The trans is assembled as are the motors. I obviously want the castings to last for more than a decade. When I get time, I'll tackle this - trans case first & let everybody know how it went. Guess I'll try knocking the excess off with a brush that's not too aggressive, apply the corrosion block, clean that off & see if I can score some Tectyl to apply at the end.
Thanks a bunch everybody for the info and comments.

Ok, so far, I think we have
1. a temporary Soln (Corrosion Block - BTW a tall silver spray can - green=letters I think),
2. the original factory treatment, Tectyl,
3. and a possibly affordable new, high-tech solution.

There is also the black coatings I've seen done (see above posts). re those, all we know is that some people are using that; not for sure that it is a good solution.

Here is one more thought: The new C-GT has real Mg Mag wheels. What treatment is PAG using on them? I'd think a $600,000 car would have a pretty good protective coating on its wheels....

OK, regarding Tectyl 553.

I talked to Daubert Chemical (after several pelicans) and Ashland Oil – Valvoline (after several Pelicans.) Normally they only sell Tectyl 553 in 55 gal and larger quantities. I know they can sell it in smaller containers, I have some. I’m going to try and get them to offer it in 5-gal containers where Porsche people (Pelicans) can just call, give credit card number, and get it shipped. As soon as I talk to our local Ashland rep, I’ll get back to the supplier and see if I can organize this process.

This is one of the seemingly dumb but very important things every shop and interested owner should have access to. Perhaps Wayne can repackage it into quart or gallon containers.

I agree with Randy, there are later and probably hi-tech coatings. Tectyl is decidedly low-tech and works very well.

Randy’s point on CGT magnesium wheels is well taken, what is the corrosion prevention? The 10-spoke 5 ½ x 15 magnesium wheels were completely painted with what? I have several center-lock magnesium 935 wheels that seem to be uncoated and still OK holding up my TV for 20+ years. It is all about environment and the very long term survival of these parts.

Best,
Grady

There is also something called Dow 7, or something like that, to protect magnesium from the elements. I think that this is what Porsche used on the engine fans to get that yellow-green finish. From what I recall (maybe from a post on Pelican) Dow 7 is a WW II vintage treatment, which is not much used today. Has anyone found a source for this?

Grady, you never cease to amaze me. You have quite the TV stand. :cool:

Count me in for a 5-gal container.

Grady:
when you get the Tectyl deal approved (if you do), PM me with the info (or post it for all to see) for a can.
ThanX

I am a chemist by training (Caltech class 1984, PhD).

Magnesium is a highly reactive second group metal used as an alloy component in real world applications (metal casing, wheels, etc where strength and low weight are needed). The other element alloyed is most likely aluminum which although is heavier imparts more strength and is more corrosion resistant.

Both of these metals resist further corrosion by forming an outer layer of oxides which is tough and almost invisible. Corrosion is a chemical reaction of the metal with air in the presence of water and accelerated by heat. If one can remove either water or oxygen (in air) then oxidation or corrosion is prevented. That's what these suggested paints and coatings do (block the contact of bare metal surfaces to air or water).

Using any acids with reactive metals inevitably dissolves away the "rust" (in the case of iron, white powdery residues in aluminum or magnesium alloys known to chemists as alumina or magnesia....Milk of magnesia antacid remedy for upset acidic stomach....well I digress). So it is not recommended to use vinegar or worse muriatic (hydrochloric) acid or phosphoric acid (metal etch prep for painting).

My best suggestion is go over the case manually with fine steel wool to rub off the grit and crud. It will be harder to overdo the cleaning and spray on a clear-coat paint (blocks water and salts). Porsche had in the past and present use Cosmoline- a heavy wax coating to protect the engine and other metal parts during trans-Atlantic shipment in the wet ship's cargo holds.

tshih,

Thanks, good post.

Yes, Tectyl 553 is a Cosmoline-like coating. Cosmoline was a WWII preservative wax base coating used extensively to protect metal parts on the way to war.

Today there are many issues concerning environment, worker safety, ease of application and removal, and much more. From what I understand, the current products are far superior to their WWII ancestry and protect better than the original Tectyl 822 applied to the early 911s. It still looks the same, just works better.

I prefer to use a stiff bristle brush and Stoddard solvent to clean the surfaces. Only when that is insufficient would I use exceedingly fine steel wool in limited locations. The more the surfaces are molested, the more likely severe corrosion will occur.

Best,
Grady

OK, cleaning -- I've cleaned 3 of these things recently (due to replacing the first two).

The big problem is all the tiny and hard to reach crevices from the ribs on the case. After using a pressure washer and solvent (both are good because you will have both polar and non-polar solvents to get at the mixture of dirt and grease), you can use a curved tool to get into those crevices or small brass brush. A dull wood gouge can be used. Use it to scrape not to cut into the alloy.

Brake cleaner works great. That will not get it "Zeke-acid-wash" clean & shiny, but it will be plenty clean for the non-concours on the bottom of the car set.

If you are rebuilding it, then jsut stop at the pressure wash stage and send it out to be cleaned and coated (as soon as we figure out what coating process to use and who offers it).

Start here . About halfway down the page is a bit about restoring vintage Halibrands. Finish up with the "Gibb's Brand" article. I have a sneaking suspicion this is the same stuff Grady was talking about, in an aerosol. Maybe not. I've had no luck is procurring any, but thanks for reminding me. I need to give them another call. Sounds like WD-40, Boeshield T-9, and liquid wrench rolled into one and times by ten.

To keep this thread current:

Here is the link to Daubert Chemical.

Here is the Technical Data Sheet for Tectyl 553.

Here is a list of 16 related Technical Bulletins for the handling and use of Tectyl 553.

One thing I don’t see listed is how to properly dispose of unused product.
Randy, can you chime in here?

I still think this is an opportunity for PelicanParts (Wayne hint, hint) to do it correctly. He could contract for someone to repackage it in 1 gal. appropriate containers and retail it for less.

It seems I was thumbing through some current Porsche technical literature and found Tectyl listed for the current cars. I’ll look. It may have a Porsche P/N and outrageous price.

Here is a current related thread:
http://forums.pelicanparts.com/porsche-911-technical-forum/241234-anyone-interested-buying-tectyl-553-a-post2124887.html#post2124887

Best,
Grady

EDIT to get the link to work right.

I used brick acid, ie mild hydrochloric acid used to clean cement off bricks, very cheap from builders supplies/merchants. Work it in with a stiff brush, wear gloves and googles, use lots of fresh water to wash it away. I then painted my gearbox (tranny) in a bright silver paint to stop future corrosion. I was given this advice by the guy helping restore my car, i'd never have thought of it myself.

regards

Andy

Carrera 3.0 restoration pics

What I did was pressure wash my tranny and follow Randy's suggestion to go to a marine store for a spray can of Corrosion Block. I sprayed it on before I shipped it to John Walker. Seemed to work OK as far as coating the metal. It left a sort of oily film. The transaxle was really nasty before I treated it. I don't have any idea how long it will last. John didn't say anything negative about it after he got it. I'm interested in buying a gallon of Tectyl 553, if anybody gets some & makes it available.

Was hoping to hear more on this subject. Marv - How has the Marine Block worked?? Grady - Any progress on getting the Techryl product??

I’ll give it a try.

I just asked Daubert Chemical to have a sales rep contact me. I’ll get some engineering samples of Tectyl 822 and send some to Wayne. My goal is to organize the packaging of Tectyl 822 in 1 gal containers so Pelican Parts can sell it retail. One more PP product and a boon for Porsche cars.

Best,
Grady

That would be great, Grady - thanks!

Grady,

I've cleaned about 20 914 tranny's now.. and had no idea that they needed to be coated afterwards.

I'm in for a gallon if it works out.
brant

I sprayed both trannys with Corosion Block after I got them back from John Walker. It seems to do a good job of taking care of the corrosion and is easy to apply. Just spray on and rub down with a cloth. I've had both in storage for a couple of months now and they are good sofar and show not signs of developing any corrosion. I suspect they will be pretty much free of corrosion for quite a while. I should be putting the good one in in two or three months. I also have a couple of 2.7 cases I think I'll treat also.

Hey Grady - I just tried this CRC Marine corrosion block on my 901 after a ballpin replacement and 1st gear syncro rebuild. Dried to a waxy yellow. Similar to the old cosmoline and smells the same. There is a coating on the whole thing even though certain areas show a darker yellow.

http://forums.pelicanparts.com/uploa...1140286094.jpg http://forums.pelicanparts.com/uploa...1140286107.jpg

waxy yellow...

- can you check the ingredients on the can or on the MSDS?
Maybe you've found a way to get small amounts of the stuff...