Urethane right over BLO?

[Cliff Rohrabacher]

I'm thinking about applying a Alkyd urethane directly over BLO without the shellac seal/undercoat.

Never tried it - have you how'd it work?

I don't have any shellac in the shop let alone any that's de-waxed.

[Larry Fox]

You might be tempting fate. I don't have much experience with poly but I understand it has adhesion issues under the best of circumstances. Maybe a run out to the BORG for a can of Zinnser Seal-Coat for the piece of mind.

Edit: I just re-read and you didn't say poly. Sorry. I would still want a seal / bridge coat in there.

[Cliff Rohrabacher]

You might be tempting fate.

That's my concern.

a can of Zinnser Seal-Coat for the piece of mind.

Yah I think I shall.

How long do you let the BLO cure up?
I've read a week, and some folks say a few weeks.

[Howard Acheson]

I'm thinking about applying a Alkyd urethane directly over BLO without the shellac seal/undercoat.

Never tried it - have you how'd it work?

I don't have any shellac in the shop let alone any that's de-waxed.

There is absolutely no problem with any oil based finish directly over BLO. After all, oil based varnish and poly varnish is made from linseed oil. There is no need need for a sealer/barrier coat for any finish applied over BLO. Waterborne acrylic and lacquer are completely compatable with BLO.

Just be sure to wipe off the excess BLO after letting it set on the surface for 15-20 minutes and then let it fully dry for 48 hours.

[Cliff Rohrabacher]

48 hours

That seems about right to me.