Finishing

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Finishing and SCAQMD

July 15, 2009 in Finishing | 2 comments

I’m back!  I lost some momentum on posting to the blog when I went on vacation last month.  I’m hoping to get back on track and posting about once a week starting with this post.

My hall table was finished with gel polyurethane, which up until recently was one of my favorite finishes.  Woodkote made a very nice gel poly, called Jel’d Poly Kote, which I found to be easy to apply, allowed recoating in two hours, had reasonable build qualities, a generous working time, and gave great results.  What more could you ask for?

How about not changing the product???

Apparently, to meet the South Coast Air Quality Manangement District’s 2006 VOC requirements, WoodKote had to change the formulation.  According to the the MSDS, the old product had a VOC count of 589 grams/liter; the new product VOC is 273 g/l.  The old product had 35-45% naptha and 20-30% alkyd resin, the new product has no naptha and 15-25% alkyd resin.  I’m no chemist, but I know that naptha slows drying, and higher amounts of alkyd resin would(?) increase the build.

The result?  A runny, slow building, fast drying (short working time) product that is no better than any other of the gely poly’s I have tried (Rockler, General Finishes, and Behlen, if I remember correctly).  Very disappointing.

I’m just finding this out now because I finished off my old can in the middle of finishing the hall table.  If you know of another gel poly that is worth trying, please comment.  I’d love to try it out.

Woodkote Jel'd Poly Kote 275

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Adventures in Finishing

May 2, 2009 in Finishing, Hall table | No comments

I have a pretty good handle on finishing, at least as far as hand-rubbed finishes go.  I even received an award for the finishing on a piece in 2002.  The finish was shellac and wax, which on a hard wood like shedua is really beautiful.

But we all make mistakes, especially when we get in a hurry.  In my haste to get the hall table completed in time to make the Design in Wood entry deadline of May 1, I goofed.  The doors, which are MDF panels with applied sawn veneers, had been sanded on a wide-belt sander to get rid of some minor tearout.  They were dead flat, but had relatively large sanding scratches in them.

I carefully sanded them, using a random orbital sander, starting with 120 grit and working up to 320.  I then applied a coat of oil/varnish blend (one part tung oil, one part polyurethane, one part mineral spirits).  The next morning, I took a look at them and noticed an area, about 2″ in diameter, that was a little darker than the surrounding area.  (Insert a few choice words here).  Big scratches…

That was last Saturday.  I knew I had to resand.  A little voice in the back of my head said, “You should resand both doors – they may not look the same after re-sanding only one.”  But I ignored that little voice, and I paid the price.

It went something like this:  resand one door, reapply OV blend (looked really bad); resand both doors, reapply OV blend (didn’t look like the rest of the project); resand both doors to remove all finish and get back down to raw wood, reapply OV blend (finally got it).  I’m leaving out all the painful details:   removing as much of the finish as possible prior to sanding with mineral spirits, uncured oil clogging numerous sanding discs, hours of time and energy which could have been spent on making handles (more on that later).

I knew better.  I would have told a student the correct thing to do in the same situation.  I was in a hurry and thought I might get away with it.

Lesson 1:  Slow down.

Lesson 2:  Listen to that little voice.

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