Hello, I bought a cheap ARF airplane to mess around with. I hit the ground pretty hard with it and cracked the "nose" almost right off. What types of glue can I use to repair it? I ask because I know some glues will eat styrofoam.

Are you sure it's Styrofoam? Maybe EPP? Or Depron? Or Elapor? It makes a difference, y'know, and if it "almost" cracked the nose off it probably isn't Styrofoam because that stuff usually just goes "completely broken".
What airplane is it - model, maker, source?

http://www.estesrockets.com/products.php?number=4160

Either Foam Safe CA or Gorilla Glue is usually my choice for foam. If you use the Gorilla Glue, make sure you have the two pieces firmly held together, and go easy with the glue. A little goes a very long way, and it expands.

Brad

No one, makes "styrofoam" planes.

They are actually made with beaded polystyrene.

In turn poly can be easily repaired with plain old white ( Elmer's ) glue.



Decompressing the beads is the problem.

Anyone know how?

Deep repairs with Elmers glue take forever to dry. The glue near the surface will dry first, sealing off the glue that is further down and prevent complete drying. The safest bet for a thorough cure is to use either epoxy or Gorilla glue.
If the foam is badly compressed, glue in a wedge of scrap foam [into the void] with Gorilla glue.

Gorilla glue expands as it dries, which helps to fill in any voids. A good thing.

I don't use it on foam because of it's color when dry.

White glue can indeed take longer to dry, but when it has the repairs are all but invisible, ( as long as there is no undue compression ).

With Gorilla glue, the glue joint appears brownish.

To decompress the beads, pour boiling water over the area or, if you can, dip the area in a pot of boiling water. You may have small "warts" on the surface afterwards, but if you heat a large spoon in the same boiling water, you can use the backside of the spoon to iron the warts down. Use a pot holder or gloves to hold the spoon handle. [X(]
btw, I went to Walmart and bought a Low-Temp hot-glue gun for about $4 and it works great on nearly every foam made. Foams are great insulators though, so hold the parts together for a goodly while to let the glue cool off.

Thank you for all the replies. I just so happen to have some Gorilla glue and will use that.

P.S. I was really surprised at how well this cheap little airplane flew. I had lots of fun with it yesterday. This opened up the door for me to move on to a more realistic RC airplane.

Great idea.

A heat gun concentrates too much heat in a small area.

Water tends to be at a uniform ( and lower ) temperature.

Have you tried this?

Do the beads re-expand even if a bit?

Thanks.