Is there a trick to make reproduction decals stick? or last more than a few months.
I use wax and grease remover let it completly dry.

after 1 year. I think this started lifitng after a few days.


1 week ago.


after 1 year. I think this started lifitng after a few days as well.

 

Afraid I'm not much help.

1. I use a cleaner / degreaser first. Stuff I use is called Oomph and It's made by STP but is no longer produced by STP. Simple Green also works well. And some folks I know use Dawn dish washing liquid to degrease the surface area. Do this step over-and-over-and-over until it is squeaky clean and change paper towel often to avoid smearing and recontaminating the area to be cleaned
2. scrub the area where the decal is going with a soft bristle brush like a tooth brush, maybe a tad stiffer bristle depending on where the decal is going and what surface the decal is going on
3. my last step is to wipe the area with denatured alcohol from the local hardware store
4. I have on some occasions tried to rough up the contact surface with a Dremel and wire brush attachment if the area just does not seem to be coming clean enough. I mark where the decal is going and tape around the outside edge of the pattern to avoid roughing up any areas outside of the decal pattern and try not to over do it with the Dremel to the point of removing paint and damaging the contact surface
5. Last ditch effort, I've also used a 3M super adhesive on the back of the decal, let it cure for about 5 minutes per the instructions and then position the decal. This one is last ditch because the decal has to be located exactly where you want it the first time. There is no peeling and re-applying with the 3M super adhesive. Once the decal is on the surface I use a small hard rubber roller to roll from the center of the decal toward the outside edges to remove any bubbles and small creases in the decal and wipe any excess adhesive away from the edge of the decal carefully with mineral oil. Really important to get the decal positioned straight and without big wrinkles or bubbles in the decal. Roller will only do so much and the 3M super adhesive is tacky

Not sure if any of this helps?

 

wax and grease should be perfect... HOWEVER.. in my experience with Gm making some parts in the 90's

after the wax and grease remover try an adhesion promoter..
like this..

do not remember what we used but really made tape stick on a W car windshield moulding to rubber edge that touched

 

I use a very light coating of RTV on the label..can be removed later if you want. Waterproof but not as good holding on hot parts however.