Non Foam Floating rafts

Colum Black-Byron

Shhh....

But yep. Celery gets very heavy when it's 8 large plants across on one end of the raft. If I was clever and spaced them out, it wouldn't be an issue. Next time.

Stuart Chignell

Polystyrene has worked just fine for me but I use stuff I had made without the usual fire retardant and made in the heaviest grade available.

Ehh thanks sleepe

Sleepe

You sure that was not without?

Still not convinced that floating foam rafts (somehow I find the words floating and raft a little odd) are the way to go in a non commercial application.

Charlie

Heres another chat about it couple years ago, its got some pics of my core flute design as well as another link to one that joel is talking about

viewtopic.php?f=1&t=17852&p=409109&hilit=coreflute#p409109

skeggley

Sleepe wrote:

somehow I find the words floating and raft a little odd

You mean as opposed to a sinking raft?

Sleepe wrote:

Still not convinced that floating foam rafts are the way to go in a non commercial application

Care to elaborate? :dontknow:

Sleepe

Skeg

I am trying to design both my GB's and my DWC to be modular. And also cheap.
Low density foam is imho structurally weak subject to uv degradation (unless painted) and when floating subject to bacterial etc attack between the beads. You cannot lift a section of the bed out when planted and you have no real ability to allow an air gap (I know Andy has worked on that).
High density foam is quite pricey and still has some of the above limitations.
I put in short form my plan for DWC's on the previous page and there is a pic on the forum somewhere where I was designing seedling trays out of bakers trays and I had a HP pressure washer on them to demonstrate their strength, which is where the idea started from.
Yes you have a 2' bed width limitation unless you wish to make it more complex but they will be robust cheap the reo bar chairs should provide reasonable lateral support and they will be modular.

You will have to talk to Column about 'sinking rafts'. :lol:

hawaiinewbie

I spent so much time researching what to use instead of foam. wasn't a lot of good options that I liked. THis plastic plywood has been awesome. I will use it again but then again, I probably won't have to change it out.

dasboot

Quote:

ability to allow an air gap (I know Andy has worked on that).

Quote:

In practice i found it made no real difference to non pocketed rafts,for me poly gives me an insulation factor plus without an air gap i take full advantage of the surface area under the raft for bio colonisation,i add air for water movement ensuring the root systems have access to DO rich water,plus maximising my nitrification process within the bed.

Sleepe

Horses for courses I suppose Andy.

My DWC's will be mainly inground and I will be relying on a biofilter for at least 50-60% of the nitrification process. The airgap will be nearly 2" and I am hoping that aeration drop pipes will supply most of the DO needed.

A confession, I have never worked with rafts; I have done some work with 'bubbler buckets' in hydro and really liked them. I have also done a few things with polystyrene market boxes and wasn't so enamored. Probably prejudiced.

As hawaiinewbie said, I want these to last longer; and be modular and cheap.

hawaiinewbie

You really need a mod to change your name, 'newbie' seriously. :lol:

Plachon · **Joined:** May 26th, '08, 17:41 **Posts:** 275 **Gender:**

I made one from bamboo slats, still needs development.

hawaiinewbie

sleepe, haha, I guess you might be right. Gosh, I've been doing this a long time.

Something to consider with 2" air gap. Bottom of net pots have to reach the top of the water. So be sure the air gap isn't too big otherwise you'll have dried up seedlings. I know this through experience...

Personally I don't think of my raft bed as contributing to total nitrification. There's just not a lot of surface area in there even if you have foam floats. Another benefit of the air gap is no need for aeration in the raft bed. I pulled out the pump once I had the air gap.

rhuebott5947

Plachon wrote:

I made one from bamboo slats, still needs development.

Holy Crap I love this idea. Damn Here I've been over engineering the hell out of my Idea and this could work.

Wonder if untreated Cedar would be a good Idea.

Plachon · **Joined:** May 26th, '08, 17:41 **Posts:** 275 **Gender:**

Cedar could work, it's a bit heavy, might be best if it's not completely floating, but also uses the trough for support. Then with one or two floats in the middle.

dlf_perth

Just been browsing and I notice Matthew Russell uses rubber?plastic? play-square for his rafts....
viewtopic.php?f=18&t=21746#p454764
about half way down and bottom, always wondered about them.

Plachon · **Joined:** May 26th, '08, 17:41 **Posts:** 275 **Gender:**

Quote:

Just been browsing and I notice Matthew Russell uses rubber?plastic? play-square for his rafts....
viewtopic.php?f=18&t=21746#p454764
about half way down and bottom, always wondered about them.

It's the jigsaw matting used in gyms, not sure how food safe it is.

Backyard Aquaponics
A place to discuss aquaponics