I have searched thru the forums until my eyes are red and my fingers are numb. Although I came across several instances of inlays going across the grain of solid wood, I still can’t get my head around why this doesn’t drastically fail everytime the moisture content shifts!?!
Wood expands the most tangentially…across the grain, although quarter-sawn greatly reduces this effect. I have also learned that the rule of thumb is to assume up to 1/4″ of movement for every 12″ of width. Even if the inlay is only 1/16″ thick, it would still need to be glued down at the ends. With all that in mind, how would an inlay that stretches across the grain of a 12″-24″-etc table not split?
Beyond simple linear inlays, would a pattern inlay (e.g. a wolf head) created in solid wood that is about 12″ in diameter also suffer from movement?
Please help the perplexed!
Replies
"1/4" of movement for every 12" of width"
Don't know where you got that, but no specie I know of moves that much, especially when its pared down for inlay work. Different woods-different movement, but with inlay none approach the movement you're referring to.
Consult Bruce Hoadley's book, Understanding Wood, for a fuller scientific explanation.
Edited 4/11/2006 2:21 pm ET by jackplane
Hi Jack,
By no means is the "1/4 per foot" meant as a set-in-stone rule. Every species...heck every board...moves differently. Rather, it is simply a generalization to promote proper design that accomodates wood movement. I have Bruce's book although I need to refresh myself with it. I can't remember reading anything in it (yet) that explained how a piece of veneer will not expand the same amount across it's width as a piece of solid wood of equal width. I guess that is my confusion - the variation in rules between veneer and solid wood.Thx!
"100 Years" -- scribbled on the wall by a woodworker to remind him to do his best and as a warranty on his work -- "If anything I make fails in the first hundred years, bring it back, and I'll take care of it. After that, there will be a small charge. (Original purchaser only)"
I worried about the expansion thing the first few times but have not had a problem with pattern-type inlays in a bunch of wood types, all contrasting woods.
I guess I'm not exactly sure why, but it works.
I have a story about using the inlay kit with a few photos of things I did and to this day, they look like when assembled.
http://www.newwoodworker.com/rotrinlays.html
Tom Hintz
Because there is always more to learn!
Thx! I've checked your site out before but always fun to revisit :)
"100 Years" -- scribbled on the wall by a woodworker to remind him to do his best and as a warranty on his work -- "If anything I make fails in the first hundred years, bring it back, and I'll take care of it. After that, there will be a small charge. (Original purchaser only)"
Z,
I've lain quite a lot of stringing and banding in my time, some shop-bought and some home-made. The longest piece I will do across the grain of solid wood is 12 inches.
It may well be safe to go longer. Whether the inlay will part company from the wood underneath depends on many factors, as I understand it:
1 Different species of wood expand and contract at different rates for a given moisture-content change (applies to both stringing/inlay and the wood in which it's inset).
2 Some glues allow more stretch than others before they fail.
3 Seasonal moisture change in various locales is different. In NW Britain, where I live, the weather is changeable but the humidity tend to stay within a small band. In the most parts of the continental USA, I imagine the humidity changes are much greater.
4 Very thin banding or stringing will stretch a bit more than thicker stuff. Some bandings are deliberately made with their main wood grain at right angles to the length of the banding, so that the banding can stretch or even split minutely here and there whilst staying stuck. But you can't do that with solid stringing.
If a design calls for longer lengths of stringing or banding, I try to use veneered plywood or blockboard as the substrate. This is stable stuff and causes no real problem with long lengths of stringing (or I should say, I have not had any problems). To keep the solid wood look, I tend to lip such substrates and the banded area with solid wood of the same thickness, from 3/4 to 3 inches deep.
Another approach is to make an inlay design that changes direction at least every 12 inches, where it is generally going across the grain. Such zigzag designs may not suit the overall design of your piece though.
Hope some of this rambling helps.
Lataxe
Good points Lataxe. Thx!
"100 Years" -- scribbled on the wall by a woodworker to remind him to do his best and as a warranty on his work -- "If anything I make fails in the first hundred years, bring it back, and I'll take care of it. After that, there will be a small charge. (Original purchaser only)"
zombeerose,
In my experience (30+yrs), a narrow stringing of 1/16 will stay in place across the width of a case or top just fine. There are many such examples of old work from the early 19th century that are in good condition today. Wider strings, say 1/4" and up, fare less well, and will sometimes pop loose at one end or the other, after years of seasonal movement. Wider inlays will hold up better if they have a crossbanding as an element of their design. While hide glue obviously works, I feel that elmer's or titebond give a bit more allowance for differences in movement, in that they are more flexible.
Your figural inlay of 12" dia. will be a safer bet if you can orient the grain of the inlay's elements so that they are aligned with the grain of the board it will be inlaid into. I inlaid a mariner's star into a desk lid once. The long grain points of the star that were inlaid crossgrained would buckle every winter when the lid shrank.
As lataxe pointed out, the safest bet is to inlay into a surface that is veneered, either plywood, or solid wood that is veneered both sides.
Regards,
Ray Pine
Thx Ray. I will keep that in mind about grain orientation. :)How thick were the pieces of the mariner's star that you inlayed?
"100 Years" -- scribbled on the wall by a woodworker to remind him to do his best and as a warranty on his work -- "If anything I make fails in the first hundred years, bring it back, and I'll take care of it. After that, there will be a small charge. (Original purchaser only)"
zombee,
"How thick were the pieces of the mariner's star that you inlayed?"
They were homemade veneer,cherry and holly, about 1/16" thick after I levelled them to the surface of the maple desk lid. Last week I delivered a pair of blanket chests (cherry) with similar stars, 9" x14" of maple and mahogany, with their grain oriented parallel to that of the lids. Too soon to tell how they are holding up ;-) but I anticipate better results.
Regards,
Ray
Awesome - any chance for pictures? Does that mean that certain points had the grain running the length of their points while others, the width? How did you like the final appearance with the wood, especially if the grain direction varied?
Thanks!
"100 Years" -- scribbled on the wall by a woodworker to remind him to do his best and as a warranty on his work -- "If anything I make fails in the first hundred years, bring it back, and I'll take care of it. After that, there will be a small charge. (Original purchaser only)"
zombee,
Sorry, no pics, I don't have a digital camera. A picture of the desk is on my website, here http://www.davidraypine.com/portfolio.php?spgmGal=Desks&spgmPic=4&spgmFilters=#pic
The grain of the whole star runs horizontally. I glued paper to the "non show"face of each veneer with hide glue and then stacked the veneers together with my pattern on top, before sawing the star out. The paper strengthens the short grain (of the vertical points) and keeps the points from crumbling off. After they are cut out, I put the star back together, and glue a paper face onto the whole thing so it can be handled as a unit. Then I remove the paper remaining on the back side, and inlay. After the glue dries, then the paper on the front can be soaked or scraped off to reveal the face of the inlay.
Regards,
Ray Pine
Edited 4/17/2006 10:05 am ET by joinerswork
Thanks Ray. Neat website! You have quite a portfolio - impressive :) Do you primarily use cherry and mahogany for your reproductions?What tool(s) do you use for cutting out the inlay shapes in the main piece? That's a good idea about using the paper. I would only be nervous about soaking the paper off in the end leading to considerable dimensional change but I'm sure you keep that in mind :)Thx again!"100 Years" -- scribbled on the wall by a woodworker to remind him to do his best and as a warranty on his work -- "If anything I make fails in the first hundred years, bring it back, and I'll take care of it. After that, there will be a small charge. (Original purchaser only)"Edited 4/17/2006 12:24 pm by zombeerose
Edited 4/17/2006 12:25 pm by zombeerose
zombee,
Thanks for the kind words.
The woods I use are determined by the customer, I use a lot of walnut, as that's what is popular here in the Valley.
I use an old Sears craftman jigsaw mostly, for cutting out. I have made a treadle conversion for use with fine 2/0 blades, as the motor drive was causing a lot of breakage. I have a fretsaw and birdsmouth for using really fine blades when required for very delicate or detailed figures.
The hide glue releases readily upon application of warm water. You can see when it has penetrated the paper. It does swell things a bit sometimes, but they soon (a few minutes) dry out and return to flat.
Regards,
Ray
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