The ancient practitioners of Alchemy chemistry who got caught up in wasting their time trying to turn lead into gold were apparently using the wrong process and metal. DOG Aviation with the help of chemicals from the Sanchem Corporation successfully turned aluminum to gold earlier today.
Prior to priming, all the
aluminum airframe parts will be treated with Sanchem CC-6100 which is a cold
conversion process similar to Alodine but without the nasty environmental and
personal hazards. The process converts molecules of aluminum near the surface
into a corrosion resistant form which will then be protected with an epoxy primer. For the start of the
RV-12 project Sanchem CC-6100 will be used but DOG Aviation’s R&D
department is looking into switching over to Sanchem CC-3400 for the wings
where there are lots and lots of parts.
Sanchem CC-6100 treated rib is on the left .. untreated rib on the
In an effort to not waste the chemicals I did
not mix up a large batch … only mixed around a cup or so. First the parts are cleaned with a part C cleaner using a Scotch-brite pad and rinsed in distilled water. Next the part is exposed to the CC-6100 solution for 60 seconds and rinsed in distilled water. I noticed that small
parts which could be kept submerged turned out looking better than parts having
the solution brushed on. The golden finish was more even looking … the longer
parts which were brushed with the solution tended to have streaks. I suppose if
I were not priming and leaving the metal bare, I would not be pleased with the
overall look of the brushed parts ... but since I plan to epoxy prime it is not a big deal. That said, if I don’t switch over to the
CC-3400 for the wing ribs I will try to make a tray just large enough for the
ribs and mix enough solution to make sure the ribs are totally submerged.
The CC-6100 and CC-3400 processes each have their
own advantages and disadvantages but the end results are the same. Both
products require a wash/activation which uses a mild cleaner that is scrubbed
onto the part with a Scotch-brite pad until a break free surface is obtained.
(Break free means the water sheets evenly on the surface of the part and does
not bead up). CC-6100’s downside is once mixed (50-50 part A and part B), it
has a shelf life of only 8 hours meaning … mix only what you can use up because
any leftover solution should not be stored more than 8 hours. Upside, mix it at
room temperature and it is ready for use by either immersing the part into the
solution or wiping the part with a brush, sponge or rag. The conversion happens
in seconds. The CC-6100 solution also neutralizes any cleaner left over from
the cleaning/scrubbing phase.
Sanchem CC-3400 is a bit more involved and more
suited for manufacturing environments because there are temperature
requirements. There is an Alkaline cleaner bath that requires being kept at 100
to 120 degrees F and the CC-3400 solution requires being kept at 135 to 140
degrees F. The upside is there is not a shelf life on the mixture so you can
keep using it over and over again until the chemical is depleted and no longer
converts the aluminum. Another upside is one gallon of CC-3400 makes 11 gallons