Cement for the Farm. 



415 



water comes, else the pressure of water will force the moisture through 

 or force off the waterproofing. 



If the concrete is in place and it is later found to need water- 

 proofing, dig out any soft spots w^hich may be found on the surface 

 of the concrete. Koughen the surface, brush well with a wire brush, 

 and apply a Avash composed of a solution of one (1) part hydrochloric 

 acid to four (4) parts of water. Wash this off thoroughly with clean 

 water soon after the solution is applied in order to prevent the acid 

 eating too deeply into the concrete. Then put on a fresh coating of 

 a 1 to 1 mortar not less than one (1) inch thick. 



In some instances mixing 1 part thoroughly slacked lime to 10 

 parts of cement, in a dry state, using this as cement in a concrete, 

 will make a watertight mixture. The mixture of lime and cement 

 may be used successfully as a wash. 



Special preparation and special felts and papers for water- 

 proofing purposes are advertised on the markets. The companies 

 handling these goods will be glad to give advice concerning them. 



Forms — The moulds or forms should be of a substantial character, 

 the material and framework being sufficiently strong to be unyielding 

 during the process of filling and tamping. The forms may be held 

 together by braces, rods, wires or special devices, so that they may 

 be easily removed. Use a dressed face on the lumber next to the 

 concrete for a finished surface and prevent the concrete from sticking 

 to the forms with paper or by smearing the face of the timbers with 

 oil or soft soap. See Figs. Nos. -3-4-5-6-7. 



?'l,ji>':. ..-^ 



i 



Figure 3. Shallow trough from inverted form. 



