Tuesday, September 30, 2014

A Square Deal (15)

Post 15 in a series describing the design and build of a pair of tables in bubinga.

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Back at business after a 10-day hiatus, time to work on the two tables for my client on the West Coast. I spent the morning working on the drawings and ironing out wrinkles, taking dimensions, etc. Hit the shop for the afternoon and made some decent progress on the smaller side table.

Here are the parts I have moved along - the stretchers on the left and the posts on the right:


The stretchers have haunched tenons, with the two side stretchers also incorporating a dado for the floating panels in those locations:


Another view:


The mortises in the post associated to the stretcher tenons are also completed, save for final fitting:


A mock-up of the stretchers and posts-  the tenons will just insert but the mortises are about 0.003" tight and need a little massaging yet:


With a softer wood, one could push the parts together I'm sure, however with bubinga there isn't much room for grain compression. I'll probably try a little pre-compression (ki-goroshi) fitting so there is a slight interference fit - we'll see how it looks tomorrow.

A closer look at one of the junctions:


Another:


Over to the coffee table, I discovered upon return from my trip that two of the stretchers had bowed slightly, which was a drag. You could call it curly wood syndrome I guess. Luckily I had just enough extra for replacements. I ripped some more material to give three stretchers, along the way producing thinner boards for the side table's drawer front and infill panels:


All stock is rift~quartersawn on this project, save for the coffee table top.

So, things are moving along smoothly so far. All for now - thanks for your visit! On to post 16.

Sunday, September 28, 2014

Tilt and Turn

I've just returned from a week in Colorado, where I took a workshop in European window making. The workshop is put on by a company called Rangate through their Alpine workshops Division. Rangate is headquartered in Vancouver B.C., with an office as well in Washington State. The workshop itself was hosted by Joe Calhoun at his shop in Ouray, Colorado.

Ouray, pronounced 'yu-ray' by the locals, is a stunning small town nestled in a Rocky Mountain trench. It's located a couple of hours up a steep and windy mountain road from Durango in the south, and is one mountain ridge over to the east from the Telluride Ski resort. If you like vertical granite walls on all sides of you, Ouray is a beautiful place to spend some time. If you like riding trails in a Jeep, Ouray is without doubt the center of the universe for such activities. I've never seen more jeeps in one place before. In the winter, Ouray hosts a major ice climbing championship.

Joe Calhoun has been living in the area his whole life, and has operated a woodworking shop since 1976 or so. He initially had a shop space attached to the side of his house, but now houses his shop operations in a generous 40'x100' metal building. Like me, he started out with relatively humble equipment, like Rockwell saws and planers, found them lacking for various reasons, and then gradually moved up the ladder to SCM, etc., and finally, after a particularly good run of years, to Martin. His shop is one of the sweetest I have come across, and if you like German heavy metal, what greets the eye is surely going to cause a certain amount of drooling.

He graciously allowed photos of his shop, so I thought I share a few highlights. Here's his jointer planer combo in the nested configuration:


A Graule 170N radial saw:


Those Graule's are just awesome saws. Heavy, solid, accurate - quintessential German equipment. These saws, despite their weight, are also taken to site by German carpenters.

A Maka oscillating horizontal mortiser with vertical drilling attachment:


He has two Martin shapers. This one shown below, a brand new T-12 with sliding table:


It's very similar to my T-20 shaper, and it was interesting to see the various small changes that have been made to the new machine and its attachments. The feeder and its adjustment arm were pretty cool.

His older shaper is a tilting spindle T-27 with extension tables fitted to both sides and the large pull out support:


He also has a T-72 sliding table saw with the parallelogram miter fence, and I was excited to get a chance to play around with it a bit.

The big ticket item in Joe's shop, however, was not a Martin and was not made in Germany. It is a Soukup window making machine made in the Czech Republic:


You're looking at about $150,000 in the above photo. While it is a huge machine to my eyes, it is in fact the smallest model offered by Soukup. Essentially, it is a combination of shaper and tenoner. The shaper portion is found to the left of the operator, on the side which says 'Crafter', while the tenoner with a massive automated sliding table is on the right side. The operator spends most of their time at the front corner, near the touchscreen. A conveyor belt on the left allows for cut parts to be circulated back to the operator.

Tooling for European window making, especially when it involves tilt and turn windows, requires a lot of tooling. Here's one side of one of his tooling racks, to give you an idea:


All the above tooling is made by Zuani, an Italian company. The tooling costs for making windows can quickly dwarf the cost of the shapers themselves. A basic tilt and turn window set of cutters starts at around $13,000 or so, and can climb to $40,000.

When you make windows, you often have to make dozens of them at a time, and having certain specialized piece of equipment can be most helpful to expedite production. Below is an assembly table with a built-in Omga miter saw:


The table has sliding pins - note the white plastic pins sticking up in the above picture. The pins register against the inside of the window sash unit, thereby setting a dimension. Once the sash is registered, there is a stop which is set to the correct distance for cutting the mitered bars that trap the glass in the sash. It makes it incredibly quick and easy to precisely miter cut those parts so they fit into the sash perfectly the first time.

Joe uses a Hoffmann MU2-P dovetailer to assembly the mitered frames. The dovetailer cuts a female dovetail slot crosswise down the face of the miter and after the two miter halves are glued and brought together,  a plastic or wooden butterfly key is hammered in to secure the parts together. I'd seen one in a picture before but it was great to have a chance to come across one directly and cut a few joints on it. It seems a logical solution for the joining of slender scantlings, especially when many parts must be cut and the completed frame is not subject to high stresses.

As for the course itself, I thought it was highly worthwhile. I am sometimes in the role of teacher in my life, and because of that also relish opportunities to be a student at times. For me, investing in my career means investing in not only tools and materials, but training. Woodworking is not a static field of endeavor. I'm an autodidact for the most part, but if there is a learning opportunity out there with someone clearly experienced in a thing I am just trying to get to grips with, then it seems worthwhile to go and visit them if the opportunity comes along.

The Alpine Workshops Tilt and Turn Window course costs around $2100 for 4 days, with accommodation, food and travel on top of that. Normally this window course is for 4 students, however 2 of them dropped out before we began, leaving only myself and a fellow named Steven from Utah. That meant we received about twice as much personal attention as otherwise, got to do more hands-on work, and, as we got through the material more quickly than a group of a larger size might manage, we had extra time at the end to delve into other material, most particularly shaper operations. Joe has almost all the Aigner gear for shapers, so it was great to be able to go through a bunch of different shaper operations using those specialized jigs and fences. I really felt like I got a lot out of my time there.

On top of the wood cutting and shaping - virtually the entire course was machine woodworking based - there was instruction in finishing work, which I hadn't known ahead of time would be included. Getting the finish right on exterior doors and windows can save huge on expensive call backs due to failures in the finish. Also present for the course was Robert (Bob) Bein, a 3rd generation specialist in finishing from Long Island, New York. Another experienced finished from Colorado, Larry, was there to study under Bob, who was showing some new Italian finishing materials and methods from Sirca.

I'm no whiz as far as finishing work goes, and have tended to stay within an somewhat narrow range in my approach. I have seen other many woodworkers relying upon solvent-based, sprayed pre-cat lacquers, and the whole scene has not appealed to me in the slightest. I'm not willing to expose myself to toxic chemicals and fumes, or at least keep that to a minimum, and the finishes produced by those methods have always seemed a bit plastic-y to me.

What Bob was demonstrating during the workshop however was quite different than what I had come across previously. For starters, these products were water-based, and were applied in a manner which was quite counter-intuitive to anyone who has applied more conventional finishes. The first thing he showed was a three-step system for exterior woodwork. First the wooden assembly, a small window frame in this case, was literally showered in a priming material called an 'impregnator'. This did not, as the name might suggest, lead to the window having, ah, little window offspring, but rather it is a liquid which soaks into the wood and provides an anti-bacterial/anti-microbial treatment. The wood is dunked/soaked in this liquid and hung up to dry almost like laundry, with any drips soaked up with a sponge.

After the impregnator has dried, about half a day later, the base coat is applied. The base coat is a water-based viscous liquid that is sprayed with a slightly modified spray gun. The spray gun holds a clear plastic pot which contains the base coat loaded into a plastic bag. A separate air line runs to the pot and pressurizes it. The coating comes out of the spray gun partly by suction and partly by back pressure. What's interesting about the base coat is that it is applied very heavily - so heavily that most other types of coatings there would be runs. However this base coat is 'thixotropic' , which means that it is a gel which becomes a liquid as it is sprayed and is able to cling tenaciously to vertical surfaces without running as it returns to a gel. It dries hard from there in about a day. Bob applied the base coat to a 14 mil. thickness.

The next day, the base coat was dry, and through a cross-linking process chemically, was stretching tight and quite even. We then gave it a light hand sand with 320 grit paper and I was surprised that the finish didn't clog the paper at all and was very easy to flatten.

Then came the top coat, also a single application, and a resin which was even more viscous than the base coat. It was applied in a similar manner to the base coat, also to a 12~14mil. thickness.

The above describes a film-forming coating, which makes sense on doors and windows, and carries a 5 year warranty from the maker. It was a really simple process to follow and fairly goof-proof if you ask me.

For finishes which are 'closer to the wood', Sirca also offers an alternative type of impregnator which contains wax that is strongly hydro-repellent. Somehow they have found a way to combine way and water. It is easy to apply this waxy impregnator with a rag, then wipe it off after a few moments. When dry it provides a nice feel of the wood, and a satin sheen. As an exterior finish it would need to be reapplied yearly, a task which is easy to do as it only requires that one clean the wood and then brush on another coat over top of the previous.

I feel like I learned heaps during the course, and as a result feel much more confident about working with my shaper. I also met some great people and enjoyed my time with them. As for making windows, I have a much better understanding of European type windows, including Passive Haus windows.

If I were to describe the key difference between a European window or door - and by that I essentially mean a German type of window - and an American one, the German approach to the window could be easily summed up by this picture:


German door and window construction features stepped interfaces where multiple levels of weather stripping can be applied. The weather stripping itself is quite sophisticated in form. These windows have significantly higher insulation value, especially when using triple-pane glass, and are superior in terms of sound insulation as well.

A picture of a German type of tilt-turn window frame shows this idea quite well I think:


As you can see, the corners connect with an open mortise and tenon, or bridle joint if you prefer. The sticks themselves are generally laminates of three pieces.

A cross section shows the vault-like interface between sash and frame in this type of window assembly:


We also looked at lamination and construction strategies for exterior doors during the course, and different approaches to tenoning on the shaper. We covered a lot of ground I thought, definitely exceeding my expectations in that regard.

As to whether I'll get into making windows on any significant scale, I'm not sure I'll go that route anytime soon. At least I have a clearer idea now of what is involved, process- and equipment-wise, so that is something which has been gained, and I think that I would want to put European type windows on the next building project I'm involved with, if they apply to the situation. Windows are a major architectural component, especially these days, a significant portion of the entire thermal efficiency picture for a building, and are a major cost in the construction. Think of the energy saved across the country, particularly in northern regions, if the majority of houses had decent window thermal performance.

All for now, thanks for your visit. Comments always welcome.

Thursday, September 11, 2014

A Square Deal (14)

A brief update, nothing too major. Nothing to see here folks, move along, move along....

I've got the breadboard ends fitted onto the side table slab, and after trimming the 'horns' off the breadboard ends, cleaned the end surface up with a handplane:


With grain going in every which direction, it is helpful to be able to plane both directions without tearout, and a 60˚ plane makes that more readily possible:


The joint for these breadboard ends is similar to the ones on the coffee table in that there are twin tongue and grooves incorporated:


The main difference is that this side table top has single central tenons instead of the triple tenons as seen on the coffee table. The central dado and tongue portions are held back about 0.01" so as to ensure that the visble abutments on the table surface come together tightly.

Here's the side table top through this stage:


A did some cross-cutting of various parts to get them to length, nothing worth taking pictures of.

I then decided to do a rip cut on a $400 (gulp!) stick of Gabon ebony, which will be used as stock for the double hammerhead locking keys at the table corners on both pieces.

On stuff like this, such an expensive and hard-to-replace bit of wood, cutting needs to be thought about carefully. Certainly not a blasé cut, joint and plane session. If the wood moved too much, or the cut line followed the grain in an unfortunate manner, I would be looking at going shopping for another piece of material.

I needed to rip the stick in half, and judged it would just yield a couple of 7/8" (0.875") sticks if split right down the middle. I would need all that to allow for any movement, hoping to clean up so as to leave stock a hair over 3/4". I marked the cut lines, adjusted the fence on the smaller bandsaw, and started the cut. I saw I was a hair off my line, so I tweaked the fence and, somewhat holding my breath, ripped down the length:


Ebony dust is funny - it doesn't hang in the air but drops straight to the ground and cannot be easily brushed off your skin but you actually need to wash off to get clean.

After the rip, the sticks had bowed slightly, but definitely within reasonable expectation:


The cut quality, with just the regular 10mm Hitachi general purpose blade, was very good I thought:


I like that bandsaw!

Out of curiosity, I checked to see how closely I had managed to split that line. First one board:


And then the other:


Gee, I guess even a broken clock can be right twice a day. Lucky! I'll take it when I can get it.

I'll cross cut each of those sticks before jointing flat and dimensioning. It looks like I'll get enough out of that stick to do all the keys and probably any other mechanical fastening parts, pegs, wedges, etc.

A slight change has been made to the side table design. I realized that with a drawer and dust panel fitted, the space under the table top would catch dust and be tough to clean so I thought it wise to add some blocking strips in the spaces between the pillow blocks, what the Japanese would call mendo-ita. In the initial sketch I made these blocking pieces a contrasting color, though this is by no means decided yet:


In the above photo the legs are shorter than they will be in the actual piece. Besides the contrasting approach, I could use more VG bubinga, or some other wood perhaps(?). The drawer will have a handle fitted, and this is likely to be blackened iron or something like that, and the keys are already black, so.... I'll figure it out.

All for now, thanks for your visit! On to post 15.

Tuesday, September 9, 2014

A Square Deal (13)

Post 13 in a series describing the design and construction of two tables in figured solid bubinga. The first post in this series can be found here, with subsequent posts linked at the bottom of each entry.

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At long last I can return to this project, something which I have been anticipating for a while now. Here's a view of the two tables I'll be building:


I had rough cut the components for the two tables and let them sit for a good couple of months, so they had ample opportunity to move about all they were likely to move. I put fresh knives in my jointer and planer and took them down in size, leaving off with about 1/32" (0.8mm) to spare, as this was a close as I felt I could safely get with the small amount of tear out I was experiencing off of the planer.

Today I took the parts to Berkshire Products in  south western MA, a 2-hour drive, to have the pieces run through their SCM 'Sandya' thicknessing sander. Their machine was the most accurate and modern I knew of within driving range, however it wasn't quite as wonderful a device as I was thinking it might be. The digital readout for thickness on the machine, though reading in the thousandths of an inch, turned out to be out of calibration by nearly 3 hundredths of an inch - and showing a larger dimension than actual of course - which resulted in the first two pieces run through going slightly under dimension. I quickly adjusted the numbers I asked for, and the rest of the pieces were run through without incident and the work was done in under an hour.

Returning to my shop, I unloaded the material and then went to put a fresh set of knives in the Super Surfacer. The insert-knife stock is easily removed by taking out 5 bolts, though strictly speaking the knives can be pulled without taking the knife holder out at all. I prefer to remove it as I can more easily clean it up and inspect it for condition. With the holder out, the osae-gane for the knife is removed with six smaller bolts:


With a new knife fitted in place- it snaps into place with the aid of several incorporated rare earth magnets, the osae-gane is re-positioned - here you can see one of the two metal tubular pins which serve to reference the position on the lower edge:


Interestingly, with this quick-change knife system, the osae-gane is not positioned especially close to the knife edge, as it would be in a hand plane:


The trick Kanefusa uses to obtain a chip-breaker effect it to machine the chip breaker directly into the back edge of the knife, as this drawing shows:


Component 4 is the knife. If you look closely at the photograph shown just before the above illustration, you will be able to see the chip-breaker groove in the knife's rear surface. Neat!

With the knives fitted back into the machine, it was time to run some curly bubinga through. I've read some accounts where people state that Super Surfacers aren't so good for hardwoods - you know, those Japanese carpenters mostly work softwoods so none of their tools are suitable for hardwoods, etc., and one would think that given bubinga is pretty hard stuff, and that it is curly to boot, this would form some sort of insurmountable challenge for the machine. Well, not so much:


The surface left behind was completely tear-out free, even though the grain reversed every few inches:


I don't think I could do any better with my handplane in this material. I decided to take all the stock down to dimension with the surfacer. When I was done, there was quite a bit of 'bacon' under the machine:


By hand this would have taken me most of the day, with multiple resharpenings and likely some frustrations here and there with tear-out. Instead I was done in 40 minutes:


I am very happy to have this machine in my shop.

I was able to run the side table top through the surfacer as well, by removing one of the side rails and running half the board at one time:


Other than the table legs for the side table, which are slightly under dimension as a result of the initial sander passes this morning, all the stock is straight, clean, and within a few thousandths of an inch of the target dimensions. I will be able to adjust for the slightly undersize coffee table legs - they are only undersize by 2 hundredths of an inch.

I'm still ironing out minor design details, but will certainly be proceeding in on the coffee table soon, right after I have put the breadboard ends on the side table. As this process is much the same as the one already shown for the coffee table, I won't be photo-documenting and describing the steps. Look for more post in this series in coming days and weeks though.

Thanks for dropping by the Carpentry Way. On to post 14