Making a SM Super Classifier

So we know the problems.
Modern classifiers only sit on the top of the bucket and the over burden doesn’t get covered in water. So you have to cart 20 litres of water in the collection bucket to get the classifier to work. Lots of shovelling water on top to clean it into the collection bucket. And these classifiers don’t hold much dirt. Plus they are another odd shaped object to lug down to where the gold is sitting. And what do you do if you want to classify something up a bank and some distance from water - you need a classifier that can travel away from the main water source. And lets face it - they are expensive!.

So the challenge is to make a Classifier for about $12! One that only requires 5 litres of water in the collection bucket to get the washing working. A classifier that is easy and light to carry. And one that can process a lot of raw material.

Step one.
Get the materials and tools. All you need is a hole saw (for large holes), a 10mm drill (for small holes) and a 4mm drill bit as a starter hole. A Square and a pen.

And you need the standard bucket. Why the bucket? Well it nestles nicely with the main collection bucket and it can hold a lot of dirt. And its about $8.50. Note - the main collection bucket makes a good seat while completing this project.

Step two,
Mark out the base into 8ths.

Step three
Mark out spots to bore out the large holes with the hole saw. Drill away!

Step four
Set the square to 25cm’s. Then run a line around the base of the bucket. Then run another line 50mm above the base. This creates the lines for the holes in the side of the Super Classifier.

Step Five
Mark a point every 30 to 35mm along these lines. These will create the holes going up the Super Classifier. Quickly drill a pilot hole in each spot with the 4mm bit. And then go around with the 10mm bit.

Next stage is to get a sheet of 10mm mesh form Bunnings. This will set you back about $30. But will make about 6 SM Super Classifiers.

Step one
Mark out the base size of the classifier on the mesh by running a permanent marker pen around the base

Step two
Using tin snips cut out the mesh. Obviously it will be a circle. But cut inside the marked out circle. It has to fit inside the bucket - you will have marked out the outside!

Now all that has to be done is attach the mesh to the inside of the Super Classifier. With a 4mm (or a bit larger bolt, washer and wing nut), just drill a hole in the centre of the bucket and bolt in the mesh.

And now you are good to go!.

Except this is concept Version One. Field trials show proof of concept works. But some minor mods are needed. More tomorrow!


Field trial showed a couple of problems with Version One.

Firstly it didn’t seem to be sending quite as much classified material into the collector bucket as I thought it might. Also by just having the mesh secured in one place meant gravels ended up caught under the mesh.

Solutions. Drill more holes in the bottom. And with bits of tie wire, tie the edges of the mesh down.

The other problem was that since it was a bucket sitting inside another bucket there was a vacuum that made it hard to pull the Super Classifier out of the water.
Solution. Drill more holes. I did another couple of rows at 75mm and 100mm up the bucket. And then a series of holes right to the top.

These fixes solved the problems. And there was an added benefit. With the extra holes going up the side of the bucket a washing machine effect is created as water flows into the top holes and down into the material to be classified. As well as the holes in the bottom and lower part of the Super Classifier. So now tons of water swishes through the material.

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And finally out in the field. The Super Classifier is super effective. Three quick swishes of the classifier and that’s one shovel full of material processed.

I’ve now got the Super Sucker, the Super Classifier and the collection bucket all nesting nicely together for when I have to cart them down to the creeks.

You can see how low the Classifier sits in the collection bucket - so not much water is needed.

I’m very pleased with the end result of this project! Its had at least a 1 1/2 tons of material put through it and some pretty big rocks tossed in to be washed down. So far it appears to be holding up really well under the treatment.


Brilliant. Made afew similar concepts over the years.
Simple and cheap. Neat as :call_me_hand:

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Nice one, i made one of these but the whole bucket is full of holes, classifies it super fast with a descent amount of material in it (not too much else its too heavy)

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Well done, Ive been meaning to make one and started yesterday! But on reading about your problems with suction between 2 x 20l buckets, decided to go with a 10litre for the gravel bucket…fits inside the big bucket but with a10mm gap all around.
Went down my local creek this avo…half filled it with 5 or 6 shovel fulls of wash dirt. Threw a few tablespoons of iron sand on top and got washing. Took it home and inspected what was left of the washed material for any traces of the iron sand. I rewashed it into a bowl using a hose…so no chance of missing any of the black sand.
The answer? Absolutely no black sand (your gold) left in the 10 L bucket. Its all in the bottom of the 20l bucket with the fines and nuggets😉 Unfortunately, theres no gold in this creek.
End of the month im off to Coromandel and a few other NI places Ive been researching during lockdowns. The buckets will be coming too.

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@Flanders. The suction between the two buckets issue was 100% solved by drilling the holes up the bucket. Fully laden with dirt it still pulls easily out of the collection bucket.

The advantage I see with a 20l classifier is that it sits on the rim of the collection bucket - so you don’t have to keep digging in to pick up your 10l classifier.

Also I reckon you are probably going to need more water in the collection bucket as well you’ll loose the benefit of the wash action from the top holes in the 20l bucket.

Fair points, but i aint getting any younger and even a half full 10l pail of rocks weighs a fecking tonne!
Also, i can take the pail to where Im digging, then cart it back and dump it in a full 20l bucket of water. Pump it up and down, swirl it around , dump it out and go back for more. Think its gonna work for me anyway. Lifes a learning curve for sure. Love your super

sucker too, bro.


The mass and weight of dirt we have to classify is a problem I havent solved yet. Maybe my next winter project!

Yes, for sure. Rocks weighed in at 9kgs…and could have got more in easily. Cheers.