While searching for info on glazing windows I read that one should apply boiled linseed oil to the wood before applying the glazing compound as it will keep the wood from drying out the glazing. Later I read that you should apply several (3) coats of boiled linseed oil to old windows because it will help the window hold the paint. Later still I read that there really is no purpose to using linseed oil anymore because there are better products available now. If it is a good idea to apply boiled linseed oil, then what about the wood inside that I am not going to paint? Don't know what to do with all the conflicting information!
I know exactly what you are talking about. All those rules are good rules but to know when to apply them is a trick. Apply linseed oil to old wood and then latex paint says to apply paint to clean, dry wood free of oil. Now, which do you do? I think the linseed oil works with oil based paints and finishes but is a no-no for latex and water based products. I may be wrong but that's what I decided. Not sure how to treat and nourish wood if you are using latex. I am sure there is a product for that too. I think some of these rules have be out dated with all the new things on the market. Lair
I use either the linseed oil or a primer before using DAP33 glazing, which is oil based. Frankly, I usually just prime the mullions, rather than fool with the linseed oil.
I use BLO if the interior is to be unpainted. If the interior is to be painted I use Zinsser BIN Primer. I DO NOT use DAP33. The purpose of the primer in the rabbit is to keep the linseed oil content from soaking into the wood which would cause premature cracking of the glazing. Once cured, the glazing should be over-coated with oil based paint (not primer, as it will etch the surface of the glazing).
I use Dap33, because that is the glazing that I have always used. What product do you glaze with?
Do you use only the linseed oil on interior wood or do you then use a more durable finish over that? Still pretty confused here. I didn't think you could still get oil based paint. Once again, conflicting opinions.
No, only on the exterior, because you only use window glazing on the exterior. Windows typically have a rabbit (cut out rim that sheet glass can set into) on the outside of the sash and the mullion pieces. The glass is held in with little metal glazing points that push into the rabbit to hold the glass in place. Then, you use glazing compound to seal the weather away from the edge where the glass meets the rabbit. Traditional glazing compound takes days to skin up on the paintable side, which in theory you are supposed to wait for before priming and painting. (I never wait that long, because I work alone and find moving ladders pretty exhausting, so I always rush that step.) Meanwhile, the interior of the glazing compound takes a lot longer to dry and cure properly. If the wood is dry, then it will suck moisture out of the compound and lead to cracking and/or poor bonding. That is where the linseed oil or oil primer comes in to seal that dry wood and stop that wicking action. Oil paints are harder to find than they used to be, and subject to state regs that differ from state to state. Big retailers have largely dropped them, but last I checked the small paint store that I deal with still sold oil primer in gallons and oil topcoats in quarts. They also sold oil floor and porch paint in gallons, but they might have relabeled it commercial, which gets an exemption in PA. The environmental problem is not the oil paint, but rather the solvents that carry it and evaporate during drying. I don't feel too bad about that, because I am preserving a historic house. To cancel out that pollution, I skip the gas leaf blowers, edgers and lawn tractors that suburban folks use...
Linseed oil was a common preparation for wood. My grandfather regularly treated his tools, both wooden and metal, with linseed oil and they lasted, looked, and felt amazing in your hands!! Most products (paint, glaze, stains, etc) were oil based before the mid 20th century. Adding linseed oil when glazing windows, that admittedly take a lot of weather abuse, was standard practice. The linseed oil provided extra oils to condition and stabilize wood and the oil based products of that time. I still feel that a thin coat under window glaze (DAP 33) is a helpful step in the process if you want the glaze to last for decades and not years. A top coat of paint over the glaze is also a standard procedure but was assumed to be oil not latex. It has bee my experience that latex paint over glaze does not adhere as well as I would like but I have no evidence that it does any harm either. Interior wood stains and finishes have come a long way and linseed oil is not needed or helpful for interior projects. I have a dresser of my mothers that was refinished in linseed oil. It took a very long time more than a week for it to completely dry but 20 years later is still as beautiful as it was when I got it. It is easy to take short cuts and skip steps to save time but wood needs to be "feed" and reconditions with essential oils, like linseed oil, to continue to provide years of service. Just my two cents......
If you want to replenish your old wood windows, boiled linseed oil is a great option. Is there anything as simple or better, not really. You can blend your oil with other oil based products to make various sealer blends. You are safe if you use an oil base slow dry primer. Also depending on your mix, boiled linseed oil will take up to 72 hours to dry. are there better modern products out there, nope. Modern water-base products will not replenish and restore anything,
Erin, I use oil based primer in the rabbit if the finish of the interior is painted. If the interior is wood grain, I use BLO to insure that primer does not accidentally mar the wood of the interior. I use Sarco M as a standard but make my own when historic accuracy is necessary.
Clean out the rabbit, prime with oil based primer (or BLO), let it dry, apply a thin layer of glazing compound (bedding) into the rabbit, insert and seat the glass, install points, apply glazing compound, let it skin over until you can lightly rub your finger across the surface without any oily residue, clean the glass, paint with oil based paint (not primer) and insure that you leave a minimum 1/64" overlap onto the glass in order to insure that no air can get to the glazing compound.
Thanks to everyone for their input. I am getting a little better at this glazing thing. Hope I live long enough to finish the whole house!