| Contemporary Magazine Rack -- Bent Lamination for the Legs |
From "Wood Works"
episode WWK-207 |
|
|
|
advertisement
|
In this episode of DIY Wood Works, host David Marks builds a contemporary magazine rack highlighted by curved legs and brass support rods. Using bent lamination, black walnut is shaped into the form of wishbones to create the sides of this innovative piece. With contemporary styling, the brass rods provide a nice accent against the rich tones of the walnut. The dynamic curves of the legs give the piece an artistic design and provide the means for practical and visually appealing organization of an assortment of magazines. To begin the project, several drawings were made in order to arrive at just the right design. From the finalized drawing, the full-scale design was mapped out on a piece of MDF. One of the objectives in the design was to be able to hang the magazines in a manner that would display them attractively and protect them from damage. The design was based taking into account the average dimension of most magazines -- about 9 by 12 inches. Bending Form and Bent-Lamination for the Legs The most striking feature of this piece is unquestionably the curve of the legs created by bending laminated walnut leg-pieces. Once the full-scale design was finalized, a curved leg-template (figure A) was cut out of MDF. This thin, curved piece of MDF serves as the key component for creating the essential curve and structure (figure B) that will be used throughout various stages of the construction. Materials: Black walnut stock
MDF for template and bending form
Table saw
Band saw
Drum sander
Table router; flush-trim bit
Pattern-maker's rasp
120-grit sandpaper
Yellow woodworker's glue
Slow-setting plastic resin
Glue roller
Wood screws
Clamps
Straight-edge
Compass
Pencil
Safety glasses or goggles
Note: Cut sizes may vary. For exact measurements, please contact David Marks through his Web site -- information below under Resources. Safety Alert: Always wear safety goggles or safety glasses when working with wood, saws, drills, routers, etc. Steps:
- With the design finalized, the first step in the construction is to create a bending form for making the bent-lamination legs. The curved leg-template is double-stick taped down on a sheet of 3/4-inch MDF. The outline of one side of the curve is then traced onto the MDF sheet (figure C). Use a ruler to extend the line of the curve so that it's slightly longer than the template.
- Trace the opposing side of the curve using a compass to create the shape of the leg. The compass is used to add 1/8-inch to the width of the template to allow for a layer of cork that will be added later. The cork will help compensate for any minor imperfections in the bending form. Using the compass as a scribe, the point of the compass rides along the edge of the template while the pencil-point, set at a 1/8-inch spacing, provides the necessary offset for the curved line (figure D). As in the preceding step, use a ruler to extend the line so that it's slightly longer than the template.
- With the outline drawn out on the MDF, rough cut the master template for the bending form (figure E).
- With the shape cut out of the MDF, clean and smooth the edges using a pattern-maker's rasp. Then finish the job with some light sanding.
- Tip: To sand the curved surface of the form, attach some 120-grit sandpaper on a piece of 1/8-inch maple to make a flexible sanding strip that can smooth the contours of the curve (figure F).
- The bending form is made from five pieces of MDF stacked together. The pieces are joined together using both glue and screws. The reason that the form is so wide is that it will be used to glue up and bend the laminates for two legs at one time. Once the first curved form has been cut and smoothed, it can be used as a master template to trace the pattern on the remaining four pieces of MDF. Use the band saw to cut the additional pieces of MDF, then one-by-one, attach the pieces to the master template using yellow wood-glue and screws (figure G).
- Once the glue dries, smooth the edges of the pieces using the table router and a flush-trim bit that references the template (figure H).
- Continue adding one layer at a time, using the same process, until all five pieces are stacked neatly together for both halves of the bending form.
- Finish the form by lining one of the faces with 1/8-inch of cork. The pliability of the cork helps even out the clamping pressure and give a perfectly shaped curved leg and a uniform glue-line.
- Seal the edges of the form with packing tape (figure I) to ensure that the glue doesn't stick to the form.
- The curved legs are 1-1/2 inches wide, and are made by bending ten then strips of walnut. For each leg, all ten strips should come from the same stock so that the grain will match up. Start with eight-quarter walnut stock that's 3-3/4 inches wide. This will yield strips wide enough to create two legs at once. Since it takes 24 hours for the slow-setting glue to dry, this technique will save two days of drying time.
- Using the band saw, cut the walnut stock into strips 3/32-inch thick. Use a triangular chalk-mark on the edge of the uncut stock to keep the strips in order and the grain in alignment (figure J). Maintaining this alignment will give the look of the final lamination the look of solid wood.
- Once the strips are cut, run each through the drum sander (figure K) to get rid of the saw marks. With the strips sanded perfectly flat, the glue line will be uniform when the strips are bonded together.
- The glue-up of the laminate is a challenging one since there is so much spring-back pressure when the pieces are placed into the bending form. This can result in the sides of the form becoming uneven, which will prevent the curve of the legs from forming properly. To guarantee that the two sides of the form line up perfectly, clamp cauls down either side of the form to restrict them to the proper positioning when the clamps are tightened on the bending form. This will prevent both the form and the laminates from slipping under the tension.
- Use slow-setting plastic-resin glue to glue the strips into a bundle (figure L). The slow-setting glue provides the necessary working time for this part of the assembly. It will also provide a glue-line that's resistant to cold-creeping or separation. The wet glue softens the fibers of the wood, and makes the strips more pliable.
- With all of the strips stacked into a bundle, place them into the form (figure M), and apply pressure using clamps. The cauls placed along the edges of the form will help ensure proper alignment as the clamps are tightened.
- Getting even clamping pressure is the key to ensuring that the laminates take on the curved shape of the form. Once clamps have been used to draw the form together, add some additional clamps to ensure uniform pressure (figure N).
- Let the laminates remain clamped in the form for 24 hours as the glue dries.
In the segment that follows, the legs for the table are completed and drilled to accommodate the brass rods.
Sponsored Resource
> Click here to order your tools and materials for this project from Woodcraft!
RESOURCES :
Fine Woodworking
A magazine devoted to high-quality craftsmanship in woodworking.
The Taunton Press Inc.
Website: www.taunton.com
The Small Wood Shop (The Best of Fine Woodworking)
Author: Helen Albert (Editor)
Publisher: Taunton Press
ISBN: 1561580619
Woodworking Techniques: Best Methods for Building Furniture from Fine Woodworking
Author: Editors of Fine Woodworking magazine
Publisher: Taunton Press
ISBN: 1561583456
Mastering Woodworking Machines (Fine Woodworking Book)
Author: Mark Duginske
Publisher: Taunton Press
ISBN: 0942391985
David Marks Website
David Marks, DIY's Wood Works host, is a master woodworker. For more information on cut sizes and project details, please contact him via his Website at www.djmarks.com
Advanced Woodworking
Model: 0783539126
Author: Editors of Time Life Books
1998
Time-Life Books Inc.
Website: www.timelife.com
Popular Woodworking
F & W Publications, Inc.
Website: www.popularwoodworking.com
| 
)
)
)
)
)
)
)
)
)
)
)
)
)
)
)
)
)
