Please give me some advice regarding to shellac.

UkeforJC

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Dear all,
after I have read so much about how great shellac is as sealer and finish, I decided to try it out.
I mixed some 2 lb cut shellac (from LMI). The process of mixing, filtering, and applying it to the wood was quite straight forward.
But there was an accident, when I was going to seal the top, I dropped some shellac on the top. The top is a piece of sinker redwood.
The shellac quickly sinked into the grain and left some stain.
2013-03-17 19.34.56.jpg
See the stain line above the masking tap and some round spots next to it?

I have read that I can apply some alcohol, and the shellac will be easily wipe out. I tried it, but it didn't erase the stain. I try to apply more shellac, but it still didn't do any good.
The next thing to try after I get off work, will be sanding the whole thing off again. Hopefully it will work.

My question is, I thought shellac won't stain the wood like CA does.
Did I do something wrong?
Also, any advice on how to remove these stains will be super.
Thank you all so much.

JC
 
For a sealer I use a 1 lb cut. Just take some of your 2 lb cut and mix it equal with the alcohol. But this time do as David has told you. Shellac is very forgiving.
 
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Have you put shellac on the rest of the top?
Maybe not.
You should flood the top with the shellac, eventually the rest of the top will soak in as much as the part you spilled on.
It will even out.

Thank you guys.

I did try to flood the rest of the top a couple times, especially around the stained area. I was hoping that it will even out, but it didn't help at all.
Should I just sand it all off and restart again?
 
This may not help, but try leaving it to dry for a while. I recently tried some rattle can shellac on a cigar box uke and had some similar blotching on and under the paper label. After a day or so it cleared up considerably and is no longer noticeable. My thought at the time was that a lot of alcohol got soaked into those spots and successive layers were keeping it from evaporating easily.
Good luck!
 
You could try sanding the top, but do you have enough thickness to waste away?
I'm afraid you won't be able to sand enough to remove the "stain"
Shellac soaks pretty far into the wood, and Redwood is a very porous wood.
Also, you can thin the shellac as ukegirl says, that may help.
When I finish a top, I keep flooding the wood until it won't hold any more. I use a pad in a circular motion, I think it helps move the shellac into the wood. Then I know it is ready to start building a "finish".
 
Thank you all for your commends.

I just tried sanding the top. I sanded away all the shellac to bare wood. i am very surprised how deep the shellac soaked into the wood.
Just when I thought that I have gotten rid of the "stain", the stain reappeared when I tried to "flood" the top with the thinned shellac (1 lb cut).

I noticed that the shellac never leave a stain in the back and sides (Koa) and the neck (Spanish cedar). I only have trouble with the redwood.

At this moment, I have ran out of ideas to fix this top.
I never thought that shellac will cause such a problem.
 
Sounds to me that the wood has soaked up a fair bit of shellac mixture and just hasn't dried out enough yet. Especially when you sand it back and appears to be good to go.

Put the instrument aside for a few days and then come back to it. If nothing else, lutherie teaches patience.
 
Sounds to me that the wood has soaked up a fair bit of shellac mixture and just hasn't dried out enough yet. Especially when you sand it back and appears to be good to go.

Put the instrument aside for a few days and then come back to it. If nothing else, lutherie teaches patience.

THANKS Allen.
I will just let it sit for a few days. I really hope that the stain will go away as the shellac dries out.
Lesson learned...really need to be patient and don't drop shellac on the wood. Only on the pad....
 
So...
I have let the instrument sit there for three days, but the stain is still pretty obvious on the redwood.

Is it definitely not fixable now or...?
 
I've been staring at the original picture for some time, trying to puzzle out the very defined shape above the masking tape. Did an object fall on the top? Was the top clamped against something that shape? I'm thinking, crushed fibres in the wood, so that it absorbs vastly more shellac.

If this were my top I'd try two things before binning it.

1. Take a hair dryer to it, concentrating on the stains but being careful not to scorch the wood. If the stains start to fade or change shape, hurrah! Time/more drying will fix it. If this fails ...

2. If the top will stand it, sand back to an even colour and then just wipe on with a paper towel the thinnest possible coat of shellac. One pass across the top with the towel damp, not wet. Let it dry. Repeat a few times. The aim here is to seal the top without giving the problem area enough shellac to sink in.

Good luck!
 
I don't think that is staining caused by Shellac. I think it's more likely that it's the Shellac that is highlighting or reacting with something in the wood. I've never seen Shellac have that effect on any wood and I've been using Shellac for over 30 years! Then again I've never used that type of Top. I don't think that Shellac will go deeper than 0.3 or 0.4 mm into something like Spruce. You can try a spirit based dye and see how deep that penetrates. Shellac will not penetrate as deep as a spirit based dye.
Anyway I think the clue might be in the Redwood - the sinker bit. Maybe it's rich in tannin and it's now reacting with something you have used in the finishing process. I know that if I use wirewool on Oak I get a grey shadow or caste as the steel reacts with the high tannin content. Maybe it's something similar to this. Just a guess but I wouldn't be blaming the Shellac.
 
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... I think it's more likely that it's the Shellac that is highlighting or reacting with something in the wood.
...

That was my immediate impression when I looked at the picture - that the wood had some kind of marks in it from whatever and the shellac was just highlighting them the same way it does with grain, figure, scratches, sanding lines, etc. Or are the marks you see there the shape of the spill that got on the wood?

Just out of curiosity, was this dark (garnet) shellac you were using? One of the rules for french polishing I learned long ago was always to start with blond or lemon shellac and then go darker - I don't actually follow this rule all the time any more, especially with darker woods like walnut, but maybe it's not such bad advice after all...
 
it looks like a spill. I think it either needs to be re-wetted to the depth of the spill, and shellac persuaded to that same depth, or sanded out, which might be deep.
 
I think I'd go with what Chris suggests. And for sealing (and initial coats) I would definitely cut the shellac down to a thinner mix so that it penetrates a little deeper.
 
Thank you all for your inputs.
I think the stain was from the spill, for I didn't drop anything on the top.
And I didn't observe any damage on the top either.

I have tried sanding the top back to bare wood and revealed it with thinner shellac. It did improve a bit, but the stain is there.
I will attach a photo later .
Thank you.
 
Before and after...
2013-03-17 19.34.56.jpg2013-03-24 23.19.24.jpg

before, the spill stained the wood to a darker color.
after I sanded and resealed the wood, the stain became light color.
hm....not sure what to do now. The stain is not very obvious now, but it is still there.
 
Now it appears that the stained spot is lighter than the surrounding area.
Continue with shellac and it will even out.
 
I do not think more shellac will change the stain. Maybe some carefuly applied UV rays would help even things out. Direct sun if you can prevent it from heating up too much. Wood and finishes change color with exposure to UV, sometimes more, sometimes less. Some woods react strongly, very quickly. Too much heat would be a problem for the uke. Time may also help.

Otherwise.. chalk it up to learning. You could always strip it again?
 
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