How do YOU protect your transmission case from corrosion?, What coatings do you use? Options

[Dr Evil]

I am trying to finish my notes to accompany the rebuild video (notes will be free) and I am wanting to pick your collective brains for info on corrosion prevention for the mag alloy case. What do you do? The factory coating only lasted a few years and is long gone now. On most peoples cases, it is the oil that keeps it from corroding (IMG:style_emoticons/default/wink.gif)

[Richard Casto]

Redline Tranny Juice(no corrosion) (IMG:style_emoticons/default/bye1.gif) (IMG:style_emoticons/default/stirthepot.gif)

We are talking about exterior protection, unless you are suggesting you poor it on the outside? (IMG:style_emoticons/default/wink.gif)

If you are talking interior, just make sure it's the GL-5 version.

[Drums66]

If you are talking interior, just make sure it's the GL-5 version.
[/quote]

That's what I've heard......never tried it! (IMG:style_emoticons/default/dead horse.gif)

[jmill]

I have no idea of the cost on this stuff but they say it's clear and dries to the touch.

http://www.socomor.com/englishFT/SOCOPAC%2...H_19176AGGB.pdf

I've used cosmoline type sprays in the aircraft industry. They work great but collect dirt like crazy. It also gets sticky when warm. We would clean all the dirty stuff off every C check and then re-apply.

[Downunderman]

HPC S02

[Katmanken]

From my mag casting days, the magnesium institute book recommends zinch chromate paint. The zinc acts as a sacrificial anode to prevent corrosion, and the binder in the paint seals and protects. Comes in green and bright yellow.

My tranny has a thin coat of aircraft grade zinc chromate paint on it, and a thin coat of wheel silver.

My second choice would be the tan tectyl like wax coating suggested by the factory. Some of those coatings have corrosion protectants formulated within.

For those of you that passionately believe that paint prevents appropriate cooling, you might research the heat transfer rate through the factory recommended tectyl like coating, or the heat transfer rate through the usual coat of grease, oil, and crud.

Bottom line, uncoated it rusts, and appropriately coated, it won't.

[SUNAB914]

Aluma blast: Eastwood

[Phoenix-MN]

VHT high-temp clear

[Tom_T]

VHT high-temp clear

(IMG:style_emoticons/default/agree.gif)
Paint is another option 30-40 years out - from my tranny soda blast topic's post:

After blasting or cleaning - you may want to try a clear coat HT engine or exhaust paint like those here from VHT (or another paint/coatings mfgr.) to seal in the Magnesium alloy case material.

http://www.vhtpaint.com/flameproof.html
http://www.vhtpaint.com/engineenamel.html

They also have a magnesium metallic if your case is really badly stained into the metal.

In all cases - proper surface prep is a must to have adherence, & check each paint to make sure it's made to stick to the specific alloy on which your applying.

The other coatings & protectants will work well on a case that's in good condition (under the usual crud), but more damage &/or corrosion may require a paint job.

GREAT info guys! (IMG:style_emoticons/default/smile.gif)

[Tom_T]

From my mag casting days, the magnesium institute book recommends zinch chromate paint. The zinc acts as a sacrificial anode to prevent corrosion, and the binder in the paint seals and protects. Comes in green and bright yellow.

My tranny has a thin coat of aircraft grade zinc chromate paint on it, and a thin coat of wheel silver.

My second choice would be the tan tectyl like wax coating suggested by the factory. Some of those coatings have corrosion protectants formualted within.

For those of you that passionately believe that paint prevents appropriate cooling, you might research the heat transfer rate through the factory recommended tectyl like coating, or the heat transfer rate through the usual coat of grease, oil, and crud.

Bottom line, uncoated it rusts, and appropriately coated, it won't.

Ken - from your mag casting days - what's the best way to remove the zinc chromate safely (green if it matters)?? (IMG:style_emoticons/default/confused24.gif)

I got a set of 5 used Fuchs 2L Alloys which a DAPO had primed with Z-C then painted Phoenix Red for the LE look I suppose (or had it done). They are in very good condition under the paint/Z-C - that having protected it all these years, but I wanted to remove the paint & Z-C before I take them to Al Reed for a full-on resto & re-anodizing. I've tried Acetone & a rag, but it's painfully slow & may score the surface (as did the seller with a soft toothbrush & rag - BTW he was not the DAPO).

Any suggestions for materials & methods to safely, more efficiently & effectively remove Z-C? (IMG:style_emoticons/default/confused24.gif)

Not to hijack your thread Dr. E - but removal would be the same for paint &/or Z-C on the transaxle cases too - so it's really applicable here too! (IMG:style_emoticons/default/biggrin.gif)

[Katmanken]

When working with new parts, you apply coatings, not remove them.

That being said, paint stripper would be a good guess. Not sure what is in each brand, bit I would stay away from acids and bases (lye). Test on a small area to see if it damages the anodize.

Wood scrapers with angled tips are easy to make, softer than the aluminum, and do a fair job scraping softened crud.

Dry ice blasting can definitely strip them because it is used to strip airplanes one paint layer at a time.

Not sure if soda blasting is OK.

[pcar916]

I'm reviving this thread because I've just bought CRC SP-400.

http://www.crcindustries.com/ei/content/pr...N=03282&S=Y

It's a better solution than the CRC 5-56 I mentioned early in it. I'll post when I get finished coating both a 914 and 915 case and give a followup in the spring after a winter full of water and... stuff.

Fortunately Arkansas uses more dirt than salt. The SP-400 seems very close to Tectyl both in consistency and color and has a working temp of up to 300F.

Should be ok certainly in the winter, and track temps with a clutch/LSD should be ok as well with a trans-cooler shedding BTU's

[bulitt]

I have a 1949 Allis Chalmers tractor with some original paint on it. Unfortunately it is lead based.
Why not media blast then prime and paint with a product like PPG Omni.
Or polyurethane primer in a rattle can. The local Sandblaster uses it.

[bbrock]

I'm reviving this old thread to provide an update. You can now buy small quantities of Tectyl 846 through Amazon: https://www.amazon.com/gp/product/B00HUY9UG...=UTF8&psc=1

I've used it on both my engine and transmission case. Just did the transmission yesterday. here is a pic.

(IMG:http://www.914world.com/bbs2/uploads/post-20845-1610850919.jpg)

[ejm]

I'm reviving this old thread to provide an update. You can now buy small quantities of Tectyl 846 through Amazon: https://www.amazon.com/gp/product/B00HUY9UG...=UTF8&psc=1

You can buy direct from the manufacturer. Larger quantity, less money and free shipping.

https://petroleumservicecompany.com/tectyl-846-class-i-2/

[rgalla9146]

Every time I opened a painted trans it was a crappy "rebuilt"

[mepstein]

Every time I opened a painted trans it was a crappy "rebuilt"

Yea. The Krylon “rebuild” exists even in the Porsche world.

[bkrantz]

Has anyone tried T-9?

[bbrock]

Has anyone tried T-9?

Yes. Seems to be good stuff. I used it on my fan shroud and so far it has stayed a nice factory gray look so far (about 2 years indoors). I also treated my transmission case above with it a week before daubing on the Tectyl. I think the Tectyl will provide significantly more protection, but the T-9 is invisible and doesn't leave a waxy coating if you want to avoid it.

[914Sixer]

I used LPS 3. Leaves a waxy coating.

[Montreal914]

What was used to clean it and did it need to be gutted?