From: southern@sunny.NoSubdomain.NoDomain (Lawrence Buja)
Subject: Cleaning Aluminum (long) 
Reply-To: southern@ncar.ucar.edu
Organization: National Center for Atmospheric Research
Distribution: usa
Date: Thu, 31 Dec 1992 20:11:31 GMT

Mike Ethier asks:
>
>I want to clean the engine in my Grand Am, but it has a Quad 4 in
>it and many parts are aluminum. I tried water, but that was a 
>mistake. A powdery substance developed all over the engine. Can
>someone suggest proven method(s)/product(s) to stop this powdery
>build up and get the engine squeaky clean ?  -Thanks

Below is the cleaning.aluminum file I've collected off the net.  Please
heed the safety warnings. If anyone has any additions, please post them
up.

/\      Lawrence Buja           Climate and Global Dynamics Division
  \_][  southern@ncar.ucar.edu  National Center for Atmospheric Research
      \_________________________Boulder,_Colorado___80307-3000__________


--

          Summary: Cleaning Aluminum Engine Components.
          ---------------------------------------------

(Note: This was originally posted to rec.motocycles by Mark Holbrook
       (holbrook@alliant.alliant.com) and has since been added to.    )

Some time ago I posted a request on how to clean aluminum engine
components, mainly exterior unpolished heads, cylinders, cases, etc.,
i.e.  the stuff that gets really grungy and corroded from years of
leaking oil, road tar, salt, bugs, and neglect.  (Polished metal is a
different subject although there is some overlap.)  Since then I have
absorbed the distilled wisdom of the net on this subject (effectively
none), talked to several wrenchers locally, and tried a variety of
things.  This post summarizes my research.  Some of it is applicable to
iron, too.  Caviat: I have not tried all of them, but wanted to get this
out so that you may benefit from my experience (i.e. destroy your bike
(or cage) like I'm destroying mine.)  I list the various attacks, what
they're good for, and what to watch out for.

Before I begin: WEAR EYE PROTECTION.  WEAR SUITABLE PROTECTIVE CLOTHING
AND/OR BREATHING APPARATUS AS NECESSARY.  WORK ONLY IN WELL VENTILATED
AREAS AND KEEP THE SOLVENTS AWAY FROM FLAME.  You'll be glad you did.  I
accidently squirted xylene in one eye once during this effort and it
burned like hell.  Also avoid getting the acids, carb cleaner, and
gasket remover on anything other than what you're cleaning and dispose
of used solvents, etc. in an environmentally responsible way.

1) Normal wash: Good only for removing pure dirt and light oil.  Use
   your favorite cleaner (I prefer Dawn dishwashing detergent over
   Simple Green or other "automotive" cleaners simply because a strong
   detergent gets the most of this type of crud off with the least
   effort.)

2) Pressure wash: Removes heavier dirt and oil but not any corrosion.
   Recommended only for whole engines.  Avoid spraying at any exposed
   seals (like around the countershaft or tachometer pickoff, possibly
   the exhaust header seals, too).  OK to hit normal gaskets.

3) Dishwasher: For individual pieces you get results similar to a
   pressure washing.  Of course cleans the insides of pieces so be sure
   to blow air through passages to get out residual water.  Do or don't
   tell your spouse about doing this depending on which path minimizes
   negative spousal reaction.  (Mine was pretty skeptical - sniffed the
   dishes that were in with the parts to see if they smelled like oil.)

4) Sand blasting: Sand (silica or carborundum particle) blasting will
   seriously remove metal and leave an uncorroded, but pitted surface.
   Particles may become imbedded in aluminum if air velocity used is too
   great and/or the alloy is particularly soft.  Use with incredible
   care if at all, especially on pieces with oil/water galleries.  If
   you do, mask off all possible entrances carefully since any grit that
   gets in will be difficult to completely get out and any left in will
   likely destroy something in your engine.

5) Bead blasting: Small glass beads which shatter on impact clean off
   surface crud and leave the aluminum looking like it was tapped with a
   zillion microscopic ball peen hammers.  Same warning on keeping grit
   out of passages.

6) Shell blasting: Ground up walnut (or other hard) nut shells are the
   gentlest of the three blasting methods.  Removes crud and shallow
   corrosion and leaves the surface looking the most like it originally
   did.  Note that the blasting methods are the only ones that will get
   corrosion off metal in the nooks and crannies.

7) Kerosene, paint thinner, gasolene, naptha (in decreasing order of
   flammability and increasing order of volatility, I think): Use to
   remove oil, oily dirt, and tar.  Use a wire brush or toothbrush to
   assist in getting off thick gunk.  Does nothing for corrosion.
   Build/rent/buy a parts washer to speed cleaning of dissasembled
   pieces.

8) "Gunk" or equivalent: Gunk combines a petroleum-based solvent and a
   detergent in one can.  Does a pretty good job on heavy dirt and light
   oil, nothing for corrosion.  I think using a heavy detergent wash to
   remove heavy dirt, then a separate treatment of solvent to get heavy
   oil/tar off, and finally a second detergent wash works better than
   trying to do it all in one pass.

9) "Carb cleaner": is xylene and/or MEK (methyl ethyl ketone), i.e.  an
   active, very volatile solvent.  Good for getting the "varnish" and
   "parafin" that form on the inside (and outside) of carburetors from
   old gasoline.  Good as a general solvent, too.

10) WD-40: The solvent doesn't work as good on varnish as real carb
    cleaner, but of course WD-40 leaves the surface protected due to the
    oils in it.  Use it immediately after you have de-crudded (like that
    verb?) and brushed/blasted to keep surface shiny.

11) Hydrochloric acid: (available as muriatic acid).  Takes off
    corrosion (not oily gunk), bubbling as it does so, but leaves the
    surface dark grey.  Use a stainless steel wire "tooth" brush ($1 at
    your local car parts place) to expedite activity.  Don't use it
    unless you really like this color.  Avoid the fumes.

12) "Etching formula mag wheel cleaner": Available in a spray bottle and
    labelled "B" on the ABCDE specifier for automotive cleaning
    products, it contains phosphoric and hydrofluoric acids and bubbles
    when applied.  Use a stainless steel wire "tooth" brush to expedite
    activity.  Avoid the fumes.  Leaves a dull light grey finish which
    can be lightened up by wiping with a paper towel/cloth immediately
    after brushing with the wire brush.

13) Gasket remover: Water-based liquid that softens fiber gaskets so
    they can be scraped off without damaging the machined surfaces.  I
    mention it here because I found two uses for it: 1) it softens up
    the carbon and crud on the inside of the cylinder head, the ports,
    and the valve heads, which eased scraping those parts clean
    considerably.  2) It seems to soften/dissolve clear-coat (and other
    paint as well - be careful where you paint/spray this stuff!)

14) Wire brushes: You can get ones that fit in your drill and brush
    either circumferentially or radially (oh hell, go look at them) and
    in different wire thicknesses.  I recommend the softest wire for
    aluminum.  Also get the wire "tooth" brush (and more than one) I
    mentioned above.  Look in the welding section of your hardware store
    if you don't see them in the tools section.  You can also mount a
    wire wheel on your grinder for small parts.  Frankly, wire brushing
    (and blasting) are the only things I've found that clean off
    corrosion and leave the surface bright.  It's a lot of work and
    can't get in the nooks and crannies but gives the best results.
    Clean surface with solvent first to keep brush from simply smearing
    the crud around.

15) Scotch-Brite pads: Available in about 6 by 9 inch sheets for a buck,
    they work well on clean, smooth aluminum to brighten it up, don't do
    squat for rough-finished aluminum.

16) Aluminum jelly: I tried this stuff years ago so don't remember
    exactly what it is (more acid-based stuff, I guess) and was
    disappointed in the results.  But then perhaps that was when I still
    hoped for some magic method that didn't involve elbow grease.

17) Don't use steel wool on aluminum.  Tiny bits of it will break off
    and stick in the aluminum.  These then rust and you are left with
    "rusty aluminum"

Additional non-aluminum specific cleaners:

18) 3M metal-stripper-wheel.  This is a round plastic sponge,
    impregnated with abrasive grit, which you chuck into your electric
    drill.  These remove tar, paint, rust from steel frames, tanks,
    panels.  Probably a bit too abrasive for use on alloy, though.  With
    one of these wheels, you can remove all the paint from,say, a gas
    tank without using any evil chemicals. It also removes surface rust,
    leaving you with bare metal covered with a network of fine
    scratches, ideal for paint adhesion.  You then swab off your part
    with "metalprep", wash it off with water, dry it thoroughly, and
    paint away!  That new paint will stick like glue!

19) Get yourself a can of "Carburetor & small Parts Cleaner".  This
    milky-white stuff will take the hide off an elephant.  It'll take
    carbon off the tops of pistons.  It'll clean your carbs good.  Just
    don't put any non-metallic parts in it.  You just dump your
    castings, jets, etc into the can ( get the kind that comes with a
    dip basket ), and fish them out a half-hour or so later.
    Bright-squeaky-clean.

20) Another good carb cleaner is Berryman Chemtool.  This stuff is about
    as poisonous and flammable as gasoline, but at least it's a good
    cleaner.  Berryman's comes in a spray can, and its great fun to
    spray it on a grease- and-varnish encrusted carburetor; the stuff
    just liquifies and flows away.  I personally use chemtool to clean
    carbs I don't want to take apart or off.

21) Spray it heavily with Gunk and leave it covered over night, then
    scrub with those plastic scratch pads. For the corrosion, Aluminum
    Jelly works good, but do it after you rinse the engine cleaner off.
    My engine came out looking great.
                       Chuck Stringer <cstringe@silver.ucs.indiana.edu>

22) Being the sort who hates paying more than $50 for a motorcycle I've
    run into a lot of corroded aluminium and have had good luck with
    scotchbrite(tm) pads (plastic wool) followed by Nevr Dull. Nevr Dull
    doesn't have much problem cleaning up the scratch marks left by
    really fine scotchbrite. This works pretty well on both smooth and
    sand-cast surfaces, though it doesn't get the all the crap out of
    the sandcast surface, which in my book is Ok because it doesn't make
    it look like you've got nothing better to do with your life than
    sitting around polishing your crankcase (hmm, sounds like a
    euphemism...).  For bad corrosion (or shitty castings - like old
    ducatis) I've had to bead blast followed by 320 grit followed by 400
    grit followed by 600 grit followed by Nevr Dull, but it's usually
    just easier to buy another motorcycle. The progressive stages of
    sandpaper can also be used with some success to take the sand cast
    marks out.  As for the jugs, good luck. A brass brush will take out
    what crap it can reach, but you probably can't find one long enough.
    It shouldn't leave any visible scratch marks on a rough cast surface
    if that's what you've got. Bead blasting will cure it for sure.
                                     Latte' Jed <mason@asylum.sf.ca.us> 

23) In general, the rough cast cases clean up pretty well with some
    aluminum cleaner or carb cleaner solvents available at auto parts
    stores. Tide works ok, a brass bristle brush works really well.
      You *don't* want to polish the cases with buffing wheel, etc.
    Polished side covers, like most of the older British and Italian
    bikes had, are fine, but polishing the engine cases themselves will
    cause the engine to retain heat.
       If you do complete disassembly and have stubborn corrosion/need
    for resurfacing, a bead blaster with walnut shell grit works
    wonders.  Finding someone to do this, however, is often a bit of a
    trick.
                                   Godfrey DiGiorgi <ramarren@apple.com>
Newsgroups: rec.autos.tech