# knauf soundboard abnormal bevels



## pedtheshed (Aug 16, 2008)

the last few jobs i have been on,i have noticed that the tapered edges on the blue board has an inch wide extra deep ridge running from top to bottom.its a real pain because the internals wont machine coat flat unless you fill them with more mud(its not in my price) somebody mentioned that the majority of the board is recycled old board;wether theres any truth in that i dont know.lafarge or knauff,im not sure which board it was


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## ajpepe72 (Aug 16, 2008)

Not sure what Knauff do but I worked in the lafarge factory in the uk for 14 years. Yes old board does get added to new board, but the amount is around 5%, this is done by shredding the old board then it goes into the burners to burn the paper off. The remaining gypsum is then crushed and added to the line with the new gypsum.
As for the quality, we used to have to take a sample board off the line once an hour, and test taper depth and width, and edge angles etc, and anything out of spec should be impounded and recycled. However, if we had a major breakdown and not producing board, and trucks are waiting in the yard, then management would often send out out of spec board rather than send nothing at all.


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