[walter]

So today I decided to hit the dunes...
(I mean US Silica Co.)

The good news: They have tons of sand ↓



The bad news: They won't let me have any of it... Funny story, actually.


I called the front desk lady and said "I'd like to buy some sand because I'm doing some testing and.." when she slapped me with "Testing sand lead time is 8 weeks." and switched me to the Lab.

So then I had a chat with a technician. We talked sand..
Let me tell ya, those people are slow but thorough! I did learn some new stuff.
Decided to go with 450-700 micron pool filter type sand and maybe some 100 micron flint type (I got the lingo down...)

So then I go back to desk lady, and get this! the flint lead time is also 8 weeks lol. And you have to buy 8 bags minimum (50lbs each).

Alright then, I say, let me have that 700 micron and I'll be on my way... "Not so fast!" lady goes. "There's also a minimum order requirement. And, the bags are 100lbs!"

(chair) (chair)

-Ok. What about these 50lbs bags?
-"We have it in stock buy you have to buy a pallet."

-So how many bags in pallet?
-"63!"

-Well, here's the thing.. Listen. I just need 2 bags, can't buy the whole pallet. I'm just doing some testing and..."
-Testing sand lead time is 8 weeks!"

...

[lgalla]

Walter welcome to sand buyers annoymus.Upper Canada stone has amazing black granite sold in railcars.I asked if I drove there with my truck[300miles]could you fill it up?No!!!.Local quarry:You have dry sand and aggregates.Yes,its that big pile outside.What if it rains?It will dry out.
Walter try the US silica distributers as they maybe more willing at sample requests.In Canada I mentioned LV Lomas who is helpful at samples and 1 or 2 bag orders.Once I requested a 1 lb sample of red pigment and a 48ft truck came in two days with my sample.Good service.All customers are important to them.Funny eh!,the most common materials or rocks are hard to get,better stick with poolsands,sandblast or playsand in bags.Moving to Florida would solve the problem although it may be illeagale to steal sand from the beach.
Larry

[walter]

Larry, I got the stuff down. Took me a while but I got it.

-635 epoxy,
-(US Silica) ground silica that looks like 50-100 micron,
-(US Silica) coarse pool sand in 450-700 micron area,
-lifetime supply of 200 micron 3M Zeeospheres (don't ask...)

-the black carbon magic powder should be in the mail by now (I think Cabot finally got tired of all the phone calls).

I'm loving this stuff. I don't think I can go back ..lol!
I wish I had the time to do the testing.. But it has to wait a week or so. Still need that powder anyway...

Will report as soon as possible.

Cheers!

[Geof]

...-the black carbon magic powder should be in the mail by now...

The mind boggles at what might be the response if this package got burst in the mail.

[walter]

[lgalla]

Geof good point.This stuff is what is refered to in meterology as a black hole.We transfer the carbon black from bags to 5 gal pails and it is difficult to see if it is full as it is a black hole or devoid of light.We transfer the black in the spray booth as it is light and fluffy and black clouds are scary.For some reason if I handle the stuff,it collects on the veins on my arms,not on anyone else.It maybe due to my electrial or charged personality.If UPS breaks Walters sample,UPS may change from brown to black as corporate colors.
Larry

[Geof]

Is it an explosion hazard when dispersed as a dust? I would imagine it is and could make quite a bang; it is not that much different to coal dust.

[lgalla]

Geof,an un-researched reply would be no to explosive as carbon black is soot,same as lampblack or the black soot from a candle.I have probably used thousands of lbs of carbon black and am still here due to lack of explosions.
Larry

[Geof]

I went Googling.

Pure Carbon Black is not a dust explosion hazard, impure is.

But of greater interest is this stolen from a Canadian occupational safety site:

How can I work with carbon black safely?

This material is a VERY TOXIC (POSSIBLE CANCER HAZARD AND POSSIBLE MUTAGEN) solid. It may also be a DUST EXPLOSION HAZARD depending on the impurities present. Before handling, it is extremely important that engineering controls are operating and that protective equipment requirements and personal hygiene measures are being followed Only authorized personnel should have access to this material. They should be properly trained regarding its hazards and its safe use. Maintenance and emergency personnel should be advised of potential hazards.

I would say a good dust mask is warranted.

[walter]

Good info. Thank you.

[lgalla]

Everything is dangerous in quanity.Drinking too much water can kill you.Two componet Polyurethane can result in cyanide poisining without a body suit and air supplied respirator.My shop gass heater says not suitable for use in California.The beauty of epoxy is it is non toxic when cured {1 week]As it has no solvents and no vapour pressure it is retatively safe,taking precautions such as gloves and avoiding skin contact.As a shop and business owner,I would not ask employees to use dangerous materials I would not handle myself.Saftey is #one in our shop and any safety questions of materials will be gladly answered.
Larry

[Eson]

I wonder if epoxy resin without hardener is non-conductive. Someone help me google it down.

However im currently working at a ship supplier storage and i found a 3L damaged epoxy bottle. We cannot sell it due its state but its still intact. So i should be able to get it really cheap.

[yugami]

-lifetime supply of 200 micron 3M Zeeospheres (don't ask...)

Where did you find a distributor for that who will deal with some random yahoo? Whats considered a lifetime supply? I'm doing some testing in other areas where this product would come in handy.

[ericdwilso]

I went to my local landscape supply... They have 3/8" pea gravel... Anyone know the difference between that and river rock? Will it work for our application?
Eric

[walter]

Where did you find a distributor for that who will deal with some random yahoo?

You need to visit your local distributor of 'raw materials' and 'filtration' products.

Google search for Zeeospheres brings up TheCaryCompany.com
That's where I got the stuff. They even offered me a kilo of that black magic powder!

But... With that suit and my shades- I didn't feel like a random yahoo at all... lol

[yugami]

Google search for Zeeospheres brings up TheCaryCompany.com
That's where I got the stuff. They even offered me a kilo of that black magic powder!

Thanks, I had just run into them via google. I'm only an hour from there so maybe I can do a pickup direct from them.

[Mike Mattera]

I used to work for Hermle Machine (German Co. Here in Milwaukee area). They now build all of their machines with the composite Granite bases. They are cast in an almost finished state. They machine about 5-6 surfaces flat and their ready to start building. Top quality stuff, +/_ .00005 precision (that's 1/2 of a Ten Thousanths of an inch). But in the right environment they'll do +/_ .00003 all day long. The Composite Granite is vibration stable but also has excellent thermal properties.

Mike Mattera

[lgalla]

Eric pea gravel is smooth and rounded like river rock.Good choice for coarse aggregates.
Walter make sure the Zeeospheres are the heavy 60,000psi crush resistance type.US-Silicates also has 1/4"and 3/8"quartz aggregates.
From the guys testing E/G with a hammer I reviewed the concrete v/s poly concrete.Polymer concrete is 3to4 times the strength of regular concrete.
www.acoaus.au/v05/matprop.htm
Adding glass fiber to polymer concrete can up all the specifactions,but can't say how it will affect vibration damping.I attached a Pdf on the subject.
Larry

[romihs]

Hello all...

I finally got around doing some experimenting..

I wanted to try making a mix that was dry (not pourable). I made the mix with the following ratios:
Epoxy: 8.3%
Small Aggregate: 9.8% (0.35 mm)
Medium Aggregate: 22.4% (0.8 mm)
Large Aggregate: 59.5% (2.5 mm)

I used washed and dried quartz sands.


The mixture was very grainy.



I then 'poured' the mixture into my 'mold'.


Compacted it with some wood...


Here is a side view of the compacted mixture...


I decided to embed some cap screws and a piece of Alu angle profile that has a small hole drilled though it, so that I can test the 'strength' of the E/Q...


I decided to leave what was left of the mixture after filling the two transparent 'molds', in a 'mold' uncompacted (the blue container in the following picture) to compare properties between the two.


Some of my observations so far:
1) I can understand why manufacturers use high frequencies to compact this mixture. Tapping the containers by hand had no effect on the compaction of the mixture. High frequencies should liquefy mixtures of this consistency. This is something I would like to experiment with (using some kind of a voice coil motor to achieve 4kHz vibrations).
2) The mechanical compacting method worked well, but it took quite some time to get it right. One needs to be quite gentle when tapping the surface.
3) I felt like the medium sized sand was not needed. I will make a batch using just the small and large sized sands.
4) I noticed, while mixing, that the various sized grains would combine to produce small balls of epoxy sand with a diameter of about 3mm.

That's about all from me for now. I'm waiting for the epoxy to cure, and then I will post more info. I will cure one of the finished parts further in a oven for 10 hours at 50C to compare the differences. This epoxy actually requires this, but I am curious to see how it looks without curing aswell.

Regards

Sandi

[walter]

Good stuff Sandi! Thanks for posting.