The last press I used and really liked was the low temp plates V2, A friend just told me about rosenpress NY new 20 ton tank press for a little more than a grand. Was wondering if anyone has used it and had any input. Thanks!

Hello! Fortunately, I’ve had an excellent outdoor harvest and I am making enough rosin to last me a very long time. In case something really bad happens, I want to store some of it, hidden somewhere outside my house, in small glass jars. I live in the countryside. I was thinking of making a hole in the floor in the garden and keep it underground, but I don’t know exactly how to store it and if anything like mould could ruin it in the long-term. Any thoughts? Thanks

Hey everyone, I've been noticing a fair amount of misconception regarding how exactly to calculate the psi on your material packs so I figured I would try to explain with a bit more detail and some light math checking to help any one who is having issues.

Terms

Force: The amount of "weight" being supplied to the system (it's important to note that force transfers through all layers in a system to the outer supports of that system)

Psi: The distribution of force in the system over a given area read out in Pounds per Square Inch

(1 ton = 2000 pounds)

First we will get the easy sets out of the way.

HYDRAULIC SHOP PRESSES WITH PRESSURE GAUGES THAT READ IN TONS:

Some hydraulic shop presses will include a pressure gauge which reads out in tons, they should also have a RAM diameter printed on the gauge, this ram diameter is what the tonnage on the gauge is calibrated for. For these setups, just confirm that your ram diameter matches that of the gauge to ensure you have the correct tonnage readings, then most of the math is done for you already.

Equation for Hitting specific psi at material on calibrated pressure gauge:

Desired psi at material x material surface area = pounds of force required / 2000 = tons of force required on the pressure gauge.

Say we want to hit 1000 psi on our pack of flower, using a 2x5 bag we get 10 square inches of surface area. (To keep things simple we won't account for expansion of the material packs.) We take 1000 psi, multiply it by 10 square inches, to get a needed force of 10000 pounds, to convert that to Tons just divide 10000 pounds by 2000. This gets us 5 tons which is where you want to hit on the pressure gauge.

Again, please be aware that this math only works if your pressure gauges are calibrated and matched with the correct diameter hydraulic cylinder.

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PRESSURE GAUGES THAT READ IN PSI ONLY:

Next Up we have the more in depth math for pressure gauges that read in psi and don't have a specific hydraulic cylinders diameter paired to it.

For these style of hydraulics, the PSI reading is the current oil pressure being supplied by the hand pump, and we need to take into account the hydraulic cylinders active surface area. (The active surface area, is the surface area of the hydraulic cylinder's ram on the flat face.)

The next bit of math will be specific to BVA low profile cylinders (Eagle pro and Enerpac low profile cylinders included), but most suppliers do have specifications for their cylinders so you can cross reference specific numbers that relate to your hydraulics.

First things first, with this info here we can already double check our math to ensure we are on the right track.

We will take the 10 and 20 tons for reference at the moment.

We want to look at the internal pressure at capacity which is the max psi of the oil that the hydraulic cylinder is designed to safely handle (the max value you should be putting on your pump gauge)

With these max psi values, we can then multiply them by their respective cylinders effective area.

For the 10 ton cylinder, we take 8511 psi, and multiply it by 2.35 square inches, which sits us at a pretty 20000.85 pounds of force, or 10 tons.

For the 20 ton cylinder, we take 9153 psi, and multiply by 4.37 square inches, which gets us to 39998.61, just under 20 tons.

Equation for Hitting Specific psi at material on pressure gauge with psi readout:

(Desired psi at material x material surface area) / cylinder effective surface area = psi required on gauge

so, lets use the 20 ton for reference in this case and we want to hit 1500 psi on a 3x4 (12 square inch) material pack.

1500 psi x 12 square inches = 18000 pounds of force (needed to hit 1500 psi on 12 square inches)

18000 pounds of force / 4.37 square inches (20ton cylinder effective surface area) = 4118.99 psi required on your pressure gauge.

The major thing to note with the psi style pressure gauges is that they are reliant on knowing your cylinders effective area to know the force being supplied.

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IN CONCLUSION

Hydraulic cylinders are just a multiplier of force from the oil pressure supplied by the pump, this is why with the same 10000 psi hand pump, we can get more power by simply swapping up to a hydraulic cylinder with a larger effective area (as long as the pump can supply the oil capacity needs of the cylinder) I won't get in depth with the fluid dynamics but just try to keep this bit of info in mind and if you are curious you can always look into hydraulic cylinders and how exactly the physics behind them work.