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Making Slabs for group plantings etc
Posted: April 13th, 2012, 6:59 pm
by Luke308
I was wondering if anyone has any advice on how to make slabs for group and single plantings? I have seen many people use slate, but these are both expensive and heavy

Anyway, I googled how to make a slab for bonsai, and I came across something called "Hyper-tufa". Having read a little about it, and watched a few videos on how to make it, it seem simple enough. My question is though, has anyone got any suggestions on how to make a mould for a slab? Or is there a better alternative to use rather than hypertufa?
I did a search of hypertufa on Ausbonsai first, and Flybri seems to be the only person to mention it, but in regards to making fake rocks for root over rock and rock plantings. This too seems like a great idea.
So I guess I am wanting to know how to make a slab. Is hyper-tufa the best/lightest/strongest medium to use? What would be recommended to colour it to look like a natural slate slab? Any suggestions would be greatly appreciated especially regarding making a mould for the slab.
Cheers

Re: Making Slabs for group plantings etc
Posted: April 13th, 2012, 7:05 pm
by alpineart
Hi Luke , i have made slab tray out of villa board and render . they have definitely stood up to my treatment , "ruff as guts" , there is a post here somewhere, the same materials were used for my big Ishitsuki Figs. All the trays had NO Holes just to test there durability when kept permanently wet . All are still as strong and as sound as the day i made them .
Cheers Alpine
Re: Making Slabs for group plantings etc
Posted: April 14th, 2012, 1:36 am
by Paulneill
Bonsai 4 me. website .Harry has a section on making your own pot using concrete and fibers to add strength . You cold try using large baking trays as molds or even large plastic trays found in garden centres.
Re: Making Slabs for group plantings etc
Posted: April 14th, 2012, 1:36 am
by Paulneill
Bonsai 4 me. website .Harry has a section on making your own pot using concrete and fibers to add strength . You cold try using large baking trays as molds or even large plastic trays found in garden centres.
Re: Making Slabs for group plantings etc
Posted: April 14th, 2012, 7:33 am
by Paul B
Just a thought

...what about Hebel? tis a lightweight concrete alternative used in the building industry...can be cut easily with a hand saw and would carve/ shape easily

Re: Making Slabs for group plantings etc
Posted: April 14th, 2012, 10:31 am
by kcpoole
I doubt that Hebel would be any good as it so soft and would break under the weight.
A few here are using good old Fibreglass to fashion trays out of, and one is at the show under a Pyracantha
Slate, Sandstone, VillaBoard are all options
Ken
Re: Making Slabs for group plantings etc
Posted: April 14th, 2012, 10:36 am
by alpineart
Hi Guys , the big rock used for the Flying Dragon is Hebel panel .It is reiforced aerated concrete , even rendered it is very easily broken if the reo is cut or removed .Sealed it is quite strong but i would hesitate to use it in a slab environment as it will be too thin and the renders won't hold it together .
Cheers Alpineart
Re: Making Slabs for group plantings etc
Posted: April 14th, 2012, 4:06 pm
by lakepipes
an easy way to make a mold for a slab is to use a sand pit.
Just dig the reverse of what you want, then pour into it
When some of the sand sticks to it or is encompassed into the finish, it makes it more realistic.
If you like you can stop halfway through the pour and let it settle for a bit before adding some light reo or wire to reinforce the slab before completing the pour.
just a thought.....
Re: Making Slabs for group plantings etc
Posted: April 14th, 2012, 4:43 pm
by Sean M
there is a good video on youtube about this.
I dont know how to link to youtube but search for making a bonsai slab, and it was done by jgeanangel, has 3 parts.
I think I have the slab bug too.
Re: Making Slabs for group plantings etc
Posted: April 14th, 2012, 6:09 pm
by Pup
The Melaleuca rhaphiophylla group at the national collection is on a fibre glass slab. Not cheap as an alternative, but you can make small or large. They do need reinforcing though.
If you have lung problems be sure to wear a mask, even if you dont it is advisable. The shape is left to your imagination,
Cheers Pup
Re: Making Slabs for group plantings etc
Posted: April 14th, 2012, 9:19 pm
by Trent McKenzie
Re: Making Slabs for group plantings etc
Posted: April 14th, 2012, 11:15 pm
by Luke308
Thanks for the ideas guys. Those youtube videos offer some food for thought. However, I personally would like thinner slabs than those shown in the video. I guess it'll be weaker, but I'll have to give it a go sooner or later. It does seen a little more involved than I first thought, eg preparing a sandbox, but looks like a project to be proud of if it turns out right

Re: Making Slabs for group plantings etc
Posted: May 26th, 2012, 7:50 pm
by phillips_head
i used hebel once and i wouldn't recommend it unless it is carefully sealed, it has a tendency to suck moisture out of the soil. i found it impossible to use as a pot. makes a good material for stands though!
Re: Making Slabs for group plantings etc
Posted: May 26th, 2012, 8:09 pm
by fiveoffive