- Select Glue.
- Fill "top bottle" with water and cap.
- Apply to bottom of both soda bottles.
- Interlock the five bottle feet.
- Wait for Glue to set.
I've been very happy with PL Premium adhesive for many water rocket applications. Read more about this adhesive on another page. This is a perfect application for choosing this adhesive above others. It has great surface tension (attaches to surface of PETE bottles) and is the perfect consistancy when cured. It's semi-ridgid, not too soft & not too hard.
Add water to the bottle that will be on top and put cap on to prevent leaks.
Apply the PL Adhesive to the bottom of the inverted bottle. Mound it up in the middle, between the five feet, and on top of the five feet. Do, the same to the upright bottle.
Put the upright bottle ontop of the inverted bottle. See how the five feet interlock between the two bottles. This also centers the bottles. It couldn't have been designed any better, even if this is a lucky coincidence.
Did the bottling manufactures knowingly design these bottles primarily as water rocket first, and then for soda containers later ??? 😄
Use the tip of the glue cartridge to fill any voids, and smooth surface of glue.
Cure glue at overnight, and perferably 24 hours or more. The PL Premium will expand while curing. A "weighted" bottle on top prevents the bottles from being separated during the curing stage.