Don't use anything that conducts heat faster than air (i.e. don't use anything metal). Otherwise, you are building a convection oven for your filter. Sorry, but I don't know what you should make it out of, just what you shouldn't.

1998 Silver Frost SVT Contour born on...8/28/01[/i]
American Iron Shootout Radial Tire 2 Class Champion, Cecil County Dragway April 20, 2002