Flux

Question 1

A flux is used to help remove _____ or ____ from metals, it prevents further____ from forming while metal is heated to soldering temperatures and it allows molten solder to _____ over the area and _____ where it should

Answer 1

Tarnish
Oxide
Oxide
Spread
Penetrate

Question 2

Flux cannot remove paint, varnish and oil or grease; they must be removed with a _____ , _____, or ________

Answer 2

File, steel wool, or emery cloth

Question 3

Give me two examples of non corrosive fluxes and how they are made

Answer 3

Tallow: when the connective tissue of the sheep or cow is melted, a sturdy yellow or white grease is formed

Resin: a naturally occurring product arising from coniferous trees

Question 4

Give me two examples of corrosive fluxes

Answer 4

Hydrochloric acid and chloride of zinc

Question 5

What precautions must be taken when using chloride of zinc?

Answer 5

Wear a mask as chloride of zinc may cause irritation to the nose, throat, and respiratory tract
Ensure proper ventilation in work area

Question 6

Solder is the process of fastening two or more pieces of metal by means of an ___ that has a ____ melting point than the _____ being joined

Answer 6

Alloy
Lower
Metal

Question 7

List three factor that affect the selection of sold to be used

Answer 7

The service the tube is being used for

Maximum temperature of the fluid carried in the line

Stresses on the joint

Question 8

Shoulder is drawn into a joint of a copper pipe and fitting by _____ attraction

Answer 8

Capillary

Question 9

When soldering a joint with copper pipe and fittings, the attraction depends on three factors list them

Answer 9

Metal is cleaned properly and fluxed
Fairly tight fit between tube/pipe and fitting
Using fittings conforming to accepted standards

Question 10

Tin melts at

Answer 10

450 degrees f

Question 11

Lead melts at

Answer 11

621 degrees f

Question 12

62/38 soft solder means that it contains ____% tin and ____% lead?

Answer 12

62
38

Question 13

50/50 solder melts at _____ and runs free at ______

Answer 13

361 and 414 degreees f

Question 14

Eutectic is a type of soft solder that has the ______ ______ _______ of all tin/ lead solders

Answer 14

Lowest melting point

Question 15

Before soldering, both surfaces must be _____ _____ and the joint must be _____

Answer 15

Cleaned, flux, assembled

Question 17

Hard solder is also known as _____ or ______

Answer 17

Silver alloy brazing or lower temp brazing

Question 18

Hard solders can be used to join ______ metals

Answer 18

Dissimilar

Question 19

The hottest part of the torch flame is at the

Answer 19

Feathering edge

Question 20

______ ______ can be used in high purity areas where an open flame can be dangerous

Answer 20

Soldering irons

Question 21

Fumes from fluxes can be efficiently removed by using a

Answer 21

Smoke eater

Question 22

The flame is applied to the base of the fitting and the angle of the flame should be at _______angle to force the flux out of the joint in order to prevent contamination

Answer 22

45 degrees

Question 23

A rule of thumb is that the distance between the feathered edge of the flame and the outside wall of the pipe should be the ______ as the diameter of the pipe

Answer 23

Same

Question 24

Flux exists as one of three states

Answer 24

Liquid
Solid
Gas

Question 25

Capillary attraction

Answer 25

The movement of a liquid along the surface of a solid caused by the attraction of molecules of the liquid to the molecules of the solid

Question 26

Soft solder are alloys of metals with a melting point of less than

Answer 26

1000 degrees f

Question 27

Tin antimony alloys

Answer 27

95% tin 5% antimony Known as 95/5

Question 28

The metal alloys to manufacture soft solder include

Answer 28

Lead, tin, antimony, silver, copper

Question 29

Soldering equipment

Answer 29

Measuring tape Pipe cutter & reamer Pipe cleaner Flux and brush Solder Propane torch and igniter

Question 30

Hard solders are temperatures more than

Answer 30

1000 degrees f

Question 31

What is creep

Answer 31

Stress for long duration at elevated temperatures

Question 32

When does flux sizzle

Answer 32

300 degrees f