Make the ultimate UL all-weather ballpoint pen for taking notes along the trail with just a standard Fisher Space Pen refill (SPR4) and a short length of heat shrink tubing!
The Fisher Space Pen and the associated SPR4 refill earned the reputation throughout the world for being able to write on almost any surface, at any angle, through grease, and even under water – and as so many backpackers already use one it seems like the perfect choice for this quick little hack.
This project takes about 2 minutes and creates a highly durable pen that goes perfectly with a Rite In The Rain memo pad or small notebook. A standard Fisher Bullet Space Pen weighs 2oz (56g), the refill with shrink tubing weighs just 3g.
I used 3/8″ heat shrink tubing that has a 2:1 shrink ratio (3/32″) and found that it formed tightly enough around the contours of the refill. You’ll even see in the photograph below that if you leave a small amount of the tubing overhanging the non-working end of the refill, it will shrink nicely to form an enclosed end.
Be sure to check out my previous version of the Fisher Refill UL pen hack that does not require any heat shrink tubing, just a small piece of duct tape! For those of you growing tired of hearing about heat shrink tubing, I promise this will be the last blog post about it for a very long time =)