Linseed oil as form oil when casting?

[BiFuel]

Soon it will be time for stair casting. The steps are shaped by jG with 45*170 studs. Can I apply linseed oil to these for the form to release easier?

One more question: if I oil before casting, could I then fix imperfections in the wood with regular putty? Or will it adhere to the concrete despite the oil?

 

[Johan Gunverth]

Got a tip from Skanska Prefab (a relative works there) not to use linseed oil. Received a small can of real form oil that should last a lifetime. You apply a very thin layer in the mold. It should barely be visible. Seems to be some type of paraffin oil, but I'm not sure.

 

[BiFuel]

I heard that cooking oil (rapeseed?) might work. Haven't found any form oil in a store yet. What do you think about the filling then? It's a shame to have small knot holes and such that are visible.

 

[Johan Gunverth]

Seems to work according to the "expert": http://www.betong.se/?p=2997