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Linseed oil before painting ancient siding?

AMRadiohead3885
17 years ago

I am about to repaint one exterior wall before the weather gets too cold here in middle Tennessee. Figure I should have another 10 days - 2 weeks at most.

The siding is very old - circa 1850, yellow poplar "weatherboard" style clapboards of uniform thickness. The wood is very weathered, and the last paint job has peeled in spots. I used infra-red heat to soften and remove the non-peeling paint, which works very well. I notice that where I scraped off the old paint, there is a layer of weathered wood that is very soft, and has a fuzzy surface, almost the texture of terry cloth. The old weather-beaten boards are too irregular with dips and valleys for my orbital sander. Hand rubbing or a stiff brush seems to take most of it off, and on some boards, the paint scraper actually planes off the layer of mushy outer skin, revealing sound wood beneath.

I am trying to preserve the original siding as much as possible. Plan to use oil base primer and latex topcoat.

A am wondering if it would help to first brush on a mixture of boiled linseed oil and mineral spirits. Would that help or hinder the oil based primer from adhering to the old siding? I have been told that because the wood is so old and dried out, the oil would help restore the wood, if thinned with mineral spirits so that it penetrates below the surface. But other local "experts" say that if I do that, the oil primer won't adhere. I don't know which is correct, but one suggestion or the other has to be wrong.

I would like some more input and opinions on this before I take any action. Hope to get started on the repainting next week if weather permits.

Also, would like to hear what solutions anyone has found for wood that has rotted out around the nails. The house is constructed with the old-fashioned square cut-steel nails. Unfortunately, the carpenters drove in the nails slanted downwards, so that water would have a tendency to run downwards around the nails, instead of away from the nails and wood. After more than 150 years, many of the nails are so loose I can grab the head with my fingers and pull them out with little effort.

I have repaired a few of these using deck screws that are somewhat longer than the original nails, by screwing them into the original nail holes, and using washers under the heads where the wood has rotted out around the original nail holes in the siding boards. Some are stock #10 brass washers, while others are home-made, cut from scrap vinys sheeting.

Wonder if anyone has successfully found a better method for dealing with this problem. The screw/washer fasteners are unsightly, but at least they firmly hold the boards in place.

Don

Comments (11)

  • sombreuil_mongrel
    17 years ago

    Hi,
    you really need to get all the grey wood scraped off for the primer to stick.
    If you want, add 25% boiled linseed oil, and some extra japan dryer to the first coat of primer. Pure linseed oil would never dry considering how late in the season it is. The dryer is critical too.
    Since the wood is so weathered, a second coat of straight primer is not out of the question.
    As to the damaged nail penetrations, probably best to renail the siding with new galvanised cut siding nails. You can get these from Tremont Nail Co. Predrill new holes to prevent splitting and to start a new way into the framing. The old eroded nail holes could be treated and filled with epoxy. It would be a permanent fix that wouldn't pop out or weather, but would need to be done first, before priming. Look at www.abatron.com if you're interested in that.
    Casey

  • brickeyee
    17 years ago

    Minwax wood hardener is a better solution then linseed oil.
    It is a littel pricey, but is acrylic resin in a fast drying solvent. It will harden up damageed spots and then you can decide to fill them or paint over.

  • ericwi
    17 years ago

    I have used Minwax wood hardener successfully to repair grey and weathered wood window frames and window sills. You can paint over this application in 12 hours. I use oil-base primer on our windows and sills, followed by an oil base top coat.

  • housekeeping
    17 years ago

    I have read the suggestion to use the linseed oil and mineral spirits concoction on old wood before painting; I think the reason was supposed to be to "feed" the old, dried-out, wood so it wouldn't pull the oil out of the alkyd primer and interfere with its adhesion. I followed those directions on a house painting project. I used Sherwin Williams oil-based primer, topped with two coats of their best quality latex exterior paint.

    To my dismay, I immediately started to get mildew showing through the paint, and have a had a continuous problem with it, ever since. The new paint was only on a portion of that particular wall. On the adjacent area without the linseed treatment, there is no problem with mildew. The work was done nearly a decade ago, and the problem started the first summer after the work was completed.

    Since this disappointing experience I have seen references to linseed oil being mold's favorite food, and wondered whether it was good advice. As a substitute, I have read suggestions to use a different formula from the Forest Products Research Lab. I haven't been able to track down the exact formula, but I would ask for more information about this over on John Leeke's website: www.historichomeworks.com

    I think the theory that "feeding" old, exposed, overdried wood prior to painting is probably sound, but I'm not sure if I know exactly what to serve for the wood's dinner.

    The good news is that the paint (aside from the mildew arising under it) is still well-adhered to the building. I'll probably have a terrible time getting it off in order to start over when I'm ready to fix it. I regularly clean the mildew stains off with a solution of chlorine bleach, TSP and elbow grease. I just did it a few weeks ago, and I'm enjoying the lovely paint at the moment.

    Frankly I'm really baffled about what would be best, and it's kind of stalling my progress on repairing some window frames as I am not sure what to do with these old window frames.

    HTH,

    Molly~

  • corgilvr
    17 years ago

    Molly,I've used Abatron on sills and damaged frames that need significant repair. I am, thankfully, on the last window of the year. After stripping and hand sanding, I haven't found too many serious problems. Abatron does a good job of filling voids. I always paint the entire exterior with an oil based primer before reinstalling glass. I sand and apply a second coat after the glazing compound has skinned over. After another light sanding, I apply two coats of the exterior trim paint. Everything seems to have remained very sound through the seasons and there are no storms on the protect the new paint and glazing. Another vote for Abatron here.

    Molly, if my window frames were really awful, I think I'd have replacements made. I have also collected old sash from homes replacing windows or being demolished. Some of the old sash still look brand new after stripping all that paint.I have been able to use two of them and one is in a floor to ceiling window. My carpenter will recreate any sash and is far less expensive that any company I have compared his prices to. If you wanted to send a picture, I'm sure he would give you a ball park figure for a replacement so that you could compare costs in your area.

    I don't want to paint too rosey a picture. I was about ready to throw two sash against the barn wall two weeks ago. I just had to walk away from the frustration, scream at my bewildered looking husband and go buy a pair of shoes. I'm now ready to put the trim color on that window and call it a year. All of this gets so frustrating at times and I always feel that these sorts of repairs can wait one more season. Abatron usually ships on the date I order, so that may fit into any time frame. Good luck with the repair and painting.

  • sombreuil_mongrel
    17 years ago

    Housekeeping:
    The mildew problem is a known issue here, too. That's why I pressed for adding japan dryer. once the oil is catalyzed in a thorough curing process, it's no longer food. I also recommended a max. of 25% adulteration into primer.
    One thing I forgot to mention is a product called Mildex (MildX?), supposedly inhibits mildew formation on finish paint.
    Casey

  • housekeeping
    17 years ago

    Corgiluver,

    I don't need wood hardener (consolidant) or filler on these barn sash, just something as an undercoat. I would ordinarily have used the linseed oil/turps mix, except for my bad results on the siding. I've been trying, in a not very active way -LOL- to track down the FPL formula (which I gather has recently changed due one component winding up on the too-toxic-to-use list).

    I've used Abatron stuff on other projects where I have voids or rotten wood that needs dutchmen, but generally just replace muntins or other parts that need it during window rehab, rather than trying to build them up or piece them out. I had a bunch of muntin stock and rails stock made up (and sometimes I cannabalize old sashes, too.) And I am blessed with really old fashioned sash held together with wooden tenons, which makes them simple to diassemble - in fact many of them save me the trouble by doing it on their own!

    I haven't gotten into it as much you have, but you are my mental role model when my mind turns to rehabbing windows!

    BTW, what are you using for glazing compound/putty these days. Some of my old faves have disappeared from the market.

    Molly~

  • corgilvr
    17 years ago

    Molly, lucky you with the easy apart windows. Mine have tenons secured with dowels, but the dowels have never been easy to remove. This post got me going and I put a final exterior coat on my window yesterday. It's a second story window so I try to do as much on the ground as I can. I'm in a race against age, mine more than the house. I may try drilling a dowel out of a rescued sash to see if I can get it apart. We are making wooden storms with tenons and dowels and repair pieces can't be much more difficult to fabricate. Can you hear my husband moaning?

    I think it is going to become more and more difficult to purchase anything oil based. Do you think linseed oil will also "evaporate" from the market? I know I'm starting to sound old, but I just can't completely accept the latex is better theory. Will oil based glazing compound also be banned? I think there are water based glazing compounds that do not require any wait time to skin over. I use UGL compound and it sometimes takes 10 days before I feel comfortable enough to prime over it. I'm usually ready to have an excuse for a break at that point. If you know of a better compound, please let me know.

    I'm sure the original poster is well on his way to complete his painting project, but I thought this site had a decent sequence of repair for a variety of old house projects. I'm sure many of us can identify with the "before" examples. It would also be nice to have input from the forum experts on the methods used on the site. Has anyone used the Multi Wood Primer mentioned on it? I think I'll order a can and try some if no one here has negative reports.

    I'll bet someone on the Old House Journal forum has an FPL formula for you. I can't imagine having to repaint our barn with latex paint on the next go round. I get a mental image of us crossing some border and smuggling the banned ingedients and paints back into the country.

    I hope people will chime in on the site I've included. If it has been discussed in the past, someone just needs to yell at me and direct me to the thread. I'm up early to finish prepping the the parting bead and stops and am praying that I have enough sash cord to finish this.

    Here is a link that might be useful: repair and paint old siding, etc

  • john_shearerpainting_com
    13 years ago

    We have used linseed oil and the minWax consolidant; they both work well. Essentially using oil like lotion on dry skin. The Linseed oil penetrates deeper but can take a longtime to dry; minwax dries faster but costs more and does not penetrate as deeply. In this video we use linseed oil before the epoxy and primer
    http://www.youtube.com/watch?v=XTM8HVpjgfE

    John
    www.wepaintseattle.com

    Here is a link that might be useful: Shearer Painting

  • macv
    13 years ago

    So-called "oil-based paint" is commonly thought (for obvious reasons) to have an oil base but it doesn't; it has a solvent base and therefore should be called "oil modified, solvent based" paint and in fact it is in many technical specifications.

    When you use boiled linseed or any other vegetable oil by itself you are leaving out the solvents, hardeners, pigments and driers normally found in paint. The result is an organic material that takes forever to dry. I believe the favorite food of fungus is cellulose but I suspect vegetable oil is high on their list too.

    I have had better luck with Abatron than MinWax hardner.