I don't understand classifier sizes and equivalents. I see some posts that call for 1/4" classifier and other posts that talk about +30 and -100 classifiers. Does someone have a conversion chart or equivalency chart for screen sizes? I want to know what size my three classifiers are, and if they are small enough for my blue bowl.
Thank you for your patience!
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When people talk about mesh numbers, they are talking about the number of openings per inch (one number indicates square openings, two numbers indicate rectangular openings). Take it one step further and the thickness of the wire starts taking away part of the opening dimensions. When classifiers or wire cloth is described for screening purposes, it should be assumed that the Tyler screen series is being addressed. You can do an internet search for Tyler Mesh Size and find a listing for wire size and opening size for all of the mesh numbers. You can go further and find screen wire and as long as you match the OPENING SIZE you should have a very close equivalent to the Tyler specification. A very good source of screen wire is McMastercarr.com and they have a lot of products with full descriptions of wire size, opening size, availability, fast shipping, and combined shipping costs. I have been using their stock number 9230T525 as an equivalent for Tyler 20 and 9230T523 as an equivalent for Tyler 18 mounted between 2 inch PVC pipe and a 2 inch PVC coupling.
Howard is correct, mesh size or screen size is pretty much the number of openings that are found per one inch of length, though sometimes even that is confusing becuase the size of wire can reduce the number of openings and then you git into the discussion of micron size particles and lose more folks than door "B" is gonna under the big "o" health care act!!
Depending upon what a person is trying to do with material, a #2 or half inch classifier is great for most sluice boxes, but if you want to use clean up devices some of them are better if you use classification to same size particles because then gold is the heaviest thing in the material and is always at the bottom and will not get knocked out of the bowl, off the riffle of a spiral wheel, out of a Vee Mat or push from the vortex of a chunk of conveyor belting.......
Here in North Central Idaho we have a lot of red garnet in the sand, and while it is lighter than gold, between it and the black sand it can and has knocked the smaller fine flour gold out of the catch.... making it frustrating trying to recover it. by classifying all to size anyone can pan the heavies out and recover the gold very easy..... and a person would be surprised how much of that minus 100, minus 200 and smaller adds up over time but you hardly ever see if you do not have those screen sizes to work with.... that said it might take awhile to pay off the expense of all those classifiers if depending upon how often you get out and play and what your primary recovery device is! for the most part most people use a #2, #8, #20, #30 and a #50 and are happy w ith what those screen sizes bring them in return, while i find a #70 and #100 are handy here on the the 2 main rivers that we "play" in with the Gold Cube on sandy beaches, up higher in the mountains we just do not run across as much really flour type gold in the same drainages.... its still there but perhaps not as much as the time it sometimes takes to dry it out and shake it through the smaller screen openings....
the #2 and # 8 will do for sample panning too, if there are not much for nuggets where ya are then you may want to consider a #12 mesh for panning purposes and just check pan the larger material, or run a metal detector over the toss out pile.....
While i am a retailer of prospecting supplies i also understand that folks dont always have the means to buy each piece of equipment profiles right off... so ifin ya can sneak the colander out from the cupboard while yer wife/girlfriend aint looking and that screen is usually about a #20 mesh classifier..... same with window screen, but the windown screen wont last as long and usually ya git caught afore ya git it put back in place..... pesky mosquitoes tell on ya too once it gits a hole in it!!!
Dane as I understand (but I have been known to be wrong more then once) a #4 classifier is 1/4 inch square openings thats 4 openings to the inch a # 30 would be 30 openings to the inch and so on hope that helps. the -100 would be any material that is small enough to go thru a #100 screen thus the minus.
Dane McCabe > Howard HadsallJuly 6, 2012 at 7:42pm
At the very top right hand on the page is a search box. run blue bowl in it. There are a couple of different discussions that all have useful info including one about screen size for it.
Replies
When people talk about mesh numbers, they are talking about the number of openings per inch (one number indicates square openings, two numbers indicate rectangular openings). Take it one step further and the thickness of the wire starts taking away part of the opening dimensions. When classifiers or wire cloth is described for screening purposes, it should be assumed that the Tyler screen series is being addressed. You can do an internet search for Tyler Mesh Size and find a listing for wire size and opening size for all of the mesh numbers. You can go further and find screen wire and as long as you match the OPENING SIZE you should have a very close equivalent to the Tyler specification. A very good source of screen wire is McMastercarr.com and they have a lot of products with full descriptions of wire size, opening size, availability, fast shipping, and combined shipping costs. I have been using their stock number 9230T525 as an equivalent for Tyler 20 and 9230T523 as an equivalent for Tyler 18 mounted between 2 inch PVC pipe and a 2 inch PVC coupling.
Howard is correct, mesh size or screen size is pretty much the number of openings that are found per one inch of length, though sometimes even that is confusing becuase the size of wire can reduce the number of openings and then you git into the discussion of micron size particles and lose more folks than door "B" is gonna under the big "o" health care act!!
Depending upon what a person is trying to do with material, a #2 or half inch classifier is great for most sluice boxes, but if you want to use clean up devices some of them are better if you use classification to same size particles because then gold is the heaviest thing in the material and is always at the bottom and will not get knocked out of the bowl, off the riffle of a spiral wheel, out of a Vee Mat or push from the vortex of a chunk of conveyor belting.......
Here in North Central Idaho we have a lot of red garnet in the sand, and while it is lighter than gold, between it and the black sand it can and has knocked the smaller fine flour gold out of the catch.... making it frustrating trying to recover it. by classifying all to size anyone can pan the heavies out and recover the gold very easy..... and a person would be surprised how much of that minus 100, minus 200 and smaller adds up over time but you hardly ever see if you do not have those screen sizes to work with.... that said it might take awhile to pay off the expense of all those classifiers if depending upon how often you get out and play and what your primary recovery device is! for the most part most people use a #2, #8, #20, #30 and a #50 and are happy w ith what those screen sizes bring them in return, while i find a #70 and #100 are handy here on the the 2 main rivers that we "play" in with the Gold Cube on sandy beaches, up higher in the mountains we just do not run across as much really flour type gold in the same drainages.... its still there but perhaps not as much as the time it sometimes takes to dry it out and shake it through the smaller screen openings....
the #2 and # 8 will do for sample panning too, if there are not much for nuggets where ya are then you may want to consider a #12 mesh for panning purposes and just check pan the larger material, or run a metal detector over the toss out pile.....
While i am a retailer of prospecting supplies i also understand that folks dont always have the means to buy each piece of equipment profiles right off... so ifin ya can sneak the colander out from the cupboard while yer wife/girlfriend aint looking and that screen is usually about a #20 mesh classifier..... same with window screen, but the windown screen wont last as long and usually ya git caught afore ya git it put back in place..... pesky mosquitoes tell on ya too once it gits a hole in it!!!
William
www.diggitprospecting.com
Dane as I understand (but I have been known to be wrong more then once) a #4 classifier is 1/4 inch square openings thats 4 openings to the inch a # 30 would be 30 openings to the inch and so on hope that helps. the -100 would be any material that is small enough to go thru a #100 screen thus the minus.
At the very top right hand on the page is a search box. run blue bowl in it. There are a couple of different discussions that all have useful info including one about screen size for it.