Foamboard to frames?


CGF, Certified Grumble Framer
Sep 22, 2003
Atlanta, Georgia
I'm framing a map which is 38" x 50". I'm putting it in a frame that has a rabbet depth of 1 1/4 ". I'm taping two pieces of 3/16" x 3/4" wide foamboard together and taping that assembly inside of the frame to hold the plastic in place and to provide a ledge for the map assembly to sit on.
Is it all right to tape two pieces of foamboard together and then tape the assembly to the inside of the frame as a single unit? If using tape is the normal practice, what type of tape should I use or is there a better way to adhere the foamboard to the inside of the frame?
I greatly appreciate any comments.
Thanks DS
DS -
You didn't say whether you are using a mat or spacers to keep the map from touching the "plastic" (acrylic)? We would use 38x50 sheets of foamboard as a "filler" and finish the frame as normal w/ a dustcover. If you are just using the foamboard strips around the perimeter of the frame to hold the map & glazing in place, I think it would fail rather quickly. Also, the large "hollow" area in the middle of the frame would most likely warp or bow. And, if you attach a dustcover, it will puncture easier than if you "filled" the package.
Normally when we use foamboard as a "filler" we don't tape or ATG together. Due to changes in temperature, humidity, etc. anything in a frame package is subject to expansion/contraction - by taping the two pieces together, it might cause some slight buckling that could cause the map to also buckle or warp.
DS, welcome to the Grumble.

Normally these kind of questions are better answered on the Warped side....but I'll try to give it a shot here.

As to taping two piece of foamcore together.... the foam and tape police have been known to react to things like this but not to a true taliban degree. I think it was more like

If you are not sure of your ATG staying stuck over the lifespan of your shop, or into the next popes reign. At which time I'm sure he can pass a new tape between the foamcore law... :D

Sorry, I'm trying here....

If you are worried about the tape giving way, add some little dots of white glue...AKA PVA [polyvinyleacitate] along the foamcore. When it dries, it's all bonded for life.

If you miter the corners of the "slugs", they will rest in there with out tape or glue, for eternity or until the baseball shatters teh frame.
Maybe I didn't make myself clear - sorry for that. I have the acrylic laying down in the frame, I'm then taping 2 pieces of 3/16" foamcore to the inside of all four sides of the frame so that it holds the acrylic in place. Then the package which includes the map on foamboard and another piece of foamboard glued to it rests on top of the foamboard mounted on the sides. The acrylic is approximatey 3/4" off of the map assembly. With the acrylic, 3/4" foamboard mounted on all 4 sides of the frame, the (2) 3/16" foamboard glue together with the map dry mounted on the face of the top board, I don't knew any filler. Thanks again.
OK. Sounds like you are making what I might call a shadowbox presentation. All you need to hold the foamboard with map in this package should be some brads, put in parallel to the face of the foamboard/mat. Don't put your faith in any sort of tape. Many of us have found to our sorrow that it deteriorates over time. Better to use dots of white glue here and there and then brads to act as a mechanical way to hold things in place.
You can also use framer's points... you will need the points and a point driver. United Manufacturing carries both the brads and the points/drivers.

Is the map white? You can make the exposed 3/4" strips of foam board (between the acrylic and the map) look very nice by covering the board with a 3/4" strip of mat board the same color as the map. You can use ATG to attach the strip of mat board to the strip for foam board. Gives a nice finishing touch.

Welcome to the Grumble!