Halo Lit Letters???

I was wondering if anybody knows how to do halo lit letters? I saw a Tige on here a while back that was done this way, but couldn't find it in the search.
I was thinking about making the letters out of metal, then milling the releif in the back for the LEDs. The problem with this is you will see the mounting bolts/screws. So then I was thinking about letters make out of acrylic. Not the translucent stuff but the opaque. But I still have the problem of the bolt/screws showing.
What I'm trying to do here is, make it look like the letters are just floating so you can't see any mounting hardware. Then back light them so they glow.
Also this is not for my boat...it for another project that I'm working on. The letters will be mounted to a steel tube. So the bolts will have to go through the letters into the steel...

If you make them out of metal, you can weld some studs to the back of the letters. Then they won't have to be through bolted.

or just drill and tap a hole in the back of the letters (not all the way through) and bolt from the back side.

The letters will be on tubing, no way to get through the tubing to bolt into the letters...

Double side tape is definitely the way to go. You'll want to router plexiglass to match the outside edge of the lettering. Then trim the inside of the plex so that it is basically a ring, polish (can be done quickly with a torch) the inside and outside edges of the plex or frost it and lay LED strip lighting along the inside edge facing out.

You may have a lot of light bleed out of the back of the lettering if it's not up against a solid surface so you may want to paint the back side of the plex.

^^^^^ double sided mounting does an excellent job. You could still weld on some tabs, drill some holes to line up in the tubing and slap some JB Weld in there. I don't know what kind of an application this is going to be on but between the mounting tape and JB Weld you should be pretty set.