I have a question.
I recently salvaged some 1/4″ thick walnut paneling. One of the projects
I would like to use the wood for is a desktop.
My plan was to use MDF w/ a 1/4″ thick “veneer” of walnut and breadboard
ends. It would be difficult at best to edge glue a 40″ x 72″ x 1/4″ top
together and then glue that to the MDF. So, I need to edge glue the
“veneer” at the same time as gluing it to the MDF substrate.
Any suggestions as to techniques (and the best glue to use) would be
greatly appreciated.
Sincerely,
Joel Jorgensen
South Lebanon, OH
Replies
You might want to look at a post entitled "warping wood table" -post 19240.1 in the Breaktime general discussions section- thicknesses are slightly different, but I wonder if the effects might not be ths same:
Hi Dick,
Thanks, but this walnut is 30 years old. There's got to be a way to glue it to a MDF board and have it be stable. Wouldn't this be MORE stable than a solid walnut top?
jj, It seems to me that there might be a misconception here. Just because the walnut is 30 or so years old, that doesn't make it stable. It will still expand and contract across the width as it absorbs or loses moisture. If you attach it to an MDF ground, you have to ask yourself, will this stuff (the MDF) move with the walnut. The answer is no, it will not. MDF does expand and contract because it is made of timber, but it is certainly much more stable than solid timber. There is a thread on this MDF expansion topic active as I write. I think it's in the General Discussion folder. Go and have a look at it if you have chance. And as one of the contributors noted, MDF does actually have a sort of grain pattern, so it moves proportionately more in one direction than the other.
Anyway, it's my experience that trying to veneer thick stuff to man made board as you propose is always doomed to failure. (I think there is also a topic on this very subject active somewhere in this forum-- perhaps in the joinery section.) Usually what happens is the assembly buckles, or the veneer cracks and breaks off. Standard veneer at about 0.6mm thick is relatively weak, and tends to stay where it's held, but your 1/4" thick stuff should be considered as a thin plank, with all the normal characteristics of solid timber. Much better in my experience would be to individually join the face of each of your thin walnut pieces to a plank of lesser figured, but similarly grain patterned walnut. Then treat these made up planks as you would any other solid timber plank edge jointed glue up. Slainte, RJ.
http://forums.taunton.com/n/mb/message.asp?webtag=tp-knots&msg=5659.1 Here's a link to the MDF movement discussion.
I can't find the discussion i mentioned on the warped table top where the topic was solid timber 'veneered' to plywood causing problems. Maybe it was another forum, but if someone knows where this discussion is, and it happens to be in this forum, do post a link. Thanks.
Some people are born a couple of nips under par. I'm not one of them.
Edited 4/4/2002 11:21:23 PM ET by Sgian Dubh
Edited 4/4/2002 11:49:16 PM ET by Sgian Dubh
post 19240.1 in the Breaktime general discussions section
This is the post, I just couldn't turn it into a link. How did you do it (without taking the thread to far off topic)?
I am preparing to make a writing desk from 36mm birch plywood with a top of 3mm thick glued up maple pieces 6cm wide. Do you think this would be a problem? With glue would be good?
Ruud Joling The Netherlands
Ruud, I think you might be pushing the limits of what might work. 3 mm stuff is quite thick, and therefore strong, and bound to exert considerable influence on the ground, i.e., the 36 mm thick ply, which I'm guessing is two pieces of 18 mm glued together? My suggestion would be to veneer a piece of veneer of equal thickness to the back side of the plywood to create something of a balance. Ideally, you would use the same species of 'backing' veneer, but it would help no end to use anything of the same thickness. Your writing desk has an exposed top, obviously, but the underside might be enclosed via such things as being part of a cabinet including drawers, doors, etc.. This factor, along with any stabilising and restricting construction on the back side might help to reduce the influence of moisture exchange on the 'hidden' or relatively protected underside, which might be helpful in keeping the whole fairly stable, and might even lead to omitting the veneer altogether on the 'back' side. The application of a film type polish on both sides would also help in reducing the speed at which moisture might be exchanged between an exposed surface, and the body of the structure. All of the previous advice was 'generic' but I hope it was helpful. Get back if you want to expand on the subject.
Of glues, I'd probably choose from PVA, hide, or urea formaldehyde. They all work well in their different ways.
I'm rather sorry that I cannot speak or write in Dutch. Your English seems to be pretty good though. ;-) Slainte, RJ.Pass the Prozac--------pass the Viagra. I've always wondered what it's like to be a dozy stiff.
I may have missed it but I did not see any discussion about balancing panels to minimize warping. By balancing, I mean that the top surface and the bottom surface of the sheet stock has to be treated equally or warp will occur. If only one side is veneered, as the wood expands and contracts with changing moisture content, the panel will go concave/convex depending on whether the wood is expanding or shrinking. With the opposite side treated equally, the two surface will restrain each other. Commercially manufactured plywoods have an equal number of plys from the neutral center axis.
I am always extremely careful when dealing with composite panels to the point that I even try to balance the amount of finish on both sides. Then again I basically do this with even solid wood but I may be a bit more neurotic than most !!
I consider veneering to be extremely skilled woodworking Working with thick "veneer" as you are attempting is tricky primarily because you need to apply uniform pressure in two directions simultaneously. I am unaware of any good system for doing this. The only other approach would be to glue up large faces of the 0.25" material and then subsequently apply it to your substrate. For that amount of work, you might as well use solid stock and save the thin material for thin flat panels in frame and panel construction. And just because something is free doesn't make it a deal. .
Stanley, You just missed it, that was all. The reference to 'balanced' panels was there in my last post, but I didn't push it. As to film finishes, other factors can reduce the exchange of moisture at the microscopic level, e.g., exposed cabinet top, and enclosed cabinet interior. Balance is important of course, but the top surface may be exposed to one environment, which might be somewhat different to that experienced by the internal surfaces. Therefore following a stringent regime of veneering and finishing a panel equally on both sides may not always be the best practice. Slainte, RJ.Pass the Prozac--------pass the Viagra. I've always wondered what it's like to be a dozy stiff.
Sgian:
I think it is really stretching the limits of credibility to assume that the interior and exterior of a given cabinet are at significantly different exposure conditions. Unless the unit is tightly sealed or has a particular micro-climate (as possibly due to the presence of water), the relative humidity conditions will more or less be the same. Likewise it is possible that there will be some level of spot temperature variation between inside and outside, but I doubt if this is excessively different or beyond the typical exposure range. Since both temperature and humidity combine to create a given Relative Humidity and hense Equilibrium Moisture Content, I will continue to think that exposure conditions for inside and outside (or top and bottom) are more or less equal. Therefore, for stability, I treat both surfaces equally. I may not sand and rub the non-exposed surfaces but I will give them a quick spray coating.
You might want to look at the data regarding Moisture Excluding Effectiveness (MEE) published by USDA Forest Service. Over short intervals (time = 1 day), the MEE of three coats of semi-gloss nitrocellulose lacquer is 79% (implying that this finish excludes 79% of the adsorbed water that raw/unfinished wood would pick up given exposure to 90% RH after equilibration to 30% RH conditions).
PS -- Thanks for the help regarding Q.robur; it looks like the job is a go and they are willing to spend the difference.
Stanley, you said, "it is really stretching the limits of credibility to assume that the interior and exterior of a given cabinet are at significantly different exposure conditions." I certainly wouldn't push for any argument with you regarding that statement. For probably 99% of the time I aim for and recommend 'balance' in veneered work, as my earlier post to Ruud, for instance, suggested. The rest of my answer there was full of words like 'might' and 'maybe' all intended to indicate that there are sometimes special circumstances where veneering and equal treatment on both sides of a ground may not always necessary.
It's true that the standard advice is to 'treat both sides the same,' yet there are numerous long surviving examples where such treatment hasn't occured- tea caddies, knife boxes, bombe style cabinets, English Georgian cabinets including chests of drawers, writing desks, davenports, etc., and so on, and so on. Most of these items are a pine or poplar box that was subsequently decorated with veneer or marquetry. Now it may be argued that much of the polish used in those days was little better than no polish at all in terms of slowing down the movement of moisture at a microscopic level, and the interior was usually left bare. Significantly those out of balance panels are are still here and usable 200 years on from when they were made that way. It's probably the case that a lot of furniture was made this way a couple of hundred years ago to save cost- veneering skills were an expensive commodity, and much of that furniture failed and no longer exists.
Thanks for letting me know that I was able to help with the oak job. Slainte, RJ.Pass the Prozac--------pass the Viagra. I've always wondered what it's like to be a dozy stiff.
I am jumping into this fray a bit tenativly because what I have tried with some sucess seems to be contrary to the general opinion I have successfully constructed some entry door units that are anywhere from 1 3/4" thick to 3 1/2" thick using "thick" veneers laid on a torsion box inner frame to lessen the weight of the slab. I have been using the same species to construct the torsion box and filling the voids with foam for a bit a insulative value. The outer Skins are glued for width and then properly sized and flattened to the approriate thickness so that after the unit is pressed, I do not have to work it any more than to Scrape/sand for finishing. The torsion box is made to whatever thickness is neccessary to allow the least amount of work needed on the skins.
Now entry door units are subjected to the very worst effects of the enviroment not just humidity differentials but also temperature, driven rain/snow and are expected to perform flawlessly for their life. I have not have any of these units fail on me as yet, BUT I have not had them in service for more than 5 years.
So, my real question is this am I looking at certian failure in the future or is torsion box construction an alternitive that might satisfy the current question of using thick veneers? Joe
Joe, it sounds to me that you are sort of breaking the rules, and working with the rules at the same time, therefore achieving something of a balance. Presumably the inside of your torsion box is pretty well sealed, and structurally of course very strong, therefore they are apparently able to withstand the effects of the veneer applied to either side. At least one or two have withstood the test of time for five years now, so you report.
Inevitably they will eventually fail- all timber structures do, including exterior doors, but some examples of woodwork do last hundreds of years, and I believe a few examples sealed in the Egyptian pyramids have survived for thousands of years, for example. And I'd say that if you are comfortable with the idea of of offering a five year warranty on the doors that you make this way because of your experience using the techniques you do, you're in darn good shape with your clients,................wouldn't you agree? <g> Slainte, RJ.
While I didn't find anything condescending in Sgain's post, I do have questions in relation to his comments. I've been digging into part of this for a while trying to get a feel for why wood seems slightly more stable over time. I agree that it never stops moving with MC changes but it seemed to move a little less after cycling through seasonal changes a few times.
Digging a little and a friends comments brought me to the term hysteresis. I've read quite a bit about it and, as I understand it, after a series of seasonal cycles wood will actually take on slightly less moisture at a given increase in ambient humidity. I can't find any research that indicates there's much difference in the way wood looses moisture over time but I also wonder about that. I also wonder about cell wall elasticity and how it may change over time.
Don't get me wrong--wood never becomes stable in relation to its moisture content. I'm just saying that my experience and research of others indicates there are, over a period of time, some changes in the way wood reacts to moisture content changes. Hysteresis just happens to be one of the areas I'm digging into. I'm finding lots more questions than answers. Old as it is, wood working still seems to have some mysteries--even if it has precious little to do with this thread.
Edited 4/11/2002 1:35:57 AM ET by Larry Williams
Larry, Interesting observations. The cells in timber become less likely to change the more often they are asked to change by the changing environment within which they exist. In other words, cut down a tree, and the cells are just what they are. Dry it, the cells and their walls shrink. Then make a piece of furniture from that (or a plane even?) and then subject the timber and its cells to the original humidity again, and the cell(s) won't quite 'stretch' back to their earlier form. In other words, a case of diminishing returns for the same input, and a general levelling out of expansion and contraction expectations. I don't know the answer, but you proposition certainly is intriguing. I wonder if there is a wood technologist lurking hereabouts that might have a theory,...or even Stanley? <g> Slainte, RJ. Pass the Prozac--------pass the Viagra. I've always wondered what it's like to be a dozy stiff.
Within the range of bound water, wood follows sorption/desorption hysteresis curves.
Now since 95% of those reading this statement probably neither understand what I have said nor know the reason that this happens, I will attempt to clarify.
Within wood water exists in two ways -- free water within the open cellular spaces and bound water within the cell walls at a chemical/molecular level. Respectively, this is referred to as the aBsorbed and aDsorbed water (aD as in adhesion). For the most part the free water is present at oven dry moisture contents greater than 25%. Removal of free water does not cause any dimensional change.
When wood dries below 25% (referred to as the Fiber Saturation Point [FSP]) it begins to shrink. The adsorbed water is chemically bound to the cellulosic components of wood (the cellulose and the non-cellulosic polysaccharides) at the hydrogen and hydroxyl sites on these 5 & 6 carbon sugar monomer units. When the water molecule is removed, the sites at which the water was present now cross-link with contigious molecules. With the removal of the water (molecular weight 18), the distance between the contingent molecules is reduced by the size of that single water molecule. Energy is required to break the water/cellulosic chemical bond. Unless wood is stored at absolute zero, such energy is always present.
The drying of wood (desorption) of wood below FSP follows a particular graphic curve. The wood’s equilibrium moisture content is plotted with the vertical axis being the moisture content while the horizontal axis is time. A separate curve (below the desorption curve) exists for the re-adsorption of water, hense the concept of hysteresis. The fact that water is readsorbed by wood at a slower rate can be explained by the fact that energy must be present to break the now existing cellulosic to cellulosic cross-linked chemical bonds before a water molecule can reattach (re-bond) at an appropriate site. With the rebonding of the water molecule, the distance between the two cellulosic molecules is enlarged.
The key word in the above paragraph in truly comprehending wood moisture content equilbration is rate. For a given set of temperature and relative humidity conditions, wood will attain an equilibrium moisture content. At any given equilibrium moisture content, the wood will shrink or swell to a given dimension (a range actually with +/- tolerances depending on MC distribution). The constancy of attaining Equilibrium Moisture Content is fact, but it is fallaceous to assume that because of hysteresis (ie the rate of change) that the wood is more stable dimensionally.
Even though the wood appears to be "more stable", it is not. I will prepose that it remains "stable" (and by that I mean that checks and splits do not develop with the changing moisture contents/dimensional variation) because both the rate of change and the exposure parameters are within the elastic limits of the wood. If the wood were subjected to conditions beyond this hypothetical elastic limit, such as excessive wetting followed by excessively fast drying, it is likely the wood, at some points, would fail. Another example of this might be a piece of furniture from the Pacific Northwest that is suddenly transported to the deserts of Arizona such that the "normal" variation range is changed.
This is probably more than most wanted but there is no simple way to otherwise clarify the concept of hysteresis. I hope it helps ! !
Awe, go on....
Seriously, I have a question about the initial concept of "thick veneering". I agree with Sgian that 1/4 inch thick timber is a "plank", with all its characteristics, not veneer. Certainly the 1/2 inch thick stuff on the referenced table was doomed. How thin do you guys need it to go before it is called "veneer"? I guess the assumption is that the definition of the word in this context includes the idea that it is now thin enough to be safely glued to a ground and used as we think veneer can be used (i.e. not doomed to fail as described above).
I checked Krenov's Impractical Cabinet Maker, where he devotes a chapter to the use of "real veneer", bandsawn stuff glued with either white or yellow glue to a ground... (1970's style). The thickness he discusses is 2.5-3 mm, as I recall (a bit less than 1/8 inch). He gives examples of when and where it makes sense to use veneered surfaces, such as a cabinet back. I've never tried it, but the concept still gave me the worries. Movement is always a consideration. But then, who am I?
Just a few days ago, I received David Charlesworth's second book (if Sgian remembers insignificant matters, he may remember me as the one raving so sincerely about David's plane blade honing advice in another post). The last two chapters describe a beautiful cabinet made by a student. As the design placed the door within the carcass, David convinced the student to use a mdf ground and sandwich it in bandsawn veneer. They also used maple plugs at the corners of the mdf, where the hinge screws would be set. Elsewhere in the book he mentions such veneer to be in the same general thickness range as Krenov mentioned in his book. It is expressed in millimeters, and I am an imperial kind of guy, but my translation is roughly between 1/16 and 1/8. Okay, okay, as one might suspect, I do indeed take anything Mr. Charlesworth says with a presumption of validity. Never failed yet.
Do these thicknesses make sense to you? Couldn't some of the initial questions here be answered in part by a discussion of the point at which "veneer" transitions into "plank" size?
I have a further question about interior/exterior moisture gradients, if that is an appropriate word. How in the world do humidors not come flying apart? How does one not necessarily use a frame and panel-style lid ( if it's thick enough to contribute to an effective seal, how does it not force the lid sides apart?)? Does shellac, the most food friendly-type finish, adequately inhibit moisture exchange? Why am I asking about humidors in a thick veneering post?
All this learnin'. Sometimes I liked it better when my grandfather would tell me I was just as happy as if I had good sense...
Cheers.
Greg, I remember the discussion.
I think of 3mm thick and less as candidates for describing as a veneer, but there might be exceptions- notice that word 'might' appearing again in my posts. I'm all metric, so I'm happy there. I can't read Krenov, but that's neither here nor there, and don't ask me to explain because I'll ignore the question.
Humidors? You can make a solid lid to fit that helps to reduce the exchange of moisture. Run a groove on the inside face of the sides near the top. Work a groove towards the bottom face of the lid on the edges and ends to form two tongues. The tongue formed at the bottom face of the lid fits the groove in the box side. The groove in the lid edge abd ends spans the distance between the groove worked in the box side, and the top edge of the box side. The higher tongue on the edge and ends of the lid just fits over the edge of the side, and this is what causes the comparatively good seal. I wish I had a good picture to hand that I could post, which would explain all very simply. The verbal diarrheoa above will have to be read very carefully to make sense of it I'm afraid.
Shellac is a pretty good finish for reducing microscopic moisture exchange, but perhaps not as good as post-catalysed lacquer or varnish, but better than wax or a pure oil finish such as linseed or tung. Slainte, RJ. Pass the Prozac--------pass the Viagra. I've always wondered what it's like to be a dozy stiff.
Sgian,
Thanks for the reply. I'm tempted to ask the Krenov question, but am too sensitive to tolerate being ignored. Besides, I "might" be able to guess at the answer anyway. Boy, you've sounded a bit like a lawyer in this. But I respect you too much to call you a name like that.
Your description was clear enough. Maybe I'll try it the next time, having already committed to the one currently under way. As yours is described, the top's upper lip rests above the side's upper edge, right? Thus the top is allowed to move, yet the sort of double groove design helps retain the moisture. I guess the top lip doesn't reach as far as the side's outside face, which could make for an interesting reveal, maybe chamfered?
But again, this started as a thick veneer thread, even though its essence was really wood movement. And a really good thread at that.
Cheers
Greg, you understood the description just fine from what I can see.
In reply to your unasked question, the words of Krenov are unreadable, irritating, aimless, twittererings to this woodworker,................. but others seem to find him inspirational, which I do find interesting. Slainte, RJ.
Sgian,
Thanks. I think I'll try that top design next time. There are some interesting design possibilities there. Are traditional tea caddies made with similar considerations?
I didn't ask, but didn't need to either. Kind of figured (if you don't mind the pun). Since you mention "inspiration", though, I must add something. I'd never been much inspired by many pictures of his work. Just so many cabinets on stilts.... Drove over to the winter show at Ft. Bragg and saw the students' work in person. Seeing them was like being hit somewhere inside my chest. Wasn't the least bit prepared for that feeling. It changed from 20 ft to 10 ft to 1 foot away. No kidding. Happened to run into the old man after lunch that day. He couldn't have been nicer or more gracious. Invited me up to the shop where I met some truly nice and open students. I haven't looked at anything the same since. I didn't go seeking that inspiration, either. Just heard he was retiring and wondered what the fuss was all about.
Getting back to the original thread, isn't the point always going to be the same? Wood moves. Maybe the amount could theoretically be reduced in very well seasoned and once thoroughly dried timber, but still wood moves. Whether on mdf or plywood or torsion box ground, any layer in there which is thicker than approx. 1/8 is (or darn well "might") going to exert sometimes significant force as it does what wood does.
Greg, Insofar as tea caddies were probably intended to keep tea fresh and dry, I suppose it makes sense to try and restrict the movement of moisture in and out. But then someone's always going to open the lid to brew up a pot, so perhaps the fancy designs were originally meant to prove how wealthy you were to be able to afford that rare and expensive commodity, tea.
I've heard from many people that Krenov is a fine man- one of my friends was in Fort Bragg last summer taking a course, and said just that- and undoubtedly a fine craftsman. He's an inspiration to thousands of woodworkers. I just find his writing style unreadable, and I've tried several times.
There are always going to be failures and successes in furniture making, and veneered projects, whether or not they are veneered as typically advised as a balanced item are subject to unexpected failures and successes too. One factor that might lead to a failure for example is to build allowing an unsufficient amount in the construction for the idiosyncracies of timber movement. If you allow only for the range of movement that might be expected in a house in Arizona, that wouldn't necessarily be enough if the piece is moved to a coastal location somewhere in the US Northeast- and then there is always the possibility that a piece sits in a container on the deck of a ship for three or four months en route to another country. Who knows what environment furniture designed for longevity will experience in its lifetime, but we just have to try and think of every possible worst case scenario, and build for it as best we can. Sometimes things work, and sometimes they don't, but hopefully we have many more successes than failures. Slainte, RJ.
http://forums.taunton.com/n/mb/message.asp?webtag=tp-breaktime&msg=19240.1 Table top woes discussion in BT.
Thanks Dick. I found the discussion following your lead. I right clicked on the topic title in the column on the left, once I'd found it, which needed a bit of extra clicking and a box opened up, and one of the choices was 'Copy Shortcut' (or press key T.) I copied it. I came back to Knots and opened up the 'Reply' box within which I'm replying specifically to you, and hit Control V, which is the same as pointing and clicking at the top of your browser page with the mouse on Edit, and Paste in the tool bar. I'm still trying to get to grips with how this new forum works myself, and the resultant link above is inelegant as opposed to old WebX method for posting links, but I'm a persistent bugger, so I'll get there.
The effect of gluing the 1/4" thick veneer to MDF proposed here will be the same as in the dinning (sic) table being discussed over at BT, i.e., failure. But some people do get fooled by, ahem,.... craftspeople that really couldn't pour piss out of a boot even if they turned it over in order to read carefully the instructions written on the sole. <g> Slainte, RJ.
Some people are born a couple of nips under par. I'm not one of them.
Edited 4/5/2002 2:18:54 AM ET by Sgian Dubh
Edited 4/5/2002 2:24:01 AM ET by Sgian Dubh
Edited 4/5/2002 3:04:04 AM ET by Sgian Dubh
http://forums.taunton.com/n/mb/message.asp?webtag=tp-knots&msg=5691.1
Thanks RJ, don't follow the link, I was just testing.
Funny thing about that tabletop, between the cost of the ply and the labour to make that trick work, it is a more expensive way to go than solid wood.
Sheeesh....it was just a question. No need to be condescending. Unless of course YOU need to be condescending.
Question. Who would write instructions on the sole of a boot?
There was nothing condescending in my posts, jj. You asked for information. I provided it. I can't help it if you don't like to learn that veneering 1/4" thick walnut to an MDF ground is almost 99.99% certain to fail.
The mention of instructions written on the sole of a boot is an old joke, and I was exchanging it with Dick, and the joke was at the expense of the cabinetmaker that made the table under discussion I linked you to over at BT. There, an owner is experiencing the problems I'd expect using the technique you asked about, i.e., they have a ten year old table top made of 1/2" timber veneered to plywood, and it's warping badly. If you do the same, that's what you'll get, or worse. Call providing you with that information, and suggesting to you an alternative strategy condescending if you like, but to me it's just something I know, and I've always been more than willing to pass on such information to other furniture makers. Slainte, RJ.Some people are born a couple of nips under par. I'm not one of them.
Whew, I thought this was going to get nasty there for a moment......
BTW, I tried that boot trick.. Yep, I wrote the instructions on the sole then pee'd in it and when I went to read the instructions for pouring out the pee it ran out all over the floor. Too bad the same trick won't work for the floor. ROFLMAO....... Just humor Sgian.... Thats all it is.Steve - in Northern California
jj.... As far as what Sgian is saying about the process. He's right... Matter of fact I've yet to find a time when he's ever written anything on this board that wasn't absolutely good advice. Some of it might seem a little caustic at times but I think its because he gets frustrated when he has to tell us how to do things correctly more than once. I too get that way when people refuse to listen to good sound advice. BTW, I don't mean to include you in the later group. I think your question has been answered and you are attempting to find a better way to solve your problem now. This is a very good place to find the answers you need. Steve - in Northern California
Thanks Steve, that I am. As for Sgian, I don't doubt that his advise is sound. I simply infer from his tone that he dervives alot of his sense of worth from being RIGHT.
I think he'd feel better about himself if he balanced WHAT he's saying with HOW he says it.
Ah, well jj. You know nothing about me, and I obviously know nothing about you. There was nothing in my 'tone' for you to infer. I simply passed on what I know. Being offended by my 'tone' is like being offended by any other professional that you turn to and provides advice that you don't like the sound of. I don't circumlocute, and a spade is just that, not an earth moving implement. Political correctness is not one of my strong points. I'll carry on posting the way I do, and I'll feel just fine as I always have, and always will. If you don't like what I say there is an option on this board that allows you to ignore all my posts. Slainte, RJ. Some people are born a couple of nips under par. I'm not one of them.
So. My latest plan. I went out and bought some 4/4 walnut. I want to glue up a 36"x72" panel, add a 1-2" 8/4 piece on either end(to give it a mroe substanitive look) w/ 8/4 breadboard ends.
OK? Bad idea? Advice?
Yes Sgian, I'd even be interested in your comments too:).
jj
Not a bad idea at all jj. The breadboard ends can go a long way towards maintaining flatness, especially if the top overhangs from other restraining structural elements by a long way, say 12" or more. It's a nice feature and very attractive if used decoratively as well as structurally. If there are other structural parts that will hold the top flat close to the end of the top, I'd question the need for breadboards. With solid tops you often, but not always, need to find a means to hold it down flat, yet allow it to expand in the width- it depends on the structure of the whole. Slot screws are a classic means, and so are 'buttons'.
I'd prefer to move on from our wee spat, and you offered an olive branch, so let's just do that, eh? I'm more helpful than new visitors to forums I visit sometimes realise,..........but I'll never back off from a fight if I'm in the right mood. Slainte, RJ.Pass the Prozac--------pass the Viagra. I've always wondered what it's like to be a dozy stiff.
While I have nothing technical to add to this discussion, and I'll certainly stay away from the hydrant marking that's going on here, I do have an observation to throw in: Many, many decades ago, furniture often came with veneer upwards of 1/8" to 3/16" thick. Having been in the business of selling antiques and "vintage" (pre-1950's) furniture for several years, I handled several pieces such as this. Now, I have no idea what type of substrate they put underneath the veneer, but separation/creeping/cracking were not a problem.
Maybe there's a restoration specialist out there somewhere who could chip in with some info.
I think you'll find that most often in those cases that would correspond to this issue, the substrate was solid wood of a lesser value, and usually with the grain in the same direction. the whole panel was then treated as timber, not ply.
thicker veneer is a huge subject with me, I have a big problem with the paperthin nonsense commercially available and used in "high end" pieces. I tend to try to talk the client into allowing me to make my own veneer in situations where veneer is necessary, or leave the job to others. I just don't understand how something can be marketed as an heirloom, and be absolutely ruined the first time someone drops their keys on it, or hits it with the vacuum cleaner.
but that's a different battle, and one I didn't mean to start - sorry...
the point is, thicker veneer was often used, but not 1/4" - that's a board. at times when it was as thick as 3/16", it was still treated as solid lumber, because it will act that way...
sb
"readjustthetruth"
Scott -- thanks. That was great info, and an interesting post.
I've followed Sgian's posts for a long while now and Knots has been richer for them. (Since back in the days when someone posted a jpg of a canned Haggis) Just listen to his Scot's burr when you read him and his tone is just right.
BJGardening, cooking and woodworking in Southern Maryland
Hi BJ! I don't take any offense at all from Sgian's posts or his tone -- it's pretty obvious he feels he's head-and-shoulders above the rest of humanity in many regards, and he's entitled to his opinion Me? I prefer human frailty to sainthood any time.
Whenever someone gets "snippy" on this board, I just re-read Michael Dresdner's words from his statement in January of this years (emphasis added):
Well, it's the 9th inning at Safeco field and the Mariners are about to attempt a miracle come-from-behind win, so I've got some seriously important cheering to do from my livingroom bleacher seat.
Forest, I'd lost track of this thread, having not visited Knots for a few days, so I didn't see your comments. Interesting. You're pretty good at lifting your leg on the hydrant in an understated manner. Perhaps you have my personality traits nailed down to a T. Perhaps not. And perhaps you arrived at those conclusions after checking out some of my contributions to Knots. Might you be a professional psychologist or character analyst to be able to ascertain my character just from what I say here? I can discern little of your character from your recent posts, with the exception of some inkling of what your experience is, and knowledge is, regarding the subject of woodworking.
You say you worked with antiques for years, "Having been in the business of selling antiques and "vintage" (pre-1950's) furniture for several years, I handled several pieces such as this. Now, I have no idea what type of substrate they put underneath the veneer, but separation/creeping/cracking were not a problem." In all those years of working with antiques I have to assume that were you were unable to look beneath the surface, unlike my character which was instantly discernible, apparently?
It happens that I do know a bit about furniture making. Doctors, lawyers, physicists, mathematicians, chemists, land surveyors, plumbers, electricians, geologists, engineers, historians, geographers, etc., etc., also study their subject, pass exams, and work in their field for a few years too, and some are quite knowledgeable in the field they work in.
Am I head and shoulders above everybody regarding everything in life? Hardly. Slainte, RJ. I've seen more sense in an empty wallet. (Anon.)
Sgian, didn't you see that new button that lets you analyze member personalites by posts. ROFLOL... O.K. I'll stop, its been a long day.Steve - in Northern California
Pine was the most common substrate forest, as any antique dealer that knows their antiques, and studied their saleable items thoroughly would know. Oak was also a common ground, along with chestnut and ash. How do I know that pine was the most common ground? Simple. I've taken apart, repaired and restored more western antiques than I really care to remember, including stuff from as far back as the 1300's, which wasn't veneered, unsurprisingly. And those Asians, such as the Chinese and Japanese, and Middle Easterners are really pretty sharp people too when it comes to furniture making.
Why did I repair such pieces? I repaired them because the cracking/separation/creeping of veneer from the ground, along with a host of other flaws is common, and the owners wanted them repaired. Anything made after 1900 is modern, and anything pre- 1837 is antique to me. Maybe you've just joined the hydrant marking group. <g>
Slainte, RJ.
I've seen more sense in an empty wallet. (Anon.)
Edited 4/5/2002 11:48:46 PM ET by Sgian Dubh
Edited 4/6/2002 12:01:16 AM ET by Sgian Dubh
Edited 4/6/2002 2:41:37 AM ET by Sgian Dubh
Edited 4/6/2002 2:52:02 AM ET by Sgian Dubh
Joel -
Something I did once was similar. But where the plywood butted together, I routed a 3/4" groove and inlayed a 3/4" solid walnut strip. I used a sharp bit and put masking tape over where the groove was to be to prevent tear out. It turned out well.
PlaneWood by Mike_in_Katy
PlaneWood
JJ,
My father built me a one-of-a-kind coffee table which is now becoming a family heirloom. Unfortunately, he laminated strips of jarrah wood about 1/4 inch thick onto a 1/2 inch plywood substrate for the top. He wanted to make the strips thick to allow for re-sanding and re-finishing.
The strips of wood have now expanded and contracted individually and are splitting apart. There is really nothing I can do to repair thr table. What a shame, as my dad is not here to build another one!!!
FWIW, I have worked with veneer that is 1.5 mm thick without problem, but would not go any thicker.
Cheers,
Pieter in Perth, Western Australia
JJ, I did not read all the posts to your question so excuse me if I duplicate a covered detail.
I do lots of laminating and have had great sucess with 1/8 or slightly thicker veneer but I would not recommend a 1/4 inch veneer on any manmade substrait. The one time I tried it the joints opened up just enough to be noticed, Not good.
My suggestion would be to glue the veneer to another thicker walnut board then edge glue everything together the usual way. To hide the glue joint try routing a profile edge so the joint is concealed in the detail of the profile.
It has been mentioned that the age of the lumber is not an indication of it's moisture content; moisture content is critical in limiting wood movement, so get it checked by someone with a moisture meter, or buy a moisture meter. The lower the moisture content the better. Although technically not qualified to state absolutes in woodworking, I will state that if your walnut lumber has a moisture content of less than 9%, you can successfully glue it to an MDF substrate. Keep in mind that the room where the piece lives after it is built will also determine the success of the project; large humidity swings from summer to winter is not good. A humidifier during the winter and air conditioning in the summer is better; climate depends a lot on location, and knowing your location could lead to more specific advice concerning humidity control. <P> Step number two will be to build a balanced sheet; it would be best to use the same veneer on the bottom of the panel as the top; a different species of wood similar in expansion to walnut would suffice. Another suggestion is to thin the veneer to less than 3/16", either before or after gluing it to the substrate. <P> Gluing process; I would suggest edge jointing the pieces carefully and flattening the surface to be glued to the substrate carefully. Then apply glue to the edge of the veneer, and hold it together with masking tape, or veneer tape if you have some handy. Then use a sheet of 1/2" or if you have 3/4" ply that would be better, and a sheet of plastic between the ply and the veneer, clamp it down using cauls (boards on edge) that extend over the width of the panel. Books are written about this subject, and although you really don't have to know that much to make it work, it is an intersting subject. It has been mentioned that this would be a considerable amount of work (I agree), and solid wood would be better (I disagree). I love to see wood salvaged and put to use, and hate to see 38" diameter walnut trees pushed into a trash pile and burned. It could be an interesting project that teaches you a lot if you tackle it.
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