Sealing wood

[DrMike27]

I’ve found my raised bed design for the fall is going to be the most economical by using white wood stud and sealing it. My question is what is the best and safest way to seal wood? I know in general you want little-to-no VOC content, but just wanted to get some opinions here.

 

[DirtMechanic]

Boric acid solution in a vacuumed bag for a week. Its the core that will get eaten. You could soak it, but wood being cellular causes an issue.

 

[DirtMechanic]

I believe there are liquid preservatives available that use a form of copper which can also be vaccuumed to enhance penetration. Any uv stabilized deck coating can serve the surface but anything trapping moisture behind a film layer hastens the rot if the wood cannot dry out. That means you may just consider a stain and oil. A lot of oils breathe. If you can use a liner or prevent geound contact, you future labor will be reduced greatly. Spar varnish even comes to mind, but I would think a modern product or an oil.

 

[Chuck]

I haven't done a cost analysis but it seems to me that using white wood plus the sealant will, in the long term be more expensive than using a material that is resistant to rot, such as rough cedar. I have rough cedar 4x4's that have been in the ground for almost 4 years and they are not set in cement. They show no signs of rot yet.

 

[DirtMechanic]

To hell with prices. Its too much work to do twice and my back has gotten stingy with what it will let me do.

 

[mgmine]

Chuck is right on. Pain old 2x4's will not last even if they are sealed. At Home Depot a 2x4x8 is $2.57. A gallon of wood preservative is another $25.00 and if you could find a quart it would be at least $12. A pressure-treated one $3.67. Do it once and be done with it. A year from now you'll forget that it cost a few additional bucks to use the pressure-treated lumber.