Anyone made a gravel sieve?

[Brad_S.]

I need to put down a gravel base for a roadway and don't care what size the stones are. I have a nice supply of bank run gravel and want to separate the stone from the dirt, the caveat is I need to do it cheaply. I can't justify buying a commercial unit and my fabricating skills are poor. I'm wondering if a section of heavy steel mesh or grating mounted at a 45° angle on heavy timbers and dumping a little material at a time in a back and forth dump motion will suffice or will it just plug up? Before I invest too much time and money, I thought I'd see if anyone here has made something like this.

[sawguy21]

That should work as long as the material is dry. I remember doing something similar when dad was mixing mortar, I was the official shoveler and screen shaker.

[Norm]

I'll be interested to see the ideas too. We have a large vein of sand and gravel that I've dug out before but need something to screen the sizes also.

[Sprucegum]

Yer on the right track - set your screen so you can dump on the high side, as the material runs down the screen the fines fall through and the larger stuff runs off the end.

The trick is to not dump too much on at once or the small stuff gets carried over the end by the big stuff. Local gravel pit owners use a conveyor to control the feed rate on to the screen. Changing the screen size gives you whatever size aggregate you want.

[isawlogs]

 We had some when I was hauling for bush road making . They where made of steel .. which dont matter , make it out of what ever you have .
Thing is , the 45° angle aint enough . You need a steeper angle for the material to run off . Some of the small stuff will runoff with the larger ... aint no worries you can pick it up after and screen again .
   If When the screen gets plugged up ... alls you need to do is put the bucket of the tractor under the screen  and lift and go forward till the screen is almost vertical ... ( ours being made of heavy steel , we would push over with the loader and then pick it back up .  ) But do this after you have cleaned up under it . If you build it sturdy enough you should be able to move it with the tractor bucket .. by lifting it up from under the front opening .

  I did one on the farm with chain link fence . I think I had like a 60° angle on it this one was made with helmlock , 6x6 for the legs and frame , 3x6 for the screen suport . If memorie serves me right ...  :-\  I had the screen suport at about every 18" going from top to bottom . I had put some 2 " boards for rthe skirt . Was not all that wide , might of been a little over the 6' or so and as high as I could go and still be able to get the FEL above it and be able to empty .

   For those who would like to know how we made ours .

    4x4 x1/4  frame 3"x3/8"  flat bar welded to the frame at 2 inch intervals across from top to bottom on edge , there is a 2x4 suport in the midle of the slope to suport the flat bar . We had a steel skirt around it to contain the sand .

[Brad_S.]

Thanks for the input. You Canadians came through with some great input on this one! 
I had envisioned setting some posts in the ground and building a stationary unit, but a portable one as described makes much more sense for my needs. Also easier to slap it around a little when it plugs up.
Thanks again.

[logwalker]

If you have a rock pit near you you can ask them if they have any old screens. They change them out before they wear out and have a lot of life left. I got a nice set a few years ago and have used them quite a bit. It still is very labor intensive. A vibrator of some sort would help a lot. Joe

[Don_Papenburg]

The vibrator could be made from an electric  motor with an offset weight on the shaft

[isawlogs]

It would be nice to have a vibrator on it , but that implise having a motor to run it gas or electricalicity wich aint available at my pit .  :-\ 
A good steep angle works fine .  ;)

[logwalker]

If it was a robust frame you could shake it with the front end loader. What size are you going for? Joe

[Handy Andy]

  This is a great topic, but don't understand how this works to sort the dirt from the gravel.  I have an old railroad bed running through my property, and I would like to sort the gravel from the dirt, but much of the gravel is chat, very tiny crushed rock.

[isawlogs]

This is a great topic, but don't understand how this works to sort the dirt from the gravel. I have an old railroad bed running through my property, and I would like to sort the gravel from the dirt, but much of the gravel is chat, very tiny crushed rock.

  This is basicaly a box with a steep angle roof , holes the size of wich you would like the bigest stone to be in the material you would work with ( da screen ) . One side of the box is open ( high side )
  You would be using a FEL ( front end loader  ) picking up the material that needs being seperating ... like sand from stone . Lift it over the high side and dumping over the screen , as the material runs down the screen it is seperated . you pick up under what is good ... the larger stuff goes to the back .  

[Brad_S.]

Here's a commercial version.
http://www.rocktough.com/

[Sprucegum]

Jim, seperating small crushed rock from dirt can be more challenging than what Brad is doing with larger rocks.

Why? - crushed rock has sharp corners and angles that get stuck in the screen easily
         - small rocks weigh the same as dirt and get carried along with it
These problems can be overcome with a viberator on a lower-sloped screen OR you can wash he gravel, if you have access to lots of water. For that you build a sluice box like the  gold miners used to use.

[sawdust]

We used a device we built for our gold sluice. Called a grizzly, steel rebar set with what ever gap desired between bars. the bars were set into a  "made of two end boards of triangular shape connected by iron rods along two sides so that a grating is formed on two of the sides of the triangle."

rocks tumble to the sides and the fines went down through the middle. we ended up with two pile of rock one on either side of the long tom.

kind of a confused description I could draw a picture for you, but not on the computer!  :-[
sawdust

[Sprucegum]

Never mind those piles of rocks - show us you piles of gold  ;)  ;D  ;D