In which way are you using it?
Hi ! Why do you need to seal it ? What or how are you planning on using it ? It would help to know . In general , if you have to cover it , I would use a clear matte finish , that way it would look as close as possible , to natural . My problem with sealing it is that it won t have the same look or feel that makes it so special.
sea glass doesn't need to be sealed because it isn't painted glass. The color is all the way through. Do you want it to be shiny instead of having the matted look that sea glass is known for? Use a glossy polycrylic spray on top and maybe it will look less milky. if shiny is what you are looking for, save yourself the trouble and just buy different glass that is shiny. shiny inexpensive Glass beads can be found in craft stores and if you want really different glass, go to a stained glass store. They will have a slew of different types of glass you won't have to add any sealers to because nothing is painted.....colors are fired in.
If you used sea glass spray on from a can use a clear spray to protect it. Buy one in matte finish. If you have real sea glass you don't need to seal it.
Here are some videos and information for you!
Spray with a clear sealant
I love sea glass! I've collected it for years, finding it on the beaches in Maine is a fun treasure hunt. Sea glass is created by broken glass getting repeatedly slammed on the rocks and sand by the waves, wearing down the edges and creating a frosted finish on it. Therefore seaglass is not meant to be sealed... the frosted finish is part of the charm of it. Here is the page with all the posts I've written about my projects and visits in Maine.