Haze in French polish

[Mando2020]

Hi everyone - do you think the hazy areas that appeared during my French polish will go away with further layers? It's my first time French polishing. Overall it looks ok but when I look closely these hazy spots detract. I tried to capture in photos, see center of rosewood piece as opposed to edge, and see recurve area photo. Maybe I'm too picky, but I think the finish should be really clear. I've read a lot of threads, and thought maybe it's moisture as it's been 50-60% RH lately. Tried a/c getting it below 45%, but still get this problem. I'm using 1.5 lb cut, 8 drops shellac, 4 drops Everclear, 3 drops walnut oil. Cotton tee for applicator, keep pad moving, etc. Also I'm still seeing pores on ebony headstock - guess I should have filled with epoxy first? Thanks for any advise.

[rcc56]

Haziness can be caused by trying to build too much finish in one session, not waiting long enough between polishing sessions, or building the finish too thick. Let it cure for a few days, and see if some of the haziness goes away.

To fill pores, you can apply several coats of highly thinned shellac, 1 lb. cut or even thinner. Build until the pores are filled and level sand before building with your normal mixture. There is also a technique called "loading," which involves rubbing in very thin shellac over a light sprinkling of pumice.

Try level-sanding your ebony, then start building on it again with very thin shellac. Level-sand once more when you think the pores are sufficiently filled, then you can go back to your 1 1/2 lb cut mixture.

I don't add oil directly to the shellac mixture. I instead prefer to apply a drop or two directly to the pad from time to time.

What kind of shellac are you using? I recommend a high grade of shellac flakes, available from a supplier such as International Violin Company. Pre-mix your shellac, let it sit overnight, then filter before using.

[Mando2020]

Thanks rcc56. I've read some of your posts albeit after I started having problems (live an learn). I'm using Stewmac ColorTone® shellac (super pale platinum blonde dewaxed flakes) and followed instructions on their site too, except I used Everclear. The shellac looks pretty clean, haven't filtered it. But I'll get a filter per your advise. I did have the flakes for almost a year before dissolving them, and did so as you described. They were inside in controlled temp and a dark shelf.

I must have done something wrong from the start though. I've seen some describe a oil varnish first coat then level sand before French polish. I didn't put on the varnish though, just started with shellac right over the color (per Stewmac their shellac "makes an excellent sealer over stains"). I probably put on too much on that first coat - I was trying to cover the color so it wouldn't rub off. I did it with the same pad I'm now using for polishing. But even after I got that first coat on I didn't really notice the "vapor trail' with only a 8 drops of shellac. The photos are after 3 days of drying, the haze remains. Should I continue except with less shellac and same amount of alcohol and oil to see what happens, or should I sand it out in that spot and try to repair? I'm putting the drops of all onto the cotton pad, then covering with cotton T shirt. I keep the pad in a jar. It's moist and tacky with shellac before I put drops on. And for polishing I only do a few long strokes before I can notice some resistance. Then I switch to circles and figure eights.

I'll follow your advise on the ebony. Will let you know what happens.

I'm learning, ...I hope. The thing I may need the most is patience. I would love to play it!

[Mando2020]

Prior to posting my question I watched a video that alcohol vapor is sufficient to draw moisture out of the finish and reduce hazing.

https://www.youtube.com/watch?v=CAPrChLnqN4

So I put a very small amount alcohol in a flat dish and covered the headstock in a plastic bag for about 15 minutes. It reduced the haze, and surface looks pretty shiny. But the pores were still there and haze appeared again with more polishing (I was putting on a thick layer thinking it would fill the pores and not as you advised thinning the mixture so it can get into them).

And here's a lesson learned the hard way for anyone reading in the future - I got careless one day and forgot to take it out of the bag before leaving the house for about 4 hours. When I got back, and after some self directed shaming, the ebony veneer had dried so much it split. So I immediately filled with black epoxy and had to sand everything down again. Looks ok now, but I don't know if it will stay that way come winter. Oh well, like I said - learning.

[rcc56]

Shellac flakes have a shelf life. If the flakes haven't dissolved completely after sitting in alcohol overnight, they may be too old.
You can filter through a cheap paper towel.

According to my notes, a 1 lb. cut is approximately 1 tsp. shellac flakes combined with 4 tsp. of alcohol.

When you seal color, just coat lightly once or twice for the initial pass and let dry for at least day or two. Then coat again and stop if much color builds on the pad. You can proceed when your pad no longer picks up a significant amount of color.

It doesn't hurt to change your cover or move to a fresh section every now and then. I've learned to change it when it gets a gummy build on it or it won't soften with a drop or two of alcohol.

If hazy areas don't disappear after drying for a day or two, you will probably have to sand those areas down. If you try a drop or two of pure alcohol on your pad with a drop of oil, you might get lucky. If you do, wait before you build again.

Be sure you don't use too much oil. Add a drop or two when you recharge the pad. If it keeps sticking, it's time to quit for a while. If you're not seeing a "vapor trail," you're not doing something right. Try adding a drop or two of alcohol to your wadding.

LMI has a good tutorial on French polishing on their website. I don't do it quite the same way, but it's a good place to start.

Patience is important. Learn when to quit for the day, and learn to allow 1 to 3 days for drying between sessions. Early in the build, you can sometimes coat fairly lightly in the morning and again fairly lightly in the evening. Then wait.

There's a paradox in French polishing: The faster you try to build, the longer it takes. The hardest part is learning when to quit, and learning how long to wait before you start the next session.

Haze can be caused by humidity, or by re-coating a layer that has not dried enough, or by simply building too thickly or quickly. Shellac finishes must be fairly thin or they will cloud no matter what you do. I tried to match the finish on an old Larson guitar that needed a repair that involved blending an area of bare wood with the original fairly thick finish. On that one, the old finish was simply too thick to match by using shellac alone, and clouded no matter what I did. I finally got good results when I went back almost to bare wood, built thickness with a two or three coats of oil varnish, then finished with several coats of shellac.

Keep at it. You'll figure it out.

[Mando2020]

The haze is coming out of the top and back with a new pad, 3 drops of alcohol and 1 drop of oil. Seems like such a miniscule amount I'm surprised it had an effect. But I guess it's just enough solvent to make the shellac already on the instrument move? Thanks for the encouragement.

It hasn't worked on the ebony though. So I sanded off the shellac and started over with 1 lb cut (thx for the 1 tsp flakes in 4 tsp Everclear ratio). After 2 applications the haze is there again. Actually the first layer didn't look even either, but there's so little shellac on the pad I thought some spots just weren't being covered so I went on the the second layer. I waited 24 hours between layers, and started with a new pad and cover.

I'll keep trying. But first I thought I'd ask if this appearance is just normal as you're building layers? Maybe the attached photo captures what I'm seeing better than the earlier ones. I mean, will this uneven appearance go away as I build layers?

I've seen some people say brush on two coats (seems like that would be really heavy compared to what I'm doing), level sand it, and then start polishing.

[rcc56]

I don't know where you are located, but right now the weather here is unsuitable for finish work.
When it is hot, you have to build very slowly. When it is humid, beware. When it is very hot and very humid, you must wait until the weather changes.

Are you sure that the ebony is really "hazing," or is it just an uneven buildup of gloss that you are seeing because the wood is not yet completely sealed? I'm not sure that I see any problems in your current build on the ebony. Scuff sand it and put another coat or two on it and see what happens. You can always sand it off later if you need to.

You might want to practice building finish on a piece of ebony scrap to get a better idea of what the process looks like as you gradually build finish thicker. Finishing black woods can be deceptive. Gloss won't show evenly until you have a fair amount of finish on it.

Another cause of blushing is when the current coat is drying before what is beneath it has cured sufficiently.

Your shellac might be ok, or it might be too old.

If none of the above works, all I can suggest is to take it down to bare wood, sand any ebony or rosewood to 400 grit, and perhaps clean it a few times with pure alcohol in case there are any natural oils or contaminants in the wood that are affecting the finish.

I hope some of this is helpful to you. The most important thing I've learned about French polishing is that you have to learn how thick to build in one session, and how long to wait before starting the next one. When in doubt, build lightly, quit, and if it's hot and/or humid, add extra time before building again.