Generally cracks are fairly easy to fix, unfortunately those in forearms such as yours are the worst.. The stress of firing is what creates the crack and will continue to do so. Fixing is easy. Pry the crack open, I use small nails ground into a wedge shape, pushed into the crack. Do not color the epoxy and use the slow set DevCon type epoxy glue. This should be done from the inside of the forearm. Cut a little groove along the crack, I use a V shaped carving tool for this. The epoxy is mixed thoroughly and poured into the groove which is kept on the bottom so the glue can run thru the crack from gravity. If the crack is not end to end the glue can be blown to the end of the crack with a jet of compressed air from a blow gun. When the glue is seen on the outside of the crack the wedges are removed and the crack is squeezed shut using rubber surgical tubing for a clamp. If you wish after the glue has set the forearm may be reenforced. Use a piece of fiberglass cloth available at WalMart or any auto parts store. Cut a recess on the inside of the forearm completely around the inside of the forearm. This should be only as deep as the cloth is thick. Clean well with acetone and cut the cloth to fit the recess. Make the re-enforcement as large as is practical. Mix the same epoxy and apply a thin coat to the bare wood of the cut it recess, this is the tack coat. Press the cloth into the tack coat and apply more epoxy to thoroughly wet the fiberglass cloth. The material won't want to stay put on the sides of the hole in the forearm but the patch MUST go as nearly as possible completely around the forearm. To hold the glue in place put a rolled up piece of waxed paper into the hole, then insert a ballon. When the ballon is inflated it will press on the waxed paper and help keep the glue in place. The waxed paper will keep the epoxy from attacking the plastic of the ballon and causing a blow out. If the cloth isn't completely filled apply more coats until it is. The excess may be sanded or cut out with small carving tools... or ground out with a moto tool type device. Properly repaired the forearm should be stronger than it was before the crack and it will remain so far a longer period of time.
