[DIY mortar pots] Sealing the inside of pots to prevent pH affects?

[M. Frary]

It is non-toxic, clear, and tasteless

That's what I told her.

 

[Anthony]

Gogeerah,

how the hell did you end up with clear or tasteless ?

Sending you some Bois Canois and chip chip pronto.

If we work together we can fix your --------- erh problem.
Mottie

 

[M. Frary]

how the hell did you end up with clear or tasteless

I lied.

 

[SU2]

Mineral oil is sold as a laxative. Not that that makes it totally safe for plants, but people most definitely drink it. I would trust mineral oil to be in contact with roots much more than any paint/stain/urethane product.

Just don't get it confused with mineral spirits.

Horticultural oil is mineral oil so it must be somewhat safe for plants, and honestly, I spray it on the soil too...

Good stuff, very reassuring! Cbroad, why would you spray it on your soil? Regardless of safety I just don't get what ends you'd be trying to achieve by doing that!

 

[SU2]

You could just soak your pots and at the end of 4 to 6 weeks ---------- test the ph of the
water.

Concrete pots are fun to make and plastic ice cream containers make great shapes, as
do many plastic shapes.
You can make very dense bodies that are non porous or porous bodies [ which we use for
Japanese black pines ]

You can also purchase concrete colours, I believe the max is 10 % of your mix.

Can also be white cement or gray cement or tile grouting.

Why not take a walk on the beach and find other containers.
On our side the sea purges itself of coral shapes, often nice basin
shapes that grow seagrapes [ from seed ] well.

Or hardstones that are easy to carve.
Good Day
Anthony

Good stuff, thanks!! How do you control porous v non-porous bodies?

 

[SU2]

It's not a guess honest. I use a vinegar solution to sanitize/clean all pottery and follow it up with a good coat of USP Mineral Oil. Been doing it for years and I guarantee every clay pot I have stored right now has been treated that way.

Why?

It is the recommended way to clean and keep wood surfaces in restaurants by the FDA. Also, been using it on all cutting boards, wooden kitchen utensils, and baking surfaces.

It is non-toxic, clear, and tasteless.

Grimmy

Love it, thanks!! Grabbing some mineral oil today! I already use vinegar extensively as a go-to for cleaning (I imagine you use vinegar on moldy bark if/when it occurs? Have you ever compared it to hydrogen peroxide for that use-case?)

 

[Anthony]

Tighter mixes, more sand.
Also look up on the concrete sites for winter proofing.
Good Day
Anthony

 

[Bonsai Nut]

You want to make concrete waterproof? Use an epoxy sealer like you use for the interior of koi ponds. Food grade - bio inert - clear or colored.

 

[cbroad]

Regardless of safety I just don't get what ends you'd be trying to achieve by doing that!

I guess more for peace of mind, just in case there are some eggs or pests in the upper layer of soil. I don't douse the soil, just give it a spray or two.

 

[SU2]

Tighter mixes, more sand.
Also look up on the concrete sites for winter proofing.
Good Day
Anthony

Wait wait, wouldn't tighter mixes be *less* sand? What ratio would you recommend, or rather what range (to go between tight/loose, in this context)? I'd done 1:2.5 portland::sand for my first one, came out quite dense/tight!!

 

[SU2]

You want to make concrete waterproof? Use an epoxy sealer like you use for the interior of koi ponds. Food grade - bio inert - clear or colored.

It's not water-proofing I'm after, just creating a membrane between the container and the soil- it seems mineral-oil is a really good choice here!

 

[SU2]

I guess more for peace of mind, just in case there are some eggs or pests in the upper layer of soil. I don't douse the soil, just give it a spray or two.

So it kills eggs/pests huh? On-contact or just messes them up/repels them? Very good to know, thanks!!

 

[cbroad]

So it kills eggs/pests huh? On-contact or just messes them up/repels them? Very good to know, thanks!!

The horticultural oil (mineral oil) suffocates the insects and eggs by enveloping them in a water/oxygen impermeable layer (I think???)

 

[Leo in N E Illinois]

Commercial concrete sealers usually start with boiled linseed oil, works well, lasts 2 to 5 years for a concrete patio. Available at any supply for house paint.

 

[clive bennett]

polyester resin and glass fibre reinforcement , or epoxy resin and glass reinforcement does not affect PH, will strengthen the pot and stop roots biting in . I have a pond and filter made from glass fibre 10 years and no ph changes inert to other effects on fish anyway

 

[SU2]

polyester resin and glass fibre reinforcement , or epoxy resin and glass reinforcement does not affect PH, will strengthen the pot and stop roots biting in . I have a pond and filter made from glass fibre 10 years and no ph changes inert to other effects on fish anyway

Where do you get these additives? I'll look into polyester resin, but the glass fibers (or fiberglass fibers) used to be available at Home Depot in a little baggie, they didn't have that anymore when I got the cement :/ I've been making the pots with 1:2.5 cement:sand and zero reinforcement, I just did another batch that way but will be using fiberglass meshing (the type used as scaffold/structure before laying down roofing-tar) to hopefully provide some extra strength! But really I've gotta say I was surprised at how strong my first/tester container came out, I made a couple "testers to break" out of the same mud-mix and they were strong as hell!!

 

[clive bennett]

Well i am in the UK it seems easy here just google polyester resin or fibreglass and loads of suppliers pop up, or try car repair shops they do small batch fibreglass and or body filler to cover rusted/dented car panels.An easy job just use a disposable brush and work in a cool environment quickly!

 

[Lionheart]

Have you thought about something like this? I've used it to prepare concrete to accept acrylic paint. It seals the surface very well.

 

[SU2]

Commercial concrete sealers usually start with boiled linseed oil, works well, lasts 2 to 5 years for a concrete patio. Available at any supply for house paint.

I'd originally wanted to seal the inside but now am thinking that, since the mortar-pot itself stores water, that maybe having it unsealed would be of practical benefit (act as a water reservoir), I've been experimenting w/ crayons for the outside finishing (colored wax, lets me get color and seals the outside!) and that got me thinking that, if the outside was sealed w/ that wax, and the inside left un-sealed, then the walls&floor of the container would just be an extra moisture reservoir/buffer!

 

[SU2]

Have you thought about something like this? I've used it to prepare concrete to accept acrylic paint. It seals the surface very well.

I'd be hesitant to add unknown chemicals to the inside of the pot where the roots will be touching, honestly if I were to go that route then I may as well just use a hard enamel/gloss paint to get a hard coating...but would probably do boiled linseed oil like @Leo in N E Illinois mentions!