Bottle Digging
 By Tom in IL

The Ultimate Dirt sifter

OK, you've located a privy, dug it out, and recovered some bottles.  Now what?  Before the hole is filled back in, you might want to take a closer look at that dirt.  There might be some interesting items hidden in the dirt clumps.  Detecting the dirt will help find some of the metal items only if they are not "masked" by iron or some other metal debris.  Other treasures that are not metal will not be found by detecting.  The only alternative method for finding all items is by sifting the dirt.   
I described the simple frame sifter that I use when sifting the dirt in last month's article.  It works very well, but takes time to work the dirt through by hand if the dirt is hard or has clay mixed in.  Clay does not want to break up into a siftable size to go through the screen mesh.  A helpful hint here to make the sifting process a bit quicker, would be to keep the dark privy dirt and topsoil to one side.  The unwanted clay that surrounds the hole can be put to another side away from the siftable dirt.  

My digging partner (whose name is Tom also), is always trying to come up with better ways of doing things. After digging and sifting some of these privies, he kept wondering about an "automatic" type sifter that would shake on its own.  We could just throw the dirt on the screen, and the sifter would take it from there.  This guy is always thinking.  Driving home from a dig, he would "envision" this contraption being put together from the ground up. He has welding experience and access to many of the materials needed to get the thing started.  I don't know too much about the gear ratios, belt sizes needed, or the     correct engine size that makes it all work smoothly, but went along with his ideas because they sounded good :o).  After a while, it started to take shape.  It would have to go back into the garage for some minor "tweaking" on drive speed, correct amount of "shakes per minute," sifting screen size options, and getting the right tension on the drive belt so it will disengage into neutral without still going.  But after the final adjustments, it worked great.

 

This sifter will drive itself out of the truck (pic1) and onto the site powered by the 5hp Honda engine (pic2).  To direct it's path of travel, the front end is pushed or lifted to the right or left.  Once it is at the site, it is positioned along side the excavated privy hole.  There, it is put in neutral and the shaker box is engaged.  The throttle is adjusted for the right shaking speed.  The dirt that is sifted, is directed back into the hole by a metal deflector under the screen. There are different screen mesh sizes to accommodate the different types of soil.  The screen panel can be lifted out of it's frame, and a different size inserted in.  The dirt that is shoveled onto the screen is worked by one of us using a rubber "clod buster" (pic3).  The rubber baffle breaks up the dirt clods into a siftable size without doing damage to an item that was hidden in the clump.  We don't force the clumps through.  When the accumulated harder clods builds up in the screen box, we'll raise the screen frame and dump them into a bucket positioned under the metal funnel (pic4).  They will be brought home, soaked in water, and hosed down to reveal what they are.     The sifting finds for this particular dig were slim.  A couple of white porcelain buttons was about it.  We haven't got to use it much yet, but on it's trial run, it worked fine.  I wish we had this sifter for the previous privies we've dug.  We will be thoroughly checking each one we dig in the future.  We have permission to dig at another house site and will put the sifter to use there.  I will probably do an article on it and show the results of how it performed.  So long for now --Tom  DETEC10@aol.com