The easiest way to make a bottom bait buoyant is to insert High Density Foam into the boilie. To do this a hole has to be generated through the centre of your chosen bottom bait by using a Boilie Punch.
Before a hole is punched through the centre of the bottom bait make sure that you have the right diameter of High Density Foam for the Boilie Punch that you are using. The Boilie Punches and High Density Foam are available in 6mm, 8mm and 10mm.
When cutting into the boilie with the Punch be sure to do a little at a time and eject the cut out material, with the Boilie Punch’s internal plunger, to avoid the boilie from splitting.
Select and insert, using a gentle screwing motion, the nearest coloured High Density Foam, to the boilie that you are using. Once the High Density Foam has been pushed into and through the boilie trim the foam flush with the sides of the boilie using a Craft Knife.
The High Density Foam should be a fairly tight fit within the bore of the boilie to prevent water penetrating inside and softening it.
Use a Boilie Needle to mount the boilie on a Hair by penetrating the boilie at right angles to the High Density Foam.
Just add a counter weight to sink the now buoyant boilie and you now have a Pop-up presentation.
Tight lines,
Gaffer