Question About Shellac

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tippie53
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Re: Question About Shellac

Post by tippie53 »

actually you need to be careful. Shellac is not always the best sealer . You need to look at the chemistry of the finish you are using. Some nitro lacquers will have adhesion issues and often if may be 3 or more years down the road. US Government dictates what volatiles are allowed. Some were removed that allow a good melt in of nitro to shellac.
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sylvan
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Re: Question About Shellac

Post by sylvan »

I have been using shellac as the base coat for my nitro finishes for 20 years or more. I have never had an adhesion problem with fresh shellac. I understand that some have had issues with something other than nitro as a finish coat but I have not seen it using Nitro.
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tippie53
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Re: Question About Shellac

Post by tippie53 »

which shellac do you use Sylvan?
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B. Howard
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Re: Question About Shellac

Post by B. Howard »

I have seen problems with tru oil over Z-poxy reported numerous times, not sure if shellac is the cure here. Think I would opt for a different porefill under the oil. A 1/2 Lb. cut of dewaxed shellac is pretty much my norm when using shellac as a sealer. Zinnser's Bulls eye Seal coat is a good premade shellac sealer. But it must be fresh, the product has a set and fairly short shelf life so it should be bought from a supplier that has a quick turn over of the product. As long as your lacquer is Nitro based and not to heavy on the acrylic modifiers it will work fine over shellac.

With all that said, I will tell you that if I use epoxy as a pore fill, I wash coat the entire surface at the end and use it as my sealer, no need for shellac, just scuff it to anchor the lacquer and shoot. One less operation, one less different film in the stack to fail.....
You never know what you are capable of until you actually try....

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sylvan
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Re: Question About Shellac

Post by sylvan »

Zinnser's Seal Coat is a good shellac. However, they have stopped putting the date made on the can so I no longer use it. I just cannot tell whether it is still fresh or not. I now use flakes I get from shellac.net and mix with alcohol. My bottles are dated and, whether it is good or not I dispose of it 6 months later and make fresh. I do the same thing with glue. The materials are cheap, your labor is not!
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tippie53
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Re: Question About Shellac

Post by tippie53 »

thanks
In the few times I have seen issues , it is indeed possible the age of the shellac used may not have been a concern.
Also Sylvan , what is the grit of sandpaper you use before finishing.
John Hall
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Re: Question About Shellac

Post by sylvan »

I go to 220 grit on wood before finishing. I never go higher until finish is applied.
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Randy
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Re: Question About Shellac

Post by Randy »

Been using shellack for over 20. I agree with sylvan get flakes from a reputable dealer store them in a dark dry place. Learn the right proportion you need weather your sand coating or French polishing. Go on the web and watch someone fill pores etc and use this great finish. Old shellack will not harden and any finish on top will stay soft. Date it and test it if you don't know how old it is. Put a dollup on a mirror or flat shinny surface and let dry 24 hours. If your finger nail pressed into it the next day leaves the slightest indentation TOSS IT.
Use or learn to de wax your mixture. This all sound complicated but it's the simplest and easiest of all the finishes in my opinion and has stood the test of time over every finish available.
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