Putty is a material with high plasticity, similar in texture to clay or dough, typically used in domestic construction and repair as a sealant or filler. Although some types of putty (typically those using linseed oil) slowly polymerise and become stiff, many putties can be reworked indefinitely, in contrast to other types of filler which typically set solid relatively rapidly.
Chemical composition
Putty, or
Lime mortar, is made from a mixture of calcium oxide (CaO) and water (H
2O) in proportions of 38% and 62% by weight respectively, as result, the solution forms hydrated lime (Ca(OH)
2) which takes up about a half of the weight.
The other putty mixture may be a calcium carbonate (CaCO3, 750-850 parts) based with an admixture of CaO (ash calcium, 120-180 parts), white cement (40-60 parts), and talc powders in much lower concentrations (fractions).
Applications
Use in construction
Putty has been used extensively in glazing for fixing and sealing panes of glass into wooden frames (or
sash window), although its use is decreasing with the prevalence of PVC and metal window frames which use synthetic sealants such as
silicone. Glazing putty is traditionally made by mixing a base of whiting (finely ground
chalk) with
linseed oil in various proportions. Historically,
white lead was sometimes mixed with the whiting.
[Paul N. Hasluck, Ed., The Handyman's Enquire Within, Cassel and Co., 1908; page 439.] There are a number of synthetic alternatives such as
polybutene-based putties, where the polybutene is a low
molecular mass oligomer replacing the
linseed oil.
Butyl rubber is also added to the mixture to provide some strength and flexibility.
Painter's putty is typically a linseed oil-based product used for filling holes, minor cracks, and defacements in wood only.
Putties can also be made intumescent, in which case they are used for as well as for padding of junction box in fire-resistance rated drywall assemblies. In the latter case, in the putty produce an endothermic reaction to mitigate heat transfer to the unexposed side.
In woodworking, water-based putties are more commonly used, as these emit very little odour, are more easily cleaned up and are compatible with water-based and latex sealers.
Two-part hardening putties
Polyester putty and
epoxy putty are thermosetting polymers that can be molded by hand, but become permanently rigid after curing.
Pratley Putty is an epoxy putty used primarily for steel bonding.
Milliput is another popular multipurpose epoxy putty. Bondo is a polyester-based automotive body filler, which is commonly used in collision repair.
Plumber's putty
Plumber's putty is the common name encompassing a variety of products of completely different compositions, all used for making watertight seals in
plumbing.
It is a pliable substance used to make watertight seals around faucets and drains. The putty is a basic component of a plumber's toolkit and is often used when replacing plumbing fixtures. Plumber's putty formulations vary but commonly include powdered
clay and
linseed oil. Other formulas use
limestone,
talc, or
fish oil.
Plumber's putty contains and/or so it can stain porous materials such as marble or some plastics.
RTV silicone or epoxy sealants may be used in place of putty.
Other uses
Certain types of putty also have use in the field of terminal ballistics, where the putty can accurately represent the average density of the human body. As such it can be used, for instance, to test the penetrative power of
, or the stopping power of
bulletproof vest.
Modeling clay and play putty, such as Plasticine and Silly Putty are common .
See also
