Chair Build Days 4 and 5

Much has taken place in the shop since the last post two days ago.  Yesterday, I pulled another piece from the water and was quite pleased to see a 39% MC reading.  This meant it was time to steam and bend.

After soaking for about two and a half days.

First I had to do a little adaptation to my steam delivery system.  Up until yesterday I had used the 12' hose connecting to special fittings on both the steamer and steam box.  The problem is 12' of hose is 9' too much.  In the past I was unable to get my steambox up to 212 degrees, and I believe it was because of a heat loss in the hose.

Wallpaper steamer requires the fitting on the hose.

Hose fitting to connect the hose to the wallpaper steamer.

 After lopping of 9' of hose I was left with 3' of useable hose with a fitting on one end and open hose on the other.  What I discovered was a 3/8" ID hose inside of the black exterior hose.

Black hose acts as an insulator around the white hose that carries the steam.

 Next I removed the brass fitting from the steam box and on the drill press bore a 7/8" hole that provided a tight fit for the black exterior hose.

Brass fitting was required when using the hose as it came from the manufacturer.

While the steamer was bringing the temperature up in the box, I carved a piece into a 7/8" round bow. I marked the center with a line and an arrow so that I would know what side to put up.  It is best to figure this out before you have a very hot piece of wood in your hands that needs bent in 45 seconds. I mark the wood in such a way that the tangential plane is against the form.  The tangential plane is parallel to the bark and the radial plane runs from the pith to the bark.  This would mean the growth rings would be parallel to the bending form.  I am happy to report that my steam box made it to 212 degrees with ease.

The steam box actually held 212 degrees without a problem

  

The bow was in the box and the timer set for 1 hour.  When working with green wood I will usually steam pieces for 30 minutes.  Since I was working with wood that had been air-dried I rehydrated the pieces and doubled the steaming time, as suggested by Pete in his book Chairmaker's Notebook. While the steaming was taking place I prepared for the bending.  As I said before, once the piece comes out of the box you have a short bit of time to wedge the piece at its center point (arrow up facing the form), bend, pin and wedge the the ends before it cools too much.  When the hour was up I put the bow in the form and bent away.  I was so so happy with the results. It bent like I had just taken the piece out of a freshly cut tree.

The only place where a fiber or two raised , SUCCESS!

 
I attribute the success of the bend to being able to rehydrate the material and being able to deliver a consistent flow of 212 degree steam through out the steam box while using a defect free piece of oak. I was so psyched with the results I carved two more bows and put them into the steam box for an hour.  Well it would be great if I reported only my successes, but that isn't me.

The other two bows came from pieces whose grain was not as straight as it should be (understatement of the week) and as a result I ended up with a few small delaminations.  I was able to use some polyurethane glue and tape to repair those.  This morning I steamed and bent two arms that I carved and they were out of some wood that I most likely should have cut short of the wonky grain and used for spindles.  However I had to give it a go (I need help). One of the arms suffered major delaminations and required glue, clamps and then tape.  At this point this arm has become an experiment.  The other arm fared a bit better but I will most likely burn it also.  It is said that a picture is worth a thousand words, well here you go.

Delamination in the bow caused a kink most likely rendering it unusable.  There is some extra material on the bow, therefore if I am able to fare the curve without loosing to much material it will be used.

This is the repaired delamination that caused the kink.

This arm bent the best but the wonky grained prevented me from being able to keep it flat in the form.  As part of my experimentation I have clamped it to my bench top with holdfasts to see if it will set in a flatter profile.

Moral of the post: If you find yourself wanting to bend pieces like these DON'T!  Seek help!

Five bends with one for sure usable bow and four ahhh maybe's.  I guess we will see how or if I am able to recover.

When the day ends it is time for the clean up crew.  My grandson Zane telling me "I help Pappy".

I have an arm that I had bent earlier so I am good to go there.  I usually bend more than one component just in case, and it appears it was a good thing.  Next I will be carving the spindles and then setting them aside to dry with the bendings from this past session.  Until the next time may you be blessed with straight grain always.

~ Ray Schwanenberger

Chair Build Day 3

I woke up this morning and my foot was feeling good so, after my morning cup of coffee I headed to the shop.  I opened my Quercus alba rehydration device (white oak soaking in water in a trash can) and pulled a thick piece of spindle stock from the odiferous brackish water.  I checked the moisture level with my meter and I am happy to report it measured 29%.  Since the reading increased by 11% in just one day and I had turnings to do and finish carving the seat, I decided to let the rivings continue to soak.

After one day soaking an increase in MC of 11%

I moved onto finishing the carving of the seat.  The seat on a Sack Back is called and oval seat and the grain runs from side to side.  On a kids chair I carve the bowl to approximately 3/4" deep.  I like to have the area where the legs cross over the front of the seat about 1/2" lower than the spindle deck. This makes for a very comfortable chair that does not cut off the circulation to the legs.

I did not remove the extra wood on the back of the seat so I had plenty of material to clamp in my bench's leg vise in order to work on the front and sides of the seat.  I used my bevel up draw knife to make the relief cut to the front of the seat that gives it its distinctive profile.  I then used a drawknife and spoke shave to fair the curve on the sides of the seat.

Front of the seat.

Next I removed the excess material from the back of the seat blank.  I then took great care in clamping the seat in my vise and finished fairing the curve around the back of the seat.  My leg vise chop and the portion of the bench face covered by the chop are lined with leather.  This is to aid in gripping and helps to keep from damaging the material being held in the vise.  A note of great importance; When clamping in a bench vise, a seat blank that has been cut to size and carved, ALWAYS clamp on the spindle deck.  NEVER clamp onto ANY PART of the carved seat.  Don't ask me how I know this will save you grab mental anguish.

Next I removed the material where the legs cross over the front of the seat.  To do this I used the drawknife, scorp, travisher and spokeshave, taking light and deliberate cuts.  It was ultra critical to pay close attention to the grain.  With so many undulations in this area it was very important to ensure I was cutting downhill with a skewed blade.  A slip or misguided cut at this stage could result in a tear out that may not be able to be repaired.

I then finished up with several shaped scrapers and sand paper.  On some of my first seats I didn't use sandpaper.  Curtis Buchanan explained that the seat was the largest surface on the chair and naturally draws ones eye to it.  For this reason, Curtis scrapes and sands to ensure the finish is at a very high level.  At this point I close my eyes and run my fingers over the seat surface.  I have learned that my eyes do not see the surface as well as my fingers can feel it.  The slightest bump or dip is easier to find and fix.

Circled areas are slightly higher than the surrounding surface.  I could not see them but I could feel them. 

After sanding the seat bowl down to 120 grit I planed the spindle deck with my No. 4 hand plane, re-carved the gutter and set the seat aside.  Next I turned the four legs, two side stretchers and the medial stretcher.  I am using bamboo turnings for this chair.  The double bobbin turning is sometimes misidentified as the bamboo turning.

Finished Seat

Bamboo leg turnings

Four different type turnings from left to right:
Baluster; Blunt Arrow or Ball & Cylinder; Bamboo; Double Bobbin w/A Bead

Tomorrow I will check on the soaking oak and begin to put the undercarriage together and attach it to the seat.

~ Ray Schwanenberger

Chair Build Day 2

The big white oak, as you can see it has begun to split by itself.

Above is the oak log that has been residing by my garage for what I have determined is almost two years.  I recruited my future son-in-law to split the white oak into a few manageable pieces for me. When I went out to make it accessible, and take the picture, I was happy to uncover previously split and rived pieces.  You can see them between the log and the wall.

Previously split and rived pieces I uncovered.

While I was unsure what the moisture content of the log would be I was certain that the previously split pieces would be too dry to work with.  I used my froe and rived the largest piece in two and then took a moisture reading from the freshly opened face. As I had suspected the wood was fairly dry, the meter read 18%.

Shavehorse doing double duty as a saw bench.

I cut the pieces for the arm/bow and spindles to their rough length and then using my froe and riving brake rived the pieces to rough size.  Click here to see a video of Curtis Buchanan demonstrating how a froe and riving brake are used.

Enough roughed out parts for uppers of three kids Sack Back Windsors plus some spare spindles.  The pile on the far left is the only waste from the riving process.  

Two arm/bow pieces with a bit of curve in the grain.

Two of the arm/bow rivings had some grain that was a little curvy.  I am not overly concerned with this.  I will carve these pieces following the grain, which will provide me with strong pieces.   Because I will have followed the long wood fibers the piece may not be straight, but it will provide me with the best chance for a successful bend.

Since the moisture reading was 18% I decided I was going to soak these pieces in water for a few days before working with them.  I want to give myself the best chance at making successful bends.  I also want to see, if after rehydrating, the spindle pieces are any easier to carve than they would be at 18% EMC.  After 3-4 days I will remove one of the largest and smallest pieces and take more readings.  If I am able to get a spindle to 25% I will carve it and see how the piece responds.  I am hopeful to get the arm/bow pieces to at least 50%.  I don't know this is all an experiment on my part. I will be posting my not so scientific findings when I find them.

Pieces ready to be rehydrated in a freshly cleaned trash container.

I followed Pete Galbert's advice and sealed the ends of every piece with Anchor Seal.  After allowing them to dry for a few hours I placed all of the pieces into the trash container and filled it with water. As luck would have it I discovered a few holes in my rehydration device.  I have since sealed them with silicone and am waiting on it to dry while I make this post.

One problem, which I'm sure you have already figured out, is wood is buoyant and will not stay submerged unless it is weighted down.  I did think of this however, I figured I would "stir" the pieces every day, hopefully entrapping the floaters under the already submerged pieces, causing them to become floaters.  I did put a clamp on the hinged lid so as to keep a family member from blindly tossing a bag of garbage into my floating punji sticks resulting in something very nasty.


~ Ray Schwanenberger