I would like to know what glue to use to glue these backdrops to foamboard?
jimbob7
I would suggest white glue, rolled out very very thin on the foam, and possibly spritz it with water to slow the drying so that you will have time get them positioned and rolled out smooth.
Alternately, you can use spray contact cement, and have only one chance to get it perfect.
I’ve had big trouble with water based glues on paper backdrops. The paper stretches, forms bubbles, and generaly ruins itself as it turns into goofy shapes.
Best results for me have been with 3M good quality spray adhesive. (NOT CHEAP SUBSTITUTES).
I spray entire back with adhesive making sure each corner has an adequate amount. Wear a mask to protect your lungs! Then I place it on the back board. I suggest wood or drywall instead of foam. It will set quickly, but there is a brief time when you can smooth it with a brush and/or wall paper roller.
Suggest experimenting with scrap pieces first to learn technique.
My limited experience is with 3M spray. It works real well, but you do have to put it down right the first time.
I also had a bad experience with paper backdrops. No matter what I tried (glue, spray adhesive, etc…) the paper seemed to wrinkle and/or form air bubbles. Then there is the issue of trying to hide all those seams (Ugh!) I would recommend you paint your backdrops a sky blue, with clouds. If you do decide to go with paper backdrops, many modelers trim away the sky portion, leaving just the background scene. This is then glued to a pre-painted blue sky. its much easier to disquise paper seams around backdrop buildings than it is the sky portion.
I used double stick foam tape and some patience. With care you can pull the tape up to reposition or reuse the backdrop. Spray adhesive eats through uncoated extruded styrofoam board (or at least the solvent that allows it to be sprayed does) so if you go that route - test first.[:D]J.R.
Wallpaper Paste.
The paint on many of the paper backgrounds is water soluble. So, do not use a water based glue, or spray the surface with water. If you must use the blue or pink foamboard as a base, I would highly suggest that you “prime” the surface, first. As suggested by others, cut away the sky blue around buildings. Which is quite easy, with a sharp exacto knife and metal straight edge. Cutting away the light blue sky on the commercial paper “Instant Horizons” of landscape with pine trees, is a bit more difficult. One can take a sample of the commercial paper sky blue to any paint store, and they can use electronic equipment to match the sky color, exactly! Be sure to order a flat paint. I start with the darker blue, at the top of the backdrop, and progressively adjust to the blue that is an exact match of the commercial paper backdrop. To hide any mismatch of color, I paint in clouds, to hide the transition. I, first, use spray adhesive to attach the straight base of the paper background. Then, (with a roller), progressively spray and attach the higher (cut out sections). Finally, Spray over the attached “Instant Horizon” with a non-reflective sealer. The “Instant Horizon” should, then, not buckle! Bob
I’ve tried lots of adhesives and you can’t go wrong with 3M spray or similar. I’ve used contact cement and that works well if you are mounting the whole backdrop including the sky but if you trim the sky off, it is almost impossible to apply the contact cement precisely to the wallboard or whatever you are mounting to. Invariably you will not get the top edge glued properly to the wallboard and it will peel over time. Stick glues are a waste of time. They won’t hold. Above all don’t use white glue unless you want to ruin your backdrop.
Spray glue and spray paint will eat into foam. Use 1/8" masonite board instead of foam. (the brown board that’s smooth on both sides. It’s more durable and easier to glue a backdrop to. It’s only $10 for a 4’x8’ sheet. (foams not very good for backdrops.)
I used Loctite Contact Cement to glue the backdrops to foamcore board. It can’t be used on bare styrofoam, though, because it contains toluene and MEK.
I used the 3M adhesive but I used the foam core boards sold at Walmart. They are strong enought to support themselves yet very light weight. You may have to add a sitffener to the back to prevent warping but mine have been up for over a year with no sign of warping yet.
Tom