Desiccant Sachets

[Bino Pete]

I've just recently replaced my desiccant Sachets out of my desiccant cap because they had turned green. I've been told that the old green ones can be regenerated by placing on a radiator. I have done this for two days and they are still green - how long should I leave them and is a radiator the best place?

[almcl]

Assuming your sachets contain silica gel, it is true they can be regenerated - a cool oven, say around 100C or so should do this - but silica gel is white or colourless so if  yours have turned green, they may contain something else as well, perhaps as an indicator, or not be silica gel at all.  

Did you get a manufacturer's product sheet with them?  If so, this may contain information about conditioned weight of individual sachets and from this it is possible, by weighing them, to work out what the moisture content is and from this, the %RH they will attempt to maintain in whatever container they are placed in.

 

[Bonnylad]

Try YouTube and the regeneration of silica gel packets. Saw it some time ago. Frying pans and particularly microwaves seem to be the way to go (but don't quote me.)

[Bino Pete]

8 minutes ago, almcl said:

Assuming your sachets contain silica gel, it is true they can be regenerated - a cool oven, say around 100C or so should do this - but silica gel is white or colourless so if  yours have turned green, they may contain something else as well, perhaps as an indicator, or not be silica gel at all.  

Did you get a manufacturer's product sheet with them?  If so, this may contain information about conditioned weight of individual sachets and from this it is possible, by weighing them, to work out what the moisture content is and from this, the %RH they will attempt to maintain in whatever container they are placed in.

 

These are the ones - https://www.firstlightoptics.com/astronomy-optics-cleaning-protection/flo-10-x-spare-desiccant-sachets.html and this is the info - https://www.firstlightoptics.com/adapters/flo-125-2-inch-desiccant-cap.html

[Dave In Vermont]

An oven will work - but don't raise the temperature high enough to cause the packet itself to catch fire! You could dump the contents into a metal container of some form, and then transport it into where you need it.

All you're trying to do is drive the H2O out of the silical-gel, so any temperature above the boiling-point of water (100C or 212F) will work - the higher, the faster. This can be repeated many times.

A chemist,

Dave

[almcl]

Pete

I think it's probably this material https://www.interraglobal.com/products/silica-gel/yellow-silica-gel#.V7w4hXtwbMI or a near relative,

in which case getting the temperature just above 105C (220F) and holding it there until the weight remains constant should do the trick.

[Stub Mandrel]

Or buy Sani-cat silica gel cat litter and put it in your own container :-)

Cheap as chips!

[BGazing]

any reason why this

https://www.firstlightoptics.com/adapters/flo-125-2-inch-desiccant-cap.html

is to be delivered only to uk adresses? @FLO?

[spaceboy]

As it happens I have just done mine today. Gas MK3 for 1Hr stirring at 15 minute intervals then leave them in the oven to cool. That's doing several bags though  http://www.ebay.co.uk/itm/40g-Bags-x-10-Silica-Gel-Desiccant-Self-Indicating-Loose-Orange-to-Green-/121816283671?hash=item1c5cd0fa17:g:T1sAAOSwkZhWSbFT all emptied out in to an oven proof bowl.