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  1. #1
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    Default Wood Movement Question

    I am planning to use web frames in the construction of a cabinet with solid cedar sides. This means wood movement must be allowed for. Most of my woodworking sins in the past have been about failure to allow for wood movement.

    I will use dominoes, two per joint. The timber components will be 70-75 mm wide. Only the drawer dividers will be glued into the sides, with two dominoes at right angles to each other.

    In a previous lifetime it was suggested to me that the dominoes should not be glued into the rear drawer divider, to allow the sides to both expand and shrink.

    However, it occurred to me that I might use a dab of construction adhesive or similar in the joints normally left dry. My purpose is to ensure the web frames stay together during assembly and to stop the dominoes "rattling" in the drawer divider. Does this sound like a workable approach, or is the construction adhesive likely to be too strong to allow movement to occur with seasonal changes?

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  3. #2
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    We need a sketch Of what you want to do .

    Rob

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    The tenons are shown in red and blue. Red is not glued. Blue is glued.

    Web Frames Glue.jpg

    The tenons into the sides of the cabinet are shown in pencil at the ends of the drawer dividers. Planning on using two for each joint, at right angles to each other to ensure at least one glues long grain to long grain.

    The front of the cabinet (drawers) are the same shape as the sides. In the sketch below the legs and frame are assembled with dominoes.

    FRONT ELEVATION.jpg

    On top of that sits a 24 mm thick frame that has a routed edge which protrudes about 20 mm past the bottom edge of the superstructure which sits on top of that routed frame, in a similar way to the pics below of a craft cabinet. However, the sides and top of the craft cabinet are laminated MDF (finished thickness of laminates is 2 mm), so no allowance for seasonal movement is necessary.

    Rework 4.jpgRework 1.jpg

  5. #4
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    So this cabinet has a top and bottom and those frames are what your wanting to do ?

    Or this cabinet is a chest of drawers and those frames are to be used in between each drawer as well as the top of carcase and the bottom ?

    Just another quick sketch of the carcase and where your using these frames would be good .

    From what I can tell though . No don't do it that way . If its the two things I questioned above .

    That design would allow expansion but not shrinkage .

    Say its a chest of drawers.
    If you do a frame like that just glue it all up and build it so its 20 to 25 mm short of the back of the cabinet to give the back room to move in , for shrinkage space . The Back has to be fixed to something so another solution to that problem has to be solved for the top and bottom of carcase. So I'm talking of the frames between drawers. The top and bottom could be done the usual way.
    Domino glue it at the front L&R to the cabinet sides and screw it to the chest sides down the left and right sides . With no glue.

    The frame idea adds more work and problems to something that was solved a long long time ago . I dont know what your building though so give us a look at the whole thing your thinking of making in a quick sketch please.

    Rob

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    Perhaps, Rob, it would be better if you outlined your preferred approach.

    I have done a bit of reading. There are many approaches one might use to overcome seasonal movement. The last I read recommended that the front and rear drawer dividers be tenoned into the sides, and that a trench be cut into the sides into which a drawer runner was fitted, unglued, and held in place with nails. I am assured that this is one time honoured English approach.

    I am not after a time honoured approach specifically - just one that will work. In the above case I am a tad concerned about torsional rigidity, although the back and top will help.

    The approach outlined in the top sketch (red and blue) was one a senior woodworker here recommended some time ago. A 2-3 mm gap was to be left between the unglued timbers so they can shrink as well as expand, as noted in the sketch. I am a little concerned that it might be fiddly assembling the web frames with the sides when the rear drawer divider is not glued into place.

    If anyone has bright ideas on other approaches, I'd be pleased to hear them.

  7. #6
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    John . I started typing my last reply and at that point the only picture I had seen of yours was the frame . Not the three under that .


    John . I'm a Cabinet Maker and so was my Dad . And we lived in a sea of Antiques . As far as I'm concerned and by what I have learned there is a few simple well and truly proven ways . And plenty of silly ideas after that . Specially since the internet has been around .

    Your way with the trench behind the front rail and a nail up the back is a late faster way of one of the best ways .
    A dovetailed front rail and trench behind that with a drawer runner fitted and held in there by a dust board sitting in a slot is one of the best ways . The whole piece can breathe and move and live on forever .

    First . Your grain is running up and down like the arrow I drew in isn't it ? All this is worth nothing if its the other way around . I went and looked at your other post so I think it is that way ?

    What I am drawing here has links to the best ways but was more a later cheaper faster way . Not as good but it worked .

    Your top and bottom can be done like the top piece I drew , a front and back piece , dovetailed in . Or like the bottom I drew , A whole board dovetailed in . Of course they are left back a bit at the back to receive the back of the cabinet. .

    The front drawer rails are dovetailed in and either left proud and the front of the dovetail chopped off , the front left of the cabinet gets a thin 3mm to 4mm veneer glued over to hide the dovetails . Or the Rails are put in flush and the front of side and the front of rails are covered with veneer or mouldings .

    Instead of a channel behind the drawer rails in the sides, a small tenon on the drawer runner fits into a slot at the back of the drawer rails and the runner is just screwed or nailed to the side with a touch of glue at the front .

    The mid runners also have a tenon and fit and glue into the middle of the drawer rail slots at their back and sit up level with the left and right runners . The back can have thicker vertical pieces runung down and be trenched to take these mid drawer runners or a faster quick way is to glue and skew nail them through the back .

    IMG_3646.JPG

    So with this the sides can expand and contract , they are held from bowing in and out though by the way the top and bottom are fitted. The drawer runners need a gap at the back, 19mm will do on a small thing like that . And Cedar is super stable . The only slight problem could be if the thing shrank , the mid runners would be flexing the back out and having an effect of the front rails . This is something that has never been solved if the mid runners are fixed my way which is what you see most of the time . A solution would be to fit cross rails to the back and rest the mid runners on that with a gap for shrinkage .
    The front rails being dovetailed in means its never going anywhere . Just a domino there and warpage means its opening up if the glue fails. Torsional rigidity will be fine in such a piece.

    Regards Rob

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    Do you have an inverted router in a table ? For running the slots ?

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    Thanks, Rob.


    You have given me much to think about. Sorry about fouling up the placement of the pics. I edited an earlier post instead of making a new one.


    The grain does run vertically, as your arrow indicated. I suppose that's a large part of why we are having this conversation.


    I am yet to cut a dovetail, either by hand or with a router (I do have a Jet 1.5 HP Closed Stand Shaper). This is how I have been making drawers:


    IMG_1784.jpg

    I played with the idea of fixing the top and bottom drawer dividers using the same method; cut a rebate in the sides and glue and dowel the dividers into position. I even toyed with the idea of putting three dividers in place, front, centre and rear, to provide additional rigidity. But the problem of gluing long to short grain arises again.

    The front of the cabinet is the same shape as the sides, so the drawer fronts will be about 47 mm thick at the top and near the bottom. I had intended for the drawer fronts to extend over the dividers so the dividers are not seen. This means that the drawer dividers are recessed in from the front of the cabinet rather than flush with the front. This is a departure from my normal practice which is to fit the drawers between the dividers, like this:

    IMAG0023.jpg

    In this case, I want the front of the cabinet to be a single flowing line interrupted only by the gaps between the drawers.

    I will now pause to allow some think time. In the meantime, if you or anyone else has a bright idea, I'm happy to see it here.

  10. #9
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    Rob,

    Just for completeness, following is the advice received some time ago about a similar, but easier job. It involves using either sliding dovetails or mortise and tenon joints as indicated. I was concerned that a mortise and tenon joint in this situation glued long grain to end grain. If using a domino, one could turn one or both of the dominoes in each joint through 90 degrees to glue long grain to long grain, which was my plan at the outset of this project. I have a finished thickness of 24 mm in the components.

    Web Frame 1.jpg

  11. #10
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    The saga continues...

    First, thanks again to Rob for being so generous with his time and his knowledge. It's what I like most about this place. Blokes like Rob, Ian, Wongo, PJT, BobL and more than a few others have been wonderfully helpful. Wongo alerted me to my wood movement (and other) sins and has been a great help. Ian provided a lot of advice and got me started with veneered panels, and some lovely pieces using book matched veneers have resulted. BobL guided me as I converted my dust bowl into a cleaner, healthier workshop. PJT was also very helpful. He even visited me in my shop.

    Spent all day studying, researching, understanding my limitations and planning. Read Rob's notes several times (I'm a slow learner, ask Wongo).

    At this stage the plan is to do a practice run cutting dovetails to fit the top frames to the sides, as per Rob's drawing. My thinking is that these dovetails will never be seen, so even if they are not perfect, I can glue them with epoxy and ensure a good joint.

    Rob, I've never used a wide timber board at the bottom (or top) of a cabinet (excepting when using veneered panels), but it made immediate sense. Because the grain is running in the same direction as the sides, it can be dovetailed along the sides because both components would be moving together. Have I got that right? Should I be concerned about different pieces of wood moving at different rates? How about power? In this case, when the wood in the cabinet moves, the thicker timber, in this case the sides, are likely to develop more power than the thinner sections. I think I am over-thinking the issue here, but thought it worth checking.

    Finally, Rob. The plan is to use 75 mm wide timber for the dividers, tops and bottoms. Is it OK to cut one large dovetail per piece, as opposed to two or three smaller dovetails? My current thinking is to cut the tails on the band saw and to clean them up with a chisel. I plan to do the same with the two triangular pieces, ensuring their grain direction matches the tops and bottoms and the sides.

  12. #11
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    Quote Originally Posted by John Samuel View Post
    The saga continues...

    First, thanks again to Rob for being so generous with his time and his knowledge. It's what I like most about this place. Blokes like Rob, Ian, Wongo, PJT, BobL and more than a few others have been wonderfully helpful. Wongo alerted me to my wood movement (and other) sins and has been a great help. Ian provided a lot of advice and got me started with veneered panels, and some lovely pieces using book matched veneers have resulted. BobL guided me as I converted my dust bowl into a cleaner, healthier workshop. PJT was also very helpful. He even visited me in my shop.
    Nice post John . Thanks !

    Quote Originally Posted by John Samuel View Post
    Spent all day studying, researching, understanding my limitations and planning. Read Rob's notes several times (I'm a slow learner, ask Wongo).

    At this stage the plan is to do a practice run cutting dovetails to fit the top frames to the sides, as per Rob's drawing. My thinking is that these dovetails will never be seen, so even if they are not perfect, I can glue them with epoxy and ensure a good joint.
    GREAT Idea !! Just what I was wanting to say to you . I started typing up a reply today saying Its about time for you to start dovetailing . I started going into the details , It started getting complex and I gave up .

    Quote Originally Posted by John Samuel View Post
    Rob, I've never used a wide timber board at the bottom (or top) of a cabinet (excepting when using veneered panels), but it made immediate sense. Because the grain is running in the same direction as the sides, it can be dovetailed along the sides because both components would be moving together. Have I got that right?
    Bingo John !!

    Quote Originally Posted by John Samuel View Post
    Should I be concerned about different pieces of wood moving at different rates? How about power? In this case, when the wood in the cabinet moves, the thicker timber, in this case the sides, are likely to develop more power than the thinner sections. I think I am over-thinking the issue here, but thought it worth checking.
    Yes. The thicker piece will be slower to respond to changes. That's the design though and if the sides are that thick then that's the way it is . Your using Red Cedar . Nice stable stuff . If you use the same wood throughout your doing your best . If your not it'll be ok . It could be a lot worse if your were using some of the more reactive woods . Its not a big issue . You could seal the inside surfaces to help . If the piece is kept in a stable environment then it'll be OK I think.
    By doing the two rail top and bottom , the thick sides and the top and bottom two rails way are not fighting with different movement issues as much as a single board top and bottom any way .


    Quote Originally Posted by John Samuel View Post
    Finally, Rob. The plan is to use 75 mm wide timber for the dividers, tops and bottoms. Is it OK to cut one large dovetail per piece, as opposed to two or three smaller dovetails? My current thinking is to cut the tails on the band saw and to clean them up with a chisel. I plan to do the same with the two triangular pieces, ensuring their grain direction matches the tops and bottoms and the sides.
    With the dovetails in the tops and bottoms of sides, One large is not that good really . With the good old stuff they were spaced every two fingers apart . Either your index and your middle finger side by side at the end or usually the thinner index and middle placed one on top of the other , your middle resting on your index nail sideways . That was the normal size for drawers . If you want to save a bit of time do three fingers per tail . But no more . Its all those tight tail sides to pins that'll give the thing much more strength. And you will be more happy looking at it when its done . A good job never ceases to make you feel like its a good days work .

    You want to cut the dovetails out with a hand saw and cut out the pin space after that on the band saw John . The hand saw gives a better straight DT side than a band saw. There's a little trick to using your grip as a depth gauge and just going in a number of times , not all the way to the scribed line . Then with your hand grip as as top on the table you go side to side . I get it very close this way and try for perfection and never get it . If anything is left make sure its on the right side of the scribe line so a sharp chisel can take it off as a next step.

    This sort of construction is good stuff John . You work out the width of the cabinet and the length of all the rails tops and bottoms . You glue the triangles on to the end of the tops and bottoms as squares so you can clamp them on easy and cut them to triangles later. All over size in length . Then everything is cut to exact length . The squares cut into triangles. And because you cut them all square and exact length a gauge can mark the shoulder length of the dovetails off the ends . Id just do the tops and bottoms first . Get them cut and the carcase assembled with no glue . Clamp a block in a corner to hold it square, And scribe off that at the front positions to get the exact shoulder lengths for the drawer dividers. To be safe .
    You could mark them all out at first and cut the drawer divider dovetails as well at the start but if there is some slight difference in the carcase your in trouble .

    I must be having a god time . Its a long response

    Seeing someone move in the right direction gets me going John . Just get one step at a time right and it'll all fall into place . Your making will be changed forever. If your not sure ask or throw up a sketch first.

    Rob

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    Rob,

    You overestimate my skills with hand tools. I plan to cut the tails using a SUV bandsaw with a one inch TCT resaw blade. It cuts very straight lines very cleanly. The outsides of the tails will be cut very close to finished size with the band saw, after which time I will cut the inside edges of the tails and then a bunch of kerfs finishing just short of the line will be put in the waste material between the tails. Sharpen the chisel and finish them off. Then comes the female part of the joint.

    My biggest concern is the sliding dovetails for the drawer dividers. This is all new to me, so I'll be doing some research about how to set up the shaper to cut these slots in the sides as well as the tails. In fact, if my test pieces are not pretty, I may revert to M&T joints for these ... time will reveal all. If I use the shaper, I'll likely make up web frames so the runner is dovetailed for it's full length (glued only to the front divider) and glue only the dividers into the sides. It will be fitted to the rear divider using an unglued floating tenon ... I think.

    Once the carcass is made, it's easy. I'll cut and shape the drawer fronts to match the sides and so on.

    But this will not happen tomorrow. Spent today doing day 1 of a 2 day bike riding course. Day 2 tomorrow. Wed and Thurs are occupied with grandurchin minding duties. Saturday I pick up a bike. It will happen when it happens.

    It is Surian cedar rather than Aussie red cedar, but it is a very stable timber. Most of my pieces have been made with Surian, NG Rosewood or camphor laurel. The camphor has featured mostly in the jobs constructed with book leaf veneered panels. The cedar and the rosewood are both quite stable timbers. I dropped a piece of Surian into a bucket of water yesterday. It grew from 77.21 mm to 77.46 mm. That means the sides would grow about 1.3 mm if given similar treatment ... so a 1.5-2 mm gap between the runners and the rear dividers should be plenty. Every time I have used high expansion wood, such as Vic Ash, I have bought quarter sawn wood to minimise the movement.

  14. #13
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    Rob,

    Pleased to report that I survived day 2 of my motorcycle riding course.

    When I cam home I walked into the shed and an issue immediately arose when I looked at my sketches. Normally, I would build with web frames. The bottom web frame provides the runners for the lower drawers. If I make it so that triangles are fastened to the top and bottom drawer dividers (as per your sketch for the top divider), I need to figure out how to fit drawer runners to the bottom web frame.

    The obvious solution was to screw and glue in a (say) 25 mm wide piece of timber between the two triangles, but with the grain running in the same direction as the divider and the triangles. Another was to dispense with the triangles and glue in a 77 mm wide piece of timber between the ends of the lower dividers (with the grain running in the same direction as the dividers) and dovetail the whole darned thing to the sides, effectively making a web frame.

    Or do I? The distance between the outer edges of the drawer dividers is 400 mm. Each divider plus its triangle is 154 mm, so the gap between the tips of the triangles is only 92 mm. In this case do I ignore it because the drawer has adequate support from the dividers and the triangles?

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    You going for a bike license John ?
    Id just do the bottom as a whole board like my drawing . That's the only way for the bottom . Unless you did the triangles and they meet with enough for the drawer to run through on . You can do the top the same as well .

    Rob

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    Thanks, Rob.

    The same issue exists for the top frame, because the drawers need something above the sides to cock onto as the drawer opens. Either way, it will get sorted out.

    I got my bike learners permit last night. Bike arrives Saturday.

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