Let's revisit some of the natural and effective finishes we have used for centuries before the days of chemical finishes.
1. Wood Finishes
Natural Oils and Waxes
|milk paint pigments & hemp on floors,|
hemp on window frame,
still unsealed cabinets
Linseed, Tung, Hemp and Walnut Oil are drying oils (although some claim Walnut is a semi-drying oil so I would not recommend it over the others). They all penetrate, harden and preserve wood and provide a long-lasting finish that does not turn rancid. (Note: other oils like coconut are not recommended because they are non-drying oils and will go rancid).
I used Hemp Oil on all the interior wood in my chemical-free tiny home. I am really happy with it. But the ladder to the loft does get very grimy though the dirt does wipe off. Hemp should be reapplied every few years. Use refined hemp oil (made for floors) as opposed to the edible oil from the grocery store.
Wood can then be finished with a beeswax polish for extra durability. I don't know how long it takes to dry, but I found that it was sticky for a while and attracted dust and grime. I used beeswax on the window sills to provide a water-resistant finish and I'm really happy with it in the end. This Beeswax/Carnauba Polish would be great, or you can make your own, but use one of the drying oils listed above. I wouldn't recommend using olive or other (non-drying) oils that can go rancid on wood. Here's a how-to on finishing wood with natural oil and wax.
Wax needs to be re-applied every year.
|Photo from homesteadhouse.ca|
Non-toxic milk paint pigments can be used as a stain applied to the raw wood before finishing with oil and wax. Here is my how-to for these pigments as they are very tricky to work with! I used them on my floors, my bathroom cabinets and my two stairs.
I have used ECOS sealer on the wood in the kitchen as it is a little more durable and waterproof than hemp. I also wanted something that did not darken the wood as much as hemp. I can't recommend this clear varnish enough (though the shipping was very expensive to Canada). It is truly zero-VOC from my own assessment, and to me is benign. A happy surprise after testing so many "0 VOC" paints and tile sealers that took me out.
AFM wood sealers are also reported to be good. AFM Lock in New Wood Sealer finished with AFM Hardseal or Polyureseal.
2. VOC-Free Paint?
There are a myriad of paints claiming to be green or zero-VOC but it's not easy to find out exactly what is in them, and some ingredients like biocides might not be listed. For example, conventional manufacturer - Benjamin Moore makes a zero-VOC paint called Natura that is high-quality, and comes in great colours but contains a mildewcide (something you should avoid). It was intolerable for me while wet. If you want something that is easy to source at a hardware store this is your best bet - just make sure they are using their zero-VOC pigments with it. (Note: other harware store brands like Behr make a zero-VOC base but do not carry zero-VOC pigments).
Colourhouse is another zero-VOC paint that contains a mildewcide.
Here are my top three latex paints in no particular order:
Mythic Paint - The paints and primers are zero-VOC. It looks like they are going out of business though you still might find this in stores. I will update as it unfolds.
ECOs is another top brand of mine. I have been impressed by their wood sealer though I have not tested their paints. They are also the only company I know to make a zero-VOC sealer that can seal in toxins from regular paint and from drywall. Their primer and paints are zero-VOC and do not contain mildewcides.
AFM Safecoat Zero-VOC Paint - Tintable to thousands of colors. It is zero-VOC with zero-VOC colorants. Recommended by many EIs as well. (Though the primer is low-VOC.)
Good Natural, Non-Acrylic, Options:
Milk Paint I used Milk Paint in my chemical-free house to seal in the dust on the walls. On unfinished wood you need to add white glue to milk paint and I have not found a glue that I found 100% tolerable. Milk paint is also not great in a high moisture area like the bathroom because of the casein. (It could be prone to mould in a high moisture area). I would avoid it if I did things again.
Auro Natural Paints - (Natural Source, Clay-Based Paint) available online, ships to US and Canada.
Try AFM Safecoat Low VOC Transitional Primer or their New Wallboard Primer for new drywall (both low-VOC, but they seal in toxins). ECOs is another trusted brand that makes primers including a new wallboard primer. Sherwin Williams Promar 200 is a zero-VOC primer (also no mildewcide).
AFM makes MetalCoat Primer (zero-VOC), the Mythic Primer above can be used on metal. For small applications, you could try non-toxic DecoArt No-Prep Metal Paint.
Plaster is applied directly to earthen walls or pumice-crete.
There are clay-based plasters and lime-based plasters. I prefer lime because it is naturally mould resistant. Plasters can be tinted with natural pigments. Here is a detailed post on my experiences using clay plaster and limewash in my tiny house.
To learn more, get yourself a copy of The Natural Plaster Book.
4. Earthen Floor Finishes
If you don't have ox blood on hand, no problem, you can seal your earthen floor with any of the hardening oils we talked about under wood finishes (above). I would use Hemp Oil. This blogger claims that Walnut Oil went rancid with time. Beeswax can also be used in the final coat for extra protection if desired.
Sealing Toxic or Exterior Wood
Plywood and MDF should also be sealed with one of the above sealers if you must use it (it gives off formaldehyde).
To protect exterior wood against the elements, you could use something a little stronger (as the VOCs will not be within the building envelope) like: AFM Naturals Clear Penetrating Oil. I used AFM Waterseal and also considered this zero-VOC product Cedar-Seal.
Sealing Tile, Concrete, Stone
For sealing grout use AFM Safecoat Grout Sealer or AFM Safecoat Safe Seal.
I used Murco as a joint compound and found it totally tolerable but it is not compatible with MgO board. It has cracked at the joints which is something other builders have noted as well. This compound is compatible with MgO.
1 biocides, ammonia, crystalline silica, ethylene glycol, phthalates, isocyanate, mineral spirits, benzene, propane sulfone, petroleum distillates, nitrobenzene, ammonia, naphtha, and phenol. Sources: North Carolina Cooperative ExtensionService, Grassroots Info, & Cleveland Clinic.