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hazing on french polish
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Author:  Peter Pii [ Tue Feb 26, 2008 10:42 pm ]
Post subject:  hazing on french polish
I french polished using zinnser shellac. I let it cure for 8 days before I put the strings on and set it up. I've played it now for aprox. 4 hours and where I hang my arm over the lower bout the finish has hazed. Is this normal with french polish? Did I let it cure long enough?
I was under the impression that 3-4 days is enough cure time.
Can I repair just the area that is hazed or do I have to do the whole top?
this is my first attempt at F.P. thus the quetion about what to do. It looks pretty good and I don't want to screw it up.
Peter
Author:  Michael Dale Payne [ Wed Feb 27, 2008 9:21 am ]
Post subject:  Re: hazing on french polish
Pictures would be nice hazing is a bit vague. I assume you mean the sheen is dulling as apposed to a clouding with in the film or in other words within the film not just on the surface. You say this is where your arm rests on the body as you play. A couple things come to mind and you may not be happy to hear one of them.

First we are going to assume you did the FP process well. Does the Haze go away when wiped down with a lightly damp soft cloth? If it does the the issue is only the sweat and oils from your skin is left behind on the shellac but is not softening the shellac. If it remains after wipe down this is probably still the issue but you may be among the those with a pH level in your skin and sweat that slightly melts shellac. I have ran into 4 such clients over the years. Not to fear the shellac will glaze back out but this may be an ongoing issue for you.

This problem is often related to people that drink a good bit but is not at all limited to such habits

Now if you did not firmly spirit off after each of your body sessions and glazing sessions well you can build a film that is not as hard as it could be and be more susceptible to your sweat.

In any case your not doing any real damage to the finish chemistry. The shellac can always be brought back to the sheen you want.

One more thing some of the stores will not rotate the stock and hold on to cans of Seal Coat for 5 or six years. While for furniture this is not a biggie for instrument finish the shellac does reach a point where it will not completely harden. I uses Seal Coat regularly but i always do the drop test on glass to be sure it still hardens properly.

Drop on eye dropper on a clean sheet of plane glass allow it to harden for 48 hours take you thumb nail and impress into the drop. If the easley leaves am mark recessed the shellac be it Seal Coat or made from flakes has gone bad or old as it were
Author:  Peter Pii [ Wed Feb 27, 2008 10:53 am ]
Post subject:  Re: hazing on french polish
The haze stays when wiped with damp cloth.
I don't have this problem with other finishes so it must be that I didn't apply properly.
The date on the zinnser can indicates it is fresh.
Quote:
Now if you did not firmly spirit off after each of your body sessions and glazing sessions well you can build a film that is not as hard as it could be and be more susceptible to your sweat

If the the hardness of the the finish is directly related to the amout of pressure applied during spiriting off. That might be my problem as I have a faulty shoulder and elbow.
How much pressure is required?
Quote:
This problem is often related to people that drink a good bit but is not at all limited to such habits
Eat Drink Guess I can't take this one to camp with me this year!!
So to repair this do I just spirit it off again or do I need to add more shellac also?
Thanks for your help
Peter
Author:  Michael Dale Payne [ Wed Feb 27, 2008 11:07 am ]
Post subject:  Re: hazing on french polish
piiman wrote:
The haze stays when wiped with damp cloth.
I don't have this problem with other finishes so it must be that I didn't apply properly.
The date on the zinser can indicates it is fresh.
Quote:
Now if you did not firmly spirit off after each of your body sessions and glazing sessions well you can build a film that is not as hard as it could be and be more susceptible to your sweat

If the the hardness of the the finish is directly related to the amount of pressure applied during spiriting off. That might be my problem as I have a faulty shoulder and elbow.
How much pressure is required?
Quote:
This problem is often related to people that drink a good bit but is not at all limited to such habits
Eat Drink Guess I can't take this one to camp with me this year!!
So to repair this do I just spirit it off again or do I need to add more shellac also?
Thanks for your help
Peter


Keep in mind the date code could be fresh but the shellac still be bad Same thing happens with flakes

You do not need to bare down real hard when you spirit-off. just firm and quick in line with the grain

You probably do not need to add more boding, just spirit off, and do a couple of glazing sessions.

Other finish like nitro and cat poly are not as quickly susceptible to softening as shellac because the are chemically cured Shellac is in it original chemical state (baring impurity processing) You have just transported it from a bottle to the body. the Alcohol was only a carrier and flashed completely off. That is also the reason it is so easy to repair.

Fix it. Then try always wearing a long sleeve shirt for a while while playing. This will help determine if the issue is you skin chemistry or the shellac. If it is your skin chemistry and you FP the neck as well I would expect you are having issues there as well.
Author:  Michael Dale Payne [ Wed Feb 27, 2008 11:25 am ]
Post subject:  Re: hazing on french polish
Why not take it to camp? The repair should only take an hour or less
Author:  Peter Pii [ Wed Feb 27, 2008 11:52 am ]
Post subject:  Re: hazing on french polish
Quote:
Why not take it to camp? The repair should only take an hour or less


Yup, what the heck!
I'm not used to the idea that F.P. is so repairable.
I'll try to repair the hazing this afternoon.
Peter
Author:  Todd Rose [ Wed Feb 27, 2008 12:27 pm ]
Post subject:  Re: hazing on french polish
My sweat destroys nitro (turns it to soft, sticky gum), but has no effect on shellac.
Author:  Michael Dale Payne [ Wed Feb 27, 2008 1:54 pm ]
Post subject:  Re: hazing on french polish
Todd Rose wrote:
My sweat destroys nitro (turns it to soft, sticky gum), but has no effect on shellac.


Now that is interesting. I have one client that I have refinished his twice. The original was Waterborne KTM9 then we went to French polish and finally to Nitro. I figured that was the last of it. Well just a couple weeks ago I saw him outside a local Jazz bar and he said he was doing the same thing to the nitro. I quickly told him to please take his hand off my truck paint! laughing6-hehe
Author:  Philip Perdue [ Thu Feb 28, 2008 12:05 am ]
Post subject:  Re: hazing on french polish
Peter,

You didn’t say what Zinsser product you were using. Are you using Bulls Eye Shellac traditional finisher and sealer or Bulls Eye SealCoat universal sanding sealer? I believe the correct product for French polishing is the Sealcoat as it is 100% wax-free. There are many members here with a lot more knowledge of these products and I am sure they will chime in. I’m currently practicing my finishing before choosing the finish for a guitar and a ukulele. Now if I could only find some wool for the French polishing it would help. For now all is on hold until I’m finished with an upcoming Poker Tournament.

Best of Luck

Philip
Author:  Peter Pii [ Thu Feb 28, 2008 1:13 am ]
Post subject:  Re: hazing on french polish
I'm using the bulls eye shellac.
cheescloth and linen for the pad
Author:  Michael Dale Payne [ Thu Feb 28, 2008 10:49 am ]
Post subject:  Re: hazing on french polish
piiman wrote:
I'm using the bulls eye shellac.
cheescloth and linen for the pad


Ok there is an issue. THe Bulls Eye Shellac is not wax free and is not instrument quaility shellac. Not sure this is the cause of your problem but I can tell you you will never have a good hard film. I am supprized that you felt the film was good and clear in the first place. But that is an other story.

In the future use only 100% wax free Shellac for French polishing. Zinzzer's BullsEye "SEAL COAT" is their only shellac product that is wax free. they also do make a French polish in a bottle but I don't like it because the lube oil is in the mix.
Author:  JWarwick [ Thu Feb 28, 2008 11:47 am ]
Post subject:  Re: hazing on french polish
What Michael said. The Bull's Eye shellac is useful for sealing jigs, perhaps, but not much else.

If you want to use a pre-mixed shellac, the Liberon product is decent, and I also like Jeff Jewitt's concentrate. You can find it at his website, Homestead Finishing Products:

http://www.homesteadfinishing.com/htdoc ... %20shellac

If you get serious about French polishing, it's a good idea to learn how to mix it yourself. You'll have much greater control over the final results, IMHO. There are lots of secret recipes for FP, and I'm sure you'll find many passionate opinions about which is best. Finding the recipe and-- MOST importantly-- the method of application which works for you is part of the journey, and all the fun.

Best,

Jim
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