Blotchy shellac colour coat

[tom.gibson]

I wanted to put down some subtle amber colour on the soundboard prior to a Tru-oil finish. I put on some blonde shellac first, then a few coats of amber shellac, padding it on. It worked well on test pieces, but the colour wasn't quite even enough on the real thing. So I (no doubt stupidly) tried to 'smooth it out' with some straight alcohol which made it truly blotchy.

Can I fix it by persevering with padding on more amber shellac? Or should I sand back and start again?

If it's a matter of starting again, how to avoid uneven colour, except by spraying?

[belbein]

What wood was the soundbosrd and what quality was the wood?

[tom.gibson]

Adi spruce, very nice quality for ear and eye alike. It's not an absorbtion problem, though: the soundboard was well sealed with blonde shellac first. The amber shellac is just unevenly distributed over that seal coat. (It hasn't sunk into the exposed end grain of the recurve etc. I know that problem...)

[michaelcj]

Been there, done that. Only real solution is to sand it off and try again. I's suggest sticking to one shade and if you want the amber color go with that.

MJ

[Marty Jacobson]

No need to sand it off... I'd just remove it with alcohol. Not a ton, you don't want to raise the grain or soak the glue joints. Just make a pad and load it with alcohol. You will be able to remove the color coat this way. Then reseal with blonde and re-apply the color coat.

[tom.gibson]

Marty, my attempt at removing the amber with alcohol is what made a slight uneveness into a horrible blotchiness. Perhaps if I persisted it would come good. Question is: how to apply the colour coat evenly the second time round. I've only used blonde shellac before and colour uniformity wasn't an issue.

[Pete Jenner]

Tom, it's a tricky business. Why didn't you seal with the amber shellac?
Why do you want to use Tru-Oil over the top of the shellac?
If you think the blonde is a better sealer, why not colour it with a little spirit based dye.
In the past I have used Feast and Watson's 'Prooftint' available at Bunnings or other retail hardware outlets. It comes in a variety of colours and doesn't seem to effect the shellac at all.

[Tavy]

It may be too late now, but you'd likely get an more even colour using wood dyes on the bare wood and then sealing - it's very hard to put shellac on evenly enough to use it for colouration, especially if you're going to be sanding it back level before the top coat.

[tom.gibson]

Pete: I found amber (and especially garnet) shellac on bare spruce gave a very uneven colour for me, especially on recurve-like areas with exposed end grain. Over a clear shellac seal coat, on the test pieces, the amber looked nice and even. It wasn't actually too bad on the real top until I stuffed it up wiping with alcohol. As for using Tru oil, I'd like to give it a go. Looks good on my tests, nice to use, no need for spray (which I'm not properly set up for) and no need to do black magic with fads and oil etc. I've sprayed lacquer before and it turned out well, but it chips, looks too toffee apple for my taste, and makes the instrument smell forever faintly toxic when taken from its case. Tru oil, or some other oil varnish, applied by hand appeals to me. I have experimented with the Feast Watson tints in shellac and it does seem to work well, but the straight amber shellac was pretty much the colour I was after. T'is a tricky business indeed.

Tavy: Yes, too late now. I considered dyeing the top, but since quite a few folk seem to use and recommend amber shellac for an 'aged' colour prior to whatever final finish they use I thought I'd go that way. Perhaps the best way to get a really even cover with it is by spraying. I was hoping I didn't need to purchase a decent gun...

Any tips from the shellac gurus?

[pfox14]

I'm no shellac guru, but it sounds like you need to sand it down and start again. Shellac can get "blotchy" if it's too thick and not spreading evenly.

[Bill Snyder]

Like Marty mentioned you do not need to sand it off. You can remove it with alcohol and the fact that it got blotchy when you tried to even it out with alcohol is not a concern since you are going to remove the amber and not just spread it around.
This was padded on amber shellac. I used paper towels to apply it. I don't remember how many times I stripped it back using alcohol and started over. I never was really happy with it and eventually stripped it and came back with a solid, maroonish finish.

[bmac]

If you are not willing to sand it down to bare wood then the only reasonable solution in my opinion is to use an opaque coat of chosen color... You will lose most or all of the wood grain, but it offers the opportunity of it looking like an intentional color and not a half successful repair job. Your delema is not at all unusual by the way, as you may have guessed.

[Marty Jacobson]

If you think sanding is the best option, use mineral spirits as a lubricant, as it will not raise the grain if you go through in some places, and start at 600 grit, no lower. The wood is not the problem here, so don't approach it like you're sanding wood.
You just want to sand the high spots in the finish, where the ridges are.
Remember that thickness of colored shellac is directly related to the perceived color shade. If it's all the same thickness, it's all the same color. So your problem is one of finish geometry, not finish color... if that makes sense. At least, it's helpful for me to think of it that way.
I still think sanding is a waste of time in this case, btw.

[bernabe]

One thing [well 2] to think about using alcohol to remove the dye is that it will work it [dye] into any tiny low areas, tiny scratches, etc which may show through the new stain if at all lighter. You also will have a mixture of dye and shellac being moved around which could be worked deeper into the wood in areas where the seal coat is being dissolved and pulled up. The good thing about the fact you sealed the wood first is that less wood will have to be removed if sanding ends up being your decision. Your in a tricky spot right now and if your top grads and stiffness allow, Id sand it.

[Bill Snyder]

He did not use any dye.

[bernabe]

Sorry...miss-read that.

[tom.gibson]

Thanks everyone for the advice. Clearly it's possible to get an even colour applying shellac by hand, since French polishers manage it all the time. I suppose the question is whether it's possible for me, or whether I should give up and try spraying.

Marty: I recall you mentioning somewhere that you preferred to put colour in the finish, rather than dyeing the wood. If that's right, what kind of process do you use? The results are certainly beautiful.

[Marty Jacobson]

Thanks everyone for the advice. Clearly it's possible to get an even colour applying shellac by hand, since French polishers manage it all the time.

I don't believe that's true, at least not in today's world. These days, French polishing is usually a clear topcoat over some kind of sealer/base coat. The only time I've used any color in shellac applied during French polishing was during restoration work, for blending.

For your purposes, you could use shellac, tinted with Trans-Tint or naturally colored, in a Preval sprayer. That's basically a do-it-yourself rattle can, where you can put whatever you want in a jar and spray it that way. Works about as well as a rattlecan.

If you have access to a real spray rig, then your options are virtually unlimited.

[michaelcj]

Well I still do French polish..the old way... on the tops of my guitars. I've done it on some of them for back and sides as well. Pore filling goes slow with pumice but I like the natural look and thought of "non-toxicity".... That is unless I nip at the everclear I use to dissolve the flakes.

But it is a slow and tedious process... but then so am I. I have a mandolin [A-5] project coming up after I finish the next guitar and am looking forward the the tiny body that will be a breeze by comparison to a 000-28.
So French polish can be done and is quite beautiful and a bit zen.... but you have to be patient and put in the time.

Marty, "French Polish" is a technique of applying a shellac finish...so by definition "French Polish" is today what it always has been. Any other combinations of finish products or application processes is simply not French Polish.

To the OP: sand it back till you have removed the "splotchy" or to bare wood. you can stain the bare wood with a water soluble dye,,[alcohol in the shellac wont disturb it], and continue on with either the blonde or amber shellac. Sorry but there is just no way that I am aware of to do a quick and dirty shellac finish by hand that doesn't end up looking like a quick and dirty finish.

Mike J

Mike J

[Marty Jacobson]

Mike, I hear you. I was referring to applying tinted shellac using the French polish technique. Might have been the best way to do things in the Queen Anne days, but is overcomplicating things now, with affordable good spray equipment available.

[bernabe]

"Building up" with amber or garnet, etc. shellac by FP method will start to get splotchy if to the extent that your building a color shade. Most use it for a couple of sessions for but mainly build most coats with blond to avoid the splotchy look that develops. Im with Marty, that if you want to evenly shade a more pronounced color on top of a natural colored base, FP'ing a tinted shellac isn't how Id do it.

[michaelcj]

I agree with both Marty and Bernabe that trying to add color [shellac] over "clear" shellac with the traditional technique is bound to cause problems. The alcohol in the shellac can't help but react to some extent with the previous coats.
Some of us either do not have spray capabilities or choose not to employ spray for various reasons.

My point is that if you want to use "french polish" it is still a useful and beautiful technique...you just have to approach it realistically.

For color: water based stains on the raw wood. Or the color from the shellac itself [ie: blonde, amber, orange, garnet, button] and stick with one of those colors for all of the shellac.

Mike J

[SanzoneGuitar&Mandolin]

The preval sprayer that Marty mentioned really is great for even application of shellac (and it's only $4). I like to wipe on a coat of blonde shellac or two, wait a day and scuff. You can then add color to thinned shellac (aniline if preferable) and spray a light coat. Usually through multiple light color coats, the desired result can be acheived without bleeding or blotchiness. If you add color to your very first coat, the dye will permeate the recurve/runout areas. Dust and haste will cause major headaches, so keep it clean and take it slow. good luck

[belbein]

Well I still do French polish..the old way... on the tops of my guitars. I've done it on some of them for back and sides as well. Pore filling goes slow with pumice but I like the natural look and thought of "non-toxicity".... That is unless I nip at the everclear I use to dissolve the flakes....

I don't know nothin' bout finishing other than: FP works for me.

[Michael Lewis]

Practice makes perfect, maybe. Any material with color will become darker where it is thicker. The 'trick' is to apply the material evenly, and you can easily see if it is or not. It can be done by hand but will require a great deal of skill. I suggest you spray the finish to get the color even, and you can French polish over that with super blond or similar shellac with little or no color.

Spraying material with color also requires skill to get it even, there is no way around it.