Best way to adhere layers?

[Deren]

What's the best way to adhere layers (i.e. different colored painted layers)? I've searched the forums and there are some posts suggesting double sided tape (3M VHB) but that would leave a small gap which would be enough to create a different appearance. Also how long would VHB last? And would it last very long if used outside? Welding of course would cause the paint or finish on the top layer to burn. Rivets or screws of course are secure but visible. Is there a particular adhesive (JB Weld? Some other type of epoxy?) or technique people use?

[ctgolfer1]

There are different thickness VHB tapes, I have the thin one and it has worked very well outdoors but I only used it last fall.
There is a body epoxy that is used for car body panels, 2 part, very expensive and takes 12 hours to dry. Last bit I borrowed was from a body shop friend.

[abmetal]

We're layering a sign now that's powdercoated and we're using two different methods. We're using 3M Press-in-Place emblem adhesive for the large items and Loctite HY4070 epoxy for attaching letters/words. I talked to the folks at Loctite commercial division and they told me the HY4070 was for powdercoated surfaces.

Allen

[Blackslacks]

I made a layered sign some time ago and I used 1/4" connector nuts. I plasma scribed the locations for the nuts on the back of the text and plasma punched the matching locations on the backboard. Then, before finishing ,I tack welded the nuts to the script and drilled the holes in the backboard, then, after finishing, just bolted the script on. Worked good and stood the text off about 7/8". Of course the welding had to be done before final finishing.