138 THE OLIVER PLOW BOOK 



When a plow mouldboard becomes pitted it must be 

 polished to the depth of pitting before it will scour. 



If plows have this high earth polish and fail to scour 

 the trouble can nearly always be traced to soft spots in 

 the mouldboard, or to the soil itself. Assuming that the 

 mouldboard does not contain soft spots and the soil does 

 not contain enough silicon to scratch the mouldboard, 

 the trouble may be caused by the plow not running in a 

 true line of draft, or the soil is too loose for the proper 

 amount of pressure to cause the mouldboard to shed 

 properly, or it may be a combination of all these causes. 



Side draft causes the mouldboard to work out of its 

 normal position, thus making unequal pressure of the 

 earth on the mouldboard. 



The remedy for this trouble is to adjust the hitch so 

 that the plow bottom works in its normal manner. 

 Whenever a plow fails to scour it is always advisable 

 first to be sure that the plow is running correctly. If 

 this does not remedy the trouble lowering the plow an 

 inch or two will put more pressure against the mould- 

 board, thus forcing off the earth which may be clinging 

 to the bottom. It may be necessary to operate at this 

 extra depth long enough to put on a new polish. Often 

 times lowering the bottoms and travelling a distance of 

 fifteen to twenty feet will suffice. 



Occasionally soils which scour readily have spots in 

 them that cause the plow to stick. These spots are 

 nearly always the result of a change in the soil texture. 

 That is, the spots where the plow sticks are caused by 

 the soil being looser. If the driver will watch these 

 places very carefully he can frequently cause the 

 plow to scour readily by increasing the speed when passing 



