Hello Mustafa,

It's a nice idea you have to dye sands with different grain sizes, but 
it seems ineffective to me.
I have several comments.

Chinese Ink to dye sand works, but it leaks when you wet the sand for 
cutting it at the end of an experiment.
Oxyde powders work much better. They come in various colours, you only 
put a spoon for 2-3 kg of sand
with a little demineralised water, you mix (take gloves !), and you let 
dry for a few days, shaking
from time to time. It takes 10 min. to prepare several kilos, very easy, 
and the oxydes stay on the
grains after wetting.
I buy Oxyde powders in DIY shops or shops that sell cement, sand, 
bricks, because they are usually used
to dye cement, concrete, etc..

The effect of using layers of sands of different sizes may not be 
negligible, it depends on the thicknesses
and on the difference between the sizes, but in any case, it won't be 
large, and it can be interesting,
because sedimentary basins are indeed layered.

I don't know about the effect of the dye on the behaviour of the sand, 
but it is probably very low.

Finally, to avoid to re-sieve the sand, I use layers of natural sand 
(not dyed) separated by very thin
layers of died sand. That way I save dyed sand, have a uniform sand body 
(same grain sizes), and
can recycle the sand without sieving because it is only slightly 
coloured by the thin layers of the preceding
experiment.

Have fun with your students !

Cheers,
Bertrand.


On 19/11/2015 14:20, Mustafa Kaplan wrote:
> Dear all,
>
> I am a research assistant at METU, Turkey. I am trying to prepare 
> sandbox model for classes. It will be expensive if I order sands from 
> the mentioned web site.   I have collected quartz rich clean beach 
> sand. What i am planning is first sieve and dye them to have different 
> sized and colored sands so that I can physically separate them after 
> using. Does anyone tried dying the sands? I am not sure about the type 
> of dye I should use.
>
> I considered the physical effects of the grain size difference and dye 
> on the model as minimal.
>
> If you have further suggestions, they will be greatly appreciated.
>
> Regards,
>
> Mustafa
>
>
>
> Alinti "Resor, Phillip" <[log in to unmask]>
>
>> Hello Everyone,
>>
>> First of all I want to thank so many for the advice and the 
>> discussions of sandbox modeling.
>>
>> In the end we bought our sand from US Silica 
>> (http://www.ussilica.com/). They have dealers all over the US (even 
>> in CT) so that we didn’t have to pay shipping, which exceeded the 
>> cost of the sand from most other dealers. They have a variety of 
>> products available with data on grain size and sorting. We also 
>> ordered a little colored sand from 
>> www.coloredsand.com<http://www.coloredsand.com/>.
>>
>> Finally, I want to encourage folks to contribute to the efforts of 
>> Kim, Michele and Karen (below) as it would be great to have all of 
>> this information in a central repository, freely available to all. I 
>> think it’s good to get our students thinking critically and 
>> quantitatively about analog models.
>>
>> Happy Modeling,
>>
>> Phil
>>
>> From: Tectonics & structural geology discussion list 
>> <[log in to unmask]<mailto:[log in to unmask]>> 
>> on behalf of Hannula Kim 
>> <[log in to unmask]<mailto:[log in to unmask]>>
>> Reply-To: Tectonics & structural geology discussion list 
>> <[log in to unmask]<mailto:[log in to unmask]>>
>> Date: Friday, November 6, 2015 at 10:52 AM
>> To: 
>> "[log in to unmask]<mailto:[log in to unmask]>" 
>> <[log in to unmask]<mailto:[log in to unmask]>>
>> Subject: Re: Where to purchase sand for analog modeling - USA
>>
>> Phil and others:
>>
>> This discussion reminds me of a workshop held back in May at the 
>> University of Massachusetts, on Analog Modeling of Tectonic 
>> Processes. One of the plans coming out of the workshop involved 
>> putting together a page (or set of pages) on SERC, with information 
>> and resources about teaching using sandboxes (and other analog 
>> models). The Teaching Sedimentary Geology group has a similar set of 
>> pages 
>> (http://serc.carleton.edu/NAGTWorkshops/sedimentary/models/why.html , 
>> and other linked pages). Michele Cooke, Karen Leever, and I are 
>> currently working on very rough drafts of content for these pages, 
>> and we would like to include the sorts of things being discussed in 
>> this thread (such as how the choice of grain size or sorting or 
>> roundedness or wetness of sand can affect things like cohesion or the 
>> internal friction angle). We would also link to lab activity 
>> descriptions (like this one: 
>> http://serc.carleton.edu/NAGTWorkshops/structure/activities/121835.html) 
>> that others could adapt to their own courses.
>>
>> If you are interested in contributing to this effort in any way 
>> (contributing lab activities, reviewing content before it goes live, 
>> providing suggestions for materials that are effective for modeling 
>> various types of structures or rheologies, contributing photos or 
>> movies of experiments that you’ve done, etc.), please let me know.
>>
>> Kim
>>
>> Kim Hannula
>> Associate Dean of Arts and Sciences
>> Professor of Geoscience
>> Berndt 301
>> Fort Lewis College
>> Durango, CO 81301
>> 970-247-7463
>> [log in to unmask]<mailto:[log in to unmask]>
>>
>>
>>
>

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