Replies

1. 
   MichaelTheFinisher | Oct 20, 2007 04:24am | #1

   Did you start with the edges first,then do the top.If you continue to see streaks thin it more.and sand the streaks down,Shellac isn't your top coat so you should be fine.

1. 
   ohiobob | Oct 20, 2007 04:35am | #2

   Thanks, the edge of the wood is not the problem. When it dries it looks like some parts have more shellac than others with a thin line showing. I had planned on the shellac being my top coat. WHat grade should i sand it with . I am using 320 and you can see sand marks when i am finished.

1. 
   SteveSchoene | Oct 20, 2007 09:31pm | #7

   You are applying a very. very light cut of shellac, just a shade more than 1/2 lb. cut. That's only about 6% solids content and the rest DNA.  That's one reason that a fresh coat won't fill sanding marks -- almost all of each coat evaporates away.   Shellac doesn't need sanding between coats, it adheres just fine by melting into the lower coats. 

   The high solvent content may also be contributing to very rapid drying, making it difficult to keep a wet edge so one explanation is that what you are seeing is overlap marks.  You may also be attemping to compensate by applying full wet coats.  In that case, surface tension effects may be pulling more material to the edges of the brush stroke or pad swipe.

   I do two things differently--it's not the only way that works.  I use about 1 1/2 lb. cut (5 parts Seal Coat to 1 part DNA) for applying with a pad.  I use 2 lb. cut for brushing, but I use a much different brush.  What works for me is to use a flat watercolor wash brush such as those made with Taklon Gold bristles, which are very fine.  This kind of brush doesn't carry a lot of shellac, but it lays down very smooth, very thin coats.  I work quickly, applying shellac in only one way, never going back to get a missed spot or to work out an overlap.  If they don't occur all at the same spots this little holidays and overlaps with average out in a few coats.  I only sand after several coats to eliminate major problems.  Remaining small overlaps or rough spots will dissappear.  When I have build the film I want (and shellac prefers not to be very thick) I start a rubbing out process by sanding with 600 grit paper (400 grit if there are big problems), progress in to about 1200 grit, and then finish the rub out with rottenstone lubricated with parafin oil.  Polishing compounds work well too.  It's the rub out process that eliminates the kind of very minor problems you are experiencing.   

    

    

1. 
   ohiobob | Oct 20, 2007 09:43pm | #9

   Steve, I will try the 5 parts seal coat to 1 part DNA. That seems thick compared to what i have been doing. I don't have a taclon brush so I will try the cloth application.

    

2. 
   kent51 | Oct 20, 2007 04:50pm | #3

   If alcohol dissolves shellac and shellac is your top coat, is it possible that wine might get onto the table top, dissolve the shellac, and as a result, stain the wood?

   You might want to consider something a bit tougher for the top surface.

1. 
   frenchy | Oct 20, 2007 05:13pm | #4

   Kent51

     You are simply wrong..

     While alcohol will disolve shellac Wine is very low in alcohol percentage.  Thus in order for it to "strip" the finish you would have to leave it a long time.. An awful long time to do any damage at all. 

    Frankly if my guests were to spill that much wine and leave it without dealing with it.   I wouldn't ever invite them back.

     Try it yourself.   Make a test piece, let it set for a month and then spill a glass of wine on it..  Now walk over grab a towel and wipe up the spill..

     See?  No damage!

         That's right up there with the myth about water and shellac..

    Sure if you leave a glass in a puddle of water over night you will form a white ring.. However we had an airconditioner leak into the house and form a great big puddle.  That puddle had to be there for hours before I discovered it because it took several towels to wipe it up. the floor is fine.. no whiteness at all. 

    Any finish can be damaged with neglect, but the beauty of shellac is the ease of repair..

3. 
   frenchy | Oct 20, 2007 05:18pm | #5

   ohiobob. 

      I suspect that you took too much care in apply it.. shellac dries insanely fast which is why I flood it on and never go back. Never go back over it!

   It's that second brush wipe which causes the problem.   You can fix this one of three ways.

   first flood another coat on of really thined out shellac 

   second color sand the ridges off.  start at 220 and go in steps to 4000

   third french polish it..

   
   

   ---

   Edited 10/20/2007 10:20 am ET by frenchy

1. 
   ohiobob | Oct 20, 2007 07:33pm | #6

   Thanks, I may try a 3 to 1 ratio and slop it on you suggest. Boy, this is a small piece. I would hate to have to do this on something large!

4. 
   saschafer | Oct 20, 2007 09:40pm | #8

   You tend to get that if you use a brush. What's happening is that the surface tension of the liquid is causing it to "bead up" (as much as it can) along the wet edge of the brush stroke. When that bead dries, it's a bit thicker than the surrounding shellac.

   You can live with it if you're willing to put on a few coats and then rub it out with some fine sandpaper on a sanding block. It won't happen at all if you use frenchy's ultra-thin shellac technique, or if you use a padding technique. In both cases, you're applying extremely thin layers of shellac.

   The padding technique is similar to French polish, but without using oil: Prepare a pad of absorbent cotton cloth (t-shirt material; you can get it at any paint supplier--the better grades have less lint). You can wrap it with something like a piece of an old pillow case for a smoother outer surface, but it's not absolutely necessary. Wet the pad with denatured alcohol so that it's fully dampened but not dripping, then apply a small amount (a half teaspoon or so) of 2 lb-cut shellac to the "working surface" of the pad. Then wipe the pad in long, fast strokes across the surface until the shellac is consumed (the pad will begin to stick). The coat of shellac will be very thin, and the first couple of coats will be absorbed and won't evenly cover the surface.

   Apply three coats as above, about an hour apart, then let it dry 24 hours. After 24 hours, sand lightly with P320 paper on a sanding block to remove any raised grain nibs, dust, insects, etc. Repeat the process of (1) three coats an hour apart, (2) wait 24 hours, (3) sand lightly, until you've built up the finish that you want. Don't worry--at first it seems like it's going to take forever, but after the first two or three coats it goes much faster, and the second sanding is much easier than the first.

   I usually apply a minimum of six coats, but it depends on the wood. A wood with open grain (e.g., walnut) takes more shellac to build a smooth, even surface.

   There are some FWW articles and videos available on this site that describe the process in more detail. Do a search on "padding" to find them.

   -Steve