Replies

1. 
   hdgis1 | Aug 18, 2008 03:34am | #1

   I have no historical reference here to serve my answer, yet I would be inclined to think that cutting these curves out of thicker stock for a couple reasons. Foremost among them are joinery considerations. If cut out of thicker stock, it is much easier to cut the tenons. Cut and shape them to proper size (by whatever method you choose) and then cut curves. If using steam bent stock the rail itself must serve as the tenon. Second, bent wood doesn't want to stay bent. It nay stay that way for 10 or 20 years but it will want to unbend.

   As for the rockers, I'd say there is some advantage to using bent wood. Seems it is easier to keep grain organized in such a way that you can avoid weak spots in rocker. Having said that though, there is precedence for doing it both ways.

   Chris

2. 
   oldusty | Aug 18, 2008 06:21am | #2

   Doc ,

           It may depend on the grain type and specie and the look you want , steamed bent or curved laminations will give a  continuous look and grain pattern in some woods .

          I've cut them out of blocks and laminated also , and the continuous all long  grain direction sure is stronger then the short grain areas that happen .

       For looks , for strength , how about economy , simplistic .

        Most of the Mission furniture that I've seen stained was nice curved flowing q Sawn grain , but the pieces that got painted or " grained " like the original faux finishing may have had bandsawn slabs .As well as secondary woods .

           If you could look through the wood pile and find a slab with a curved grain thang going on , tell them what your doing offer to pay extra to find a board .

               good  luck         dusty

1. 
   Doc | Aug 20, 2008 03:04am | #3

   Thanks for the responses.  I'm leaning towards cutting the back curve out of a thicker piece, but steam bending or laminating the rockers.  I know that steam bent pieces tend to slowly lose their curve, so that was my last choice.  Thanks again for the assistance.

1. 
   doorboy | Aug 20, 2008 05:22pm | #4

   I respectfully disagree with the "steam-bent pieces eventually straighten themselves out" theory. When steam is introduced into the wood, the cellular structure is softened. By clamping it in place, you are actually distorting those soft cells and they will remain distorted after they dry. You actually change the shape of the wood piece.
   There is no doubt that there IS some springback, but after that settles down in a week or so, there should be no more movement.
   Good luck with the project and post pictures if you can. There's plenty of Arts and Crafts enthusiasts on this forum.

3. 
   tom77 | Aug 20, 2008 05:58pm | #5

   Hi, Doc,
   I have built chairs with curved back splats and crest rails, and in each case, I used bent laminations. They are stronger than the alternatives and it is easier to control the curvature. They also preserve the grain pattern of the original blank. If you maintain the sequence of the laminates after resawing, it is difficult to see the laminations after glue up. Bent laminations are the standard way to form rockers. (see Maloof chairs) There will be some springback when the lamination is removed from the form, but this is minimized by using more layers of thinner stock.

   The joinery for chairs is greatly facilitated by using a horizontal mortiser with loose tenons. If you don't have access to a mortiser, there are numerous articles showing router jigs for the same purpose. (See articles and books by Jeff Miller)

   Good luck, Tom.

1. 
   Doc | Aug 21, 2008 01:20am | #6

   I agree that bent laminations would be stronger, but what was likely the original technique on old rockers.  Were the horizontal back slats and rockers typically steam bent, or were the curves cut from thick stock?  I'm don't know any of the specifics of different period furniture, I was just curious what was likely the original technique.  And again, this was specifically to an Arts and Crafts chair.  Thanks again.

4. 
   EarlJ | Aug 21, 2008 04:08am | #7

   Good question,

   I think it all comes down to historical accuracy or practicality and ease of producing. Gus Stickley as with many other 1st and 2nd tier makers of the period would steam bend chair rails. Curiously enough however the curved aprons of many of Stickley's tables were cut from solid stock. Problem with this is that this method does not stand the test of time and failures have been seen on originals at the weak short grain ends. ( This info found in Bob Lang's Shop Drawings for Craftsman Furniture.) And of course bent laminations are a great way to go if your not too concerned about historical accuracy. I think really that is doesn't matter as I'm sure all the latest glues, methods, and machines would have been embraced by Stickley if he was around  now.

   Tenoning curved chair rails is pretty much a breeze. Lay the bent rail across the dry assembled back post assemblies and mark the rails where they meet the posts. Add however much for the tenons and then using a cut off section of the bending form as a backer to ensure the end of the rail is flat to the table, run the piece through the saw for the cheeks using a tenoning jig. Then cut the shoulders as appropriately with hand saw and trim to fit. (Those others who use this method may explain this better than me)

   Craftsman/Mission/Arts and Crafts furniture may not be everyone's favorite but if you want some pretty tough pieces that provide comfort, robustness, substance and ability to withstand children, its the way to go. My Eastwood chair has provided much fun and amusement for my toddler who uses it as a ladder to climb up and ambush his teenage sister. Have fun!.

    

   Earl

    

1. 
   Doc | Aug 21, 2008 04:43am | #8

   I really appreciate your response, but I have to be honest, I'm a bit confused by the method you described.  I understand using the unused cut off of the bending jig as a cradle or support to cut the rail tenons, but you describe lying it on the table saw but also using a tenonning jig, which to me means to stand the piece vertically.  Not sure if you mean to cut the cheeks with the piece vertical in a tenonning jig, or flat on the table saw using the blade to nibble away the cheeks.  And unless I'm missing something, won't the mortises have to be cut at an angle that matches the curve?  I don't see how the back will have any strength if I cut the tenon so it meets the inside of the chair post close to 90 degrees.  Or is it possible to steam bend the ends more straight and assume that it will hold?  Sorry again for the confusion.  The rest of the chair joinery is straightforward, but the handling of the curved portions is new to me.  Thanks again.

1. 
   EarlJ | Aug 21, 2008 06:48am | #9

   Doc,

   I knew I did a poor and labored job of descibing the method to you. I've had a think and I'll try again. The book by Paul Kemner, Building Arts and Crafts Furniture illustrates the method well and shows the set up and orientation of the work piece. What he does is cut a piece of scrap equal in length to 1/2 the length and inside curve of the work piece with the other side straight to mount up against a Delta type tenoning jig. He places the work piece to mate up with the curve so that both the form and the workpiece meet the saw table. You will see that, contrary to my previous instruction that said the end grain should be flat, this method has the rail tucking in slightly which will give you the offset needed.  Boy I could never write a book!

   Hope this is better. My scanner is screwed up at the moment so I'll scan the photo from the book and put it in anotehr post tomorrow.

    

   EArl

1. 
   Elcoholic | Aug 23, 2008 02:21am | #10

   I've always steamed them using QSWO.  As far historical accuracy it would be interesting to research and see what method he published in The Craftsman, if any.  Since the magazine was intended for DIY'rs with simple handtools and basic skills I doubt they were sawn.  Given the technology of the time they were probably steam bent.  No chance they were laminated.John O'Connell - JKO Handcrafted Woodworking

   The more things change ...

   We trained hard, but it seemed that every time we were beginning to form up into teams, we would be reorganized.  I was to learn later in life that we tend to meet any new situation by reorganizing; and a wonderful method it can be for creating the illusion of progress while producing confusion, inefficiency, and demoralization.

   Petronious Arbiter, 210 BC

1. 
   EarlJ | Aug 23, 2008 05:50am | #11

   Same here John, QSWO is the only way to go but Cherry is not bad for the lighter more prairie pieces. I agree that laminations would have been out of the question at the time from both a production standpoint and glue technology. Also, based on issues seen on solid sawn curves for aprons having short grain failures steaming would have been the eay to go. I think they may have cut curved on aprons due to their tighter curved that chair rails.

    

   Earl J

2. 
   Doc | Aug 28, 2008 04:13am | #12

   So assuming I steam bent the horizontal back aprons of the chair, wouldn't I have to cut the mortises at an angle to accomodate the curve?  I don't see how I could transition the curve at the very end so that it can accomodate a mortise that is cut straight into the back legs.  Am I correct in assuming the mortise angle would have to match the curve?  And if so, how do I cut shoulders on a curved piece so that the shoulders meet up leg flush?  Am I correct in assuming that this is a good place to build a jig to hold the curve up and down and use a router to cut the tenons.  As I said, the rest of the construction is straight forward, but this part has me stumped.