painting old wood windows

[gildalilly]

My cedar cottage is south facing and is about 40 years old. There is a big bay window with single pane windows in 15 squares about 18" square. I have had to repaint the window trim at least every two years because no matter what I do the paint is peeling after I return in the spring. The wood is also starting to deteriorate but I really don't want a viny window which to me would destroy the character of the place. Someone recently advised me to "treat" the wood with kerosene prior to painting it to prevent peeling. This sounds a bit suspicious. Any thoughts, or advice? thanks

gildalil

[homebild]

This theory of treating with kerosene is completley asinine.

You either need to properly prime the wood before painting OR thin the paint before painting.

Proper thinning usually means thinning your paint with a 50%-%50 solution of paint to thinner for a first coat....thinning your paint with a 75%paint to 25% thinner for the 2nd coat....then applying full strength paint with subsequent coats.

For a latex paint use water as a thinner.
For oil based paints use mineral spirits/paint thinner as a thinner...

Kerosene?

Get real....

[podmanic]

"properly prime" appears everywhere, but no one goes into it in detail. I have an 1884 house in Maine with paint literally falling off. It has never been scraped so the original detailing on moldings etc. is perfect. I intend to remove the paint with a stiff brush (it works), sand with 120 CAREFULLY to get to healthy wood, and then start priming with 50-50 boiled linseed oil and turps, followed by the best oil primer I can buy...followed by, best oil paint I can buy. Am I missing somethin here??
Mike

quote:Originally posted by homebild

This theory of treating with kerosene is completley asinine.

You either need to properly prime the wood before painting OR thin the paint before painting.

Proper thinning usually means thinning your paint with a 50%-%50 solution of paint to thinner for a first coat....thinning your paint with a 75%paint to 25% thinner for the 2nd coat....then applying full strength paint with subsequent coats.

For a latex paint use water as a thinner.
For oil based paints use mineral spirits/paint thinner as a thinner...

Kerosene?

Get real....

[kactuskid]

I've never used the lindseed oil or turps on my home, but mine also faces south and I live in the wintery north. I scraped and sanded as you said, and then used an oil based primer and an acrylic topcoat. By the best you can offord as you get what you pay for with paint. Here's a couple of links to help you out. The first talks about paint quality and what to look for in a good paint. The second is Zinzzers site, they have great primers, one that may interest you is their Cover stain and their Peel Stop. Hope this helps

http://www.paintquality.com/quality/quality_old.htm

http://www.zinsser.com/subcat.asp?CategoryID=1

[mrcaptainbob]

Ah.......50-50 boiled linseed oil and turps, followed by the best oil primer...followed by, best oil paint..... In early high school I worked weekends for a family doing the odd jobs. The lady gave me the 'stuff' her husband had for painting the garage. It was the 50-50 blend. When he got home he explained why it was necessary to do so. He told of how it chased the moisture from the wood, add needed oils to keep it from drying and cracking and provide a base for the primer. To this day I don't know if the science of that is right or wrong, but I do know that it worked quite well.

[podmanic]

The science does work, but not as he thought. "Feeding" wood is a longstanding misunderstanding. "Adding oils" is not what is happening, rather, greater penetration of the coating with consequent better adhesion is the result. The "drying" of linseed oil (or nut oil, poppy oil, tung oil etc.) via uptake of oxygen molecules at the unstaurated polymer sites allows for cross-linkage of the oil and a strong film to be formed. Thinned linseed gets in as deeply as possible, and when followed fairly shortly by an oil primer, creates an excellent, deep mechanical bond. I know this stuff academically, but I wanted confirmation from guys who actually do the work...and you have given me that. Thank you.

quote:Originally posted by mrcaptainbob

Ah.......50-50 boiled linseed oil and turps, followed by the best oil primer...followed by, best oil paint..... In early high school I worked weekends for a family doing the odd jobs. The lady gave me the 'stuff' her husband had for painting the garage. It was the 50-50 blend. When he got home he explained why it was necessary to do so. He told of how it chased the moisture from the wood, add needed oils to keep it from drying and cracking and provide a base for the primer. To this day I don't know if the science of that is right or wrong, but I do know that it worked quite well.

[podmanic]

The turps/linseed oil is somply a pre-primer...in order to get the best bite possible in the wood. Many thanks for the sites, I'll check them out. I'm still thinking through acrylic-over-oil as the best route to go...it is counterintuitive since the two systems do not have similar chemistry, but everyone assures me the surfactants used in the exterior acrylics bond well with the oil primer...go figger.

quote:Originally posted by kactuskid

I've never used the lindseed oil or turps on my home, but mine also faces south and I live in the wintery north. I scraped and sanded as you said, and then used an oil based primer and an acrylic topcoat. By the best you can offord as you get what you pay for with paint. Here's a couple of links to help you out. The first talks about paint quality and what to look for in a good paint. The second is Zinzzers site, they have great primers, one that may interest you is their Cover stain and their Peel Stop. Hope this helps

http://www.paintquality.com/quality/quality_old.htm

http://www.zinsser.com/subcat.asp?CategoryID=1

[kactuskid]

If you are stripping the old coats of oil paint off, then it would be best to apply an oil based primer and a latex topcoat, preferablly a gloss for the trim, it'll last much longer than an oil based topcoat. Oil paint becomes brittle over time.

But, if you have alot of coats of oil paint on your house and you're not going to strip it off, then you're probably best to stay with an oil based topcoat. Here's another link that may help in providing you with better detail for you to make your decision. It explains all the ins and outs about it.

http://www.thisoldhouse.com/toh/knowhow/exteriors/article/0,16417,212675-2,00.html

[podmanic]

The good news is that the paint is literally falling off...right down to the wood...and it has never been touched previously so all the molding details are as they came from the mill in the 19th century. Bad news is that with so much wood already exposed, I'll have a lot of (careful, fine) sanding to do to get the weathered surface down to a point where the primer bond is good.
Many thanks for the link.

quote:Originally posted by kactuskid

If you are stripping the old coats of oil paint off, then it would be best to apply an oil based primer and a latex topcoat, preferablly a gloss for the trim, it'll last much longer than an oil based topcoat. Oil paint becomes brittle over time.

But, if you have alot of coats of oil paint on your house and you're not going to strip it off, then you're probably best to stay with an oil based topcoat. Here's another link that may help in providing you with better detail for you to make your decision. It explains all the ins and outs about it.

http://www.thisoldhouse.com/toh/knowhow/exteriors/article/0,16417,212675-2,00.html

[mrcaptainbob]

Thanks, Mike and Kactuskid for all the neat info. You guys sure provide some great info!