"Pinholes" in mylar bags
 

I repackaged some food from 6 gallon mylars into smaller 1 gallon mylars the other night. I was sort of shocked that when I held the empty/used mylar bags up to the light, I could see tons of tiny pinholes! They only broke the foil layer, not the plastic, and were only in the areas that had been folded or crumpled a lot (mostly the top several inches of the bag). Anyone else ever notice this?

Re: "Pinholes" in mylar bags
 

I can't say that I have seen pin holes, but I do know that my failure rate in keeping a seal in the 1 gallon bags is about 1 to 7. Each time I look for some type of hole and never find anything. I will even cut off the top, put in new O2 absorbers, re-seal, and it will still have the same problem, so I know it is not the way I am sealing. I will look this afternoon to see if I can find pinholes in the light. I have not had this problem with the 6 gallon bags. The 1 gallon bags were purchased from Sorbent Systems IIRC.

Re: "Pinholes" in mylar bags
 

what type of mylar bags is it? the 4.3 mil or the 7 mil or what?

Re: "Pinholes" in mylar bags
 

I assume they are 4.3 mil. I bought them from emergency essentials.

Re: "Pinholes" in mylar bags
 

They may not be pinholes, mylar is a clear film, if the metallization wears off
or flakes off you can see light through it. It may not be a hole all the way through the film.

Re: "Pinholes" in mylar bags
 

This is why using both a sealable bucket along with the mylar bag is important. The amount of transfer of any gases, in this case oxygen, through two sealed barriers is virtually nonexistant. Especially if it is stored in a cool, temperature stable environment.

Nothing is perfect, but this real, real close.

s

Re: "Pinholes" in mylar bags
 

I have had the exact same problem with the same bags from Sorbent and thought maybe it was just me. I bought the 5 gall bags to try again...thanks for posting...that has helped me out alot with this problem:D

Re: "Pinholes" in mylar bags
 

The sealed bucket is just an outside barrier against moisture, animals, and to some extent temperature changes. I would never rely on that for any type of oxygen barrier. If I do not see mylar bags sucked in as tight or tighter with O2 absorbers than what a vacuum sealer can do, I consider it a faulty seal. Those bags, if done correctly, should turn out like bricks.


Dutch Dog - I have not seem to have had any problems with the 5 gallon bags from them. At least we know that it probably is not just us if we have this common experience. Maybe we both got bags made the day a new employee was running their machines.:confused_ma:

Re: "Pinholes" in mylar bags
 

I had some bad seals using gallon mylars also. They are a little tricky to seal with an iron compared to the buckets so I bought a hot jaw sealer. They all sealed perfect and it was way easier. Probably not worth the expense if your just going to seal 5 and 6 gallon bags since it pretty easy to use an iron for those, but if your going to do a lot of gallon bags it makes things a breeze. I also trust the seal more since it heats both sides and "crimps" it too.