Antique Coffee Mill cast iron Hopper Removal Process

For all the Antique Coffee Grinder and Coffee Mill enthusiasts, we finally figured out a way to successfully remove the Cast Iron Hoppers without any damage to the Mill. The process works for removal and resetting the Hopper. To start, we take the steps to remove all the paint, back in the 1890's the Mill manufactures may has used Lead based Paints, with all the Mill we recondition or restore at usacraftsman.com, we first use Electrolysis, Bronze high speed wire brushing and Fine Grit Media Sand Blasting to remove all Paint. Once the paint is totally removed the steps can proceed to remove the cast Iron Hopper from the Mill Body.

Tools & Material needed for this process
- Set of acetylene / oxygen torches (best to use a brazing type torch tip for this process to prevent damaging the surfaces).
- Heavy duty welders gloves (to lift the hopper free)
- Medium size bucket of ice cubes
- Clamp set up to hold the Mill Body securely while performing the process.
- As always Safety Gear and a Safe work environment.

Skill Level
- Mechanical ability and skills with a torch set, also, understanding of metal properties.
Note: People without the proper skill sets should not attempt this process....

Hopper Removal Process
Step 1.) Using an acetylene / oxygen torch set, carefully heat the joint surface between the Body and Hopper. Keep the torch moving all the way around the joint (typically heating approximately a band one (1) inch wide. Heat the surface until the outer area is glowing cherry hot (red in color)...
Step.2) Quickly fill the Hopper with Ice (we used regular ice cubes from the home freezer).
Step .3) Lift the Hopper with a slight twisting movement up and off.

The objective is expansion of the Mill Body joint and contraction of the Hopper joint. By heating the Mill Body joint and then "shocking" the Hopper joint with ice, the joint can be easily separated. The picture shows an Elgin No 42 with the Body and Hopper separated.

If you have a Mill that you need to remove the cast iron hopper (or re-assembly one), go to usacraftsman.com and send us an Email (from the contact page).. We can provide the service to you or other restoration/reconditioning needs for the Antique Coffee Mills and Grinders for an affordable price, all estimates are free for Mill work.

Thanks, hope this helps and please be careful if you attempt this process. Best to have someone with the Skills and Equipment to complete this task.

Chuck