green/dry sand

[wmf138]

Hi All

Just went and picked up some sand

And the sand I got was from a sand blaster which is very fine almost like baby powder if it was glued to paper it would be around the 800/1000 grit the first tests were dry and the detail was amazing then i wet some up and the results were just as good

now the sand was Garnett I got around 15Lt's / 3gallon approx and weighs around 30kg/60bl and the best part they thow this stuff away

wetting it down I got it till it was just holding together and broke without crumbling

being new to this

so here's some questions
when mixing the Benoite into it is it 5-10% volume or weight I was guessing Volume as the sand is heavy

with it holding together very well just with water do I have to add Benoite to it

Cheers
Wayne

 

[tel]

You don't need any bentonite if you are just doing lost foam. When I do green sand it is generally by trial and error - eyball rather than weight or volume, as sands vary so much!

 

[wmf138]

;D Cheers Tel

I think I would be doing more lost foam than anything else so that makes it a lot easyier

Cheers Wayne

 

[PTsideshow]

Even more importantly, is the fact that it is blaster media and sand! be sure to wear breathing protection a real good mask.
Silicosis is a form of occupational lung disease caused by inhalation of crystalline silica dust. It is found in sand, in many rocks such as granite, sandstone, flint and slate, and in some coal and metallic ores. The cutting, breaking, crushing, drilling, grinding, or abrasive blasting of these materials may produce fine silica dust.Silicosis is due to deposition of fine dust (less than 1 micrometre in diameter) containing crystalline silicon dioxide in the form of alpha-quartz

Silicosis is an occupational hazard to mining, sandblasting, quarry, ceramics and foundry workers, as well as grinders, stonecutters and those continually exposed to silica dust.

The induction period between initial silica exposure and development of radiographically detectable nodular silicosis is usually 10 years. Shorter induction periods are associated with heavy exposures, and acute silicosis may develop within 6 months to 2 years following massive silica exposure.

So might as well take precautions now as find, find out later that a msk would have helped.

And don't let the kids or grand kids play with spent blaster sand.
glen

 

[wmf138]

Thanks for the tip

the kids are never around when I'm playing (so to speak) and I where a mask that I use for spray painting and out side

the dust off this is very heavy also theres very little no where near as much as normal sand

the specific gravity is around 4 which I gather is heavy

thanks for the tip though you never know what your dealing with now days

Wayne

 

[oilmac]

Wayne,
As P.T has pointed out, be cautious as to the exposure of your lungs to the dust, Silicosis is not a nice ailment, Now as regards your sand which seems to be fine, Do you know what sort of components &associated materials were being blasted with this sand, Is there any nasties in the way of hazhardous materials mixed with this waste sand, or anything which may react with your cast metal, &stuff up your casting?
Your sand might be a little close grained, as to its ability, to allow the eascape of mould gases, (low permeability) Should this be the case you may have to open it out a little by adding some dry silica sand, and if making iron castings, a little fine coaldust, Although dont go crazy with too much of the coaldust

 

[wmf138]

Most for the work he goes is 95% new straight fron the builders to him very little rust at all as for other stuff dont know

I'm mainly doing alloys and some brass but until I get my furnace going properly its only alloy

did do some small lost foam pieces carved letters in dry sand and came out good but these are my first attempt at these things

thanks for everyones help and wisdom

Wayne