A couple of years ago, I built a backdrop for my layout.
I mounted a 24" x 48" piece of Masonite board (1/4" thick) and painted it with interior latex paint.
I then applied a Walthers Instant Horizons Background Scenes backdrop onto the painted Masonite board using 3M Super 77 Spray Adhesive, as recommended in the Walthers instruction sheet. I followed the 3M instructions for applying the spray adhesive. For the first year or so, everything was fine. But, over the past few months, I have noticed that a series of elliptical shaped bubbles (approximately 2 inches long and 1/4 inch wide) have developed under the Walthers paper backdrop.
Has anyone else experienced this problem?
Is there an effective way to fix the problem?
Is there a better way to apply these paper backdrops to avoid future problems.
The paper used for those Walthers backdrops seems to be so thin that it literally dissolves from the moisture in the adhesive, no matter what type you use.
We made the mistake of using those at our club layout, applied with the 3M spray adhesive recommended by Walthers, and are experiencing problems with the backdrops developing bubbles and peeling off.
I suspect those bubbles formed where there was little or no adhesive, and the paper swelled a bit - perhaps due to humidity or temp.
I have not done this, but it seems that a white glue mix painted on would assure full coverage of the adhesive and last longer. Of course the white glue would only work on porous materials like wood/paper and probably masonite.
The spray adhesives I have used (for non MR projects) just never seemed to give equal coverage.
I’m really sorry to hear that the paper may be thinner.
I had some Walther’s backdrop scenes that I applied with the 3M-77 spray adhesive 20 years ago. They are still on the wall and OK, even though the layout has been gone from the attic for 5 years. I can’t get them off.
I also have one of those Walther’s scenes I put on a wall for another layout about two years ago and have had no problems with it.
I DID NOT follow the directions when applying any of the backdrops. Here is what I did: I cut the sky off as best as I could. (The room sky color is the same color as the backdrop sky color.) Then I pined the backdrop to a large piece of cardboard face down. I took it outside and sprayed the back really heavy. I mean REALLY heavy. Not just a good coating but maybe enough for two good coats all at once. Then I took it back inside and put it up right away. I did not spray the wall. I attached it at one side on a line I drew on the wall before hand, and then pressed it in place like you would if you were putting that plastic gray tint window film on a window. I used a wadded up paper towel for a squeegee pressing the backdrop on the wall going from one side to the other, working up and down as I went.
The advantage to doing it my way? You have some chance of repositioning the scene slightly as you are working from one end to the other so it goes on straight. This is because the adhesive is still slightly wet. You CAN NOT reposition the whole thing once you start, so you must get the first edge straight at the very beginning, and there is enough working time to do that.
As for trying to fix the bubbles, you may be able to put a tiny hole in the paper with a pin to let the air out and press it back in place. (Just like you would do for a decal bubble.) <
Elmer. I thought about doing that. The one question that I have is how to get fresh adhesive inside the burst bubble since the original adhesive is dry.
Take a sharp xacto blade, make a vertical slit, brush in some adhesive, and flaten the two edges down. With care, it will be invisible from a couple feet. I’ve done this on wallpaper repairs and window tint, and had success with the process.
A lot of ink refill kits have plastic containers with a hypodermic needle tip .It is a small diameter but larger than typical medical devices. I think one of them would work well. I use one of those to squirt graphite into wheel bearings on Central Valley metal trucks to improve rolling quality.