Veneer - PDF

P10 Veneer 1 Veneering http://cdn2.hubspot.net/hub/79004/file-15650534-jpg/images/uimg_3831.jpg Wood that is 1/8” or less in thickness is generally classified as “Veneer” “The art of facing a groundwork of suitable material with a very thin layer of wood. The facing or veneer is usually of sup...

P10 Veneer 1 Veneering http://cdn2.hubspot.net/hub/79004/file-15650534-jpg/images/uimg_3831.jpg Wood that is 1/8” or less in thickness is generally classified as “Veneer” “The art of facing a groundwork of suitable material with a very thin layer of wood. The facing or veneer is usually of superior and more decorative wood that could not be used for the groundwork because of weakness or expense.” A Glossary of Wood – Thomas Corkhill 2 1 Veneered Chest on Stand Veneer used to decorate an otherwise plain cabinet 3 Marquetry Using veneer to produce pictorial designs http://www.heritageinlay.com/Trad%20Floral%201web.jpg Parquetry Using veneer to produce geometric designs http://www.tabledesigns.com/images/digital/40.jpg 4 2 Parquetry Marquetry 5 Trompe L’oeil -“fool the eye”- effect using veneers (Marquetry) 6 3 Art Deco Furniture • French decorative style of the 1920s • Simple furniture styles • “Opulent use of Exotic Wood Veneer” Dictionary of Furniture – Charles Boyce • Leading exemplar: Jacques Emile Ruhlmann 7 https://modernism.com/items/39/tea-tables/269-206-american-art-deco-marquetry-tea-table-occasional-table Original 1920 Art Deco Antique Student Reproduction 8 4 Traditional veneering tools: toothing plane, glue pot, and veneer hammer 9 http://schurchwoodwork.com/wpcontent/uploads/a522-14oz-dark-urea-glue.jpg https://myclassneeds.ca/media/project/covers/Vacuum_Press.jpg http://www.leevalley.com/en/images/item/Woodworking/Planes/05p3906s01_02.jpg http://www.woodworkingnetwork.com/sites/woodworking/files/styles/large_lands cape_desktop/public/Console-Table-6.jpg?itok=SuKZJ_gs Modern veneering tools: a toothing plane, urea resin glue, and a vacuum bag 10 5 Veneer (Very Thin Wood) Decorative Veneer (Used when Veneering) Substrate Veneer (Used to manufacture Plywood) 11 Decorative Veneer • Appearance is important • Appearance factors – Species – Figure • Sources of veneer with interesting figure – Butt (stump) – Crotch – Burl 12 6 http://www.woodworkingtalk.com/attachments/f26/5996d1229277805-cutting-storing-walnut-tree-crotch3.jpg Crotch 13 Burl 14 7 ELM Burl Veneer https://www.certainlywood.com/images-new.php?item=CARP%20ELM%201601-1 Certainly Wood - East Aurora, NY 15 https://www.certainlywood.com/images-new.php?item=CARP%20ELM%201601-1 Note how fragile this Elm Burl Veneer is 16 8 Walnut Burl Veneer Certainly Wood - East Aurora, NY https://www.certainlywood.com/images-new.php?item=WAL%20BURL%201601-05A 17 Walnut Crotch Veneer Certainly Wood - East Aurora, NY https://www.certainlywood.com/images-new.php?item=CR%20WAL%201601-2 18 9 Walnut Stump (Butt)Veneer Certainly Wood - East Aurora, NY https://www.certainlywood.com/images-menu.php?item=ST%20WAL%201301-1 19 Bird’s Eye Maple Veneer Certainly Wood - East Aurora, NY https://www.certainlywood.com/images-locator.php?item=BE%20MAPLE%201503-10 20 10 Sapele Pommele Veneer Certainly Wood - East Aurora, NY https://www.certainlywood.com/images-locator.php?item=P%20SAPELE%201501-2 21 Anigre Fiddleback Veneer Certainly Wood - East Aurora, NY https://www.certainlywood.com/images-locator.php?item=FB%20TANIGRE%201501 22 11 Ebony Veneer Certainly Wood - East Aurora, NY https://www.certainlywood.com/images-locator.php?item=QT%20EBONY%201424 23 24 12 25 Hardwood Veneer Products • Decorative Veneer http://www.edgebandingservices.com/uploads/images/Sheet%20Veneer%20lg.jpg http://ww1.prweb.com/prfiles/2013/07/09/10 912664/Wood%20Veneer-1a.jpg – Appearance is important – Available as: • Sheets – With backing – Without backing (raw) – Individual leaves or multiple leaves joined together – Intended to be applied to a substrate • Manufactured Panels http://www.winwood-products.com/images/walnut-veneeredplywood-lge.jpg – Outer layer of Hardwood Veneer bonded to a panel at the factory 26 13 Substrate Veneer • Usually softwood • Used for – Inner plies of veneer core panel products – Outer and inner plies of construction grade veneer core plywood • Strength is important • Appearance is unimportant http://www.goodfellowinc.com/wp-content/uploads/2013/07/commodite1.jpg Substrate Veneer will covered in detail during the future lecture on Plywood 27 Hardwood Veneer Thickness No longer standard thicknesses Different mills produce veneers of different thicknesses Trend toward thinner veneers http://www.veneersystems.com/images/products/thumb_cordix1.jpg CertainlyWood.com 28 14 Veneer Terminology Flitch (2 common definitions) – A section of a log that is about to be cut into veneer – A stack of veneer sheets sliced from the log and kept in sequential order Book/Bundle – Typically 24 or 32 sequential veneers Leaf – A single sheet of veneer 29 Veneer Production Steps 1. 2. 3. 4. 5. 6. 7. Log selection Debarking Lengthwise cutting of log Conditioning/soaking/steaming Cutting the veneer Drying Clipping 30 15 Veneer Production 1. Log Selection – inspected for straightness and degree of defects http://www.hobbithouseinc.com/personal/woodpics/images/veneercore.jpg – Best logs are separated and sent to the veneer mill 31 Veneer Production 2. Debarking – Bark ground off log http://www.service1.org/download/img/l/o/log%20debarker%20log%20peeler%20plywood%20machine%20veneer%20peeling%20l athe%201277492848.jpg 3. Cutting log lengthwise – Options 1. Left whole 2. Halved 3. Quartered 32 16 Veneer Production 4. Conditioning – Soaking, boiling – All slicing methods require conditioning of the log* – Log is soaked in hot water (80°C – 100°C – 12 – 72 hrs depending on species – Softens the wood fibres http://www.danzer.com/uploads/pics/pic_veneer-production03_02.jpg – Boiling ensures 1. Minimal checking when veneers is sliced 2. Knives stay sharp longer 3. Less wear and tear on machines * Some logs are not soaked. See Sawn Method. http://www.shadbolt.co.uk/userfiles/images/finishes%20and%20substrates/veneer%20cutting/Veneer-log-after-steaming.jpg 33 Veneer Production 5. Cutting the Veneer Log to Veneer Slicing 1. 2. 3. Vertical slicing Rotary slicing Stay log or half round slicing Log to Veneer Sawing 1. Sawn Method Board to Veneer 1. Lengthwise Slicing 34 17 Vertical Slicing Machine Flitch Pressure Bar Veneer Stacked in Consecutive Order Dog Flitch Table Knife Frame Knife Carriage 35 Vertical Slicing Machine • Flitch table – moves up and down – Flitch attached with dogs or vacuum • Knife carriage – secures both knife and pressure bar – Advances with each slice – Amount of advance based on thickness of veneer required • Veneer is sliced as the Flitch Table moves downward • Knife Carriage moves forward before each Flitch Table stroke • Veneer is kept in sequential order • Pressure bar – Prevents splitting ahead of knife 36 18 Grain Orientation Plain Slice Quarter Slice Rift Slice 37 Rotary Slicing Peeler or Bolt Pressure Bar Knife Direction of Rotation Chuck Knife Carriage 38 19 Rotary Slicing • Uses a massive lathe • Logs used for rotary slicing are called peelers or bolts • Peelers rotated downward against pressure bar and knife • Pressure bar and knife mounted at centreline of peeler • Pressure bar pressed against peeler ahead of knife to prevent splitting • Can produce 200-400 ft of veneer per minute • Grain pattern is very distinctive – continuous tangential cut – cannot masquerade as thicker sawn lumber • Guillotine cuts sheets to length 39 Rotary Sliced Veneer Figure http://cdn6.bigcommerce.com/s-4aaphn/products/72/images/1136/ash-veneer-white-rotary-1-pieceface__70994.1468936700.600.600.jpg?c=2 40 20 Stay Log or Half Round Slicing Flitch Pressure Bar Veneer Stacked in Consecutive Order Stay Log Direction of Rotation Knife Centre of Rotation Knife Carriage 41 Stay Log or Half Round Slicing • Set of heavy steel castings (stay log) mounted to a conventional lathe • Flitch secured to staylog • Produces an eccentric rotation of flitch • Flitch oriented to present radial/tangential or other faces to the knife • Often used to produce veneer from figured faces (crotch, burl, butt) • Arc produces addition veneer length • Veneer is kept in sequential order 42 21 Sawn Method • Oldest method of veneer production • Produces lots of waste and takes time à expensive • Still used for – Extremely hard woods where boiling won’t soften the fibers enough for slicing – Brittle woods that would be damaged by slicing – Species where the colour of wood will be affected by soaking • Band Saw or Circular Saw used • Flitch of green wood secured to movable saw carriage • Carriage moves flitch past the blade • Veneer is kept in sequential order 43 Lengthwise Slicing • Creating veneer from boards rather than logs • Boards are first steamed for 6 – 48 hours • Stationary blade slices moving board lengthwise 44 22 Knife Checks • As the knife separates veneer from the flitch, the separated wood is severely bent • Veneer will crack if the bending stresses exceed the strength of the wood • These cracks are called knife checks Tight Side Knife Side Loose Side • Knife checks occur on the knife side of the veneer 45 Knife Checks • Knife checks close up when the veneer lays flat – Not obvious to the eye • Common consequences of knife checks – Parallel-to-grain cracks through the finish on the veneered surface à May not appear for months or years • When possible, the loose side should be the one spread with glue – Not possible with some veneer matching patterns such as Book Matched 46 23 Understanding Wood – page 227 47 Veneer Drying • 2 Common Methods http://www.raute.com/image/image_gallery?uuid=e4d174d9-24a6-40f1b7e2-6903befbfa30&groupId=10157&t=1309347365087 – Progressive Conveyer Method – Progressive Platen Method • Feed Rate is determined by – – – – Species Thickness Starting moisture content Desired moisture content 48 24 Veneer Clipping • Books of veneer are cut straight along ends and edges • Sometimes used to remove sapwood • Some species and many burls are not clipped http://images.hgmsites.net/hug/bentley-works-crewe--stacks-of-veneer-for-woodwork_100312850_h.jpg 49 Veneer Matching Patterns • Because veneer is so thin, the front and back of each leaf of veneer is virtually identical “BACK” • Mirror image “FRONT” • Either side of leaf can be used (but be aware of knife checks) • Sequential leaves can be arranged to create various veneer matching patterns Quarter Matched “FRONT” “BACK” https://www.certainlywood.com/images-new.php?item=CARP%20ELM%201601-1 50 25 Important The name associated with a matching pattern usually refers to the pattern/design created by the grain of the wood; not the shape of the veneer seams 51 Veneer Matching Patterns Note: Matching terminology from the presentation rather than from the videos will be used on the tests 52 26 1 2 3 4 6 5 7 8 Radial Matched 53 Book Matched Veneer 54 27 Book Matched Veneer 55 Radial Matched Veneer https://ethnicchic.com/products/boca-do-lobo-colombos-pedestal-table 56 28 Box Match (variation) http://andifurniture.com/wp-content/uploads/2015/09/veneered-wood-furniture-d4lqxqfcv.jpg Reverse Diamond Match https://s-media-cache-ak0.pinimg.com/564x/d9/cf/3f/d9cf3f63c76d44d3eee45cb7c296b1e0.jpg 57 Advantages of Veneer on Substrate vs Solid Wood • Allows use of woods that would be unobtainable/impractical as solid lumber – Crotch, butt, burl • Reduces cost of wood • Conserves wood species • Permits precise matching of grain – Diamond match, book match… • Large surface areas are already prepared – (use of pre-veneered panels vs. glue up of individual boards) • Dimensionally stable (driven by substrate material) 58 29 Disadvantages of Veneer on Substrate vs Solid Wood • Loss of status – perception by some that veneer on substrate is of lesser quality than solid wood • Risk of sand through • Edge of substrate must be concealed • Limited options in the use of traditional joinery 59 60 30 Veneer Videos https://www.youtube.com/watch?v=AmPkAuQc4-E https://www.youtube.com/watch?v=gWojGpjhs40 https://www.youtube.com/watch?v=qA9XmJfh_RE https://youtu.be/JMpk4LX2Y5Y 61 Questions? 62 31