Hi all, I was at the shopette the other day and I saw spray cans of rubberized automotive undercoating, it was pretty cheap (1.97/can) and had pretty good coverage (about 40 sqf). I was thinking I could use it to coat the insides of the 32'long x 4'wide x 4'tall plywood boxes that Im planning on using in my (eventual) greywater reuse greenhouse that will be sitting on top of my (also eventual) below ground water cisern.
Of course I have to get the drywall finished first, and the windmill, and the rest of the solar hot water panels, and then there is the rest of the stumps..... sigh.
You know, when I started this I had no idea how much damn work it was all going to be, as it is I'll get everything done just in time to die of old age, hand it over to the kids who will sell the homestead to a stranger I wouldnt like and go live in the city anyway.

At any rate, thanks in advance for any responses!

Dave

-- Dave (Ak) (daveh@ecosse.net), February 21, 2001

Answers

PS. I was also kicking around the idea of using Wonderboard (also called concrete backer board) instead of plywood, its more expensive but it should last just about forever.
Any ideas on that also?

Thanks

Dave

-- Dave (Ak) (daveh@ecosse.net), February 21, 2001.

Trying to understand... Are you building plywood boxes to contain water? If so, why not just contain it with old tubs, or empty drums? I like the idea of reusing greywater. The faucet runs for about 40 seconds each morning before I can get hot water, and I've always wished there was a way I could collect that waste and use it in the garden or the animals... Now THERE'S a countryside term: "...THE ANIMALS..."! How many of you folks use that in daily conversation without thinking anything of it? "THE ANIMALS"... Wasn't that a rock group? Eric Burden and the ANIMALS? Or something like that...

-- Action Dude (theactiondude@yahoo.com), February 21, 2001.

The boxes will be filled with a 5 inch layer of pea gravel, then a 1 foot layer of coarse sand, then a 1 foot layer of fine sand, then the rest is filled with common dirt. In the dirt I'll grow non-tuber food crops to supplement our diet.
Buried in the pea gravel are perforated PVC drain pipes that take the reconditioned greywater to a pump that pumps it to a 30 gal holding tank in the attic, the reconditioned water is then plumbed from there to gravity feed to the toilets, a spigot in the greenhouse and a spigot outside (wash car, etc).
There are two small diameter parallell perforated PVC pipes buried 1 inch from the top of the dirt and the geywater is gravity fed from the house through a couple of filters and then into those, its then in turn purified by the plants and microbes in the dirt and the purified water is taken up by the drain pipes.
This is a little simplified but you should get the idea...

I got the idea and basic design from www.greywater.com, if you're interested do a web search, there is tons of info out there.

-- Dave (Ak) (daveh@ecosse.net), February 21, 2001.

Dave: I don't know about the chemistry with the undercoating but I'm guessing the cheap stuff, when cured will rub off pretty easily. No surprise actually because its not designed for abrasion resistance. On the other hand the 3M stuff is good and is designed for abrasion resistance. I think its got a butyl rubber component in it and last quite a while, but its quite a bit more pricey.

-- john leake (natlivent@pcpros.net), February 21, 2001.

Thanks John, I hadnt thought about abrasion problems. You're right, Im also thinking that if the coating is too soft the roots of the plants might be able to burrow through it and make the box leak...

Maybe I could put a spray coat of appliance epoxy over the rubber..

-- Dave (Ak) (daveh@ecosse.net), February 22, 2001.

Dave why not just use the epoxy and bypass all the mess of the under coating?Also why buy little aerosols for $1.97 when you can buy a 5 gallon bucket of roofing tar and a brush for around $10.00?It is the same stuff that is in the cute little can the differance is in the packaging and marketing.Be prepared for an oil slick on top of what ever water you put in it until it is cured good and hard.Can you think of any sources of parafin wax or beeswax that is cheap near you? If you can, use this instead.Heat it up brush it on.Have you considered just lining the boxes with a sturdy plastic?The box will provide the rigidity and the plastic the water proofness you need. Good luck.

-- Greg (gsmith@tricountyi.net), February 23, 2001.

It seems you have enough responses,and I have nothing to add concerning grey water, but it made me think of using auto drain oil as a preservative. Brush it on or immerse until the wood won't take any more. I have some oak gates that are now over 25 years old and are still not rotted.

-- Bob Frohmader (buksnort@mwt.net), February 26, 2001.

You have to keep in mind that you will be growing food in those boxes. I'd be very nervous about lining them with any product that might be toxic. How about some of that heavy rubber that is used on mobile home roofs? Or better yet, pond liner that is made not to be toxic to plants and animals?

-- Peg (NW WI) (wildwoodfarms@hushmail.com), February 27, 2001.

The main reason Im thinking of this is cost and durability, $1.97 for 40 sqft is a lot less than the plastic membranes they sell, even if I spray a thin coat of epoxy over the undercoat its still quite a bit cheaper than anything else I can come up with.

I think my best bet is to use both, the undercoating handles the waterproofing duties, and the epoxy takes care of scratches and any leaching I might run into.

I'll take a look at the roofing tar or similar waterproof roofing material, if it can stand being constantly wet than that would be an even cheaper way to go, at this point in my state of finances I have to save every last cent I can, Im broke!

Thanks!

Dave

-- Dave (Ak) (daveh@ecosse.net), February 27, 2001.