How to Repair a Leaking Thermarest Neoair

therm-a-rest_neoair_mattress_01The Thermarest NeoAir sleeping mattress was a revolutionary piece of tech when it was released four or five years ago.  Able to withstand serious pressures and inflatable in approximately 12-15 breaths, it was the first camping mattress to provide more than two inches of loft (for side sleepers) while still packing down to a cylinder the size of a one liter bottle.

As with any inflatable product, however, puncture is always a possibility.  Fortunately, except in cases of complete blowout (and you’d have to run over an inflated one with a truck or set it on fire to do that, based on my experience), pinhole leaks are easy to fix.  In my case the damage was done not on the trail but by, of all things, my cat, who decided to pick a fight with my air mattress for reasons known only to him while I was packing for a recent trip.

Repairing a leaking Thermarest is very similar to repairing an air bladder on a raft or pontoon.

Step One: Inflate to Maximum

First, you need to inflate the mattress as fully as possible.  Overinflation is the goal here, so blow it up as much as you can then set it in a hot sunny place to expand for a few minutes only.  (You don’t want to blow it up, just force air through the leak).

Step Two: Spray in Soapy Water

Next you need to coat the entire mattress in a fine mist of soapy water.  I use ordinary dish soap in a spray bottle and liberally spray down the entire inflated mattress.  You want to identify leaks by watching for bubbles which form and either grow or fail to dissipate as the other bubbles naturally settle out.  If you’re lucky you’ll get a nice easy to identify bubble trail like this:


Step Three: Circle Leaks in Permanent Marker

This one is self-explanatory.  Don’t worry, you can clean the marker off with acetone or fingernail polish remover later if the circles bother you.  Personally I like them; they show the product has been used.

Step Four: Deflate and Apply Toluene Glue

The fourth and final step is to partially deflate the mattress, wipe the area of the leak dry, then apply a toluene based glue such as Aquaseal or Shoe Goo or (as pictured) E6000.  There are several similar products on the market.  Be aware that toluene is not good for you, so wash your hands when you’re done.  You want to apply a dime-sized spackle over the site of the leak, approximately the thickness of a dime, then finish deflating the mattress and set it somewhere cool and dry for the glue to set.  DO NOT USE for at least 24 hours.



My experience with pinhole leaks in large rafts repaired this way is that, under much greater pressure and with far thinner inner tube material, the toluene patch will make the bladder as good as new.  Similarly, my repairs to the NeoAir pictured here seem to have returned it to 100%.  If you get some deflation after a repair like this, you can always re-apply soapy water to check your seal, but keep in mind that all air mattresses of this type will naturally lose some rigidity as temperatures drop and the air inside contracts.  For this reason it’s a good idea to inflate them when you set up camp, then give them time to cool before adding a puff or two of air right before you bed down (if a rigid bed is your preference).

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