Can propylene glycol go bad?

[688sonarmen]

I use propylene glycol in my coolidor and desh top humi. Recently the Rh has been slipping to where it is now down to about 60-63% in both. The coolidor has some of the crystal stuff the you pour the glycol into when it gets dry and the desk top has that green stuff in a plastic holder with holes in it. Any help?

 

[galaga]

I use propylene glycol in my coolidor and desh top humi. Recently the Rh has been slipping to where it is now down to about 60-63% in both. The coolidor has some of the crystal stuff the you pour the glycol into when it gets dry and the desk top has that green stuff in a plastic holder with holes in it. Any help?

Retransmission required - but yes, it can go bad, or should I say the mixture on the florist foam can go bad. Wash out and dry the florist foam, or better yet, get new.

 

[Mister Moo]

And uh... it's January in most parts of the world. Cold snaps. Furnaces running. Onslaught of dry air challenging humis all over the mid-Atlantic. I observe other threads that have discussed sudden declines in humi rh during this time of year - mine included.

Yesterday was 70F and 90% rh in North Carolina. I felt like taking my cigars and humi outside for a walk and a few hours of sitting around on the back porch.

 

[SeanGAR]

I use propylene glycol in my coolidor and desh top humi. Recently the Rh has been slipping to where it is now down to about 60-63% in both. The coolidor has some of the crystal stuff the you pour the glycol into when it gets dry and the desk top has that green stuff in a plastic holder with holes in it. Any help?

Are you using 100% propylene glycol? It should be mixed 50-50 with distilled water for use with the green floral form. Otherwise, if you keep refilling with just the glycol, the mole fraction of water and its resultant humidity will keep decreasing. Some people suggest recharging just with water since the propylene glycol will not be as volatile as water, and the ratio will change with time. Me, I used to flush the entire thing out with 50-50 to try to maintain that balance. Now, I use beads in one humi and super adsorbent gel in another.

For the "crystal stuff", its hard to know based on that description whether you are using super-absorbent crystals or silica based beads. The beads should be recharged just with straight distilled water, the super hydrating crystals I don't know - I have some I bought in bulk that provide more than 70% when mixed with distilled water. So I use them in my Cigar Oasis which controlls the humidity for me. I'm pretty sure you should go with straight water with those as well but it depends on the formulation of the crystals.

 

[Jeff]

And uh... it's January in most parts of the world. Cold snaps. Furnaces running. Onslaught of dry air challenging humis all over the mid-Atlantic. I observe other threads that have discussed sudden declines in humi rh during this time of year - mine included.

With the heat running so much I've had to recharge my foam humidifier almost twice as much. Beads are looking better and better. Maybe an Oasis for my cooler in the future when money isn't so tight.

 

[688sonarmen]

Its the super absorbent crystals and 50/50 mix. I'll try adding some distled water to the mix, and getting all new materials to hold the solution.

Are you using 100% propylene glycol? It should be mixed 50-50 with distilled water for use with the green floral form. Otherwise, if you keep refilling with just the glycol, the mole fraction of water and its resultant humidity will keep decreasing. Some people suggest recharging just with water since the propylene glycol will not be as volatile as water, and the ratio will change with time. Me, I used to flush the entire thing out with 50-50 to try to maintain that balance. Now, I use beads in one humi and super adsorbent gel in another.

For the "crystal stuff", its hard to know based on that description whether you are using super-absorbent crystals or silica based beads. The beads should be recharged just with straight distilled water, the super hydrating crystals I don't know - I have some I bought in bulk that provide more than 70% when mixed with distilled water. So I use them in my Cigar Oasis which controlls the humidity for me. I'm pretty sure you should go with straight water with those as well but it depends on the formulation of the crystals.

 

[Mister Moo]

Are you using 100% propylene glycol? It should be mixed 50-50 with distilled water for use with the green floral form. Otherwise, if you keep refilling with just the glycol, the mole fraction of water and its resultant humidity will keep decreasing.

As Felix Unger once said, "When you ASSUME" you make an ASS of U and ME. SeanGAR wisely considered the less obvious (and possible) misuse of PG, etc. Good call.

Back to 50/50 PG and distilled water - it has worked for me by stuffing perf'ed tubes with Oasis foam and treating with 50/50 then, as necessary, adding 100% distilled water. What needed monthly (at most) refilling to maintain 69-70% through the Spring, Summer and Fall now needs to be fed every two weeks. I've ASSUMEd this is the effect of dryer weather... Could it be the PG or Oasis becomes "spent" or less efficient over 10-months? Dunno.

This is my first winter staring at an rh gauge in a humidor. Hard to keep the rh above 66-68% lately where it was always easy to maintain 70%. That's the bad news. The good news is, I've now discovered I prefer most cigars around 65% anyhow.

Three choices now. 1) leave everything the way it is and see what happens come warm weather, or; 2) replace the old Oasis and 50/50 PG/water with new foam and chemicals and see if it's easier to hold 70% rh, or; 3) buy the beads and forget about it.

 

[Mister Moo]

Are you using 100% propylene glycol? It should be mixed 50-50 with distilled water for use with the green floral form. Otherwise, if you keep refilling with just the glycol, the mole fraction of water and its resultant humidity will keep decreasing.

As Felix Unger once said, "When you ASSUME" you make an ASS of U and ME. SeanGAR wisely considered the less obvious (and possible) misuse of PG, etc. Good call.

Back to 50/50 PG and distilled water - it has worked for me by stuffing perf'ed tubes with Oasis foam and treating with 50/50 then, as necessary, adding 100% distilled water. What needed monthly (at most) refilling to maintain 69-70% through the Spring, Summer and Fall now needs to be fed every two weeks. I've ASSUMEd this is the effect of dryer weather... Could it be the PG or Oasis goes "bad" or becomes "spent" and less efficient over 10-months? Dunno.

This is my first winter staring at an rh gauge in a humidor. Hard to keep the rh above 66-68% lately where it was always easy to maintain 70%. That's the bad news. The good news is, I discovered I prefer most cigars around 65% anyhow.

Three choices now. 1) leave everything the way it is and see what happens come warm weather, or; 2) replace the old Oasis and 50/50 PG/water with new foam and chemicals and see if it's easier to hold 70% rh, or; 3) buy the beads and forget about it.