Curved Work - with Form Outside the Bag

      Creating vacuum-pressed curved parts with the clamping form outside the vacuum bag. March 10, 2002

By Ed Ferri

Ed Ferri is the founder of Quality VAKuum Products, Inc. and has more than fifteen years experience working with vacuum applications. QVP specializes in vacuum pressing and clamping equipment for the woodworking and plastics industries. For more information visit the QVP website at www.qualityvak.com or call 800-547-5484.

Outside bag forming is a proven technique to save time and money in the production forming of anything from simple curves to complex spiral staircases. There are several advantages:

- The form does not have to be as strong.
- The form can be used with several bags without waiting for the glue to dry.
- Less flat spots.

Here are the steps to make a curved arch or jamb.

1. Glue the laminates.

2. Stack the laminates and tape together using fiberglass reinforced tape. Apply the tape so that the sticky side is away from the work. You want the laminates to slide when being bent over the form. The tape also holds the mesh in place.

3. Wrap the laminates in plastic window screen material. The mesh is required to allow air to get out of the bag. Without the mesh, the bag would seal around the vacuum connector and prevent the bag from being fully evacuated. The fine mesh also helps protect the bag from sharp corners. Tape the sharp edges of the ends or cover with cardboard.

4. Slide the assembly into the bag, making sure the vacuum connector hits against the mesh.

5. Bend the bag over the form and apply clamps to hold the shape. The bag does not do any bending - you do. The bag does all the squeezing.

6. Evacuate the bag. It is now squeezing with 1800 lbs/sq.ft. of even and uniform pressure.

7. If you have multiple bags and a manifold, remove the bag from the form and hold the shape with a bar clamp across the bottom if the laminates are so stiff that they spring out.

8. Repeat the process for multiple bags.

Tips
A. Use a piece of fiberglass reinforced tape to hold two pieces together for a spliced joint.

B. For a small or tight radius, push the bag into a female form. The top of the bag is smooth and without wrinkles. On smaller arches, the wrinkles can make a dimensional difference.

C. Use VAK Bond 2000 urea glue for a rigid bond and no or minimal spring back.

Ed Ferri is the founder of Quality VAKuum Products, Inc. and has more than fifteen years experience working with vacuum applications. QVP specializes in vacuum pressing and clamping equipment for the woodworking and plastics industries. For more information visit the QVP website at www.qualityvak.com or call 800-547-5484.



Would you like to add information to this article?
Interested in writing or submitting an article?
Have a question about this article?


Have you reviewed the related Knowledge Base areas below?
  • KnowledgeBase: Adhesives, Gluing and Laminating

  • KnowledgeBase: Adhesives, Gluing and Laminating: Gluing and Clamping Equipment

  • KnowledgeBase: Furniture

  • KnowledgeBase: Furniture: Furniture Manufacturing

  • KnowledgeBase: Furniture: General

  • KnowledgeBase: Woodworking Miscellaneous: Accessories

  • KnowledgeBase: Woodworking Miscellaneous: Bending Wood

  • KnowledgeBase: Woodworking Miscellaneous: Woodworking

  • KnowledgeBase: Knowledge Base

  • KnowledgeBase: Architectural Millwork: Stairs


    Would you like to add information to this article? ... Click Here

    If you have a question regarding a Knowledge Base article, your best chance at uncovering an answer is to search the entire Knowledge Base for related articles or to post your question at the appropriate WOODWEB Forum. Before posting your message, be sure to
    review our Forum Guidelines.

    Questions entered in the Knowledge Base Article comment form will not generate responses! A list of WOODWEB Forums can be found at WOODWEB's Site Map.

    When you post your question at the Forum, be sure to include references to the Knowledge Base article that inspired your question. The more information you provide with your question, the better your chances are of receiving responses.

    Return to beginning of article.



    Refer a Friend || Read This Important Information || Site Map || Privacy Policy || Site User Agreement

    Letters, questions or comments? E-Mail us and let us know what you think. Be sure to review our Frequently Asked Questions page.

    Contact us to discuss advertising or to report problems with this site.

    To report a problem, send an e-mail to our Webmaster

    Copyright © 1996-2017 - WOODWEB ® Inc.
    All rights reserved. No part of this publication may be reproduced in any manner without permission of the Editor.
    Review WOODWEB's Copyright Policy.

    The editors, writers, and staff at WOODWEB try to promote safe practices. What is safe for one woodworker under certain conditions may not be safe for others in different circumstances. Readers should undertake the use of materials and methods discussed at WOODWEB after considerate evaluation, and at their own risk.

    WOODWEB, Inc.
    335 Bedell Road
    Montrose, PA 18801

    Contact WOODWEB











  • WOODWEB - the leading resource for professional woodworkers


      Home » Knowledge Base » Knowledge Base Article