Best dry sand for filling speaker cabs?

[rcavictim]

I am making some speaker cabinets that will use dry sand in an air gap between the cabinet walls. My last attempt to damp something audio with sand was way too much work. I bought 'play sand' at the building supply and discovered the stuff was soaking wet, Half a day's work later, a badly discolored frying pan and about $50.00 added to my electricity bill I had processed a 50 lb. bag of sand. Since I need a lot this time I am NOT prepared to do this again. I know that sandblasting (silica?) sand which is available to me locally comes dry as it won't work otherwise. It has very sharp edges though, not rounded like beach sand, Is the sandblasting sand going to cause me any problems that I am not aware of?

As sands go I know the dust from this particular one is kind'a nasty healthwise if inhaled. This won't be a problem once built as the cabinet spaces will be sealed.

Baking the sand myself assures sterilization. I am assuming I will not have a fungus or mold problem with dry silica sand from the bag. If you know otherwise please do tell. Should i be adding a anti-fungal powder or something? I wouldn't want my speakers to develop athlete's feet someday and run off with my best SET amp!

Jokes about how my speakers may have a sharp edge to the sound are anticipated.

Thank you for any suggestions.

Rob

[Zaph]

I use Kitty litter. I'm serious. It's cheap, dry, heavy and clean.

It's even better when it's unused. Oh, sorry, back to being serious. It does serve the purpose nicely, and obviously there's no need to pay the extra money to get the clumping type. Depending on what kind you find, it's only about 50% as dense as sand, but in general it's still heavy enough and does a great job. Some types are heavier, almost gravel based. Possibly 75% the density of sand. See what you can find if interested.

[rcavictim]

Zaph,

That isn't a bad idea. I have two cats...doh!, so I am familiar with the properties of both the new as well as the used stuff. I only left a 5/8" thick gap for the sand though so I'd probably best stay with sand this time for maximum effect, besides...wouldn't want my cats using my speakers for you know what!

[wunhuanglo]

Hi

All sand is silica (silicon dioxide) so I don't know why blasting sand would be particularly noxious, except for the fact that it is very dry and therefore more likely to become airborne. It is in use that silica dust becomes a problem. The dust forms as the grit shatters during blasting creating dust clouds.

Typical blasting grit moisture specification is less than 0.5% by weight:

http://www.enviroabrasives.com/image...DS_Ceramic.pdf

It's also probably not very subject to hosting mold either. Molds thrive on moisture, not in a dry environment. Blasting sand is dry, I believe, because it's dried artificially, so the heat used ought to kill any mold spores that were present prior to processing.

You could always fill roasting pans or cookie sheets and bake it off in the oven for a couple of hours to make sure.

[454Casull]

What you can do is build two enclosures, one inside the other, with the "front" baffles of each secured to each other so that the front is like a double-thickness baffle (the bottoms can be glued together also). Then you can pour kitty litter or liquid bitumen or even something like this:

http://www.latexite.com/pr-aptgrade.html

in between the walls.

[Overd0se]

The silica sand should work just fine. You might consider mortar sand as well. I think it is denser than silica, not sure though. It should be available from home depot, lowes , etc.

[rcavictim]

Thank you all who gave your opinions and helpful information.

Man, double walled cabinets are a lot more work!

[Dr. ODD]

HI
I used Sand they sold for the Roof of Bird Cages. It worked good for me.

[rcavictim]

Originally posted by Dr. ODD
HI
I used Sand they sold for the Roof of Bird Cages. It worked good for me.

You studied all your options and took the one that was ....cheep...cheep....cheep.

[Bas Horneman]

bought 'play sand' at the building supply and discovered the stuff was soaking wet, Half a day's work later, a badly discolored frying pan and about $50.00 added to my electricity bill I had processed a 50 lb. bag of sand. Since I need a lot this time I am NOT prepared to do this again.

LOL..you have even less patience than I have..I will use play sand. Should be no problem if left to dry in the sun...??? The sun is a much cheaper source of heat!

Cheers,
Bas