Heat, Air Movement, and Drying Time

      Finishers discuss the use of heaters and fans to reduce re-coat wait times. February 21, 2011

Question
I'm slowly converting all of our finishes to waterborne products. Now that we are entering the winter and the weather is not cooperating as much, what are you doing to decrease the drying time between coats on your waterborne finishes? I've seen dryers, IR lamps, heaters, etc. for sale and wonder if they're worth spending the money on. Or, as I read in another post, should I just use a regular fan to get the air moving?

Forum Responses
(Finishing Forum)
From contributor P:
Winter should help, as the humidity is generally lower. Keep the temps up in the 60s or higher. Heat lamps work, but check with your coatings supplier for specific recommendations.



From contributor D:
With waterborne, air flow is crucial. You need some heat, but it doesn't react with heat like solvent-borne products do. Lots and lots of air flow seems to be the key with waterbornes. At least 65F, but after you've achieved that, the movement of air is what really gets the drying accomplished.


From contributor T:
We use an IR heater in our woodshop. We discontinued using forced air because of airborne dust. What's nice about IR is it drops the relative humidity and is a source heat. I use it only when I need it. It drives the water off and sets the finish enough so we can sand quicker and recoat faster. The other alternative is using a product like accelerator for waterbase finishes. It carries the water out of the finish faster than regular solvents. We have it for shops in ultra humid areas such as the deep south or areas along the coastal regions.


From the original questioner:
Thanks for your responses. I'm in Southern California, but it's not always so sunny like you may have been told. While I'm not located in the desert or on the coast (somewhat inland), we have our share of damp and drizzly days or a marine layer that increases our humidity (currently 50% inside and high 72% outside).

What are you specifically doing to increase your air flow and are you only doing it on every coat except the final coat to eliminate/reduce debris in the finish? Are you using just ordinary household box fans or something else to increase the air flow?

Contributor T, where did you find an IR heater for the purposes discussed here? Do you have any suggestions, hints or tips for a more successful outcome when using an IR heater?



From contributor P:
I'm not doing anything to move more air around. I run a dehumidifier and keep the shop warm when spraying. I get impatient with the dry times, but I've learned to live with it.


From contributor T:
I purchased the unit from the WW Grainger catalog. The brand is made by Fostoria. They sell a wide variety of heating and air units. Small to large sizes.


From contributor D:
I have a booth, so there already is a lot of airflow.


From contributor L:
We've been waterborne finishing for over 15 years. We use two industrial pedestal fans to move lots of air. Curtain off an area with plastic sheeting where you can raise the temperature to at least 65F (more makes it work faster). Normal dry to sand time is about 20-30 minutes, so just have a drying area that will accept that much product to be rotated through. Don't put on thick coats of WB finish. Three light coats will go faster than two heavy ones, and look better.


From contributor J:
As others have said, air flow is the key here. What I ended up doing for water based jobs was changing my production methods from a mass layout and spray technique to more of a stick and move approach. I built a 400 square foot drying room with minimal heat, but good airflow provided by a few small but strategically placed fans. Now I spray cabinets one at a time and doors by the rack, moving everything into the dry room immediately after spraying. I try to do a bunch of spraying before lunch and by the time I get back, everything in the room is dry enough to sand and recoat.

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: Finishing

  • KnowledgeBase: Finishing: General Wood Finishing


    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 © 1996-2016 - 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