Proper surface preparation is essential for the success of any protective coating scheme. The importance of removing oil, grease, old coatings and surface contaminants (such as mill scale and rust on steel, laitance on concrete and zinc salts on galvanised surfaces) cannot be over emphasised.
The performance of any paint coating is directly dependent upon the correct and thorough preparation of the surface prior to coating. The most expensive and technologically advanced coating system will fail if the surface preparation is incorrect or incomplete.
Loosely adhering mill scale, rust and old paint coatings may be removed from steel by hand wire brushing, sanding, scraping and chipping. However, these methods are incomplete, and always leave a layer of tightly adhering rust on the steel surface.
Basic Surface Preparation hand Tools
• putty knife
• dust brush
• shave hook
• chisel knife
• nail punch
The task of scraping has been the bane of most engineering apprentices, however its versatility and appropriateness far outweighs the hard work it requires, or is perceived to require. Its effective use requires skill and concentration. An often overlooked advantage of scraping is the ability to take the tool to the work piece. When the work piece weighs several tons and towers over the worker, the apprentice's solution of chucking it on the mill is impractical, if not impossible. A skilled craftsman can wield a scraper and produce work that is the envy of his peers. This takes more time than the usual methods.
Sometimes referred to as a spackle knife, the putty knife is a scraping tool that is constructed in a manner that is similar to the kitchen spatula. Distinguished by a flat blade that is equipped with a sturdy handle, the putty knife can be used in a number of different construction and home repair projects. Putty knives are available in two distinct types, with each type being geared toward specific applications.
The stiff blade style of putty knife is constructed with a solid metal blade that is somewhat thick and does not bend easily. This type of putty knife is ideal for use in any job where there is a need for a rigid tool. One example of a task that the stiff blade putty knife is uniquely suited for is scraping. The scraper action can help to remove paint or wall paper, or as a means of ridding just about any smooth surface from a foreign element.
It is used for cleaning and preparing lead cable sheath and sleeves for soldering and wiping joints.
and Consists of a flat hardened steel blade riveted to a shank fitted with a plastic handle. The Blade has a sharp, beveled cutting edge which is circular in shape at one end and is brought to straight sided point at opposite end. Shave Hooks feature hardened and tempered steel blades, riveted to shanks which run through the full length of the specially shaped handle.
It is a tool for checking the adhesion of the paintings on their substrate.
A knife with a square edge, usually 1 ½ in. (3.8 cm) or less in width, used to scrape off paint or wallpaper in areas where a wider-edged stripping knife would not be suitable. Traditional tradesmans quality tool with one piece through tang tempered stainless steel blade for strength and durability, complete with hardwearing rosewood scales handle.