Just do the following in your kitchen at home.
I bought a used oil bath air cleaner for Petrus - the existing unit was busy shedding it inlet tube.
It needed a bit of sprucing up as 40 odd years were taking its toll from an appearance respective and it was covered in caked-on oil.
To clean it, I warmed it up with a heat gun and then sprayed it with Zeb oven cleaner.
After a few minutes, I brushed the zeb off with a nail brush. Only then did I realise that Zeb is an excellent paint remover.
To clean the oven cleaner off the air cleaner, I washed the whole unit in the kitchen sink with seriously hot water.
Fortunately this was done in the workshop and not at home as this is a rather messy exercise.
The air cleaner was blown dry with compressed air and then painted with primer and satin black from a spray can. Because of the winter temperatures, I heated the air cleaner again with the heat gun prior to painting
This is the start of the operation in the shop kitchen

The top is being cleaned. I am wearing rubber gloves, as previous experience with zeb left me with stained nails.

This is the bottom half being cleaned - a real messy exercise

Primer going on


New paint after forty years

Petrus with the new air cleaner.
