shallac remains a bit soft...

[Knebo]

Hi all,

So I've recently, for the first time, refitted a pallet stone with shellac. I used this one from Cousins: https://www.cousinsuk.com/product/shellac-stick-clear?code=S1522
I think it went well. I heated it on a brass plate and it gently melted (no bubbles from over-heating). Also no alcohol exposure.

Now, about week later, I notice that the shellac is a little bit soft. I can make little dents into the otherwise round-clear shape of the shellac with an oiler.

Sorry, no photos this time...

Any ideas what's going on?

 

 

 

[nickelsilver]

Shellac is kind of soft. Some more than others, some is really brittle, some melts at a lower temp, some a higher temp. We had stuff in school that was called shellac but was a muddy light brown color; worked great but didn't look "normal". I think it was more like sealing wax.

 

My last employer had a bunch of really old flake shellac that was great, and normal looking too . As shellac gets older, it's "meltability" often goes down; this stuff was like 40 years old and fine.

 

I wouldn't worry about it.

[HectorLooi]

That kind of shellac is more for mounting jewels to dop sticks for shaping and polishing. 

The shellac for mounting pallets jewels are in flakes. 

https://www.cousinsuk.com/product/shellac-flakes

You can either break off small pieces and place them on the pallet jewels and warm it over a flame or melt a small piece on your pallet warmer and dip the end of a toothpick into it and draw out a whisker of shellac. The whisker can be dabbed onto the heated jewels like solder wire.

I find that the clear shellac has a sharper, more defined melting point. The opaque, cloudy type contain oils and waxes which affects the melting point and hardness.

[Knebo]

Thanks so much already for your responses @nickelsilver @HectorLooi

 

39 minutes ago, nickelsilver said:

Some more than others, some is really brittle, some melts at a lower temp, some a higher temp.

The stick itself is really brittle. I broke of little flakes and they are proper hard. But after melting it onto the fork, it seems softer. 

 

33 minutes ago, HectorLooi said:

That kind of shellac is more for mounting jewels to dop sticks for shaping and polishing. 

The description on the Cousins website said that it's also for pallet stones, so I assumed it was fine. I basically made my own flakes from it. When pressed with a hard object, it cracked, looking almost like glass. So the heating definitely changed its hardness. I wonder if it'll harden over a longer time... .

 

36 minutes ago, HectorLooi said:

find that the clear shellac has a sharper, more defined melting point

The stick I have actually looks "better" than the picture on the website. It's yellow-ish, but actually rather clear when broken down in small flakes. 

[HectorLooi]

My preferred material for fixing pallet stones now is UV cured resin. After adjusting and testing the locking depth of the stones, just apply 2 tiny drops of the resin and shine a UV light on it for 20 seconds and it sets rock hard.

After that, the pallet fork can be washed in IPA to remove any traces of the uncured resin. If you want to remove the pallet stones, just soak it in acetone for a couple of minutes to soften the resin.

[GPrideaux]

I definitely have to try that.

[hofnerpres]

Shellac comes from beetle secretions so is organic and will vary. Flakes are the best for us and have a longer shelf life. Test before use by melting a spot away onto a metal plate and examine the hardness the next day. The colour is mainly due to wax content - more wax - darker colour and it takes longer to harden off. This is great for French Polishing where you need some lubrication as the finish is rubbed onto to the wood. We need the harder De-Waxed blonde style which is also great for grain filling open pored woods before top coating. Worth doing for the lovely smell. Picture here of the last project from a previous mad hobby. 64 coats of shellac. Love the idea of using UV cement - will steal that trick. Modern guitars are finished in a UV curing polyurethane paint - takes 30 seconds so very useful.

 

 

[praezis]

On 2/14/2025 at 11:23 PM, HectorLooi said:

My preferred material for fixing pallet stones now is UV cured resin. After adjusting and testing the locking depth of the stones, just apply 2 tiny drops of the resin and shine a UV light on it for 20 seconds and it sets rock hard.

After that, the pallet fork can be washed in IPA to remove any traces of the uncured resin. If you want to remove the pallet stones, just soak it in acetone for a couple of minutes to soften the resin.

I wonder how the next watchmaker wanting to adjust or change the jewel, will judge that ? Cursing?

Frank

[spectre6000]

3 hours ago, hofnerpres said:

Shellac comes from beetle secretions so is organic and will vary. Flakes are the best for us and have a longer shelf life. Test before use by melting a spot away onto a metal plate and examine the hardness the next day. The colour is mainly due to wax content - more wax - darker colour and it takes longer to harden off. This is great for French Polishing where you need some lubrication as the finish is rubbed onto to the wood. We need the harder De-Waxed blonde style which is also great for grain filling open pored woods before top coating. Worth doing for the lovely smell. Picture here of the last project from a previous mad hobby. 64 coats of shellac. Love the idea of using UV cement - will steal that trick. Modern guitars are finished in a UV curing polyurethane paint - takes 30 seconds so very useful.

 

 

Fellow luthier here (also been a long time). Shellac/French polish is my favorite finish. I even finish the handles on all of my tools with it (chisels need to be redone from time to time for obvious reasons). I actually prefer the garnet variety though. Adds a natural depth of color that is really difficult to beat, especially on walnut. I only break out the blonde for very special woods that don't benefit from the beautiful deep red color.

[hofnerpres]

Another Luthier. Another poorly paid activity with loads of expensive tools. The fiddle was for my grandson and shellac gives a lovely lustre and is easily repaired. UV cement should be ok to dissolve once you’ve figured out what you’re dealing with.  Warning sticker? The UV paint on modern guitars is dreadful to remove - nothing legal dissolves it.