Kev Kho Ntog: Siv cov kev kho deg rau cov raj square, xws li sandblasting thiab pleev xim, txhawm rau txhim kho lawv cov kev tiv thaiv corrosion thiab qaug zog.
Kev Tshawb Fawb thiab Kev Kho Kom Zoo: Thaum lub sij hawm siv, ua kev soj ntsuam thiab kev saib xyuas ntawm cov square tubes kom sai li sai tau thiab daws qhov teeb meem xws li tawg, tiv thaiv teeb meem los ntawm kev nce ntxiv.
