Hot spots in lacquer

      How do you handle them? January 21, 2002

What's the best way to handle hot spots? Should I wait for the spots to dry completely before shooting over them? I'm using N.C. lacquers. I have found that shooting ML Campell WW vinyl sealer over the piece solves the problem--is this recommended? The thing I don't like about this vinyl sealer is that it is hard to sand and I always get a milky finish. My finish process is to seal with Nitro sanding sealer, then coat with water white gloss (which is when the hot spots usually crop up), then top coat.

Forum Responses
I use a clean cotton rag, wet with water and wring out completely till damp. I lightly wipe over the shiny area, being careful not to damage the surface. Usually this will dry the spot.

From the original questioner:
How does water dry lacquer? A while back, someone told me that they hit the spots with ice water. I guess I'll give it a try.

I thought the WW vinyl Campbells sealer was one of the easiest to sand, as compared to other vinyl sealers.

From the original questioner:
That's what they claim, but I don't find it easy to sand and I don't see how they can call it water white. The only time I use it now is to cover the hot spots. I had three pieces this weekend covered with wet spots that stayed wet overnight. The next morning I shot them with the Campbells vinyl sealer, which eliminated the hot spots, then I sanded with 320 just to knock out the nibs and topcoated and they look great aside from a slight milkyness in two of the darker pieces, but they'll pass.

WWVS is not the best choice for darker colors. It is a good choice for pickle or light colored stains. If sprayed over dark colors, you will see a milky haze. This is due to the coconut resins added for a less amber finish. I have only found it hard to sand if it wasn't completely dry.

I don't understand your process, though. You said you used a nitro sealer, then a water white gloss (this is where problem occurs), then a topcoat. I think if you eliminated the nitro sealer and used 2 coats WWVS, then the WW gloss (Klearplast) you would get better results. WWVS has less nitro in it to begin with--that is some of the reason it needs to dry completely to sand better. Always spray 4 to 5 wet mils. If too heavy on the wet mil, the evaporation time is longer for the solvents to escape. Keep using 320 grit paper between coats to scuff sand. This will allow each coat to melt into the other.

Lisa Gilbert, forum technical advisor

One way to cure hot spots is to use VM&P Naptha on a rag. This will cook the wet finish and "set it".

Bob Niemeyer, forum technical advisor

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: Finishing

  • KnowledgeBase: Finishing: General Wood Finishing

  • KnowledgeBase: Knowledge Base

    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