I agree with Laszlo. I don't get the syringe thing, the pastry bag thing, the corner-cut baggie thing... I just scoop a little thickened epoxy out of a yogurt cup with a tongue-depressor sized craft stick and have at it. And, by the way, for most of the final fillets, tongue depressors work great for that, too.
Jim
...and better than tongue depressors, is a putty spreader with one side clipped to about a 60 degree angle, and the acute corner rounded to your desired fillet radius. Transfer your non-sag fillet mixture to a cardboard square pallet, and trowel it on, then drag the acute angle along your fillet, leaning the spreader forward and bracing it with your fingers so that the 60 degree sides scrape the plywood clean and push the material toward the center of the fillet.
on the spreader's obtuse corner, you can cut a bigger radius for the flatter joins, and use it the same way.
I just tacked with the epoxy in syringe for first time last night and it wasn't messy at all.
Way less messy than the mile long spider web stringers that come off hot glue. I used one pump resin and one pump hardener and some wood filler to slightly less than ketchup thickness and just poured it in the syringe from my very small cup after mixing for 2 minutes. Turned the Wood Duck on it's side and slowly squeezed it in the gap I created by planing the 45 degree angle on the plywood edges. It didn't run out of the groove at all and saturated the wood. Very happy with the results. Hot glue wood be a total mess. Stick to the instructions.