ADHESIVES

1
ADHESIVES
2
ADHESIVES

• TWO MAIN INGREDIENTS
• RESIN GLUE SOLID
• SOLVENT KEEPS LIQUIFIED UNTIL APPLIED

3
ADHESIVES

• How does glue work?
• Specific adhesion - results from strong molecular
  attraction between the wood and the glue and for
  this to occur, the adhesive must penetrate the
  wood cells and "wet" the fibers.
• Cohesion - the force which makes the glue stick
  to itself. This is the solid glue "line" in a
  joint. It is the strongest when the two pieces to
  be joined are machined so they mate as closely as
  possible

4
ADHESIVES

• HOW DO ADHESIVES CURE?
• SOME HARDEN (SOLVENT EVAPORATES)
• SOME CHANGE CHEMICALLY (EPOXY)
• SOME HARDEN AS THEY COOL (HOT MELT GLUE)

5
ADHESIVES

• WHAT IS MOST IMPORTANT ABOUT GLUES?
• WHEN WORKING WITH GLUES IT IS IMPORTANT TO KNOW
  ITS WORKABILITY AND ITS DURABILITY.
• YOU NEED TO KNOW HOW TO WORK WITH IT, AND YOU
  NEED TO ENSURE THAT ITS DURABILITY WILL BE STRONG
  ENOUGH FOR WHAT YOU ARE BUILDING.

6
ADHESIVES

• WORKING PROPERTIES
• SHELF OR POT LIFE (HOW LONG BEFORE IT GOES BAD)
• OPEN ASSEMBLY TIME (THE TIME YOU HAVE TO APPLY
  THE GLUE)
• CLOSED ASSEMBLY TIME (IN CLAMP) (DRYING TIME)
• CURE TIME (TIME UNTIL THE GLUE REACHES ITS FULL
  STRENGTH)
• SANDABILITY
• WORKING TEMPERATURE RANGE
• STRENGTH

7
TYPES OF ADHESIVES

• Hide Glue
• Polyvinyl Resin Glue (PVA)
• white glue longer open time, harder to sand
• Aliphatic Resin Glue (Modified PVA)
• yellow glue shorter open time, easier to sand
• Polyurethane glue Gorilla Glue
• cyanoacrylate glue (super glue)
• Contact Cement
• water based 3M Fast Bond 30
• solvent based 3M Scotch Brand

8
ADHESIVES Hide Glue

• Hide Glue (ANIMAL GLUE) is made of
  collagen from the skins, bones, tendons, and
  other tissues, similar to gelatin. It works well
  as an adhesive.
• SHELF OR POT LIFE Long shelf life, almost
  indefinite in the right conditions
• OPEN ASSEMBLY TIME short to long depending on
  how much water was added
• CLOSED ASSEMBLY TIME Long, as the glue dries
  from evaporation
• CURE TIME long, due to the slow evaporation of
  water from the glue
• SANDABILITY excellent, this glue also works
  well with finishes
• WORKING TEMPERATURE RANGE resistant to hot and
  cold
• STRENGTH strong, this glue has been used to
  make furniture and instruments for thousands of
  years.

9
ADHESIVES Wood Glue

• Wood Glue is the industry standard for
  woodworking. A ready-to-use aliphatic resin
  adhesive with outstanding strength.
• SHELF OR POT LIFE 1 to 2 years
• OPEN ASSEMBLY TIME 5 to 10 minutes (high
  initial tack)
• CLOSED ASSEMBLY TIME 30 minutes to 2 hours
• CURE TIME 24 hours
• SANDABILITY excellent
• WORKING TEMPERATURE RANGE 10C to 40C, wood glue
  is affected by extreme cold and hot temperatures
• STRENGTH Very strong, the glued joint is often
  stronger than the wood itself

10
ADHESIVES Polyvinyl Resin Glue

• PVA glue is your typical white glue that we have
  all used in school. It is similar to wood glue in
  setup time, but lacks strength.
• SHELF OR POT LIFE 1 to 5 years if it is stored
  correctly
• OPEN ASSEMBLY TIME 10 to 20 minutes (moderate
  initial tack)
• CLOSED ASSEMBLY TIME 50 minutes to 3 hours
• CURE TIME 24 hours
• SANDABILITY moderate, does not sand as well as
  wood glue
• WORKING TEMPERATURE RANGE 10C to 40C
• STRENGTH Not strong enough to be used in
  woodworking joints. It is mostly good for arts
  and craft where high strength is not needed.

11
ADHESIVES Polyurethane glue

• Polyurethane glue is moisture activated and
  expands to fill gaps. A popular brand of this
  type of glue is Gorilla Glue.
• SHELF OR POT LIFE 1 to 2, once opened it needs
  to be sealed very well
• OPEN ASSEMBLY TIME 5 to 10 minutes (high
  initial tack)
• CLOSED ASSEMBLY TIME 1 minutes to 2 hours
• CURE TIME 24 hours
• SANDABILITY moderate
• WORKING TEMPERATURE RANGE Is not affected by
  extreme cold or hot
• STRENGTH Very strong, this glue will work well
  as a wood glue

12
ADHESIVES Cyanoacrylate Glue

• cyanoacrylate glue, or as we know it super glue
  is moisture activated and offers a near instant
  bond. This glue works best with prepared smooth
  surfaces.
• SHELF OR POT LIFE 1 month to 1 year depending
  on storage
• OPEN ASSEMBLY TIME mere seconds to 10 minutes
  (very high initial tack)
• CLOSED ASSEMBLY TIME 10 minutes to 1 hour
• CURE TIME 1-4 hours
• SANDABILITY moderate
• WORKING TEMPERATURE RANGE Is not affected by
  extreme cold or hot
• STRENGTH Very strong, but this glue is too thin
  and does not fill voids. Wood is too porous a
  product for this glue.

13
ADHESIVES

• Your brain after using water based contact cement

14
ADHESIVES

• Your brain after
• using solvent based
• contact cement

15
ADHESIVES types

• Hot Melt Glue

16
ADHESIVES types hot melt
17
ADHESIVES
clamping

• THREE REASONS TO USE CLAMPS
• DRY FIT
• KEEP PARTS ALIGNED WHILE GLUE CURES
• MOST GLUES REQUIRE PRESSURE
• BRINGS MEMBERS INTO CONTACT
• SQUEEZE OUT AIR
• THIN OUT GLUE NO THICKER THAN A PIECE OF PAPER

18
ADHESIVES
clamping

• Clamp Layout 1 from edge and 8 to 10
  intervals

19
ADHESIVES
clamping

• HOW MUCH PRESSURE IS REQUIRED?
• Low Density Woods 100 to 150 PSI
• PINE
• Medium Density Woods 150 to 250 PSI
• ALDER
• High Density Hardwoods UP to 300 PSI
• RED OAK
• HPL 30 to 80 PSI
• Veneer 100 to 125 PSI

20
ADHESIVES
clamping

• How Much Pressure Can Be Exerted By A Clamp?
• Wood Screw Clamp 800 to 1000
• Bar Clamp Up to 2000
• C-clamp 1000
• Spring Clamp 25

21
GLUING AND WOOD MOVEMENT
22
GLUING AND WOOD MOVEMENT