Moisture Content

11/06/2014


From original questioner:

What is the highest moisture content of material you would be comfortable sealing with precat vinyl & precat lacquer? I won't know the exact reading until monday, but guessing around 16%. The material is Missouri aromatic cedar. Also called Eastern red cedar.

From contributor Br


9-10% is the highest I would go. Any higher and I would have it dried or use an oil. That material as I'm sure your aware will have substantial movement especially on joints. If it was just molding I wouldn't be quite as apprehensive with the pre cat.

Why are you finishing aromatic cedar? I've only used in for closet liners and wardrobes for it's aromatic properties.

From contributor Ed


BrianT
Reason for the finishing is they want me to make a harvest style table that would be used as a buffet table. Needs to be finished with something just for cleaning. All I know right now is this material was cut & sawed around 11 years ago, been stickered inside ever since then. I will get the moisture reading Mon. Could you point me towards an "oil" finish that would work in such a situation?

From contributor Br


We finish a lot of our reclaimed and new materials with danish oil. It's an oil varnish hybrid and works well for applications like this.
Check the moisture content when it comes in. It may be closer to 9 or 10.
If you do end up using a solvent based product I would go with a conversion varnish for the table. It's a lot more durable.


From contributor Bi


Putting a hard finish on cedar can be tricky. The "aromatic" part of the cedar comes from oils in the wood, and that can spell trouble for a finish.

The moisture content is going to be important for wood movement as much as finish adhesion. A m/c of 10% or less will be best.

I would not use lacquer for a table. We have built tables for several restaurants out of reclaimed wood and always use conversion varnish. It is the best finish you can use without expensive specialized equipment.

From contributor Ed


I don't know why I said precat, we used conversion varnish on every table we've ever done. We surfaced a bunch of this stuff this AM & it's reading 8.5- 9 %. A lot better than what I expected. Bill, would you use CV on this or go with an oil finish?

From contributor Bi


I'd test it first. Wipe it down with either acetone of lacquer thinner just before you shoot. That will make sure all the surface oils are gone. You should get good adhesion from there.