Gummy finish, what happened?

[Alan Tolchinsky]

Hi All, I am finishing a small cedar box starting with shellac(dewaxed Zinnser) then wipe on poly. But it was taking a lot longer for the poly to dry and even felt sticky the next day. So I used mineral spirits to remove the sticky areas and reapplied the poly. This time it dried in two hrs. or so.

Some details: I wiped on the shellac coat after coat as soon as the previous coat dried. I wiped on the poly the same day as the shellac was dry.

Thanks for any ideas on this slight dilema.

[Joe Jensen]

I read that shellac older than 6 months will not dry properly. I had the same problem with a can that was about a year old...joe

[Mitchell Andrus]

Cans of Shellac will have a date on them. More than 1 to 2 years old... toss it, opened or not.

[Howard Acheson]

As I posted on the other forum:

The issue is the cedar. Aromatic cedar can not be successfully coated with an oil based finish. The off-gasing of the cedar prevents the oil based finish from hardening. It will even soften oil based finishes that were originally hard.

The thing to do is to apply at least two coats of a dewaxed shellac being sure to get the surface fully covered and letting the shellac fully dry between coats. I'd give the last coat 3-4 days.

Like the others, I would suggest that shellac is a nice finish in itself and you may want to consider that.

As a final not, do not apply any oil based finish on the inside if the box will contain any cloth or clothing. An oil based finish will off-gas almost forever and every time it is opened, you will get a whiff of the finish.

[Alan Tolchinsky]

Thanks for the info. guys. Howard, I missed your post on the other forum. I skipped the shellac on another box and just used the wipe on poly. As you can probably guess parts of that box are still sticky too. So I'll take your suggestion and apply at least two layers of shellac and wait longer. Thanks for the info. and I'll report my outcome. Alan