Thursday, November 6, 2014

A Square Deal (36)

Before returning to the table build, here's a pic of the finalized arrangement of two 55 gallon drums under a pants wye at the end of the cyclone, carrying forward what was described in the preceding post about the revamping of my dust collection system:


An amusing thing happened when I turned it on for the first time. The two drums were placed about 8" apart from one another, and when the system was powered up the suction was sufficient to lift the empty drums very slightly and cause them to slide close together until they touched. Now that's suction! The revamped system seems more powerful with greater CFM rate, however it also seems slightly louder too. I plan to build a sound-deadening enclosure around the motor and impeller assembly soon enough. I'm happy with the results of the changes made to the system. This should serve me for a good while.

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With the side table build, things are now moving into the finishing work, which commenced with a new finish I am using:


I decided to move away from oil-based finishes with metallic dryers, like Waterlox, etc.. After the Colorado window making course a couple of months back, I saw the benefits of the newer types of water-based finishes, especially the minimal VOCs and easy clean-up of brushes, etc., with soap and warm water. I also like the getting away from the hazard posed with oil based finishes in terms of the disposal of oily rags. Water-based finished dry by contact with the air, rather then through the agency of metallic driers.

Also, after reading Bob Flexner's books on finishing, I came to see finishes a bit differently, and realized that any finish I was going to be using contained resins, and the type of resin that dries hardest, and yellows the least over time, is one that is (poly)urethane based. Waterlox, by comparison, uses a phenolic resin base. General Finishes Enduro-Var has an added component so it imparts a slight amber tone, which I was thinking would impart a slight darkening to the bubinga. I also liked the quick drying time of this product as compared to oil-based finishes I have been using in the past.

So far, yesterday I put one coat on the legs, stretchers, and apron parts. Today I sanded those parts with #320 paper, and had no problems with clogging. It cut cleanly and easily. So far so good.

So, a second coat now on the legs, aprons, and stretchers:


It was a super overcast grey day today, with steady rain, so the lighting was rather dim and everything looked a bit dull when I snapped the photo, for reference's sake.

I then got into a session of finish planing the table top:


Quartersawn curly bubinga is something I prefer to tackle with the 60˚ single blade kanna, my dear friend Mr. Tenkei:


The top edge of the top and the breadboard ends have also been chamfered (not shown).

A while later, the top was into its first coat of finish:



At the end of the day I had a few more parts getting into the finishing round, like the drawer floor panel:


And the drawer walls, the dust panels, and the rear demountable panel:


Moving along steadily. the next few shop days will be pretty much a repetition of today's work.

Thanks for your visit. Post 37 anyone?

10 comments:

  1. CHRIS;
    Glad to here everything is up and running again. The new finish looks nice. Will you be giving a review? Want to see the hammerhead design! I think I know how it is assembled. Thanx again!

    J.T.










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  2. So i understand that there is no glue in the project, why then is there no finish on the joinery? Are you worried about the wood swelling and joints not fitting? Also with the waterbased finish now are you pre raising the grain or did everything turn fuzzy after that first coat of finish.
    Keep up the great work.

    John G.

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    1. Hi John,

      good to hear from you!

      There is no finish on the joinery as it would make the joints too tight. I'm trying to keep the finish out of joint intersections, though I will put a dab on the ends of tenons which will be of the through variety.

      The Enduro-Var did not raise the grain to any noticeable extent. I think it might do so more overtly in other species, however in bubinga I noticed no grain raising. Keep in mind though that the material was planed before it was finished, rather than sanded. Planed finishes don't tend to exhibit much grain raising as compared to sanded finishes.

      ~C

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  3. Hi Chris,
    Did You test the water-based finish on bubinga before or is this Your first time?
    (Sorry: Stupid question, but I had to ask.)
    I had bubinga project years ago and I had very many problems for lacquer to peel off/chip off like the wood surface had been sprayed with silicon. (which it was not.) Partial solution for that problem was French polish, and 20 times more labor. In the end I was forced to redo the project from santos palisander with great results. But I could not get bubinga´s great red color. I´m somewhat jealous for those cool red bubinga pieces You have there.

    I´m always very delighted when You update. Its very cool to see how You use European Martin machinery and Japanese hand and machine tools side-by-side. Your enthusiasm for details is empowering. It feels even here, in north Europe. Keep up the great work.

    Yours,
    Jukka

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    1. Jukka,

      thanks for your comment.

      Interesting to read of your troubles finishing bubinga in the past. I have never had any issues with adhesion with the wiping varnishes, like Waterlox, which I have used in the past. Bubinga is not an oily wood either, so I am puzzled why you had those issues - perhaps it was something to do with the lacquer finish itself? Mybe something got added to it by mistake somewhere down the line.

      Bubinga also glues well, and woods which glue well typically do not have issues with finish adhesion as far as I'm aware. It is the oily and waxy woods which typically present the challenges in that regard.

      This is my first time using Enduro Var, however I was not apprehensive about trying it out, and certainly wasn't concerned with adhesion. So far, two coats in, I am finding it easy to work with and am impressed. No problems so far.

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  4. Hi Chris, I appreciate your effort at bringing the values of past technologies into the present, so I am curious, why not use the traditional finishes historically used with this type of construction? How does urethane fit into the goal of a repairable, long term product? I'm not a nitpicking purist, I'm simply curious. Great work as always.

    Peace,
    Harlan Barnhart

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    1. Hey Harlan,

      thanks for the comment and that is a great question, worth taking a moment or two to consider.

      "..traditional finishes historically used..."

      Well, depends upon whether you mean East or West I suppose. Considering 'west' first, according to Bob Flexner,

      "...the best studies done on surviving pieces of furniture to determine original 18th century finishes usually report wax or oil at the bottom of what is now a finish film."

      Waxes offer extremely limited protection to the wood, and must be frequently renewed. It's really not a great choice, especially for a table.

      When Flexner talks about the use of oil finishes in the 18th century, he is referring to Boiled Linseed Oil. BLO is a finish which, to quote Flexner again,

      "[is] easy to apply, they cure soft, so they have to be left too thin on the wood to be protective or durable."

      I've never made much use of BLO. 'Tung Oil', a more 'modern' alternative, is, as Flexner points out, a bit of a scam, since the makers are essentially selling you wiping varnish with some small amount of Tung Oil added. It also cures somewhat soft - a bit harder than BLO mind you - and in order for it to harden in a reasonable time frame, requires metallic driers which are toxic.

      To use genuine 100% Tung oil would mean waiting a week or more between coats, and I'm afraid that is not a commercially viable proposition. My shop is colder at this time of year and i would imagine the coats might take 2 weeks to dry, and then a couple of months wait for it to harden sufficiently to polish out.

      Shellac came into popular use in the early 19th century. Many older pieces which were initially finished with BLO and/or wax were later re-coated with Shellac. I consider shellac to be a less than desirable choice for a table, given shellac's relative vulnerability to damage by coarse or sharp objects, heat, solvents, acids, alkalies- and alcohol. There seems little reason to choose shellac as a finish over new wood, as Flexner also notes.

      Now, considering finishes used 'east', there is of course real lacquer, which comes from the poison ivy plant and requires special conditions to cure properly and an extended period of time must be allowed for the finish to be competed. I am extremely allergic to poison ivy and have no desire to work with any product containing urushiol. So, that's out.

      The finest pieces of Chinese classic furniture were made from Huanghuali, a rosewood. This is a naturally oily wood which is very hard and the only finish choice seems to have been wax. The cocobolo andon I made a few months back was finished just with wax. It seemed an appropriate choice for that wood and for a piece which is seldom handled and which does not see the wear and tear of a table or chair. It's also for my own use- if it were for a client, I might opt for a different finish perhaps.

      To be continued...

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    2. "How does urethane fit into the goal of a repairable, long term product?"

      Again, a fair question. If this table lasts a couple of hundred years, say, then I would imagine it would get refinished many times during that period. A refinisher down the line might opt to strip the finish entirely and put something else on - it's totally out of my control. While I might be concerned about whether someone working on the piece years down the line will sufficiently understand the construction to be able to disassemble the piece without damage, I am rather less concerned with the issue of refinishing. There are many competent refinishers out there and that situation is unlikely to change as long as there is 'civilization'.

      I selected Enduro Var because it is water based, easy to work with, dries quickly, and is non-toxic. That makes it 'non-traditional' right away as the chemistry problems with making water-borne finishes work well only seem to have been solved well in the past dozen years. Early water-based finishes for woodworkers from a decade back had their problems, but these seem to have been solved. The relatively non-toxic nature of these water-borne products, their easy clean up with soap and water, the lack of flammability of the rags, etc., are extremely appealing to me.

      Tradition has never been about faithfully observing something written on a stone slab in hoary antiquity.

      If we think 'tradition' in woodwork is about doing something people did in the 1800's then I am led to wonder if there were people in that day who were bemoaning the fact that things were just not the same as in their idea of the 'good old days'?

      At some point, at the end of the neolithic, maybe there were people that were complaining about the new-fangled metal tools not being 'traditional' - give me a nice stone axe, eh - now THAT'S traditional. Clearly, it's ridiculous, such ideas about the meaning of tradition, if you follow them to their logical end.

      Tradition is about an approach to craftsmanship and the material with which we work. It is about conscientiousness and caring about outcomes, not following some inflexible set of rules. Otherwise it is dead.

      ~C

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  5. Did you explain elsewhere your reasons for applying the finish to the pieces rather than to the assembled table?

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    1. Potomacker,

      thanks for your question.

      The finish is applied to the individual pieces rather than the assembled table because it greatly facilitates the finishing process. Pieces receive between 4 and 6 coats of finish, and each coat is sanded before the next one goes on. If the pieces were assembled, sanding the intersections between pieces, again and again, is much more onerous a task, and tends to result in a slight build up of finish at the junctions where it is most awkward to work. Imagine sanding between the junction of the pillow blocks and the underside of the table top, for example. Also, if you finish after assembly, even if you did everything perfectly, a piece could shrink due to seasonal movement and the edges around a panel, for example, would reveal an unfinished perimeter. You see this sort of thing on some factory finished pieces - the kitchen cabinets in our house as one example.

      The trade off to sanding the pieces individually is that it can lead to difficulties when fitting up, due to excess finish getting into dadoes and mortises, panels becoming slightly too fat to fit, etc., so you have to take care to mask these areas and also inspect and clean them out thoroughly before fitting the parts. There is also the risk that there may be some uneven junctions between parts which fit flush to one another, like the breadboard ends and the table top in this piece, due to disparate amounts of finish build up. How I deal with that is to fit the parts together about halfway through the finishing process (necessitating the removal of masking tape on the parts) and go over the junction to level it out. Then the parts are separated and re-masked for the remaining coats of finish. If, in the final assembly, I discover a slight unevenness along a junction, there is plenty of finish built up there to allow for a final smooth out.

      There remains the possibility that the drawer front will need some final fit tweaking after it is finished and assembled, however that will only involve working on the drawer front's top edge, and maybe end grain portions, a relatively minor task to re-coat afterwards, without creating areas which are difficult to sand. The drawer design means that the drawer sides are kept well away from the frame and thus there is no danger of scraping or marring the finish of the sides when fitting the drawer.

      ~C

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