Thread: Neverending oil spots on Tassie Blackwood benchtops

I have never had this problem with Tasmanian Blackwood, was the timber properly dry, correct moisture content, I am not a fan of oil finish on benchtops if it is sap a oil finish will not stop the process it could take many months or more for the sap to stop running.

Does it get worse in humid weather? I have had blackwood "bleed" some oily substance which I am told is natural resins absorbing atmospheric moisture and oozing out through the pores. It went away after I finished with polyurethane. Not too sure about how an oil finish would affect that though. Looks pretty ugly in your case.

The same thing happens to me with thinned oil finishes such as FW Tung oil or most of the 'danish oils'.

The timber soaked up the oil, and then spewed it back out as the finish began to set/cure. It usually happens within the first couple of hours. A wipe with a clean dry cloth is usually enough to get rid of them while they are wet and juicy. If they have dried, a light sand and recoat will be needed.

This problem occurs primarily on coarser grain timbers, and I've found it to be worse again on the sapwood of coarse grain timbers.

Eventually with enough coats, the timber will be properly sealed and the final coats won't penetrate as far and therefore won't spew back out later.

Check very carefully to make sure that first coat is fully dry before recoating. Oil finishes occasionally go cranky on you and that first coat fan end up soft/sticky. Air circulation and plenty of sunlight/UV goes a long way to settling them down and getting them cured out.