[koreanizm]

How and what material do you use to do this?

[AO]

go to a scarp yard or plumber and get a plasctic pvc tube with end caps. fill that with rocks. cement etc depending on your bag size. then wrap it as tight as possible with old blankets clothes etc.

[wmhunt]

Personally, I would skip the pipe and the heavy material. I would (and have) filled a heavy bag with nothing but scraps of cloth. Mine is more than 100 pounds using only cloth. A bag with a solid core running down the center tends to swing a bit too much for my liking.

[AO]

depends on the bags i guess. i fill my thai bags with cloth only but a 100-150 heavy bag i always core those.