How do I Remove Very stuck on Exhaust Manifold Gaskets?

[KM7]

I'm changing the exhaust manifolds. They came off easily, but the gaskets are really stuck on the engine block. They may be the original and 35 years old ! I've tried a hard plastic scraper and gasket removal spray. I have a one-sided razor, but I'm concerned about cutting into the metal. So far, I'm not making much progress. These original gaskets seem Very tough!!

Any suggestions? Heat? A drill with a (soft) wire wheel? Keep soaking with gasket remover? What else?

Thanks

 

[Scott Danforth]

Soak with penetrating oil

Then use a metal paint scraper or a gasket scraper.

I have use wood chisels in the past

 

[Mc Tool]

Soak with penetrating oil

Then use a metal paint scraper or a gasket scraper.

I have use wood chisels in the past

Paint scraper ....not to wide , maybe 1 inch and cut half the blade off to stiffen it up a bit and grind a bevel on one side ....like a wood chisel . Ideally you dont want to shave any metal off but as long as its not a chunk the odd nick isnt going to ruin the gasket surface . Exhaust gaskets are fairly thick and when fitted with a bit of exhaust sealant not a problem . Cast iron is pretty hard compared to aluminium .

 

[IslandExplorer]

Oscillating multi-tool with nice sharp straight flat scraper blade for the win. Usually that gets right under it and will do a good clean job, and it's easy on your hands.

Can ping it with light ball peen hammer taps directly on it to get cooperative fractures started if extra resilient gasket. Go easy with hammer. One ping only.

 

[IslandExplorer]