Here is one way to seal a Mylar bag inside of a typical five gallon bucket for long term food storage.
If you are storing food (rice, beans, wheat, etc.) in a Mylar bag inside of a plastic bucket, you will not need to use food grade buckets – because the food itself will only be exposed or in contact with the ‘Mylar’ and will not be exposed to the plastic lining of the bucket wall itself. You may choose to buy inexpensive 5-gallon buckets from your local home improvement store in this case.
For foods that will be stored directly in the bucket, consider using food-grade buckets, which you might find for free at your neighborhood bakery or grocery store, or look for them for sale at preparedness supply stores.
Mylar bags will completely seal the food. This, along with an oxygen absorber dropped into the bag will keep the food fresh for years.
You may also choose to use Gamma Seal Lids which will make your life much easier when it comes to opening and using your food inside your buckets. These lids conveniently screw on and off and are also air tight.
How to seal a Mylar bag for long term food storage
If using a Gamma Seal Lid, first snap on the gamma ring to the top of the bucket.
Then, or otherwise, insert a Mylar bag that is fitted for a typical 5 to 7 gallon bucket (I’ve seen all three size buckets – the diameters of the buckets are the same, but the buckets are simply taller for 6 or 7 gallon).
Dump the food stuff into the Mylar bag to keep for long term storage (e.g. long grain white rice). Be sure to leave about two inches of head space from the top of the bucket to ensure that excess Mylar bag material will fit beneath the lid and the lid will screw on all the way.
Oxygen absorbers come new in a sealed air-tight bag. When the bag is opened, the oxygen absorbers should be used immediately and any extras should immediately be stored in a glass mason jar with the top securely screwed tight – otherwise the O2 absorbers will rapidly become ‘spent’. If doing multiple buckets, get them all filled with the Mylar bags and food first, and do the O2 absorbers last.
Add a 2,000 cc oxygen absorber to the filled Mylar bag with the food.
Set the heat setting of the Iron to high (no steam). The Iron will not melt the Mylar, so don’t worry. If you are worried to ruin the Mrs. good Iron, then buy a cheap one and use it just for this…
Use a smooth flat board or any sturdy flat smooth object that won’t damage from heat, and place it underneath and across the open end of the Mylar bag.
Iron across the open seam of the Mylar, against the board underneath, while stopping just short of the end, leaving an opening to burp out the excess air.
Run the Iron across the seam a few times while pressing mildly.
Then burp out the remaining air that is inside the Mylar bag through the small open end that has not yet been sealed. The oxygen absorber that you dropped into the bag just prior to ironing will absorb and remove the rest of the air after it’s sealed, so don’t worry about burping every last bit of air out – just get what you can.
Position the open Mylar corner at an angle compared to the original ironed seam, place the flat board underneath and Iron across a few times to make the final seal.
Fold the excess of the Mylar bag into the five gallon bucket and wait 12 hours before checking back to be sure the oxygen absorber pulled the remaining air out of the bag. This will let you know that the Ironed seal is good to go. The bag should have a vacuum sealed crumpled look. If it doesn’t, you may need to do it again (with a new O2 absorber).
I like to leave a nutrition note inside the bucket for whatever is inside. You may want to label the outside of the five gallon bucket with the ingredient as well as the year and month. I like to use white artist’s tape, which sticks well to things and is perfect for labeling (and cleanly removing).