This is NOT a pen finish question... but other

[PreacherJon]

I am doing about 30 Redheart Jar lids for Mother's day presents' (see pic for prototype with shellac and a satin clear coat spray). I found out that Redheart fades easily with sunlight. So, I decided to get a UV protection Spar Marine Varnish. Now... my question/query/conundrum.... I almost always use a Shellac first on projects (other than pens) as to seal the wood up. Shellac works with oil and water based finishes. But I'm wondering if I should use it with this Marine UV protection Varnish. Does anyone have any ideas? ( the jars will be filled with Lindt chocolates with a white ribbon )

 

[howsitwork]

it should work fine to stop the finish over concentrating in the end grain areas. Once cured it's compatible

 

[penicillin]

Redheart and all color changing woods will change no matter what. Light and oxygen are the enemy. Sealing them with the UV-resistant spar varnish will help slow the change but it will not prevent it forever. After you're done finishing the jar lids, I recommend that you store them in a dark place until it is time to present your gifts. See:
https://www.wood-database.com/wood-articles/preventing-color-changes-in-exotic-woods/

 

[Curly]

What does the spar varnish call for a first coat? Shellac will probably be fine but why not follow the instructions?

 

[jttheclockman]

Shellac will work under all finishes as well as a finish in itself. You would want a dewaxed shellac though. Redheart will turn darker over time. UV is the culprit so store in dark area and you will be fine. Many times colored woods depend on where it was harvested and also when. There are many documents on this stuff out there. Bob Flexner is a guru when it comes to finishes and one I trust.