest
size has been about 2ft x 3ft. They are particularly beneficial when running the
skins through the C frame while dimpling or while back riveting stiffeners to skins.
Use them to cover anything that could produce a scratch. I keep about 6-8 pieces on
hand. They're also good to cover sawhorses when you lay large finished pieces like wings
across them. Involve your spouse or significant other. Have them help you pick
out an appropriate color/texture for your shop decor!
I like to use wood dowels in place of steel machine screws wherever possible.
For instance, while building the HS on the jig, I used golf tees to hold it to the jig
rather than the recommended machine screws. They are easy to insert and remove and they
won't enlarge the hole diameter from chaffing. They'll break before the piece
bends. They're cheap and easy to replace. The supply is plentiful around
my house. Recently I used a tapered dowel for a temporary pin to mount the gear leg
to the mount. The taper was made on a belt sander in about two minutes. This long
tapered pin was easily inserted, found center, and easily removed.
When inventorying parts, I like to mark on the plastic coating the part number in magic
marker in three inch letters. This is so I can't miss it when searching for it
during building. It gives easy identification. I hate to waste precious building
time searching for parts that I've already found once.
Early in the building process I was sensitized to possible metal fatigue due to metal
etching stemming from construction labeling. I don't know where this came from but
the first month of building both wings simultaneously nearly drove me crazy keeping track
of left - right, top -bottom, tip - root, leading edge - trailing edge, etc... in my
head. Then I started labeling everything with a laundry marker. I now mark the
jig and parts. And prime over labels. Can't label too much in my
When inventorying the bag parts, I transfer them into plastic zip lock freezer bags.
Each bag is marked with the bag number and parts contained in it. This gives me good
visual and documentary identification. The bag parts are placed in one of three
boxes marked rivets, fasteners, or miscellaneous. The rivet box is further organized
by diameter, length and type (AN470 , AN426 or pop rivet). This technique really helps to
find parts while building. While building the wings, the AN3-XX bolts were stored
according to length. Baby food jars worked well for this but
freezer bags would work too!.
I like to hang red shipping tags on or in the vicinity of components that I haven't
finished or have skipped construction steps. These tags are the fluorescent red 1 inch
shipping tags available at office supply stores or Walmart. This is just a visual reminder
to go back and complete the step. It eases the memory load during
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