Where to get case sealer?

Where are you 'local' to??

I would not use Dirko for a case sealer, it is too thick. It is great for sealing overlapping cooling tin, VW used it on the type 4 tin.

Dirko, a paste-like, cold vulcanizing, elastic sealing and filling compound, gives excellent adhesion to metallic and non-metallic surfaces. Even if fissures, cracks and joint movements are present, Dirko guarantees a secure seal. It has a variety of uses as a gasket, as an addition to a gasket or as a sealant from the outside. Dirko stops oil, water and air leaks. Even parts with hairline cracks are made good again in a few minutes. Ideal for cylinder head joints, gearbox joints, sumps, bearing casings, instrument casings, water pumps and axle tubes. Temperature Range of Dirko is from approximately -50c to approximately +180c

You really should use Curil K2:

Curil K2 is a Non-Hardening Sealing Compound which can be applied with an excellent sealing effect on assemblies which require minimum torque loss and where high surface adhesion is required. Components with groove surfaces can be sealed efficiently and will remain functional under conditions of mechanical, chemical and thermal stress. The components can be easily dismantled. Curil K2 can be applied with a brush with the optional hand-pump that screws to the tin can it comes in. It insures great effectiveness in the sealing of internal combustion engines, gearboxes, pumps and other power units and particularly at disconnecting points such as cylinder head base gaskets, gearhousing gaskets and threaded connections of all kinds. This is especially appropriate for engine crankcase halves, cylinder base, alternator/generator tower and fuel pump mounting base. Also for the Cylinder Head Nuts on the Wasserboxer where they have to be sealed when torqued on. Temperature Range of Curil K2 is approximately -40c to approximately +200c.

I have never tried Gasgacinch for case halves, I have always used it to hold a gasket on during assembly.

Gasgacinch. The professional engine sealer with multiple uses. Use it to seal the case half together. It's great because Gasgacinch stays flexible, and never becomes brittle. It grows with the engine case as it heats up. Use it to hold gaskets in place during assembly. Gasgacinch withstands heat and hot oils.

How about using what just about every diesel and automotive maker has specified for the last 10 years on zero clearance metal-to-metal joints (or "flanges"). It's called Gasket Eliminator. There are many specialized formulas but aircooled VW's need the common 518 which you can find at any parts store. It works, it doesn't stink like that yellow goo, and it's easy to work with with no mess dripping down the case afterwards.

If VW of Germany was still supporting these engines, they would specify a Gasket Eliminator.

And don't forget to use it on the oil pump to case mating surface with no gasket. It will never leak (thanks to Jake Raby for that tip).

RT