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How to Repaint a Window Sill with Cracks in its Paint

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Jul 10, 2013, 08:06 AM
How to Repaint a Window Sill with Cracks in its Paint

The window sill has visible cracks in the paint. However, the paint is not peeling. I have already tried light scraping and light machine sanding. What is left is shown in the photo below. I need your help for various approaches to repaint, so that the problem does not surface again soon...

I suppose covering the existing sill with a new sill could be a last option, since the window frame will be installed after the sill repairs. Do you think that would block the window from being removed in the future, though?


Jul 10, 2013, 08:18 AM
Your cracks are caused by having many layers of paint applied to the sill over the years. While you could use a filler in the cracks and then sand smooth before painting, ultimately you will just be adding another layer or two of paint to the sill, making the problem worse. In other words, if you paint on top of all those layers of paint, eventually it too will crack.

The long-term solution is to scrape almost all the paint off, fill to repair any damage, sand smooth then reprime and paint. Sometimes it is easier to just replace the sill with new material.

Jul 11, 2013, 09:33 AM
Replace it or I would use a stripper on it and get it back to bare wood.
A stripper like Peel Away II, or a citrus stripper is safer to user

This message has been edited. Last edited by: joecaption,

Jul 11, 2013, 12:03 PM
that is a mild case of what is called "alligatoring." trying to fix it will make it worse, there is too much darn paint and it can't flex any more. you do have to remove it, reprime the bare wood with a good sealing primer, and repaint.

sig: if this is a new economy, how come they still want my old-fashioned money?
Jul 11, 2013, 11:27 PM
Thank you all for your suggestion. There seems to be a consensus.... ;-)