Two Types

o make it easier to understand the many different finishes available, I've found it helpful to classify finishes into two types according to the way they cure.

Type 1 finishes are evaporative, or solvent-release finishes. Shellac and nitrocellulose lacquer are in this category. Type 1 finishes cure as their solvent evaporates into the atmosphere, leaving the solid components of the finish behind as a film. Reapplying the original solvent to the cured finish will dissolve it.

Type 2 finishes are reactiw. or conversion finishes because they cure by reacting with the oxygen they absorb from the atmosphere. This is often referred to as polymerization. Varnish, polvurethane, and drying oils, such as linseed and tung oil are examples of Type 2 finishes. Type 2 finishes may also contain a solvent, such as mineral spirits, but the solvent is used as a thinning agent and is not a direct part of the curing process. Reapplying the original sol-

ii htfpfbf fir divlde^finiahes into two types-type X and Type 2 according to.the way they ctire. Type I finishes arc evaporative ^'finishes. They cine when-thc solvent evaporates. Type 2 finishes are rcactivc finishes'. They ctiretn- reacting with the oxygen

^ alien« .Type I and Type 2 finishes in the Wdebar heluw.

Sfcelhrc and vnrrHsh^.liSajdNfe-^ifcVl finf«fMrtpF»r/^

materials—are good examples to Illustrate the basic differences between these two finish types. Shellac is an evaporative, or Type 1 finish. Varnish is a reactive, or Type 2 finish.

aIUL.past several dyades, _ -W. ^and it willjmore"thjVn lfkelv ~~ con finuejo^Tiange in tfie

[changing naturejnajkes varnish .. _.

to JeFine precisely." ~ enturies. was a combination of res-.jTCTDjjs, aners and solvents. (Add colored pigments you .have enamel paint.)JEEe resins—solidified ^gums trom plants and trees— jmpaTted body, hard-nessrj?toss. and water resistanceitLthe finish."The oils, usually linseed or tung, imparted toughness and flexi-— bilitv. The driers—salts of lead, cobaltor manganese —accelerated the drying rate. And the solvents-turpentine or mineral spirits—reduced the viscosity.

The quality of varnish was determined by ho\v_ these ingredients were combined. For example, the" ¿. less oil used, the harder the film. These so-called "short oil" varnishes were used on pianos and quality furniture that required rubbing with fine abrasives^o

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Woodworking Tools and Installation Tips

Woodworking Tools and Installation Tips

There are a lot of things that either needs to be repaired, or put together when youre a homeowner. If youre a new homeowner, and have just gotten out of apartment style living, you might want to take this list with you to the hardware store. From remolding jobs to putting together furniture you can use these 5 power tools to get your stuff together. Dont forget too that youll need a few extra tools for other jobs around the house.

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