What should I seal my planter boxes with?

I'm looking into making small wooden planter boxes for house plants. I want a way to make sure that they don't leak water everywhere. Does anyone have any thoughts on natural options for this? The planter would be leaving my control and thus can't require a reapplication every year or something like that.

Here are a few options I've found but I'm not sure how natural they are. These two list big claims but no ingredients list:

http://valhalco.com/index.php
https://ecowoodtreatment.com/

This one lists an ingredients list:

http://www.heritagenaturalfinishes.com/

Any advice you have is appreciated!

Shawn

Personally, if I see a product that claims as much as your first two links do but then it doesn't list the ingredients, I start thinking snake-oil (or at least I suspect it of having less than ideal ingredients). Of the three, I would definitely go with the Natural Finishes if you must buy a commercial product ... however, I would just buy beeswax and make my own sealer from that.

There are plenty of formulas for beeswax sealers out there--especially in some of the old formularies. I know people used to mix beeswax with turpentine or kerosene for furniture polish (not sure how well that would work for planters) but the basic idea is to use a solvent to thin the wax so it can be painted on and so that it will penetrate. I'm sure there are environmental solvents that will work. This https://lovelygreens.com/how-to-make-natural-beeswax-furniture/ takes you to a very simple recipe using beeswax and olive oil. I would imagine almost any vegetable oil would work as well though, and not be quite as expensive as olive oil, but if you want to use olive oil and want it cheap and in bulk, there is a wonderful online store called Jedwards that sells bulk oils. They are very good oils and you can choose between conventional and organic. https://bulknaturaloils.com/  I've purchased from them many times for oils to make soaps and I have found them to be high quality and generally less expensive than other suppliers.

Would ethanol work for that thinner? I'd be very hesitant to use something like turpentine or kerosene in a planter.

Kyrt Ryder wrote:Would ethanol work for that thinner? I'd be very hesitant to use something like turpentine or kerosene in a planter.

I don't think alcohol would do it. I believe it needs something with oil in it. That's why I suggested a vegetable oil--totally non-toxic.

"Citrisolv" is a good solvent/thinner for applying oils and getting them to penetrate wood instead of ethanol or other petroleum products I have not used it with wax but it works really well with oil. We applied a citrisolv /walnut oil finish to our mesquite counter top in several coats and it has worked really well. Totally non-toxic. Citrisolv is made from orange peels( D-limonene). We found ours in the health food store. Walnut oil is one of the oils that will polymerize( as does Linseed oil) as it dries. Good for sealing cutting boards, cabinets, wood countertops and ....earthen floors!
After several oil/citrisolv coats, we applied the wax.

We bought 5 gallons of walnut oil- food grade- from Liberty Naturals.

A couple of things you need to be aware of. 1) There is a difference between Finishes and Sealers. You can have a planter that is finished beautifully and yet leaks like a sieve. There is not, that I am aware of, any one product that will do for both. 2) Wood, no matter how well sealed, in touch with water will eventually rot. I made some planters out of redwood with roofing tar as a sealer. Ecological disaster that they probably were, even they did not last for ten years before turning to mush. If I were doing this, and wanted to make some attractive planters for sale or gifts, I'd look for someone thermoforming liners out of empty plastic bottles (we have to find something to do with the damned things). Here is a source I picked practically at random. http://www.deepstreamdesign.com/abs-plastic-planter-liners.html

Good Luck!

Plastic.

Thus is the reverse of the usual question.

THAT is how to keep wood from rotting outside.

But you want INDOOR planters.

Get plastic sheet, and without putting staple holes in it, glue it down.

Imagine you are putting a coffee filter in a measuring cup.

Hot glue around the edges.

Make folds where necessary, and glue the flaps down.

Of course, the problem is that it will hold water perfectly.

Too much water and the plants will drown.

Put in sphagnum moss to absorb the excess.

Hey guys, moderator here to give this thread a nudge.

Let's avoid plastic based solutions.  People were doing this long before plastic came around and I bet there are loads of options to seal a planter that doesn't involve crude oil.  

At permies we seek solutions that are organic or better.  

https://en.wikipedia.org/wiki/Encaustic_painting

The suggestions about beeswax reminded me of encaustic. It's basically an easy way to harden & color wax. Not sure of waterproofing properties but it seems like it would work very well for many years.

r ranson wrote:Hey guys, moderator here to give this thread a nudge.

Let's avoid plastic based solutions.  People were doing this long before plastic came around and I bet there are loads of options to seal a planter that doesn't involve crude oil.  

At permies we seek solutions that are organic or better.  

I'm not sure how many indoor waterproof basins existed before plastic, unless you're maybe talking about metal basins, which can't really be painted onto an existing wooden box.

I think the difficulty here might lie in competing goals. At permies, it seems like we like natural solutions, because ithey are sustainable, so we like constructions that can decompose and return to the earth once they've served their purpose. By which, if we're being specific, we mean that, when exposed to water, they will rot. Trying to find a solution that will rot when exposed to water, while at the same time keep a box from leaking water and have a decent shelf life without ongoing maintenance, seems to me to be mutually exclusive objectives.  It's possible that, if you're looking for a tub that can stay indoors (or possibly it's for outdoors, I'm not sure. Just that it "can't leak water everywhere") you're either looking at metal or some plastic-based solution.  If you're looking for something that can be applied to an existing wooden structure, that probably eliminates metal as a possibility. Maybe a fired clay? But again, that's not something you can do once it's already applied to the wood. If you're just looking for an insert, then maybe.

I think I read somewhere that these forums are also for appropriate technology. Especially if we're talking about reuising or recycling plastic taken from the waste stream, that is sometimes an appropriate technology, no?

There are many ways to make wood waterproof, or very nearly.  Think boats.  Maybe there is a solution there?  

Another question is why make it waterproof?  It's crazy, but I've seen a lot of sealed wood rot quickly when unsealed wood stays strong and intact for decades.  

The OP says he's looking to prevent water leaking everywhere.  We could mitigate this by using ceramic pots inside the planters, or glass jars.  A better solution would be to train the people on how to water the amount required.  Sealing the wood is another solution (again, think boats) or that combined with something that will absorb extra moisture.  

Plastic is another option, but I think we're up to the challenge of finding a plastic-free solution.  

r ranson wrote:There are many ways to make wood waterproof, or very nearly.  Think boats.  Maybe there is a solution there?  

Probably not. I used to own a wooden sailboat, and  every year I had to scrape the hull and repaint it, which goes against his 'no aftercare' condition: even so, what kept the wood from rotting was that  the salt in the  water that leaked in anyway permeated the wood. Older boats used tar rather than paint,which lasted longer, but even that needed to be reapplied from time to time. Tar also has a quite distinctive odour, which some people love, and some ...not so much. There is a substance called 'brewer's pitch' which is/was used to seal barrels and othe staved containers, which *might* work.  Barrel staves are held much more tightly together by the barrel bands than the joints one could get with screws or nails, so I'm not sure that the pitch would have enough gap-filling ability, but it might be worth a shot.

EDIT: Here's a source, and a video showing how to use it to seal a canteen. It's possible that if you were *really,really* careful, you could use a natural bristle brush to paint the hot pitch on the inner surfaces.

http://www.townsends.us/brewers-pitch-bp293-p-373.html

I understand you want to make boxes waterproof but I don't think that anything you apply is going to last. What about a metal tray for the bottom of the box? It could either fit inside the Box or go under the box and the box would sit on it. Think of a pot and saucer. Personally I would probably try to put an external tray , similar to a saucer. Any excess water would be caught by the tray, a tray can be emptied, which would extend the life of the planter box. It would also be beneficial to the plants because any excess water would have somewhere to go. Finish the wood with a nice stain or something like that, and then make the tray. Another option would be to find some glass trays, make your planter boxes fit them. I use a glass tray salvaged from a microwave to catch moisture from my fermented veges. Maybe something like that?

Kyrt Ryder wrote:Would ethanol work for that thinner? I'd be very hesitant to use something like turpentine or kerosene in a planter.

Hey, just so you know you can get 100% pure gum spirits turpentine. It's a natural product of pine trees. The big box store turpentine is the chemical concoction. The natural stuff has even been used as a medicine for a very long time.