Rumble restoration polishing

Rumble restoration polishing

It’s a simple machine but the hardest to get used to, every time I phoned the company for advice they told me something different every time! In the end after spending many many thousands of pounds on grinding/polishing media I’ve got it sussed – sort of – sometimes the machine has had a mind of it’s own.

Today it’s an important part of our works department and it’s working most days.

The machine is a big square box, lined with rubber, with a motor underneath driving the box so it vibrates. Small different grinding media is added in the box along with the part to be worked on. Water is added as is a cleaning soap. Then it all works by sending the vibrating media over the part as the media and part tumbled – also called a tumbling machine.

This can take an hour or all week for it to work.

Here I’m showing what you can get if you lucky. We have different medias to do different finishes, depending on what needs doing. Here we’ve polished a Lambretta casing.

First you need to hand clean any casting flashes – this is heavy manual work with die grinders and angle grinders. Then it can go into the first stage rumble restoration polishing. We use a plastic media that grinds down the surfaces – imagine an alloy casing polished down with 1-1200 grit wet and dry paper all over. That would be impossible by hand but this machine does this easy. This media matts off the surface, once done the machine needs emptying, cleaning out then different media adding. To polish were using 3mm round ceramic balls. Get the soap and water right and given time the surfaces start to polish.

You can do this quite quickly if you don’t want a high gloss shinny finish, you can do it so all the surfaces are smooth to the touch inside and out – this makes for a lovely engine to work on with a nice finish like a new die cast casing. Leave it longer and the surface polishes even more like chrome but not quite.