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Captain McGroovy’s Pirate Ship


Mr. McGroovy's Cardboard Pirate Ship Plans illustrate simple, easy techniques for building a cardboard pirate ship playhouse using Mr. McGroovy's Box Rivets™ and your own large boxes.

View pirate ships people have made >>

Approximate size if built with...

  • Refrigerator boxes = 6' x 18'
  • Washer/dryer boxes = 5' x 15'
  • Wardrobe boxes = 4' x 12'
  • Dishpack boxes = 3' x 8' (toddler sized!)


Boxes NOT included. See How to Get Free boxes.

What are Box Rivets?

Choosing Rivet Size

Mr. McGroovy's Box Rivets™ come in two sizes: single-wall and double-wall.

Single-Wall Rivet Size

The single-wall rivet size works on normal sized cardboard, called "C-flute". Moving boxes, dishpack boxes, some washer/dryer boxes, and even small refrigerator boxes are made from C-flute cardboard.

Single-Wall Rivet Dimension

Double-Wall Rivet Size

The double-wall rivets works on thick, two-layered cardboard, called "double-wall" of course. Wardrobe boxes, some washer/dryer boxes, and larger refrigerator boxes are made from double-wall cardboard.

Double-Wall Rivet Size

Box Rivet Building is a *SNAP*

How Box Rivets Work

Box Rivet Instructions

nail punch

Holes Making Method

My preferred method for making holes in cardboard is to use a standard nail punch (without the hammer). It's easy to just hold it in your hand and poke it through. It's tough but not too sharp, and leaves a nice 1/4" hole.

Pull, don't pry

Mr. McGroovy's Box Rivets™ are Reusable!

An adult can usually slide their hands between connected layers, give a quick tug, and box rivets pop apart without breaking.

Occasionally you will come across a stubborn rivet, which can easily be removed with a common hammer (pull, don't pry).

Top 5 Reasons Rivets are Better than Duct Tape

  1. Projects stay together and last longer
  2. Reusable - construct a new project every week
  3. Easier to Use - big projects go together in a snap
  4. Faster - more time for creativity and enjoying your project
  5. More versatile - build with cardboard in new ways