I spend a lot of time in the outdoors either foraging for wild foods, mushroom picking, trout fishing, hiking, fishing in general, camping for a day or two, etc. An important part of my gear for these activities is insect repellent.
I keep a small spray 'pen' of insect repellent in the glove compartment, tackle box, backpack, day pack and back pocket. They are scattered here and there so they are always with me. Those little spray pens of DEET insect repellent are very handy to carry about and very lightweight.
Unfortunately, they are manufactured in such a way so that people can't refill them. They are labeled 'nonfillable container'.
That's a shame.
Those pens are actually part of the cost ( probably a dollar ) when you buy that repellent for near $3.00. When it is empty you throw it away when it could still be a fully functioning little spray pen.
Using something over and over rather than throwing it away after one use makes environmental sense AND it can save money cents.
I got to thinking about refilling those spray pens one time when I was getting all bit up by mosquitos while picking golden chanterelles that were in absolutely perfect condition from a patch I had just discovered.
I did not want to leave just then, but jeepers creepers, those mosquitos were driving me crazy and the little insect spray pen that I had with me became empty after the first pump into my palms.
The mistake I had made was not removing part of the label so I could tell readily how much repellent was remaining inside the pen. Inadvertantly I had taken an almost empty one into the woods. That's bad. It's dumb.
Now that I have figured out how to refill those 'nonrefillable container' pens I have them always in the full condition.
Empty insect repellent pen.
A bigger stock container of insect repellent ( like a 4 ounce pump or whatever you use ).
Let me just say that I use Repel 100 in this tutorial only because that is what I use. I like Repel 100 because it is handy in the 'pen' format and because it is very high in DEET ( 98.11 % ). With high DEET a very small amount last a long time.
The higher the DEET the better it is for protection against the bugs that carry Lyme disease and west nile virus. But that is just me.
Use whatever you like but the principle of refilling nonrefillable containers is still something that can be done to stretch a buck.
With regard to diluting DEET
Although I do not do it, nor advocate doing it, i've been told that you can dilute DEET with rubbing alcohol. Apparently that is what the 1.89% 'other ingredients' are.
Adding equal amounts of '91% rubbing alcohol' to whatever brand of DEET repellent you use effectively doubles your stash. Of course the concentration is close to halved.
Just make sure you start with a product that is high in DEET. You don't want to dilute a 28% DEET product too much.
One extra note on diluting with alcohol. Absorbtion is greater with more alcohol in the mix which might cause more DEET to be taken in by the skin. Some may have a concern about that. If so apply only to clothing areas.
My method of stretching my DEET supply in the field, a little bit, is to put just a little water in the palm of the hand, spray some DEET in it, mix it a bit by rubbing my palms together, like you do with aftershave, and applying where needed.
As a side note. Here is an interesting article about the effectiveness of celery extract ( G10 ) as a mosquito repellent.
Anyway, getting back on topic.
Below you can see the product container types.
The PEN is $2.97 and the content is .475 fluid ounces.
The PUMP is $7.88 and the content is 4 fluid ounces.
Yeah. Wow! The insect repellent is the same. The DEET % is the same. It is just so much more economical to buy the pump than it is the pen. But the pen is so much more convenient.
If you bought 8 pens ( 8 x $2.97 = $23.76 ) you still would not have the same amount of DEET repellent ( 3.8 fluid ounces ) as is in the pump.
Another way of saying it is that by purchasing the pump you have the equivalent of over 8 pens.
The 'Pen' has a net volume of .475 fluid ounces.
The 'Pump' has a net volume of 4 fluid ounces.
It makes sense then to buy the pump and use it for the source for refilling the pen.
Now to the Refilling:
First thing to do is remove the label from the pen so we can see what's going on inside AND so that when in the field you won't do what I did by taking an almost empty pen with you when you go in the woods in the Summer.
The pen is almost empty. Just a little bit of repellent on the bottom.
If you have a tall shotglass that would be great. If not you could make do with something else that is tall and narrow.
Unscrew the cap from the 'pump' and pour some repellent into the shotglass. Pour enough in so that when the upside-down pen is put into the shotglass the volume of the repellent is above the nozzle of the pen.
Place the pen 'nozzle down' into the repellent in the shotglass.
Now we start the refilling process. Push down on the pen until a bubble comes out the nozzle.
Pump down on the pen. Do the pump far enough so that bubbles come out of the nozzle.
Do it again. Do it again. Again. Again. Keep doing it ( see that there is a bubble each stroke ) until you get the amount of repellent into the pen that you want.
If there comes a time when you can't see bubbles anymore when pumping ( all the air has been expelled ) then you need to get some air inside again. That's easy enough. A couple of squirts into the shotglass will introduce a bit of air back into the pen then resume pumping upside-down again.
Twenty to thirty pumps should do it.
Keep pumping until the volume of repellent inside the pen is where you want it.
You will note in the photo above that there is a little repellent inside the nozzle housing at the top. Just pump the nozzle a few times into the shotglass. A few squirts will help clear it out.
A couple of spritzes into the shotglass will help clear the repellent that gets hung up inside the nozzle housing during the refill operation.
Nozzle housing is all cleared out.
Pour the remaining repellent from the shotglass back into the pump. Screw on the lid and put away for future use.
Wipe the pen clean with a little soapy water. Then wash your hands real good. DEET will ruin many plastics and rubber items that you touch if you leave it on your hands.