Vanisle_BC
Greener Thumb
Posts: 987
Joined: Tue Apr 14, 2015 1:02 am
Location: Port Alberni, B.C. Canada, Zone 7 (+?)

Enviro-friendly water-protective treatment?

What affordable, non-toxic waterproofing coatings or DIY treatments are there for coating wood, that could be considered environmentally friendly? (Having built a small plywood boat I'm a fan of epoxy, but I shouldn't even whisper that! :)) The question arises for me in the context of container & raised bed gardening, wood seedling trays, growing boxes etcetera. I'm sure there are many non-gardening pursuits where the question arises too. Who has thoughts & suggestions?
"There are two kinds of people in the world - those who think there are two kinds of people in the world, and those who do not" - Robert Benchley

User avatar
applestar
Mod
Posts: 28180
Joined: Thu May 01, 2008 11:21 pm
Location: Zone 6, NJ (3/M)4/E ~ 10/M

Re: Enviro-friendly water-protective treatment?

I don't know if this counts as an answer, but I think first step is choosing your wood. Start out with resistant ones -- I guess most typical ones are cedar (but there are different kinds of cedar... ATM I can't remember which one is strongest without surface treatment... is it white cedar?), Douglas fir, locust....

...in Japan, they use a kind of juniper for wooden bathtubs and laundry tubs, bath seats and benches.
Learning never ends because we can share what we've learned. And in sharing our collective experiences, we gain deeper understanding of what we learned.

User avatar
rainbowgardener
Super Green Thumb
Posts: 25303
Joined: Sun Feb 15, 2009 11:04 pm
Location: TN/GA 7b

Re: Enviro-friendly water-protective treatment?

Shellac is a natural wood finisher and sealer. It is a resin produced by the Coccus lacca (lac beetle), that is harvested from trees in Southeast Asia. It is so non-toxic it is used in foods (the shiny finish on grocery store produce) and cosmetics (e.g. hairspray).
Twitter account I manage for local Sierra Club: https://twitter.com/CherokeeGroupSC Facebook page I manage for them: https://www.facebook.com/groups/65310596576/ Come and find me and lots of great information, inspiration

User avatar
applestar
Mod
Posts: 28180
Joined: Thu May 01, 2008 11:21 pm
Location: Zone 6, NJ (3/M)4/E ~ 10/M

Re: Enviro-friendly water-protective treatment?

I don't know how well they work for wood in direct contact with soil, but two old standards are boiled linseed oil and beeswax. Both are used individually or heated and blended together and by applying to heated wood and rubbing in.

...speaking of heating, a wood finishing technique I once learned for pine wood was scorching it by burning the surface and then wire-brushing the burned soft wood between the grains.
Learning never ends because we can share what we've learned. And in sharing our collective experiences, we gain deeper understanding of what we learned.

pepperhead212
Greener Thumb
Posts: 1690
Joined: Wed Oct 15, 2014 5:52 pm
Location: Woodbury NJ Zone 6B

Re: Enviro-friendly water-protective treatment?

Shellac and boiled linseed oil are DEFINITELY not waterproof wood finishes, even on indoor furniture. There really aren't any non-toxic, long lasting outdoor finishes, that would seal and protect the wood for many years, esp. in contact with soil. And even things like epoxy or marine varnish that form a seal, run into problems with expansion and contraction of the wood. This is why stains, that soak into the wood, last lonher, though this still would not protect well in contact with soil. White oak, white cedar, and cypress are good woods to use for outdoor projects (red oak and red cedar - the ones usually found in Home Depot and Lowe's - not so good).
Dave

imafan26
Mod
Posts: 11617
Joined: Tue Jan 01, 2013 1:32 pm
Location: hawaii, zone 12a 587 ft elev.

Re: Enviro-friendly water-protective treatment?

Most modern treated lumber is safe. None of them use arsenic any more. CCQ treated wood is approved by the EPA.

That being said, wood rots and termites love wet wood in the soil, so I use hollow tile. It requires few skillsor tools and while concrete can leach, my soil is acidic and it has not been a problem for the twenty years it has been in my garden.

https://extension.oregonstate.edu/questi ... eated-safe
Happy gardening in Hawaii. Gardens are where people grow.

Return to “What Doesn't Fit Elsewhere”