Replies

1. 
   sbaia_ | Feb 05, 2002 09:00pm | #1

   *
   OK there's two "ll"'s in shellac. My bad
   Steve

1. 
   David_Paterson_(aust) | Feb 06, 2002 08:24am | #2

   *The lads seem a bit shy about answering this type of question (I had a similar problem a cople of months ago). I have been doing a lot of trial and error and talking to a couple of french polishers and reading some old texts. So, FWIW he is the result so far:I think what you are trying to do is called reamalgamating, and it used to be standard practice. It has the significant advantage of retaining the patina of the original polish. The technique seems to be to use a riubber with high spirit content (little shellac) to disolve the surface. Then you continue as fr normal polishing.The significant problems I have encountered are the presence of other stuff - some sort of gunk that only partly disolves and then causes adhesion problems, repairing deep scratches (use layers of shellac aplied with a fine brush to build up to the original layer), and trying 000 steel wool to break down the old surface (the stuff breaks up in sticky shellac and contaminates the polish layers quite deeply - there has been some suggestion of scothbrite pads instead). I have also successfully started the process by brushing the first couple of coats straight onto the old surface after cleaning with dry steel wool to get rid of wax.Thats all so far, hope you have less trouble than I did ('though it has bee an interesting journey)David

1. 
   sbaia_ | Feb 06, 2002 08:25pm | #3

   *David,You mention a high spirit content and little shellac. Do you mean mineral spirits. I thought Alcohol is used to dissolve shellac, not mineral spirits.I'll try giving the suggestion of adding a couple of coats of shellac with alcohol to a small area to see it's affect on the original finish.Thanks,Steve

1. 
   Danford_C._Jennings | Feb 06, 2002 08:55pm | #4

   *Steve,Might be helpful to know whether this is an antique and whether or not this is veneered. Spider webbing on a shellacked surface usually results from a wood movement issue. BTW, I've not heard of using mineral spirits either but, it has been a very long time since I've been involved with restoration work.Dano

1. 
   Dave_Arbuckle | Feb 06, 2002 09:08pm | #5

   *I think spirits is Australian/British English for alcohol.Dave

2. 
   David_Paterson_(aust) | Feb 07, 2002 01:05am | #6

   *"spot on" to use another quaint term.In the early literature, French polish was 'spirited out' to remove traces of the oil used for lubrication. My untutored interpretation of this has been to increase the alcohol content as I finish. I am still very much a tyro at this so correction would be welcome.When I started to try approaches to repairing an old piano, I tried several approaches to getting started. the best has been, clean the old surface with either dry steel wool or wet with mineral spirits (I assume that is American English for mineral turps) The risk with doing it wet is that the residue settles in small holes and some times leaves yellow spots in the polish which are very difficult to remove so I have drifted toward the slower process of doing it dry. (Same with sanding between coats) Next, put on a couple of fairly generous coats of very thin shellac, the second coat while the first is still tacky which seems to allow better penetration. wait until dry which might take a couple of days depending on the other gunk in the original coat, but which is obvious when sanding with 400 open coat paper (always on a block)returns powder rather than clogging with oil. At this stage I have had a very good renewed finish, except that it has flow marks form the thin coats. I then repair any scratches (see latest FWW, and if the hole in the polish is not too big you can 'move' some of the old polish into the hole with a small stiff artists brush, alcohol and patience a bit like panel eating - this keeps all of the original colour). Finally, smooth (pumice or paper) and polish as always.This is a very slow process for one of my skills, but the retained patina has been well worth the effort so far. I have also been able to retain two original decals of the maker under the polish, which would have been impossible if I had stripped the piece.My failings so far are that I have been unable to get rid of all of the oil, and under close light there are drag patterns from the rubber. Still, for me cabinet work is at least as much about the journey as the finished piece - its never perfect is it?

3. 
   sbaia_ | Feb 07, 2002 02:54am | #7

   *Dan,For the most part, the piece is solid mahogany, but the side panels may be veneered. Since the rails and stiles on the doors also exhibit cracking in the finish, I believe the damage has more to do with light, humidity, etc then with wood movement.David,I like the aged look of the mahogany and stain that was applied. I'd hate to loose that by stripping the piece so I'm going to give your suggestions a try. The worst that could happen is I have to strip the piece, but maybe I'll learn a little and save beauty time has added to it.ThanksSteve

4. 
   Danford_C._Jennings | Feb 07, 2002 03:07am | #8

   *Stevei ...humidity, etc Oh. Only trying to help. Now that I understand where David is "coming from" I won't add anymore....Dano

5. 
   sbaia_ | Feb 08, 2002 01:46am | #9

   *Dan,Don't take my response the wrong way - I was just providing an answer to your question. Don't stop putting your ideas in. The less people respond, the less there is to learn from.The problem with message boards they're hard to gauge people's intent. My intent is always to be positive when responding.Steve

6. 
   Danford_C._Jennings | Feb 08, 2002 09:36am | #10

   *Steve,Didn't take it the wrong way. My quoting you was to help. Humidity causes wood movement, wood movement causes shellac to spider web. Dave provided the method to repair those spider webs. What more is there to add?Dano