The Supercar Registry - Aluminum Intake finish

Here it is...I can't figure out why there is gobbledy goop in the writing but I think we can figure out what the author is saying....Thanks Alan.

COLOR IT ALUMINUM

By Bill Halbert

The Corvette was the fir~:t l\merican production car to make extensive use of aluminum for the engine assembly and other mechanical components of the car. The 1956 Corvette sported an optional aluminum dual four-barrel intake manifold, thermostat housing, and valve covers. The year 1957 saw the introduction of the famed "fuelie Corvette," witb. tbe fuel-injection unit and most related parts being cast of aluminum. Soon to follow in the late fifties and early sixties were air cleaners, carburetors, bellhousings, surge tanks, fan clutches, radiators, transmission main cases, tail housings and side covers.
Except for the radiator, which was usually painted gloss black, the aluminum components were raw, unpainted aluminum. When new, this metal is clean and bright, adding an eye-pleasing contrast to the Chevrolet-orange
engine assembly. Since bare aluminum is light in color and.a relatively porous metal, prone to oxidation and staining, years of exposure to all kinds of elements, certainly not the least of which is dirty motor oil, makes it more difficult
.than a cast iron or steel component to restore the finish to assembly line condition. If a steel or cast iron component originally had been painted, slight rust, tarnish, or discoloration problems could be easily solved with one pass from ~ can of spray paint. Definitely not so with aluminum! Even after the component is
. restored, keeping the item fresh in appearance requires some care and maintenance.
"Necessity is the mother of invention," the
timeless truism borrowed from a Seventeenth
. .
Century play Love ill a Wood, applies just as
well today. The process detailed in this article

comes from a personal experience over a decade ago when I just couldn't seem to get an aluminum intake manifold from a 1962 Corvette fresh enough to suit my satisfaction. I had scrubbed the "clean" intake for two days with soft brushes dipped in various cleaners and continued getting out a blackish substance that seemed to never end. Not being entirely satisfied with the appearance of the manifold, even though it was totally "clean," I sought a better process to give it the appearance it had
the day it left the factory. .
Remember the major objective of this process is to restore the item to factory finish --no brighter, no shinier, no different than it originally appeared when the car came off the assembly line. Over the years, I've observed various products and remedies for brightening
those stained aluminum pieces, including the use of chemical cleaners, bead-blasting, metal polishers such as Brasso or Never Dull, steel ball abrasion, buffing, aluminum paint, and aluminum jelly. With an exception- or so, depending on the particular component, each solution results in either an appearance that is not original or is not as cosmeticaliy desirable for originality purposes as you might like.
Any technique that cleans or "restores" the aluminum by frictional means, regardless of what it's called, si.q1ply presents the possibility of wearing away <5r even damaging the original surface to some degree -- there's no other way to get to the underlying "skin" of the part. The other alternative is to put something on the surface; this could be s.ome type of chemical coating, such as paint, or aluminum can be plated to resemble new aluminum. If the p'art is painted using a can of bright aluminum or silver paint to cover the surface and hide imperfections, as in painting a motor orange, it

30

looks painted, unattractive, and definitely not original. It will look like a motor bought at a cheap rebuilding business where volume, not quality, was paramount -- definitely not what you want for your pri?:ed possession, or else you wouldn't be in NCRS. Some plating is too shiny, in my opinion, to look like the original aluminum part (especially that which comes out looking more like plating than new aluminum). However, plating the piece looks better tban four coats of bright aluminum paint. Now, I have not viewed samples from every business; you may know of one that does excellent work. Since there are several, each member should ask around and see the finished product before spending any money.
Parts such as valve covers can be cleaned using Brasso or Never Dull, but the result is usually a part so shiny it seems to "glow in the dark" -- this is not what you're after either. A few treatments of aluminum jelly provide results that aren't bad, but whether using jelly or Brasso, it's always difficult to get between the ribs, around the bolt holes and Corvette inscription, and in the 90-degree bend where the cover flares to hold the valve cover gasket on the underneath side. What usually happens is most of the cover looks fairly decent, except for the residual oxidation a~d discoloring around the areas just mentioned; hence, the tendency is to beadblast, paint, or plate the part to get a uniform appearance -- or just clean it as best you can and "make do."
In 1980, no business I was aware of provided "aluminum refinishing" service. Today, several do this work, and most do a reasonable job, although my personal opinion is that after "refinishing," some parts, depending on the business, may not exactly resemble the finish as it came from the factory. In particular, no aluminum part was ever plated with any-thing. It was just a raw aluminum production line part that was installed in whatever condition the supplier delivered it.
A genuine bona fide "restorer," whether it's of cars, antique lamps, or whatever, is
sometimes forced to find an acceptable solution to a restoration problem and is willing to conduct some experimentation. If you don't want to do-it-yourself, worry about the. results, or just want to "buy" a Top Flight car, the rest of this article will be boring and of little use to you. However, if you want an inexpensive, easy-to-accomplish solution to cosmetically freshen or "restore" any cast aluminum part that easily can be done in your garage, read on for at least one answer that you can easily perform.
This is not a sales pitch that the idea or solution is any better than many of the already available services for aluminum. However, based on the results from my own experience, I believe the approach outlined in' this article is a reasonable alternative that's easy, attractive, inexpensive, and should give the owner a sense of "restoring it yourself" -- if that's what you want.

-
Clean~ng The Cast Aluminum Parts
Let's begin with the cast items first -- the
cast aluminum parts of the fuel injection, assuming it's disassembled, the carburetor, intake, thermostat housing, bellhousing, fan clutch, valve covers, and even the transmission m'ain cases, side covers and tailhousings, if you want to go that far. Don't be tempted to bead-blast the part. Beadblasting partially or wbolly destroys the original surface and texture of a par~ tbat will never be manufactured again. Also, beadblasting is easily detectable in the judging process, if that's a concern. Further-more, it's totally unnecessary when freshening the aluminum finish.
Instead, get a can of Krylon "Dull Alum-inum" #1403 spray paint, a pint of lacquer thinner, and a soft 2" wide paintbrush -- a soft, used, natural-bristle brush works well. Now don't trash the idea yet, because we aren't going to "paint" the aluminum piece in the usual sense. We're just going to freshen or cosmetically enhance the already cleaned item
(Colltil/lled on next page)

31
using what amounts to more of an aluminum tillt. You may not realize it yet, but you bave enough supplies to freshen every cast alum-inum component on ten cars, and your "capital investment" should be no more tban $10.
For whatever reason, not all stores stocking Krylon paint carry the "Dull Aluminum" color. Most seem to carry the. "Bright Aluminum" color, but if you use that, you won't like the result -- it looks just like what its name says it is, bright aluminum paint. I assure you the "Dull Aluminum" paint is currently available. I can even purchase it at a local hardware store in the small West Texas town where I live. If you can't find it at a store near you, contact me, and I'll send you a can (for about $2.97 plus postage).
. The first task for cleaning all the aluminum pieces but tbe air cleaners and surge tanks is to purchase a reliable chemical cleaner, such as Simple Green or a carburetor cleaner that is safl!for aluminum, to remove the really grungy and gritty material that's collected on tbe
aluminum piece. Read tbe label carefully to make sure the product is safe for aluminum. One major caution to be aware of in the cleaning process is this -- longer may not be better! Don't just leave the aluminum pieces you are working on dunked in a drum of chemical cleaner for several days or while you go on vacation! lance observed tbe result of leaving an aluminum intake manifold in a drum of cbemical cleaner, described as safe for aluminum, for about two weeks, and it was not a pretty sight! The manifold was severely pitted and a horrible black color. Fortunately, the manifold was only an aftermarket product that was easily replaced. Caution is tbe watchword when you mix chemical cleaners and alum-inum! An educated guess is most of the really nasty stuff sbould be dissipated within one or two bours. Wbat's left can be coaxed loose with a soft bfl!sh (such as an old toothbrush) dipped in the same cbemical cleaner, then gently
."scrubbed" over the surface of the aluminum piece. If you're working on the fan clutch,
here's one further caution: protect the seal of the fan clutch from the cleaner. Rather than immersing the clutcb in cleaner, it may be more prudent to put a piece of rag around the shaft and use a parts cleaning brush dipped in cleaner to get any grease or <?il off the clutch. However, read and follow the instructions enclosed with the particular product you're using.
Wben tbe part is as clean as feasible, its appearance still may not be satisfactory enough for sbow use or to suit your personal prefer-ence. Most likely, it still doesn't appear as factOlY fresh as you might like, even tbough it is clean. You may have noticed the soft brush may continue to scrub loose a black substance that seems to never end. Because aluminum is somewhat porous, years of motor oil, grease, and an endless list of other substances have literally soaked deep into the pores of the metal.
Mter removing all of the obvious grunge, base off the item with fresh water and let it dry completely. Now pour a very small amount (maybe 1/16" to 1/8" deep) of lacquer tbinner into a ceramic cup or small metal container and spray about five seconds' worth of paint into the cup of lacquer thinner to "color" it aluminum. You are now ready to do the cosmetic work on the part. Begin by ever so lightly spraying the part with the Krylon "Dull Aluminum" paint. If you acbiev7 scarcely any detectable paint coverage, it's probably too mucb. Just a few quick, light passes holding the can at least 12" away for a good. dispersion is probably enough. Immediately dip the end of the paintbrush in the cup of lacquer thinner sprayed with paint, and begin brushing or working the paint into tbe porous metal. Do this
all over the part before tbe paint totally dries. Keep a moderate amount of this thinner/paint mixture on the brush while worKing the paint
around on the surface of the part. Not only will this further dull the already dull aluminum paint, but it helps spread around and thin out any evident paint on tbe surface. The lacquer thinner virtually dissolves the already sparse paint rigbt into tbe metal pores before tbe

32

thinner evaporates. Not uSing thinner now, but just tbe soft brush, keep brush.ng tbe nearly dry paint until a uniform ~ppearance is evident and it becomes impossible to brush the liquid paint around because it has somewhat dissipated into the pores and the thinner has evaporated. No brush tnarks or detectable paint should be visible at this point. Tbe "Dull Aluminum" paint is so thinned, it might be best described as a IUJ./1'lI1bcr than 'point. Do some experiment-~tion to get a natural finish. Once you get th~ bang of tbe procedure, it becomes easier and easier ..- just like skiing or diving, practice helps you develop a certain feel or technique.
Did you spray on too much paint, or d('le~ tbe part you ate working on look painted? Don't worry if the paint is too heavy. Damp~n some paper towels in lacquer tbinner, wipe off the excess paint, and begin again. If the tint doesn't appear heavy enough to cover the . discolorations or stains on your part, simply spray more paint into the thinner, and brush the part Once mOTe. You be the judge herd Also, don't worry about ruining anything on your ~Iuminum piece. The worst possible outcome is ~bat you aren't satisfied with tbe resull and choose to send it to a profcssional refinisher. Lacquer thinner will even remove dried paint, so by using it, you can always return to the starting point and be no worse off than before you began.
I'm not certain what each professional business uses, but this tecbnique, properly applied, sbould provide decent resull~ at nearly no cost. Whether the car is for show or is a ", driver, this approach pTOvides 1he ownet with a quick, inexpensive way to enhance tf1e rooks of
'the engine compartment that should pass the . scrutiny of any judging process with flying .colo~. It may take a little practice, butl believe you wi1l be satisfied with the outcomc. If you
follow the instructions and have only a .
moderate amount of patience, the paint (now more or a tint) is scarcely, if ill all, detectable. The part comes out really looking fresh, and bas an added benefit beyond being quick, easy,

and inexpensive. The micro-tbin "coat" of paint seems to make the part somewhat easier to maintain than raw, bare aluminum that readily stains from soaking up any liquid that might splash onto it.
Oil Filler Thbes
When you have finished "fresbening" tbe intake, it is possible that the paint on the oil filkx tubt; needs to be. re.done. The 1958-62
judging manuals specify a cofor caned II Argent SHver." Not having done a survey of all available shades of paint, I can'~ .teU you for certain that no one sells this shade, but I've never seen it in any store or eYen in the
. Corvette specialty catalogs. If you've ever been in ,3 wrecking yard and seen a late 1950's or early-60's Chevy with the original motor (and oil filler tube) color, you wiII immediately know what color tbe manuals are describing. The paint appears metallic or ,hanunertone and bas a distinct greenisb cast in the silver. Using an original filler tube as a guide, I've dis- . covered if paint t«at seems to closely or almost exactly match the original Argent Silver. It is the Dupli-Color brand name, and the paint color is Light Pewter (M). The can bas numbers DS-FM 241, and FM code 11, and it was used on 1981-83 Ford Motor Company calS.
Valve Covers
Valve covers are definitely the most difficult of the cast aluminum components to acbieve a decent result on, owing to the nearly smooth surface and few pores for even a micro-thin coating to vanish into. Just a tad too mucti paint, and i( looks like wIatt rall doo't want -- like you painted it. If this paint is not uniform Or does not cover the valve cover enough, the oxidation and cosmetic imper-fections wi11 show through and contrast with even the extremely thinned paint we've been using.
I I ere's the approach that seems to work best
with the covers. Follow tbe usual procedure
(contin/led on next page)
and get uniform coverage with as thin a coat as possible. Now, let the Krylon paint thoroughly
dry overnigbt. If tbe surface has a painted look, take the soft bristle 2" paintbrush (dry), and run it up and down the cover and in all the crevices just like you were painting the cover over and
over witb a can of brush paint (but you're really using just a dry brusb). This dulls the paint furtber and literally wears away just enough paint so a very natural satin aluminum finish becomes the final result. It took me approx-imately five minutes per cover to brush it "just right" for my taste. It's virtually impossible to detect paint, yet tbe stains and imperfections are not visible either. Don't brush too bard or . for too long, or you will nearly be back where you started, as I discovered tbe first time I did this. Have patience! After you develop the technique, you can create a finished set of . covers in about thirty minutes. (For years, heat, time, and motor oil from underneatb have not caused any noticeable change in the appearance
of the valve covers I performed this technique
ooJ .
If your valve cover gaskets are leaky or
need to be replaced, Mr. Gasket makes a cork gasket that has a thin layer of rubber on both sides of the gasket for a leakproof seal. These can be reused many times while performing routine valve lash adjustments before replace-rp.ent is necessary. They are called "Ultra Seal" gaskets, and the Mr. Gasket part number is 5860. Most speed or performance auto parts stores stock these.

Surge Tanks
I've not had any success in using the tinting
procedure on surge tanks due to tbe extremely smootb surface on this non-cast aluminum part. I've seen any number of original tanks tbat
have been beadblasted, I assume in an attempt
I
to renew the original aluminum look. If ever
beadblasting is noticeable, it is on this part. When newly manufactured, surge tanks were
'fairly shiny. Using aluminum jelly and a soft toothbrush will usually restore the surge tank to

34
ils original finish, although several treatments may be necessary to get it completely clean. I3rasso or Never Dull will also clean it, after removing lots of the blackish substance (oxidation). A few applications may be necessary here to really clean the part.
If you've never seen Never Dull or heard of it before, it is a pre-treated cotton wadding tbat comes in a small blue can. Usually, antique furniture or refinishing businesses sell it because of its universal applicability on metal surfaces (like brass pots, metal binges and clasps, etc.). It also works w~ll in cleaning any stainless part on your Corvette.

Aluminum Air .Cleaners
Reproduction aluminum air cleaners on
solid-axle Corvettes are generally far too shiny to be considered an original finish. Some owners even polish the already shiny surface to give a brilliant shine to the already too-shiny surface. The 1961-62 NCRS Judging Manual describes the origiJ]al appearance to these cleaners as "polished, neither mirror-like nor dull brushed finish." While this helps some, a picture may still be worth a thousand words. Secure a copy of Noland Adams 1953-62 Corvette Restoration and Technical Guide --Volume One, and turn to page 330. Notice tbe
. picture of the air cleaner in the lower left-hand corner on the 1961 as shown in Car Life Magazine in September of 1961. As disappoint-
ing as it may be, that picture is a very accurate representation of what a genuine factory appearance actually was. The lower right-band corner of page 365 also shows the contrast, but there's no indication of how old tbe car is when the picture was taken. I'm old enougb to remember these cars wben they were show-room new; if the owner hadn't polished the air cleaner, which was a rare occurrence, given the desire in those days for a "street-rod" appear-ance, the original finish was only moderately shiny. The finish could even be considered "satin" or "semi-shiny". If your air cleaner finish is nearly identical to the distributor shield

.lish, it isla,. too shiny! The shield is highly
lisbed stainless steel and should look that
:y. The air cleaner is aluminum and should \'e a very distinct difference in finish. It was polished sheet aluminum fabricated into an . cleaner by the supplier, and it should look
',,(inctly aluminum. Again, looking in Adams'
',)ok, can you notice tbe difference in https://www.yenko.net/ubbthreads/imag...lins/smile.gifpearance'between the sbield and the air . eaner? In my opinion, tbat's a very accurate
presentation of the contrast between the two "ces before the original purchaser polished it " the first time to suit the "customized" look
that era. -
Since aU of the reproduction air cleaners TentIy available are nearly brilliant in 'earance, the problem is how to dull the
'sh to look like the original without
.1aging the surface? Actually, most owners
i probably not ?Nant to fopow this next
,cedure becaus~'it dulls the shine somewhat
1 certainly does not particularly "enhance"
; ile looks of tbe air cleaner (like putting overspray on tbe bood latches to duplicate a factory appearance). For show car owners who
. might want to tone down the shiny surface, however, the process can be performed with no harm at all to the air cleaner. Purchase a bottle of aluminum jelly (NOT naval jelly!), get a soft paper towel (like Viva) or a soft cloth, and turn on your outdoor water hose. Pour a blob of aluminum jelly on the air cleaner, continuously wipe it all over for about one minute with the soft paper towel or cloth, not letting the jelly clry, and then hose off the cleaner thoroughly.
',ightly dry the surface with 'another soft paper owel or cloth so it won't water spot, but be
'areful whenever you wipe tbe surface. If the
aper towel is one of the "bargain basement" :-ands and is not soft enough, it can scratch the
)ft aluminum surface of lhe air cleaner. and
. "
)u wiII be worse off than when you started.
The aluminum jelly should tone down the
nish of the air cleaner considerably. If it's not lIlled enough, repeat tbe process until the nish has a satin aluminum appearance, not the
highly polished stainless steel look it comes with. The new original air cleaners looked similar to a new piece of sheet aluminum as sold in a hardware store -- a clean satin. aluminum appearance tbat is only moderately shiny. If you ever decide you want tbe shiny . appearance on your air cleaner again, just polisbing with Brasso or Never Dull will retpm the shiny appearance it had wben you bought it.
As noted earlier, this article is aimed toward those car owners and restorers who enjoy performing tbeir own restoration tasks, at least the tasks that are feasible. Some jobs, such as chrome plating, require such a capital investment tbat it's just not practical for a single restorer to undertake. Most simpler tasks, however, including freshening your aluminum pieces, can be done personally. Give my procedure a try, and let me know what you think of the results. I always welcome any comments or inquiries.
.'.
Bill Halbert