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432 MOLESWORTH’S POCKET-BOOK
Workshop Recipes—continued.
Incrustation of Boilers.
Remedies that have been adopted with more, or
less success for boiler incrustation. (‘ Mechanics
Magazine.’)
1. Potatoes, Xth of weight of water, prevent
adherence of scale. .
2. 12 parts salt, 2| caustic soda, -ith extract oi
oak-bark, i of potash. __
3. Pieces of oak-wood, suspended, in boiler and
renewed monthly, prevent deposit. , .
4. 2 ounces of muriate of ammonia in boiler
twice a week, prevents incrustation and decom-
poses scale. •
5. Coating of 3 parts black-lead, 18 tallow,
applied hot to the inside of a boiler every few
weeks, prevents scale. , __
6. 13 lbs. of molasses fed occasionally into an
8-h.orse boiler prevented incrustation for six
months. J •. n I e • . . ■
7. Mahogany or oak sawdust in limited, quanti-
ties. The tannic acid attacks the iron, and. shoulij
therefore be used with caution. .
8. Slippery elm-bark has been used with soma
success. „ . I
9. Carbonate of soda. 10. Chloride of tin.
11. Spent tanners’ bark.
12. Frequent blowing off.
Paraffin oil has been used withexcellent results
in locomotive boilers.
Marine boilers are sometimes protected, from
corrosion by a thin wash of Portland cement
inside.