Troubleshooting Warping and Delaminating
Using a heat tunnel during fabrication of laminate tops can cause the top to warp because of temperature-related expansion and contraction of the laminate. March 13, 2009
I am getting a fair amount of warping and cupping on my tops. I am roll coating with a PVA. My tops are flat coming off the line but warp and cup overnight. The tops are warping up on the edges, resulting in a concave top which I believe is called negative warping. When doing a peel test, I have a fair amount of fiber pull but if the top is left to sit for over a week (single roll bars) the laminate will pop loose. Can anyone give me any feedback?
(Laminate and Solid Surfacing Forum)
From contributor D:
What is your process - heat tunnel, hot press, cold press, pinch rollers? What brand of adhesive are you using?
From contributor B:
You didn't mention backer - they will warp for sure without backer, itís the same thickness as the laminate.
From the original questioner:
I am roll coating both the laminate and board separately with Forbo PA318 PVA, running them through a heat tunnel at low temps to partially flash some of the moisture out of the glue, laying the laminate then running through a pinch roller. This process is creating a very strong bond which I verify on a regular basis with peel tests and plug tests.
From contributor D:
Try laminating without the heat tunnel; the heat causes the laminate to expand. As the top cools, the laminate contracts, pulls the board, and causes the board to curl or "warp". The cupping causes a lot of stress on the bond and that's why they peel after a week. You can use heat only if the panel is balanced, as Ben stated. Thicker board (3cm) works quite well with Gatorply and similar balance sheet materials.
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: Knowledge Base
KnowledgeBase: Laminates and Solid Surfacing
KnowledgeBase: Laminates & Solid Surfacing: Fabrication Techniques
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.
335 Bedell Road
Montrose, PA 18801
Copyright © 1996-2016 - WOODWEB ® Inc.