Sifting

[jeepinthemud]

I did a search, and couldn't find much..

But I am curious as to how sifting works, the different types of sifters, what is to be done, etc...

I have read many posts about how it can be an efficient way to search for things, but this is fairly new to me!

Thanks in advanced!

[Seldom]

I did a search, and couldn't find much..

But I am curious as to how sifting works, the different types of sifters, what is to be done, etc...

I have read many posts about how it can be an efficient way to search for things, but this is fairly new to me!

Thanks in advanced!

What little sifting I do in the field is done with a 4 gal. pot that has 1/4 in hole in it got it at a restaurant supply for less then 10 bucks. If I find a shell bank on the beach that's producing I will sift out several gl of material to take home and look thou in the ac.

I can set it in 4 or 5 in of water shovel in the sand and let the waves do the work. I have 2 stainless sifters that I had made 10 x 10 in one with 1/4 in mash one with 1/8 mash I use in the shop for micro stuff.

Chase has a thread that has pis of the ones he made, I will try to find it for you.

[Dave Bowen]

It depends on what you want to sift for. This weekend we were in a river sifting for shark teeth, so we were using a sifter with 1/4 mesh screen. (You can find this at lowes, home depot in the fencing section.) You get a shovel full of gravel from the creek/river/exposure, and you dump it in the sifter. You shake it side to side, back and forth, etc and what you have left in the sifter is only the material that didn't fall through the screen. This gets all the small rocks, dirt and debris out of the way. Then you just spread it around and look for fossils.

If you are targeting a larger fossil, you might use 1/2 inch mesh. I have one of each.

There are several ways to make one. I went to the dollar store and got some plastic pans, much like a cat litter box. I cut out the bottom, and drilled holes around the bottom edge. Then I cut the screen to fit and connected the screen to the box with zip ties.

The pictures of mine should give you an idea. Mine are a little too deep for my liking, so I'll be cutting them down about half way. Makes it easier to get your hand in there to sort the matrix. Also, I would recommend a light colored box. The black tends to hide dark shark teeth.

Hope this helps.

[CreekCrawler]

Sifting is an enjoyable way to search for fossils that are dispersed into a creek/river bed.Usually these waterways have gravel bars here and there where material that has weathered out of the formations has been deposited into the waterway and accumulated with other rocks /pebbles to form gravel bars.Sifting involves scooping up the mix of gravel/rock placing it into the sifter and using the water to clean the gravel of dirt and debris. You can classify the gravel using larger mesh like 1/2" then stepping down to 1/4" mesh and so on.The way to do this is by nestling the sifters inside each other and removing the sifters from the top down. I use 1/4" mesh exclusively,although I have lost many small teeth this way.You can also dry sift without water,but this method usually works best in sand. Clay type soils are your enemy, it's hard to sift when there is sticky clay that doesn't wash too well with water.Hope this helps a little.

Oops it took me so long to type this Dave,you beat me to it

[jax]

Dave and Barry got it pretty good. I built my sifter from 1X4 pine and 1/4 in screen. 12X18 in working surface gives me plenty of room to search the gravel.

Other things to keep in mind when sifting, Take something to sit on. Im sure others can speak about this. Your back will thank you. (Im still sore from the 4hrs of sifting and crawling I did on Sat...)

You can also attach pool noodles on the sides on your sifter with wire or zip ties. This will allow you to float your sifter while working in the deeper waters.

My 2 cents for the day

[Auspex]

One last step:

Once you've sifted out all non-fossil debris, put what's left in a flat-rate box and send it to me!

[Haddy]

Everybody seems to have different sifters. I have a few, but the ones I use the most are white plastic-coated mesh drawer liners / dividers. Got them at the dollar store; they have 1/2" mesh. I use two together. One is smaller and fits inside the other. I lined the larger one with 1/4" mesh (attached with plastic wire-ties) and put the 1/2" mesh one on top. So when I shovel / trowel sand and gravel, the larger stones stay in the top, which makes it easier to sort through the smaller stuff in the bottom one. They're nice because I can put 2 sets in my backpack, and work on one while the other is sitting in water which will remove the sand. Depending on the surface that I'm sifting, I am often able to just scoop with my drawer liners instead of having to use a shovel or trowel.

A friend carries his sifters in a milk crate. He uses the crate as a chair while sifting.

Other things I take in my backpack: advil and 1st aid, both sealed in baggies. Bug spray and sunscreen. Cell phone in a bright yellow buoyant waterproof bag made for phones. Water, soda, sandwich, snacks. Tinfoil (dollar store has the pre-cut kind). Waterproof camera (Pentax Optio). My backpack has a nice clip for keys so they dont' get lost.

I carry a mayonaise jar that I put some water in so the things I put in it don't jar each other. I drilled holes in the top so I can just put small teeth into it; have to open it for the larger ones. It's on a strap that I can put around my neck or over my shoulder. I've seen some people carrying bottles that have holes in the top that close but haven't found one for sale yet. Water shoes - I have a few pairs, right now usually wear water-sneakers that work out really well for the streams I've been searching in. I have a variety of wetsuit pants / dry pants and jackets that I've used for kayaking that I'm sure will come in handy when it's cooler out.

[FossilForKids]

I use to use a spaghetti colandar when I do beach or small gravel sifting in water.

[jeepinthemud]

alrighty.

so it is used for going through rock/gravel mixtures in rivers... would I also be able to use it in sand? (or would I need a finer/larger mesh?)

thank you everyone!

I had the basic idea (Sifting through rocks) just wasnt quite sure how it worked. thanks!

[Tr-J-K]

Nested sifters are great, because you can capture all different sizes at different levels. If you're building one out of wood, that's what I'd recommend (its what we used at the UCMP Blackhawk quarry). Build two legs onto one end so it is self-supporting and all you've gotta do is shake! Gravity does the rest.

[Haddy]

alrighty.

so it is used for going through rock/gravel mixtures in rivers... would I also be able to use it in sand? (or would I need a finer/larger mesh?)

thank you everyone!

I had the basic idea (Sifting through rocks) just wasnt quite sure how it worked. thanks!

You should be able to use it in sand. Mesh size would be dependent upon what you're looking for as well as how big the stuff you'd be sifting through. If you're sifting through sand, you'd probably want a pretty fine mesh. If there's rocks / pebbles, maybe a two-layer. HD & Lowes sell rolls of mesh in various sizes. You can also use collanders or even mesh in-boxes purchased at an office supply place. Trial and error, plus you may end up with a few different sifters for different purposes.

The first couple of times I went, I went with a friend. He had some sifters he'd made that were pretty nice. However, he also had a BBQ "cage" for veggies and stuff as well as a high-quality wire collendar with 1/8" mesh that I thought were great as they were the right size and they were lighter than those heavy wood things, so I could more easily climb over trees and up and down stream banks. I put one inside the other and they worked great. The last time I went with him, he was using the gear that I liked! Of course, I've since bought / made my own, but I got a kick out of it.

[silverphoenix]

You might wait on a sifter until you come on a dig with me--it's coming up in about a month. I'll let you use my sifter(s) and if you like them, then I can build you one. It would be a lot cheaper since the rolls of mesh have to be bought in bulk--not to mention that it'll save you the trial/error stage and the labor haha.

Through building about 10 different sifters and finally settling on one design, I've found out some very important features that are a necessity with any sifter:

1. Durability--going to be doing some rough labor, so it should hold up without fail for years

2. Size--too small and you can't sift squat, too large and you have trouble carrying it and shaking it

3. Ergonomics--part of size--is it comfortable to use and carry?

4. Does it get the job done? Does it do everything you want it to do?

5. Does it work in all environments that you need it for?

6. Does it look decent--ok, let's admit it, most of us say we don't care what it looks like, as functionality comes first, BUT we always like our equipment to look professional--something to be proud of (for instance my camo paint job, which does nothing but making my sifter harder to find, but it looks pleasing to me)

The sifter design I've come up with (barrel, 2 part design) has passed if not surpassed all of the above--so long as you're not needing to use it in the middle of a creek that is--then floats would need to be attached and I'd have to shorten the barrel, but it can be easily done--I just haven't needed an aquatic sifter yet, though many people do