Craig, it's time for a chemistry lesson. In the electromotive series zinc
is between aluminum and nickel (and iron as well) thus making the aluminum
in your suggestion the anode that protects the zinc. I suspect that that is
not exactly what you intend.
Zinc is cheaper than aluminum and sufficiently anodic to steel to be very
effective in preventing corrosion whether as a sacrificial anode (a lump of
zinc) or a galvanized coating (steel parts dipped in molten zinc or
electroplated with zinc). The disadvantage to anodic protection is the fact
that the process relies on the consumption of the anode, so when the anode
is fully "sacrificed" the corrosion protection ceases.
Another important chemistry lesson: Teflon in motor oil is so effective (at
clogging oil filters, that is) that DuPont (the developer of the product and
owner of the trade name Teflon) refused to sell the stuff to motor oil
manufacturers and its reason according to DuPont's Fluoropolymers Division
Product Specialist, J.F. Imbalzano is that "Teflon is not useful as an
ingredient in oil additives or oils used for internal combustion engines."
The only reason that DuPont does provide Teflon for use as a motor oil
additive is that the company was sued for "restraint of trade" and lost.
Teflon is known as a slippery material to which nothing seems to stick, but
that is the proverbial two way street - getting teflon to stick to anything
is very difficult and requires a perfectly clean surface, elevated
temperature and a vacuum, so "using the teflon engine treatments and
boil(ing) the parts in the solution for an hour or so" will make the parts
oily but nothing more.
Best regards,
Rob Housman
Irvine, California
Europa XS Tri-Gear
S/N A070
Airframe complete
From: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@matronics.com] On Behalf Of craig bastin
Sent: Wednesday, October 24, 2007 5:02 AM
Subject: RE: Europa-List: Mod 73 alternative
yes true, but I believe that the annodes used on outboard motors are zinc,
being more reactive than the alloy
thus the alloy and the nickle should both become cathodes and therefore not
corrode. The annodes are consumed
moderately quickly, but it works quite well.
As to the teflon i see most people in favour of, you may be able to do it
yourself, by using the teflon engine treatments
and boil the parts in the solution for an hour or so. they work well in your
engine too, I used one (NULON brand) in a car
I was having overheating issues in (bigger engine than standard, no room for
bigger radiator) and one treatment dropped the
running temp by around 20c. I use it in all my motors now, even though i
normally run a fully synth race oil as well.
-----Original Message-----
From: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@matronics.com]On Behalf Of Rob Housman
Sent: Wednesday, 24 October 2007 12:44 AM
Subject: RE: Europa-List: Mod 73 alternative
You are on the right track Craig, but you missed the obvious - aluminum is a
sacrificial anode relative to the nickel plated tube.
Best regards,
Rob Housman
Irvine, California
Europa XS Tri-Gear
S/N A070
Airframe complete
From: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@matronics.com] On Behalf Of craig bastin
Sent: Tuesday, October 23, 2007 4:52 AM
Subject: RE: Europa-List: Mod 73 alternative
A couple of sacrificial annodes would resolve the issue of corrosion I
think, same as on outboard motors for boats
but it is a good point, or if you had the clearance, maybe powder coating
the torque tube, or caster oil, only problem
with caster oil is it remains tacky, as all the data i have seen on caster
oil suggests the only way to remove it completely from a metalic
surface is to machine about 1mm off the surface
you could simulate an accelerated situation by putting the old bush (tp5)
and a piece of the alloy tube in a salt water bath for a week
and see what happens, ideally in the same relation as in the aircraft ie one
inside the other.
just had another thought, maybe a teflon treatment might do the trick on the
torque tube or both if you have done the mod yet
it would make the tube real easy to get on and off too.
-----Original Message-----
From: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@matronics.com]On Behalf Of Peter Zutrauen
Sent: Tuesday, 23 October 2007 9:11 PM
Subject: Re: Europa-List: Mod 73 alternative
Hi Karl,
The only concern I would have is dissimilar metal corrosion on the torque
tube. Not sure how to prevent it between the alu and the torque tube plating
besides lots of grease. I suspect that the grease will not be enough
however. With the sliding on/off and then sitting in one spot, I would
expect some metal on metal contact with the grease being wiped off. Hope
I'm wrong, but I've seen too much dissimilar metal corrosion in a variety
of situations.
Cheers,
Pete
On 10/22/07, Karl Heindl <kheindl@msn.com> wrote:
<mailto:kheindl@msn.com> >
My original plan was to replace both TP5 and TP6 with a single tube.
After removing the TP5 I realized that there was no point at all in removing
the TP6. It is only necessary to ensure that it cannot move inboard, which
would then allow the TP12 to disconnect from the tailplane etc. etc.
I simply replaced the TP5 with a longer alu tube from ACS, part number
03-37900. This butts right up against the TP6, and there is no way this can
ever move inboard. The tube is made of 6061 T6 aluminum.
Advantages:
A straightforward mod.
No cutting into the tailplane.
No misalignment problem with TP5 and TP6.
A permanent solution. ( assuming that there was a problem in the first
place.)
If anyone is interested I can give more details on how I did it.
Cheers,
Karl
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