John Leeke's Historic HomeWorks™
	207 773-2306      26 Higgins St. Portland, ME  04103
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John Leeke's Historic HomeWorks(tm)

Painting Window Sash

I am painting new wood windows. I know from prior experience that latex paints will cause the windows to stick closed once left closed for a while. Is there another type of paint (oil base, epoxy, etc.) that is better for wood windows and reduces or eliminates sticking? -- David Alpert

We never paint the parts of the sash that slide against the frame especially the side edges of the sash. On the edge of the face of the sash that will be hidden behind the stop bead we sometimes prime with a tinted primer but do not add top coats. After painting is done we treat these bare and primed surfaces with a waxy water repellent such as Thompson's. This protects the wood from moisture and helps the sash slide smoothly.
The horizontal rails of the sash should be completely primed and top coated. The only way we have found to keep these from sticking is to let the paint cure fully before they are installed. This might take several days or a few weeks of drying in a well ventilated, heated area. You could add Japan drier to oil-based paints to shorten cure time, but don't exceed the recommended amount since too much could lead to premature failure and limit the long-term performance of the paint.

Plaster Repairs

I have an 1890's building with plaster walls probably from the 1920's or before. The plaster was installed for wallpaper since it has a rather rough texture. In one room, a skim coat of finish plaster had been put over the top of this original plaster (date unknown) and has developed several cracks both along cracks in the original plaster as well as surface cracks in the finish coat. The skim coat comes off the original plaster easily with a putty knife. I am in the process of removing the surface coat back to the original plaster, but would like to paint the room again. Since the original plaster is too rough to paint, I will be skim coating the plaster again. As the previous skim coat did not form a good bond with the underlying plaster, I feel the original plaster was probably coated with a wallpaper sizing when it was originally installed. Is there anything I can do aside from scrubbing the original plaster with a strong solution of TSP to get the new skim coat to adhere to the original plaster and will the skim coat stick this time? Thanks. Calvin Wels

I suspect you are right in assuming this rough and relatively soft plaster was intended for papering. The skim coat may have failed for many reasons, but the most likely is differential expansion. The underlying plaster and wood lath system moved with changes in moisture and possibly structural shifting. The stiffer skim coat cracked because it was stronger and then lost its bond at the relatively weak surface of the old plaster.
I suggest you back up a little and reconsider your plan to skim coat. The original builders knew this plaster would move and that is why they papered. What ever you do, it should allow for the continuing movement. If you really don't want to repaper you could applying a fabric backing to the surface and then paint the fabric with latex paint which is more flexible than most oil-based paints.
If you must skim coat, stabilize the old plaster surface by coating with bonding agent. Bonding agent will soak into the porous surface sealing it and acting like an adhesive for the skim coat. It is available at masonry suppliers. I can't recommend a specific skim coat material without seeing the wall, but whatever you put on should not be stronger than the plaster beneath or you will run into problems later on. Test different kinds of joint compound, fillers and skim coat plasters by applying them to cardboard sealed with bonding agent. Determine which is weakest and most flexible by bending the cardboard, breaking the coating.
If this is too much trouble, The Glidden Company makes a plaster impregnated fabric product that you hang on the wall, dampen and trowel into place. This bridges over a certain amount of gaps and cracks in the old plaster surface.
Always test your selected materials and methods of application on a small section of the wall in an out of the way place to be sure they work and give you the results you want.

Squirrels in the Attic
We have squirrels in our attic. What can we do to keep them out?

In the winter squirrels are after food they hid in the house during the fall. They will never forget it is there and will do anything to get at it. If you block one hole they will simply chew another, and another as long as you keep filling the holes. One of my clients happened to block a squirrel in the house and then left for the weekend. It went crazy, chewing up all the new sash and interior woodwork just installed around the windows. If you can, try to live with the squirrels this winter. By spring they will have cleared out all the food and you can concentrate more effectively on keeping them out.
This technique is from a book called Outwitting Critters by Bill Adler Jr. (Harper Perennial, ISBN 0-06-096584-3, $10) It has 11 pages of other tips and tricks for squirrels including how to trap them.

John Leeke is a preservation consultant who helps homeowners, contractors and architects understand and maintain their historic buildings. You can contact him at 26 Higgins St., Portland, Maine, 04103, 207 773-2306; or by E-mail: johnleeke@HistoricHomeWorks.com; or log onto his website at:
www.HistoricHomeWorks.com

Return to Q & A table of contents.

	John Leeke's Historic HomeWorks™
	207 773-2306      26 Higgins St. Portland, ME  04103
	[Home][Library][Restoration Reports][Seminars][Forum][Internships][Office][Workshop][Front Porch][Search] info.© 1994-2011 JohnC.Leeke