wide belt sander contact drum minimum ruber thickness??

[eugene thomas]

I bought wide belt sander that needs little tuning. inprocess of changing conveyor , not really too bad so fare but need to dress thecontact roller to get everything wright.. has gouge and noticed platen is worein same spot so need to do the sandpaper trick but wondering how thin can takethe rubber before to thin... has around 7/16" thickness now but not surewhat would be the minimum before need to remove and get recoated..

thanks Eugene