hi there -
i have a magnetic tumbler (and a rotary as well) and have mixed
feelings. the heat (i think) is normal more or less. i run mine for
an hour or two sometimes and there will literaly be steam coming off
the top. remove with tongs, if you’re looking for a mirror finish,
you’re not going to get it. I use it for pieces that I can’t possibly
get to with sandpaper without harming them. (or if a matte-ish finish
is acceptable, i run it in the magnetic and then rouge, sometimes
this works very well). Sometimes there are pieces that have places
too small for the shot to get to – the magnetic tumbler is awesome
for this - especially if you just keep running it. It is horrible for
pieces with large flat surface areas (you’ll get a river effect and
actually see the marks of the cylindrical shot). But it’s also good
for getting something close and then you can go in with silicone fine
and extra fine to get it to where you want it. I really enjoy mine,
but that may be a function of the nature of a lot of my work and my
need for semi-instant gratifucation. I love being able to put an
experiment into the tumbler for a half hour and get a reasonable idea
of what the finished product will look like. Patience is a virtue but
one I’m still working very hard at!
You may also want to adjust the settings – speed, number of changes
in direction, etc, if your heat is too great. I’m by no means an
expert, but that’s what I’ve learned with my own.
Best of luck!