Scrape, Sand or Both?

Al,

It seems to me that the New England guys were going for reflective carvings with smoother surfaces.  I think the Philadelphia folks wanted a textural difference between carved surfaces and uncarved.  That doesn't explain why they would leave in rasp marks tho.  I've seen those on chair backs and things.  Funny what they left in. 

I always wonder if the sanding wasn't done in refinishing.  One thing that's not been mentioned is that rushes and sand paper really are the bees knees for rubbing out finish.  I think if sand paper was used, it would make a lot more sense if it were used for veneer and for rubbing out finishes. 

To Don's point, I don't know how conservators can tell one way or the other.  Whether the sanding was done initially, or if it was used to sand off the original finish.  I just don't know.  When you analze the layers, how do they know the lowest layer is the original.  The original surface could have been sanded or stripped away. 

Don,

I like what you are writing.  I've asked these same questions (of more than a few guys).  I get the impression that they are sticking with their answer.  According to what I've heard, 1760s-70s high style Phil Chip type stuff had very little finish.  I would also suggest contacting Chris Swan in Colonial Williamsburg. Last I talked to him, he had the same answer, tho too. 

Adam
 
Adam- Yeah, there was a lot of sanding in refinishing, and since almost everything we see has been refinished at some time or another, I think it gets really hard to tell the sequence of what happened when.
When I see tool marks- ones that seem to be good enough that they were from someone familliar with their proper use- under a thin finish, or with little or no finish, then I assume I'm looking at "original" finish. When the tool marks have rounded everything over and have left the whole thing looking a little over-worn, then I assume this is later cleaning up.-Al
 
  I thought this might be a good place to throw in a few more variables into an interesting thread.  As for the white specks in pores, I've seen,heard of,or used, the pumice,tripoli, plaster,brick dust,ash you usually here or read about in books. But , just to make you think, I know of two other ways to produce white pores.First, on old furniture,the white pores can be stripper residue. Re-finishers often used lye,and even now with modern strippers, if it isn't neutralized,the finish, waxes or what ever is used for finish can reactivate the stripper leaving white spots in the pores. The other way is when the tree is growing ,it pulls minerals from the ground and deposits them in the pores.I have an oak board that will spark when it is  run through the table saw.  I also have a board that came from a tree in a barn yard and almost 15yrs later it still smells like the farm.The mahogany that was mentioned maybe one of these?    I also recall working with George Frank, doing the benches in the Mpls Institute of Art, we used rabbit hide glue to not only fill the pores, but as a finish.          My thoughts on original finishes is that there are not many out there. People of the past are not unlike us today,if something looks bad ,you fix it or get rid of it.  I tend to agree with Al, if the finish looks old, but is thin, it may be real.That is if the furniture style is before late 1700 or for sure !800 when shellac was widely used. Or a refinished piece with bad finish, you can usually tell the difference.I recently worked on a large table dating somewhere in the early 1600's, the English Oak surface had been shellaced over a wax impregnated pores, wax may have been original. Anyway,over time, the shellac lost its adhesion and you may have guested, white spots.
An interesting way to spot old finishes or old finishing materials is by using UV light.  When I was doing my studies on Preservation of Historic Finishes, i was introduced to a board containing about 75 different finishing materials used in the old days.  Under black light each of these materials fluores a different color.  The board which is in the hands of the Smithsonian Institute is the only one known to exist, as far as I know.  Don Williams (SAPFM'S newest board member) I think assembled this for the studies of finishes.  The one I made, contains about 35 different materials, but I am still working on it.  But there are other ways to determine what kind of finishing materials were used, by chemically breaking them down.  Just something to think about        Randy                                               
 
Randy- Interesting stuff. I have noticed that the white-pores mah. with silica (or whatever makes the pores white) tends to go away when finish is put on. I try to buy the white-pore stuff when I can because it seems to have other good qualities-Al
 
I bought this "mahogany color" Behlen pore o pac stuff and it was pink!  Whats up with that?  It seemed like little more than spackle to me (which I think is what it is). 

Some surfaces on antique furniture I've seen are so full and so brown they look like plastic.  Especially knees on chairs and feet where end grain is exposed.  I tried a couple different concoctions and I didn't get that look.

Adam
 
Adam,

I tried that stuff years ago on a sample piece of wood and it was horrible!!!  Throw it away.  It's amazing how many mfg. do not properly test their products before they introduce them to the consumer.

Dennis Bork
Antiquity Period Designs, Ltd.
 
Al's comment is interesting. I too have noticed through the years that mahagony with white flecks is denser and works better and carves better. Has anyone else noted this? Does anyone know the biology behind this? Is there any way to pick these boards out in the rough? The pore flecks don't seem to be visible until the wood is planed.

Howard Steier
 
Hi Don, Adam, et al,

Though I am not strictly in the “period” furniture business I thank you for the opportunity to become the proverbial horse’s mouth to help avoid confusions about my thoughts or work since as there's been reference to my article and the PMA.

Members of this organization contact me privately from time to time and I’m always  happy to try to provide answers to their questions (hopefully as accurately as I’m able!). I know the difficulties there are in trying to understand details of construction, technique, finish etc. of “antique” furniture when access is often difficult at best, and in the case of some I’ve been in contact with, non-existent because of their location.
I can see how some of the articles I’ve written could raise as many questions as they answer. The article mentioned in this thread was a pop piece that attempted to get the word out about what was happening in the American Art and Conservation Departments at the Philadelphia Museum of Art. In 1000 or so words, the extent of what you can get across is limited when dealing with a project as complicated as that one. So without getting too long winded in this first post, let me try to provide some background on the object and our ultimate decisions about the treatment, I’d be happy to later answer any further questions anyone has.

The high chest in the article has a long and varied history at the Museum. I didn’t want to talk out of school for the article but I did footnote a report in a Philadelphia newspaper written after the high chest was restored at the PMA in 1975 that was pretty critical of what was done. There is a file about the treatment and a number of color transparencies available so we have a good idea of what occurred. Essentially a multi-layer crazed, thick, dark finish was removed from the surface with methylene chloride, yes, Zip Strip, the wood was colored with some type of water based stain, the surface sealed with “sanding sealer”, sanded with 220 grit sandpaper (the carving is still in decent shape, they must have skipped sanding it) then a nitrocellulose lacquer was sprayed on. One wag commented in the newspaper story that it looked like it had been encased in plastic. So 30 years later it still looked like a plastic finish, the stain had bleached out differently and the lacquer was becoming opaque and/or turning a greenish hue.  So to be clear, in 1975 all remnants of past finishes were harshly removed with a chemical process and water stains and lacquer top coat added. The 1975 lacquer has no historic significance to us and the opaqueness and color changes were making the chest hard to look at and along with the wood losses, difficult to interpret for viewers.

During my treatment all of the lacquer was carefully removed and we were down to the bare wood again. We’re obligated for many reasons to apply a finish to the surface, saturation of the wood, protection of the surface for dirt, etc. The use of shellac in no way reflects our thinking about what constituted original 18th century finish work. Modern conservation practice requires treatment to be reversible as much as possible. This leaves out such intractable materials as varnishes and linseed oils. I use those materials when I make things, can’t use them in furniture restoration. The shellac can be removed off with a solvent, unlike the oils. We’ve stuck with shellac instead of the modern acrylics prevalent in much other conservation work for several reasons, but mainly how it looks on wood! It’s reversible and its color and translucency as well as our ability to produce a very shiny or very matte effect allow us to finish replacement parts to match all types of existing finishes. 

Well I guess I won’t wade into the “original finish” question as I’ve gone on long enough for now!

Chris Storb
Philadelphia
 
As a woodworker who has a typical woodworker's love of touch, I much prefer to do my finishing with a polishing plane (mostly Japanese tools, certainly all wooden) and leave it at that, except for the rare occasion that I know a piece will be subjected to various spills, in which case I do a french polishing regimen. Now I'm not saying that such an anecdote is the way to decide these issues, only that woodworkers probably haven't changed all that much.

Pam
 
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