Internal engine and trans coating

[wwheeler]

Just for grins, here are pictures clearly showing the red coating Mercedes used on the inside of the block and trans case. This is a '60 220SE motor and trans and the block was hot tanked already. The black exterior paint came off, but not the internal paint. I am going to use Glyptal paint to recoat and not sure what the original was. Glyptal has been around forever though. You can also see the red coating also appears on the outside around the IP opening. It would appear this coating was sprayed and some bled over.

The exact same coating was used on the inside of four speed transmission on this car W128 car. The attached shows the Glyptal paint already painted in the box. BTW, you can get Glyptal from Eastwood. Ain't cheap.

Not sure when this coating started or when it was stopped, but was on the '60 for sure.

[Benz Dr.]

I've seen these coatings before. On later transmissions they used the same green paint on the inside as is used on the outside. I've been using a green etching primer which is very close match.

[georgem]

I have a feeling this has been discussed before however what is the purpose of these coatings?

[wwheeler]

Glyptal has many uses and the most common is an electric motor winding paint for insulation and sealing. You can get clear or this red color. In the case of engines, it is used to seal the porous internal cast iron surface which allows better oil return and helps reduce sludge build up. It is a super tough, oil proof paint and I will have fun removing the part that got on my hands. I just finished painting the block and will post pictures soon.

[wwheeler]

And now the finished Glyptal product. Just need to paint exterior semi gloss black and it is done.

[mbzse]

A prime function of this Glyptal paint is to bind any silica particles remaining in the cast metal surface, after that the core sand mould is removed.
Such grit inside will of course be bad for any mechanical device, like an engine or gear box.
/Hans S

[wwheeler]

A prime function of this Glyptal paint is to bind any silica particles remaining in the cast metal surface, after that the sand mould is removed.
Such grit inside will of course be bad for any mechanical device, like an engine or gear box.
/Hans S

Good point! Do you know what the original coating was?

[mbzse]

Do you know what the original coating was

Glyptal paint...(?)   I would imagine, any car manufacturer's foundry has bulk deals with some vendor for the paint. Or,  perhaps for some corresponding product.
Hmm, after checking the Glyptal web, I note there were numerous variants of this product. I do not know which went into M-B engines of the sixties.
http://www.glyptal.com/Glyptal_Product_Data_Sheets.htm
/Hans S

[Benz Dr.]

I would have thought that the block would be cleaned well enough that any sand would be long gone before they began assembly.

I was always told that Red Glyptal seals the block making oil run off faster and to prevent corrosion. I suppose a secondary consideration might be to seal off any sand from getting into the crank case but I don't believe it's a primary reason at all.
It's also used on generators and alternators to seal electrical wiring.

[280SE Guy]

I will have fun removing the part that got on my hands. I just finished painting the block and will post pictures soon.

Wallace, Your lucky you didn't get the paint on your "private parts".

[wwheeler]