Santa did not bring me a rosin press this year, so I decided to make my own. Since I already owned a Harbor Freight 12 ton bottle jack for my truck, no sense buying another one just for this. So, I designed my press so I can easily remove the jack and put it back in the truck after a pressing session.
All the parts were sourced at my local hardware store for about $35, except the aluminum stock. This, I already had from another project, but cheap to buy at any of the online metal suppliers for around $25. I used three 8" sections of 3" wide, 3/16" thick channel.
The threaded rod is 5/8" course thread cut 15" to accommodate my jack height but still allow for adjustment, later on. The four springs are necessary to retract the piston when you release the pressure. Otherwise, it will just sit there cooking your bud.
I scrounged the heating plates from a hair straighter I bought from Goodwill for $3. They are 2 x 2.25 inches. Each is epoxied to a 3/16" thick piece of phenolic to isolate them from the aluminum press plates. This way their energy is mainly confined to a small area and not working to heat up the whole press.
I use a digital cooking thermometer to measure the temperature and regulate that manually using a variac (variable AC transformer).
The consensus seems to be you press at under 200 degrees. For now I have it set up for around 180 degrees F. I can get them up to 225 to 235 with the current plates, if need be. The process starts by pressing the plates together and letting them heat up for a good 10 to 15 minutes. Then, I crack them apart and push in the thermometer to check the temperature.
So, the proof is in the pudding, as they say. Today, I harvested a fresh AK-47 after twelve weeks. I plan to try pressing some of this in about five days, or so. I will also compare the results with some AK-47 that has been curing since October.
I'm curious to see the difference between pressing recently dried to pressing cured flower.
Will post those results in a bit.