Wood treatment for planters

[davemere]

Hello all,

I have some planters which I'd like to treat to protect against the Great British weather. They are pine and I don't expect them to last for many years but I hope a few seasons. I'm trying to find out what the best treatment to use is. It has to be completely non-toxic as we'll be growing vegetable in the planters and they'll be in contact with the ground.

I've looked at a few products and most wood care is for sheds, fences etc and unsuitable. Linseed oil look ok but can take an age to dry, if ever. Teak oil was another possibility.

I'm a bit lost. Can anyone offer advice?

thank you in advance!

davemere

 

[Nico Adie]

Linseed oil will be absolutely fine

 

[davemere]

Hi Nico, thanks for responding.

Great news, but does it not take a long time to dry? I read that in some cases it can stay wet/sticky indefinitely?

 

[marcros]

can you line them with plastic to prevent soil contact with the wood?

 

[davemere]

Hiya Marcros, yes to some degree. They're actually open to the ground to allow the veg to run deep. So I could staple a lining to the inside, though I'm not sure if it's worth it!

Ideally I'd like to protect the actual wood

 

[Osvaldd]

raw linseed oil will probably take a while to dry and in constant damp conditions it goes moldy in my experience. BLO has chemicals in it that helps it to dry faster, but it too will go moldy, and, it has chemicals..
There is basically nothing you can do to your pine to make it last longer and be food safe, just have to live with it. And besides, if your joints aren't watertight, even if you treat your planters, moisture will get in and rot will take place.

made a few small planters yesterday myself.

 

[Beau]

Linseed can dry quite quickly when in direct sunshine but be aware it's likely to become very dark. I treated our douglas fir garden table with it and it basically came out black!

 

[ColeyS1]

How about setting fire to it ? - shou sugi ban

Sent from my SM-G960F using Tapatalk

 

[Orraloon]

Osvaldd has the rights of it. There is no non chemical fix for pine in that environment. I would use old bricks or concrete blocks and make raised beds to plant in.

 

[ED65]

I've looked at a few products and most wood care is for sheds, fences etc and unsuitable. Linseed oil look ok but can take an age to dry, if ever. Teak oil was another possibility.

I'm a bit lost. Can anyone offer advice?

It's not the 'drying' time of raw linseed oil you need to worry about, linseed oil won't protect softwood in our climate. In fact because linseed oil is prone to fungal attack in damp conditions it might even promote decay. And this is without direct soil contact!

The "chemicals" in BLO are metallic driers and they're nothing to be overly concerned with. The same driers are used in all the varnishes you've touched through your life, and just like in those once the finish is cured the metal salts are locked into the finish. They're safe enough that you can use them for direct food contact, even for food-prep surfaces.

This doesn't make BLO a better choice though, it's not a suitable exterior finish on any wood because it's still prone to fungal attack.

Teak oil might work better for you as this usually contains a resin component (they're dilute mixtures of varnish and oil generally). But they're generally intended for hardwoods and really what you want to use is a wood preservative because these are purpose-made to protect softwood from decay.

You only want a few seasons out of them? Use them as they are, pine/spruce won't rot as fast as you might fear and there's no finish to maintain to keep up the looks of the outside, just the nice grey of weathered wood.

 

[Deadeye]

Linseed can dry quite quickly when in direct sunshine but be aware it's likely to become very dark. I treated our douglas fir garden table with it and it basically came out black!

Great - you can pretend it's big oak

 

[Phil Pascoe]

Bite the bullet and use something like - https://www.envirobuild.com/products/pl ... cgQAvD_BwE or accept that your woodwork is sacrificial.

 

[thetyreman]

shou sugi ban is actually a good idea, it definitely works! I've got a bench that I burnt made from pine and there's no signs of rotting at all after 2-3 years, it's an aquired taste though visually but I think it looks nice and is far less maintenance than say varnish where you have to re-do it every year or two.