[Cob] CINVA ram

[Michael Cantrell]

Thanks, Dean!

I read and read before building the press, and I was up in the air about
stabilizing. Most of the literature suggested it wasn't that important.
Maybe in arid climates it's not, but here in Arkansas, USA, you can see that
my unprotected blocks suffered mightily. (Not that I'm griping about it; I
let this happen on purpose, for curiosity's sake.)

So before, I wasn't sure whether stabilizing would be worth the trouble- an
extra mixing step- and expense, not to mention being environmentally nasty.
Not anymore. I'm sold. What a difference! A little Portland really goes a
long way, and that sort of peace of mind is a big deal.

The benefit of CEBs for a guy like me is the ability to be working on the
house before starting working on the house. Having to shelter the blocks
while storing them would be a headache big enough to offset the trouble of
stabilizing.


As far as practicality, I'm still working that out. You've seen the claim,
I'm sure, of 2 men = 500 blocks/day. I almost wonder if that wasn't just
somebody's guess, way back when, and everybody since then has copied and
recopied the same figure.
For what it's worth, I just spent 34 minutes mixing and pressing 14
stabilized blocks. My wife was on the phone exactly the whole time, so I
checked her call log. :)
Here's the catch, though- the soil was already dug and screened. That's just
the time to mix in some portland, press, and stack.

On a related note, screened soil here is $200/dumptruck delivered... at
first I scoffed, but the more digging and screening I do, the better it
sounds. We'll see.

But anyhow, 14 blocks in 34 minutes, call it 25/hour working solo... maybe
two practiced men with dirt already screened, in a TEN HOUR day could make
500 blocks. Not impossible, I guess. But the digging and screening is a
not-insignificant expense of either time or money and shouldn't be
overlooked. So there you go.

I'm planning on building a house, but not for a couple years yet. In the
meantime, there are barbecue grills, playhouses, sheds, etc, that need
building. :)

I'll be putting more photos in that Flickr album as time goes on. I'm sure
it's got a subscribe feature, so subscribe, you all who are interested, and
for the rest, I'll try not to post too much non-cob content here.

Thanks!
Mike Cantrell

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>
> Message: 1
> Date: Sun, 14 Aug 2011 00:58:15 -0400
> From: Dean Sherwin <costman at verizon.net>
> Subject: Re: [Cob] CINVA ram
> To: coblist at deatech.com
> Message-ID: <0LPW00GTPJ53EL11 at vms173007.mailsrvcs.net>
> Content-Type: text/plain; charset="us-ascii"; format=flowed
>
> excellent job.  Good workshop skills!  I know this is an old design,
> that was designed originally specifically for stabilized earth
> blocks, I think;  from these photos we can see why stabilizing
> (adding usually emulsion or cement) is advised, for keeping the
> blocks in good shape during manufacture and transport.  Once they are
> in the wall, just like cob or adobe, the wall can be protected and
> deterioration will be much less.
> I've also seen them used in Indonesia for turning out cement
> ('cinder') blocks.  In that case the maker was saving a good bit of
> the precious concrete mix by hiding a large stone in the center of each
> one...
> An architect in Nepal told me these rams are too slow to be really
> useful and competitive.  How long does it take you to turn out blocks?
> dean sherwin
>