I repair such damaged tires by placing a patch from inside the tire on the place of the hole, you can use the same patch as for the tube, just be sure to use plenty of glue, stick patch on and keep pressure on for at least 10 min. Then I usually mount the tire on the rim, put in a tube, and then pump it up to almost max pressure. Then I leave it like that for 24 hr before going on to the second part of the repair - that makes sure that the patch is properly vulcanized to the tire, pressure of the tube upon the patch makes sure it bonds good.

Other part is taking a piece of old tube, grinding it up into rubber dust with a rough file or something similar - then mix that rubber dust with rubber glue, and fill in the hole in the tire with that from the outside. Leave to set and dry out, then repeat two to four times until you have built up slightly over the surface of the tire, then leave to set for another 24 hr on normal room temp (approx 20 deg. C). All while you work on outer part of the tire, filling the hole, keep the tire inflated and on the rim - that ensures that the hole will also be stretched out and that rubber/glue mix will fill it all up nicely. Once 24 hr curing time has passed, you may dismount the tire to store it away or just keep it on the rim. I have repaired a couple of tires this way and never had a problem with them again, at least in the repaired spot. Other areas got some more punctures Off course, do this ONLY if there is no large casing/bead/wire damage in the thread. Structure is what keeps the tire together, and if enough of the casing is damaged, the tire still might fail even if repaired properly, so be careful when deciding what can be repaired and what can't. If it's unsafe, better to throw it away and buy a new one. Remember it is preferable to crashing because the tire was far too gone to repair and it exploded while in use. I had that happen (with a completely new and undamaged tire btw), and it was no fun.