This is my second build and my first time trying to epoxy over them stick on decals. It doesn't look too good lol. From a glance you can kind of tell it's wavy, but when you feel it you can really tell. Is there any way I can sand down the epoxy to make it level wand epoxy over it without having scuff marks?

Yes, use about 150-220 sandpaper with a solid backing to keep from having localized sanding. You want to gently sand it smooth, taking off the high spots. You cannot go all the way through the current layer or you'll damage the decal, so you may want to take some off, re apply epoxy, then do it again. But this can be fixed with careful work.

Now ask the question why did the original coat turn out wavy. My wavy applications have been caused by excessive epoxy being applied or application of too much heat. So knowing nothing more than what I've read, I would recommend less epoxy, little heat (just a flash from a lighter), and longitudinal strokes with the brush. Don't dispair, you'll work it out and get better with every build.

I think too much heat may have been part of the issue. I hit it with a heat gun quite a bit to see where the finish would sqg then I would wick the excess off. I did this more than once with three coats. It got worse with each coat.

Sagging the finish on purpose and then trying to remove sags and drips only creates a problem that you do not want to begin with. The idea is not to have any sags or drips to begin with.

[www.rodbuilding.org]

Don't just look at the photos - read the text.
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I know some will disagree, but I have never found a reason to apply heat to my epoxy coatings! There are couple of good articles in this sites library regarding wrap epoxy.

Sinse you have three coats on now Block sand the finish Add another coat
NO HEAT
while turning Then stop the turner Take off any drips Turn 180 see if it drips Take any off Start the turner again
NO HEAT let set

Bill - willierods.com

Bill's way , above this comment is the best way I have found ,

William Sidney
AK

Bought some 220 grit sandpaper and sanded it down some and reapplied finish. Looks a hundred times better. Thanks guys.