More years ago than I prefer to remember Dr. Gaddy recommended to me Behlen's Jet Spray Lacquer Finish. Their number that I use is B101-0800 Clear Gloss Sheen 75-85. I found this online:
https://www.shellac.net/BehlenAerosols.html
https://albanyfoam.com/wp-content/uploads/2018/03/AFS-catalog-2018_2-27-18_LR-36.pdf
https://jtsoutdoorfabrics.com/jet-spray-clear-gloss-lacquer
https://jtsoutdoorfabrics.com/Behlen-Wood-Stain-Sprays_c_4114.html
https://www.uspaintsupply.com/brands/Behlen.html
My can has lasted for the last 15 years so it goes a long way. I hope this helps.