Papercreters: [papercreters] Recipe Ratios -was- Heat Curing

Wednesday, June 24, 2009

[papercreters] Recipe Ratios -was- Heat Curing

Wow.

I'm not sure where to draw the line semantically, but it seems appropriate to ask the question: Are you making papercrete or are you making concrete mortar with a paper additive?

The mix you are describing may be the most dense, mineral-rich mix I've ever heard about. I'm not surprised that it is heavy.

I'm glad you posted about your efforts.

A couple of comments:
Most of the recipes people have discussed have a ratio of dry cement to DRY paper of as low as 1-2, or as high as 2-1, perhaps as high as 4-1 by weight. NOT VOLUME. Your ratio by dry weight might be 10-1 or higher. With such a low paper content, I'm not surprised that you have observed no shrinkage. Your blocks aren't "drying" they are chemically curing and locking all the water inside the brick.

I'm curious what your are trying to accomplish? What are you planning on using the final product for? I can tell you right now, you won't get much insulation factor from the mixes you are trying, but perhaps that's not important to you.

I'm not trying to discourage you from experimenting with any recipe you want to. In fact, I'm intrigued to see where you are headed. Please keep us informed no matter what. This might be fun to watch.

--- In papercreters@yahoogroups.com, "Bob" <criswells.ok@...> wrote:
>
>
> I've just started using my shop press to make blocks, don't have any
> photos yet but the set up looks very hopefull. the first block I made I
> used:
>
> * 4 gals of just slightly wet office paper/cardboard pulp,
> * 2 gal of dry cement and
> * 2 gal dry sand (just local stuff)
>
> After pressing all the water out and removing the form, I went to pick
> up the 8"hx16"lx12"w block and could hardly lift it. It took four days
> to completely dry and the finish weight was 68 lbs. Whyyyyy too heavy to
> work with, so I cut the batch in half:
>
> * 2 gal sighlty wet office paper/cardboard pulp
> * 1 gal dry cement, and
> * 1 gal dry local sand.
>
> After pressing out the water from the 3.5"hx12"wx16"l block , it dried
> in about 3 days and the finish weight was 28 lbs. Still heaver than I
> wanted but workable, I'm going to increase the:
>
> * cardboard/paper pulp to about: 4 gals and
> * cut the cement to 1/2 gal and
> * the sand to 1/2 gal and see what that turns out.
>
> I really think that pressing them is the quick way to go if you want to
> start laying right away. The out put is a lot less that the super wet
> slurry but the working time is considerably less, even if they are not
> completely dry, in two days you can handle them and probably lay them
> and they can dry in the wall. The first two had such a small amount of
> shrinkage that I could not even tell that it shrunk at all.
>
> Bob
> --- In papercreters@yahoogroups.com, "donald1miller" <donald1miller@>
> wrote:
>
> Having made blocks out of both newspaper and heavy cardboard, I fail to
> see the aversion most people have to using cardboard as pulp. If soaked
> thoroughly it pulps well in a McCain style tow mixer, just takes longer
> than newprint. The fibers are very strong in cardboard and the pieces
> are somewhat bigger than pulp made with newspapers. This seems to me
> that they would bind the blocks better than smaller pieces of the
> newspaper pulp. It is analagous to the difference between particle board
> and OSB board, or waferwood panels as they are called in some quarters.
> Particle board being made of small pieces of wood fiber is not nearly as
> strong as OSB which is made from bigger chunks of wood. Maybe this
> doesn't translate over to PC the same way, but I think it would. I made
> a batch of blocks with just cardboard pulp and they are very strong even
> without any clay or cement to act as binder.
>