Wood Finishing Applications

Question 1

Oil stains are subdivided into two types:

Answer 1

PENETRATING OIL & PIGMENT OIL

both types are meant to be applied manually by brushing or wiping. penetrating oil derives its colour from soluble aniline dyes, while pigment oil stain derives its colour from a non-soluble pigments, which are finely ground minerals or earths

Question 2

Natural Varnish

Answer 2

is a transparent, hard, protective finish, choose varnish as a topcoat when a durable finish is required and there is ample time to finish the piece

Question 3

Varnish

Answer 3

They are the most durable topcoats

Question 4

Polyester

Answer 4

polyester finishes on woodworking are exceptionally hard and durable clear finish, they tend to be very high gloss and look wet indefinitely.

they have a short pot life of between 15 and 20 minutes

Question 5

4 types of Spray systems

Answer 5

Conventional air spray (small pot that screws on)

Airless

high- volume low pressure (HVLP)

air assisted airless

Question 7

Oil stains are subdivided into two types

Answer 7

PENETRATING OIL AND PIGMENT OIL both types are meant to be applied manually by brushing or wiping. penetrating oil derives its colour for soluble aniline dyes while pigment oil stain derives its colour from non soluble pigments which are finely ground minerals or earths

Question 8

natural varnish

Answer 8

is a transparent, hard protective finish choose varnish as a topcoat when a durable finish is required and there is ample time to finish the piece

Question 9

Varnish

Answer 9

they are the most durable topcoats

Question 10

polyester

Answer 10

polyester finishes on woodworking are an exceptionally hard and durable clear finish they tend to be very high gloss and look wet indefinitely they have a short pot life of between 15 and 202 minutes

Question 11

4 types of spray system

Answer 11

AIR SPRAY (pot on the bottom of the gun)

AIRLESS

HIGH VOLUME LOW PRESSURE (HVLP)

AIR ASSISTED AIRLESS

Question 12

when choosing an airless spray gun

Answer 12

Airless spray guns use a piston or diaphragm pump to deliver fluid to the spray gun tip, and atomize it by forcing it through a small-tip orifice at very high pressure various types of tips are available, airless guns are used for more commonly painting than for applying clear finishes, some operators get good results spraying clear finishes it is necessary to experiment with viscosity to achieve proper atomization and flow out in general however this technology is not suited for fine finishing work because too much product is delivered and the particles are too large

Question 13

when selecting an air-assisted airless spray gun

Answer 13

typical transfer efficiencies for pressure- atomized air assisted systems are higher than conventional spraying equipment

Question 14

surface prep

Answer 14

regardless of the type of wood, all surfaces must be clean dry and free of surface contaminants prior to the commencement of surface preparation

Question 15

surface evaluation

Answer 15

identify any gouges dents scratches or stains use a strong side light to locate these defects

Question 16

what is tactile

Answer 16

touch inspection

Question 17

when detecting contaminants

Answer 17

the purpose of wetting the surface with the mineral spirit is to identify invisible contaminants on the woods surface

any glue on the surface will become visible under the mineral spirits

Question 18

solvent wipe

Answer 18

brush mineral spirits or lacquer thinner onto the wood surface and then wipe it off with a clean dry cloth remove grease silicone and some oils

Question 19

adhesive removal

Answer 19

the best technique for removing adhesive is to use a cabinet scraper or a chisel so the adhesive can be cut from the top of the wood surface

Question 20

water stains

Answer 20

water stains are economical, brilliantly coloured non fading, non bleeding deep penetrating and have an even clear tone however they raise the grain , are difficult to apply evenly and are unstable

Question 21

end grain should have a wash coat of clear stain base or stain conditioner applied before staining as this will minimize the absorption of the stain into the porous area of the end grain

Question 22

types of bleach

Answer 22

bleach is used to remove localized stain defects remove the natural pigments or lighten the entire surface of the wood, several types of wood are available

Question 23

sodium hydroxide and hydrogen peroxide

Answer 23

commercial wood bleach kits are combined of sodium hydroxide and hydrogen peroxide

Question 24

proper bleaching procedure

Answer 24

work from the bottom to the top to minimize the potential for streaks on the surface, applying bleach with fibre-bristled brush from bottom to top

Question 25

The results of bleaching

Answer 25

different woods respond to bleach in different ways, others such as walnut can be bleached almost white