I love my Thermarest mattress, well mattresses actually I have two, a Trekker for summer and an Xtherm for winter, but inflating them can be a real pain. Not only does it leve me out of breath but the moist air is not good for the mat and in winter it can cause ice to form inside the mat. I do have the tiny electric pump but something about it always bugs me, the whiny noise it makes and it is never quite enough to get the mat fully inflated, plus of course there is the issue of needing spare batteries as everyone on the trip wants to borrow it, by day three the batteries are run down.
The mats come with a pump sack, push the bag over the valve, fill the bag with air and squeeze it into the mat, only someone at Cascade Designs forgot that by the time you have half-filled the mat air will be coming out faster than you can refill the pump sack. Not so great. Other makers like Exped have overcome this with a clever one-way valve system but T’Rest are sticking to their old and trusted design.
By luck, I stumbled upon a link to a Youtube video of a homemade adaptor. Although the design was intended to mate an Exped Schnozzle pump sack its clever use of a cheap plastic one-way valve was exactly what I wanted.
First find the valves, no problem, Amazon is your friend, less than five bucks for a pair if you don’t mind a six week delivery time from Hong Kong. When even that extended wait had passed and no valves had appeared I filed a complaint and got my money back. Two weeks later my valves appeared for free. Bonus!
The rest of the bits I found in my shop and by rummaging through the pipe fittings at the local plumbing store.
Silicone hose is most flexible and unlike PVC doesn’t stiffen with age. I also found that no additional cable tie-wraps were needed to secure the hose.
The adaptor fits both the T’Rest pump sack and also the $9 MEC VectAir mattress pump, inflation is much quicker now that no air is wasted and it is easy to bring the mat up to full pressure.