Troubleshooting Finish Flaws on a Piano

      Is that fish-eye or orange peel on that piano? Finishers help a colleague diagnose and treat a problem with conversion varnish. May 17, 2005

Question
I am trying to finish a grand piano using Valspar, AUF4116, 60 sheen with a 550 voc. Self sealed with no tricks in the finish. Straight out of the can, with catalyst, of course. The shop has been plagued with fisheye for months. Consequently, we stopped using CV and went to pre- and post-cats, added smoothie, and were done with the problem.

Well... I hate lacs, and decided to go to CV for this job and the nightmare has come back. Fisheyes. Big, pretty, mahogany ones. I have worked out most of the fisheye, but there is enough that I know I will not get an off-the-gun final coat. I more than likely will have to cut and polish this one and we don't want to, as it wasn't included for this particular job. Is there anyone out there that knows a nifty way I can do the final that will eliminate or at best reduce the fisheyes?

Forum Responses
(Finishing Forum)
From the original questioner:
Well, impatience has caused to me shoot the final coat. I now have a wonderfully textured piano finish. My thinking is to let it dry overnight, cut the finish back beyond the fisheye and hit it with post cat loaded with smoothie. Anyone see a problem with this?



From contributor D:
You need a barrier coat. Pick up a can of Zinsser's Sealcoat. It is unwaxed shellac in a one pound cut. Spray a light coat. Allow to cure, scuff 320, tack and lay down a coat of the vinyl sealer that you are allowed to use with your conversion varnish.

Some conversion varnishes require vinyl sealers which are catalyzed and some do not. Let the manufacturer of the conversion varnish dictate to you what vinyl sealer to use and whether or not that vinyl sealer needs a catalyst added to it. Then, topcoat with your conversion varnish.

You have some math to do before you do any of this. You need to figure out how close you are and how close you will be to your 4-5 dry mils of finish. If you are too close, then the first thing that you need to do to get ready is to grind down some of your existing/cured finish to lose some dry mil thickness.

Sherwin-Williams Autobody Division makes a fisheye additive for use in urethane auto coatings. A high quality xylene is what you should be using to wipe your cured conversion varnish surfaces to get rid of oily contaminants. Xylene will soften vinyl sealer. If you are using MLC products, then there is no need to get the SW additive. All the MLC solvent coatings will take ordinary fisheye additives like Smoothie or whatever.

Check with the tech support of the manufacturer of your conversion varnish to see what additive they make or what fisheye additive they suggest. Use that product instead of selecting your own.



From the original questioner:
I have wanted to use the Zinsser for ages. Can I use this to help prevent fisheye in the first place, and continue to use CV sealer and finish on top? As for your suggestion, I will give this finish an aggressive sanding. As it's already had a couple, I believe I'm okay on mils.

We once tried the automotive grade fisheye stuff and, well... I swear it made everything worse. Why? I haven't a clue.

Another thought: Can't I simply apply the Zinnser and then top with post-cat as well?



From contributor K:
Are you certain it's fisheye? Seems as though it wouldn't be over the entire surface. If it is, there may be silicone or wax residue, so you should wipe the surface with mineral spirits, and spray mist coats (let each dry) to trap contaminants. There may be oil in your spray equipment, in which case you should install an oil separator in your air line. If it's orange peel (looks and feels rough all over, not actually peeling) then:
1) atomization pressure is too low (increase pressure and adjust fluid),
2) spray gun is too far from your work (6-10 inches is good),
3) coating viscosity is too high (thin to correct application viscosity), or
4) not enough coating thickness for proper flow.

It is winter, so you might try heating your finish to 75 degrees by placing the can into a bucket of hot water or in a sink. By doing this, you can apply topcoats even if the temp is 45f.



From contributor J:
That seems unusual that you would get fisheye with your CV and not the pre-cat! Any time I use a catalyzed coating, I use Smoothie II and not the original stuff. I never have found out the difference, but I do know that regular stuff can't be put in CV, so maybe that's your problem.


From the original questioner:
Contributor K, thank you and I am going to try a few of your suggestions. Contributor J, been there and done that.

This damn contamination has got me flustered. As for the setting's viscosity, air, etc, it makes no sense. You know how it is - you have your feel and this becomes your setting for your finish. I guess not anymore. On the other hand, the finish does appear to be orange peeled, so tomorrow I'll set things by the book and shoot one of the smaller pieces. I would like some more feedback on the Zinnser.



From contributor K:
I don't know much about Zinsser, but have tried Enduro Wat-R-Base. It's available from Compliant Spray Systems (800) 696-0615. It's best if sprayed, has excellent heat resistance, easy sanding, minor grain raise, and has excellent appearance.


From contributor J:
You could apply Zinnsers and then go back to the pre-cat, but be aware that you may be starting to cram too many coats on. I still think that using the smoothie in the CV might be to blame, as it doesn't effect your pre-cat finishes! Whatever contamination you are having, it hasn't gone away, just been hiding. Do you have any I.B.I.B.(isobutyl isobutyrate)?


From the original questioner:
I used the smoothie with pre- and post-cat lacquers prior to shooting the piano with CV. The whole contamination thing started when I was using SW's CV a while back towards the end of summer. Out of frustration and a couple of EPA related issues, I switched to post-cats and loaded everything with smoothie. This took care of the problem until this weekend when I took the notion to do this piano with Valspar CV.

As it turns out, it does look to be more orangepeel than fisheye. I have sanded everything down to absolute level and plan on tricking out the air and fluid, among a couple of other things, and seeing what happens. I really do not want to put a full rub on this thing. We're not getting paid for it, and it is not what the customer wants. It's getting to the point where it's not going to make a difference, as the time trying to figure this out is costing a full rub out anyway.



From contributor E:
Ask your rep to get you some DC-56 (Dow Corning) additive for your CV. This additive is an air release and flow additive that I use in CV's. It is less sensitive than silicones. Mix 1 liquid oz. with 32 liquid oz. Butyl Acetate. Add 1 oz. of this to 1 gallon of your CV. I also like to add Hi-Flash Naptha for better flow.

I'm curious! Have you tried other batches of CV? Where is your service rep in all this?



From the original questioner:
Yes, we have tried different batches. We went down this road last summer. The thing is, we are in CA and in the midst of formula changes as well. This complicates things. I am more leery than ever when it comes to farting around with mixtures. I'm re-learning and haven't reached the epiphany stage yet.

I did pick up some Zinnser this morning, and will try it on something I'm willing to strip before committing to the piano.

As to the service repů Would you trust a guy who worked for McDonalds before landing the rep job? At SW I had a good rapport with one of their chemists, and things were sweet before they drove him out with whatever changes they were going through. I miss the guy, and hear he is doing well.



From contributor R:
I'm also in California and have used a container full of Sherwin Williams conversion varnish throughout my finishing journeys. About three years ago I quit using any conversion varnishes from any company because of all the reformulations and the problems encountered because of the newer formulas.

I also had a "call me anytime" rapport with the chemist at the factory, but that relationship has gone by the wayside. Sherwin Williams will reformulate their coatings at will, but unfortunately they won't inform the end users.



From contributor T:
It isn't over yet. My information is that all formulas must be reduced to 225 voc's before June or July of this year. The acetone will be replaced with Helifino, so with that information, I'm not too quick in adjusting to what we use now.

As for SW, they have changed their policy to include selling only to those that are willing to sign up for a government de-coder ring. In other words: a kind of permission slip, so you can buy it, and the government can track you if they have a boring day, or are in need of lunch money. Valspar, according to what I've been told, is holding out till the last minute, so the stuff I bought is still in essence old formula.

This morning I did fix my mess. We began the day shooting black lacquer, straight up with no additives. Acrylic enamel, which speaks for itself, and vinyl sealer with smoothie. Well, what caught my attention was the black lacquer. It seemed to be laying down beautifully. So I dumped the CV, got a gun, and field stripped and cleaned the snot out of it. After making some recommended gun adjustments, I shot one of the piano pieces, and it laid out sooo purdy. Stress over.



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