I've written about how outlining fonts is a bad idea. However, because of their positively ancient workflow, signmakers probably are an exception. David Blatner writes about another method here:
@Linus – since the sign maker rely on CUTTERS that follow paths, instead of a pixel based workflow, the only way is to convert thick strokes to areas. Do it by a proper transparency flattener preset. Check "Convert Strokes to Outlines". Apply your preset when exporting to PDF v1.3 (in InDesign CS5 and above print to PostScript and distill to PDF).
Of course you have to introduce transparency to all pages. Do so in setting up a rectangle above all page objects (best on master pages), fill it with "[Paper]", give it a opacity of 0 % in the effects palette and you are ready for output.
Check the results in Acrobat Pro with the touchup object tool and Adobe Illustrator (select the touchup object tool in Acrobat Pro, select all, right click and do "Edit Objects…", Illustrator will open the objects. All strokes should have a weight of 0).
Or set up a special preflight profile in Acrobat Pro that will throw an error if a path object has a stroke weight other than 0.