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I tried this up in finishings without a good answer, maybe some one here can help.
I have large Black walnut timbers that will be exposed to the outside Minnesota weather. Does anyone have experiance with a “varnish” for this application? Marine varnish will not work according to their technical experts.
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Replies
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Frenchy,
How 'bout I find some scrap, I'll do a test for you?
Dano
*Frenchy,I guess I'm confused as to the reason "they" say marine varnish won't work. Is this because walnut has a high concentration of oils in it? I would have said to use marine polyurethane. I have had great success with Petite Ultra Gold, but this was on mahogany. Could you pass along thier explanation for the record?TDF
*Deft poly with UV blockers works great for mahogany entrance doors down here in this hot steamy country.
*Tom, who's explanation do you want? I've been collecting them for well over a year and so far the answers seem to very into three catagories. The first is that marine varnish doesn't have any UV blockers in it. blah blah blah....Yadda yadda yadda! The second is that you need pigment to protect wood for the long haul, what color do you want to stain your black walnut? The third is that black walnut has tannins that leach out and break the bond between the wood and finish. (mahogany doesn't have that make-up) They all make a case for that and offer a suggestion but when Epifanes and Interlux were both adament about not using their product, I kinda gave up on that approach. I've tried the various "house" varnishes and no-one will stand behind the durability for more than 24 months. ( most won't offer any warrantee) Sikkens seemed to at least sell it evan if they were fairly adament that it needed pigment. Same with most of the others. Some recommended that I wipe it with an acetone or laquar thinner just prior to application, but those were the ones who backed away from any kinda warrantee. It's not that I'm hung up on a warrantee, it's just that if they are hip shooting I'd rather pass and frankly that's what a lot sounded like.
*do you desire it to remain looking freshly milled? if so, you have a never ending maintainance situation - my suggestion from experience is an application of raw linseed oil, maybe thinned a little with turp- repeat every few years - I think trying to hold a film on the outside of the wood is a losing proposition, esp since your material isn't dry - walnut weathers to a beautiful silver gray where exposed - by letting nature work on it there will be beautiful variations depending on exposure - DOUD
*Mike, Mahogany and Black walnut are to differant to compare. The tannins leach out and attack the iron oxcides which most use as a "UV" blocker. I suspect you'd have the same result with white oak...
*David, I can hear the neighbors gossiping now about how I never paint the wood on my house. Besides where I live they actually have an ordinance that they can force you to paint something if complaints are lodged. Besides weathered black walnut looks exactly like weathered pine or anything else. Silver grey. OH well I deserve it, I tried to think outside the box and got caught. You see my thinking is that Black walnut is a nice decay resistant wood that would look good finished. OK I know how to mill wood all I gotta do is find a nice durable varnish and give a it a coat every few years.... yeh right.
*Frenchy, install a fire protection system. Then once a year fill it full of Mineral Oil and fire it off. Serioulsy, there has to be some sort of protectant.. Have you thought about calling 3M labs. These folks are always developing stuff and may be willing to take on a challenge. It's just a thought. I don't have a number but you could probably search the net and come up with something.Steve
*Dano, Thanks but it's been offered, don't know any way to "age" a test piece fast enough to have any real answers before the wood will need treatment. You'd need one of those weathering chambers. Can you believe that I'm the first person in the world to ever think about using Black walnut outside? Honestly!!! No one has ever said that, yes I did that with this and this is the result....
*Steve, they are right in town here and yes they have an aging chamber where they do accerated aging on stuff ( they provide most of the signs used on the highway) but no they don't offer anything....
*I'll stand by the raw linseed oil advice - it'll keep the color - will have to be applied regularly, but you can add stain if things start to gray - if you apply a finish that forms a film on the surface when (not if) it starts to fail, there are few options - walnut has been used around here for barn siding and the weathering characteristics are good - in your case, I think you have to accept that you are not building a doll house that you can protect from the elements - all our shelters sacrifice themselves to keep the weather off of us - a few mils of plastic finish is not really much of a sacrificial layer in the big scheme of things - I'm sorry about your neigbors and neighborhood, I'm sure you have your reasons for where you are, like I said before, it ain't easy being eccentric - good luck very sincerly, DOUD
*David, Oh, but in my minds eye I think it's a doll house...That's why I can use these "expensive" woods because there's not very much of it in the big scheme of things ;-) About my neighbors, well there are other reasons why I live here like the weather, I mean today they say it may briefly get above freezing and if the clouds go a way we might evan see the sun! something to look forward to after about a month without it..... Ok so it's not really the weather it's not my neighbors it's, it's, "cause I live here that's why and I live here because.... because....hmmmmm. Oh I know, because my house is here! and I built my house here because.... because.... well face it, the woods too cheap to build anywhere else! That's it, I live here because of cheap wood....hmmm where's that damn twelve step program literature...
*oohmm... all is change, all is dust, the jewel in the lotus, oohmm - - well here's a toast to important descisions no matter how cosmicly insignifigant - just returned from my fathers (around the corner 3/8 mile from here) where we were having carpets cleaned this morning - I grew up in that house that my g-g-grandfather built - the original part of the structure is timber framed and walnut sided - about 6 years ago when mom got sick and all had to be moved downstairs, we built a bathroom ajoining an original outside wall, removed the plaster, exposed the timber and siding, scrubbed the walnut with stiff brush, oiled and the color is beautiful - wish I had the camera - point being I guess that this 150 yo siding had color that could be returned with a stiff brush - glad we didn't have to deal with any flakey polyurethane - plastic just doesn't age well - go Frenchy, may you not weaken - DOUD
*Frenchy, I'm still doing that wild and crazy idea thing... So I'm sitting here wondering.. What about a Wax Based sealant. Would it resist the tanins, how would it weather... Don't know any of the answers but it's and idea.Steve
*Wax in sunlight slowly "evaporates". I've used Verathane Diamond Finish, 3 coats, on doors with 4 hrs/day direct sun exposure and direct rain (no overhang above)in L.A. and it lasts 3 yrs, then I scrub it and put on another coat.
*Steve, So which do you recommend Turtle wax or blue coral? Hmmmm, where's the darn rope when you need it? Actually I've tried all of my sources, boat people, wooden car guys, and most of the manufactures and the answer is........ Nope, never done it, haven't ever thought of it, can't, won't, and NO!! Somebody is gonna make a fortune makin' and selling a clear finish that will withstand weather. Can you believe that I'm the first person in the world who wants to expose the grain and colors on Black walnut outside? I mean it's a nice decay resistant wood for cripes sake! Lacking a better solution I'm gonna put some oil or something that will hold up for a while and not leave a mess (Thanks David) and let it go. It'll look good for a while (I'll take some pictures) and when it starts to look kinda tough I'll smear some paint over it.
*And here's me in all my ignorance had always thought that walnut, especially American black, with the exception of the sapwood, was, and is, a traditional material for exterior usage, such as doors and boats. It must have got too pretty in the minds of the public or something. Why not just slap on some linseed oil every six months or so, or even better, gash on some creosote every few years? It ain't exactly a pianer yer building there Frenchy (sic). Slainte, RJ.
*Frenchy-Whats your siding going to be? My bit of advice would be make it so you dont have to be fussy in your application. You want to load up hudson (pump type) sprayer with a linseed oil based penetrating finish and be able to spray the whole house down. Having to cut in oil onto the beams will stink.I'm not sure what if any finish the old european (half timber style) houses used. Probably none. Maybe paint. Hey Skidoo, d'ya know? I have a great picture of a house in Salisbury (UK) that I'll try to post, you'd enjoy it Frenchy.I was just oiling the inside beams in my house this weekend. Even thats a pain.What can ya do...
*None, and creosote Hot, but nowadays they'll slap on some black paint type stuff so as to retain the 'black 'n white' look, but the real preservative is the timbers ability to resist rot, plus modern versions of creosote that have the advantage of not stinking too badly for weeks on end. That's about the limit of it as far as I know, but of course I could be very wrong. Everything else just seems so fussy. Slainte, RJ.
*Hotsawdust, Well I'm gonna do the brick infill thing. yep! oil sprayer is gonna make a mess. So I'll do it maybe once before I follow Sgian's idea and slap some paint on it. Much as I'd like to deny it, it's not a pianer, thanxs Sgian.
*Sgian, Why no, you can't use Black walnut for boats 'n' stuff outdoors! Jus' taint 'Merican. heck everbody knows you godda use Mahogany ta build boats 'n' cedar for outside stuff. Nobody is allowed to think outside the rules in this country 'cause if they do, we won't have a finish for them. ;-)
*Frenchy;Contact Liberty Paint up in New York state for their recommendations on a natural exterior varnish made the old way. Seems the Empress of China or Old Railroad Spar might be the answer. They can advise you. Marine spar lasted 'bout two years for me, and Empress is fairing well after six years in middle Tennessee. 'Fraid you gonna have to fill the grain though!John
*Teak too, in a boat, Frenchy? Slainte, RJ
*Frenchy, get a rope, bout 30 ft long, hoist yourself back up there and paint it with a spray can full of BLO......ROFLOLFolks, if you havent read the whole post you wont understand.So Frenchy, maybe the Fire System and the Mineral Oil aint sounding so dumb after all.... Down here again on the floor, laughing my ... off ..Gotta respect ya for given it your best shot.Steve
*Frenchy, my old man's building a house out in Montauk (way end of Long Island - you could swim to France from out there!) - the builder started this place 2 years ago, and applied something to the cedar shingles on the face (vertical shingles only) - they're still golden brown. I'll find out what he used, and get back to you - probably take a week or so to find out, so be patient...sb
*Have you considered Penofin? I think they have a clear. It would be formulated for outdoors. I have not checked to see if it will work on Walnut,but I think it should. It would still need reapplication at least every 24months,depending on exposure. On the down side it is rather expenive, but maybe worth considering.JCR
*Follow-up to last note. I just checked the Penofin site. They now havea transparent Marine Oil. Could be worth checking out. No info I couldfind specific to Walnut,but I think walnut is used on wooden boats.
*I just remembered!!! I asked the builder last time I was out there to install some cabinets, I just couldn't remember the name - Cuprinol, it's a Benjamin Moore product, I think, but it was definitely Cuprinol.seems to be working really well out there...
*J Roberts, Penofin doesn't have a very good reputation locally The wood tends to darken under it here. I'm not certain if it's our cold weather,or what, but the few homes that have used it around here have either had to replace the wood or paint the wood. They have all been cedar which I'm told by others is rather differant than black walnut.
*Scott, When I e-mailed Benjamin Moore and asked them they responded that they could not recommend any clear finish over Black Walnut used outside. While I'm a little confused about who said what ( I think I've called most of the major paint finishers) I think it was Benjamin Moore who said that the wood would turn silver under it and that would affect it's bond, causing the finish to fail. Others have said that the iron oxcides used in their finish ( for UV protection) would be affected by the tannins in Black walnut causing premature failure.
*okay, so here's where I get lost, maybe Jon Arno is lurking around and can jump in here:I don't know too much about actual tannin contents, but I do know that if I spend a day scraping, rasping and shaping walnut, or the same day with mahogany, at the end of either day, my hands and fingers are the same shade of purple. I've never thought that walnut's tannin content was so different from that of mahogany. This comes as a big surprise to me. Jon, any comments?sb
*Scott, good thought, hey Jon where are ya man?
*Hi Gang. Yup, I've been lurking, but I've kept my fingers off the keyboard in the hopes that I might learn something. I'm not up to speed on the chemistry of finishes and can't provide an answer. I can contribute this much: The problem is definitely not related to tannin interaction. Walnut wood has very low tannic acid content. The primary acids in this species are gallic acid and ellagic acid. Gallic acid might be a problem, since it oxidizes into soluble polymers. But that's as far along the trail as I can take you. I don't know what impact these polymers would have on the solvents and resins used in typical film type finishes. Since gallic acid plays a role in creating natural polymers, it's a reasonable bet it might bugger up the synthetic polymers in the finish...but that's only a guess. I'm just glad it's Frenchy's problem. If it were mine though, I think my first consultation would be with a psychiatrist to see if he could figure out why I was wasting walnut on an exterior trim project. Then I would probably apply one of the commercial deck finishes (preferably one of the penetrating oils... and definitely not a polymer, film type finish.)
*Jon, thanks for your input. I think....;-) So I should see a psychiatist hhmmm? Wel you could be right but not for the reason you suspect. Rather to help me with my wood addiction problem. In hindsight I didn't expect this much problem with getting a finish, that would hold up outside but.... I'd still use Black walnut for the exterior. You see if I were to use the traditional cedar, I'd have to pay current market prices and that's way too expensive. (The real root of my problem is that I'm cheap) I just know that I'd have to pay more for the cedar than I did for the black walnut. OK for a 20' x 8"x8" black walnut beam I paid $64.00 each, for the 12' 8"x8" I paid $38.40 and the 20' 4"x8" I paid $32.00 each. Those were all selected by me as they came off the mill. That works out to be .60 cents a bd. ft. The 9'x4"x6" I paid $3.00 each. They were a stack of that had been stickered up for about 9 months & I got those a lot cheaper. (about 17 cents a bd. ft.) Now perhaps it's "wrong" to be so extravagent with black walnut but I would have done the same with cedar had I been forced to use it instead. So instead of some truck hauling those timbers out of Canada or out west someplace I went down and picked them up myself about an hour and a half away from my house. Just think of the oil I saved for you guys!
*Frenchy, in the grander scheme of things I think you made the right decision. Western redcedar is probably the most abused major timber species in North America these days. It regenerates very slowly and is habitat sensitive. At our current rate of consumption it will probably be off the market as an affordable construction timber within the next few decades. Douglas-fir and redwood are actually easier species to replenish.Also, the prices you've quoted here on walnut are incredible. What are you buying? Are they exceptionally knotty Cants left over from veneer logs? The walnut market is a little depressed at the moment, because of the current fad for blonde furniture and interior trim, but even so, 60 cents a board foot for walnut is an outstanding bargain. I guess maybe you can forget about that psychiatrist.
*Jon, I got to pick the logs and then take only the timbers that met my standards. The 4x6's were cants but they weren't bad. Not FAS but definately #1's that was a couple of years ago. The mill I bought them at had a stack of logs that had been cut for about a year or more and without a market he was glad to sell them. Late this fall overseas buyers came by and started paying silly prices again. The highest paid was $10.00 a bd. ft. for unsawn veneer grade logs but evan only fair logs sold for $2.00 a bd. ft. Suddenly they were back in the woods buying up all the black walnut they could find! In fact based on what I paid for my timbers I could turn around and more than triple my cost. Makes me feel like a rocket scientist, but If pressed I will confess to a modest level of luck :-) My only weakness stems from finding good deals once I now think that it's my god given right. For example I have a chance to buy 3000 bd. ft. of #2 ash. The cost is 10 cents a bd.ft. $300 for 3000 bd. ft. I checked the wood and personally I would have graded it closer to #1 than #2 but then I digress. a dime a foot for 5/4 ash HMmmm. If I didn't have 36,000 bd.ft. in my driveway I know what I'd be doing tomorrow... Instead, I talked my sister and her husband into some of it and a guy a work into the balance. You know you've got it bad when you infect others with your sickness.........
*Frenchy, Just a thought here.... Try contacting the West System people . It seems to me they have a uv additive for epoxy that is used for "bright" yacht finishes IE natural hulls. My thought being that the epoxy, being virtually impregnable would stop any migrating tannins. Just a thought.
*this might be a good question to post over at breaktime - lots of outside work experience assembled there -
*As asideAn old farmer told me that they used to use walnut for water wheels as it was extremely rot resistant. It must make a great outside wood. I have used it for tomatostakes (scraps that is). It is very unimpressive looking after a year in the rain.Frank
*John touched briefly on what appears a natural to me: some sort of deck finish. My old house had a redwood deck which saw snow in the winter and a pretty bad southeastern exposure in summer. I used a product dalled superdeck about every 2 yrs. A quick treatment with deck wash and smear the stuff on with a 6" block brush and I'm good to go. I've never used Thompsons myself, but it might be somthing to think about.
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