Cave Quest VBS Decorating: Cave Formations

The Group VBS decorating book explains how to make cave formations/stalagmites & stalactites using foam board and a hot knife.  We use cardboard for decorations most years.  Last year, we got donated cardboard and had some leftover.  We decided to use cardboard instead of foam board to save on our budget.  The end result is still a colorful, fun stage cave formation!  You can also print or save a PDF of the instructions formatted for printing.

In years past, we’ve used box knives to cut the cardboard.  This year my husband brought over his jigsaw.  It was so much faster and easier than cutting by hand!  We had four large cardboard sheets (approx. 4’x8′ each) all cut in less than 30 minutes.

SUPPLIES:
–Large sheets of cardboard {can be re-used from previous years}
–Spray foam – about 1 can per sheet of cardboard {it’s only a few dollars a can locally}
–Spray paint – various colors {we used purple, teal, neon green, silver, black, brown}
-Stands to mount cave formations {we used plywood stands leftover from previous years}
–Jigsaw or box knife
-Marker
–Staple gun

INSTRUCTIONS:
-Draw formation with a marker on a sheet of cardboard.  I free-handed this, but just tried to keep the top and bottom wider with narrower areas in the middle.  It doesn’t have to be perfect by any means!  We made three large cardboard cave formations.  After my husband cut out the first, I actually just used it to trace the last one.

-Cut out the cave formation.  A jigsaw is the fastest and easiest way to do this!  I talked my awesome husband into cutting them out for us.  We made three cave formations total.  One of them went in our preschool area, while two will go on stage in the main building.

-Add spray foam to cave formations.  {I moved the cardboard outside to add the spray foam and spray paint.  It dried quickly outside and the fumes didn’t bother me out there.}  I used two bottles of spray foam for three cave formations, but a third can really would have been good.  I just sprayed a few lines of spray foam down each of the stalagmites/stalactites.  There wasn’t any pattern to this… I just tried to space them out over the whole board.  Once you get to the end of a can of spray foam, you’ll just get little bits at a time.  I actually kept using it and added little “worms” all over the board.

Painted with purple and silver

Painted with teal, silver, brown & black

-Paint cave formations.  {I waited about two or three hours after spraying the foam on the cardboard to add the paint.}  The first layer of spray paint was directed just on the spray foam.  I used a bright teal on one, bright purple on one and lime green on the last.  The second layer of spray paint was silver, painted over the top of the first layer.  The bright teal and purple still show through, but I added silver to accent and add depth.  After the spray foam was completely painted with bright colors and silver, I brought out the brown and black spray paint.  I sprayed it lightly over the whole sheet of cardboard {heavier in some spots} to add depth.  I pretty much just sprayed until I thought the whole board looked somewhat normal!

Plywood posts – 2 per cave formation

-Attach formations to plywood posts.  Like I said, we had plywood posts leftover from previous years.  They’re basically a square of plywood on the ground with a 4″ish wide board standing straight up.  I used two plywood posts behind each cave formation.  If you look at the bottom of the cave formations, you can see the plywood base of the posts.  I used a staple gun to attach the cardboard to the plywood posts.

I’m pretty excited for how these turned out!  We’ll have two on stage {one on each side of the stage}, with a cardboard & brown paper cave in the center.  I also have some gems, rock formations and a “water” area on stage.  I’ll share more of these projects as we get them ready to go!  For now, the cave formations are in our storage room behind the stage.  On VBS set up day, everything will {hopefully} be ready to go behind the stage so we just have to move it a short distance.

Thanks for visiting!  If you know others using the Cave Quest curriculum, share this post with them using the links below.  Make sure to follow Borrowed Blessings at the top of the page for more Cave Quest VBS ideas!