Best temp for purging shatter? Best poor man's heat source?

Eta Huinya

New Member
Hey all, a couple questions for the purge/vac shatter makers. As the header says, my first question is about purging temperatures. My desired end product is shatter with as few residual solvents as possible. I was originally taught that 90 deg F was the ideal purge temp for this, but during my research for a new heat source I have found many people who purge at temps of anywhere from 90-115 deg F. what is the optimal temp for creating shatter that I can get down to less than 100 ppm residual solvents?

The second question stems from the first, and that is what have you found to be a good, stable low temp heat source to maintain that temp? I would love to be able to afford a vac oven but cannot, my current budget is around $100-150. My purge chamber is a 12" aluminum pot, my vac is one of the more powerful ones. In the past I was taught using a waterbed heating pad; great for low heat but terrible heat variance and stability. I couldn't purge more than 8 hours without edges beginning to turn waxy/buttery, with residuals being around 500 ppm.

My first thought is a silicone heating mat such as sold by brisk heat, but prices are above my current budget. They are similar in many ways to what I'm used to, but are they any good? I like the 50-150 deg F temp range but uncertain about temp stability and control, anyone with input?

I'm considering making a poor man's heat source with a griddle and rice/sand bath to get me through, but if I do any advice for which griddle works best for achieving and maintaining purge temps? I would like to get chamber down to 80 or less if possible just for some working room on the low end.
 

canadian1969

Well-Known Member
induction heat plate (digital) $80
cast iron bowl $30
Sand (pure) dunno about this one, maybe from a craft store $20?
Works with oil bath at least, have not tried it yet with sand, but am going to.
 

KLITE

Well-Known Member
I used to do multi day purges at aroun d 30C. Yesterday I purged a little puddle to completion in under 6 hours, at 45C. No buddering or nothing at no point and depending on strain it will come out like glass. This one has a lot of monoterpenes and is a bit sappy although stable.
Im never degassing longer than 24h thats for sure.

6h45C.jpg

Best advice i can give you is if you have to spend a bit more to guarantee you can keep a constant temperature and a decent vac pump.
 

Eta Huinya

New Member
I used to do multi day purges at aroun d 30C. Yesterday I purged a little puddle to completion in under 6 hours, at 45C. No buddering or nothing at no point and depending on strain it will come out like glass. This one has a lot of monoterpenes and is a bit sappy although stable.
Im never degassing longer than 24h thats for sure.

View attachment 3879311

Best advice i can give you is if you have to spend a bit more to guarantee you can keep a constant temperature and a decent vac pump.
induction heat plate (digital) $80
cast iron bowl $30
Sand (pure) dunno about this one, maybe from a craft store $20?
Works with oil bath at least, have not tried it yet with sand, but am going to.
Was looking into induction heat plates but ended up going with a deep griddle filled with a layer of rice then filled with sand. It was cheapest for now, my plan is to invest in silicone heating pad with digital controller so I can have more temp control, then slowly get a oven vac system. The one I want is a little over 2 grand so it will be a few batches before I can get it though.
 

Eta Huinya

New Member
I used to do multi day purges at aroun d 30C. Yesterday I purged a little puddle to completion in under 6 hours, at 45C. No buddering or nothing at no point and depending on strain it will come out like glass. This one has a lot of monoterpenes and is a bit sappy although stable.
Im never degassing longer than 24h thats for sure.

View attachment 3879311

Best advice i can give you is if you have to spend a bit more to guarantee you can keep a constant temperature and a decent vac pump.
Very good advice, thank you. I went cheap for short term with heat for of few weeks until I can order a brisk heat type silicone heat pad with digital control. I would way prefer the oven but I'm going to have to save for that one. I ended up going with a griddle sand bath system for now, works great for temp stability but any temp changes take forever which sucks

I ended up with good quality and extremely powerful vac through an engineering friend I used to work with on fishing boats. It's the kind used to purge huge refrigeration systems and pulls 10-15 CFM. My chamber pressure gauge stops at -30 inHG, at full vac my pump pushes needle way past that.
 

KLITE

Well-Known Member
The one I want is a little over 2 grand so it will be a few batches before I can get it though.
Contrary to popular belief most vac ovens like across international and such are nothing more than barbie's toys for prepubescent girls. I thought they must be the best cause its what everyone uses in america. Total bullshit, go to a lab supplier and tell them you use across international ovens and they will point and laugh at your face.
Look for a good national producer of lab equipment and get it propper.

I can vouch for the ovens made by these folks:

www.grupo-selecta.com

In fact anything they make is the tits, their heating plates are so precise a medal should be awarded.
 

Fadedawg

Well-Known Member
Contrary to popular belief most vac ovens like across international and such are nothing more than barbie's toys for prepubescent girls. I thought they must be the best cause its what everyone uses in america. Total bullshit, go to a lab supplier and tell them you use across international ovens and they will point and laugh at your face.
Look for a good national producer of lab equipment and get it propper.

I can vouch for the ovens made by these folks:

www.grupo-selecta.com

In fact anything they make is the tits, their heating plates are so precise a medal should be awarded.
Solly, the link won't load for me for some reason, but here in the colonies Cascade TEK makes quality ovens, including for NASA.
 

KLITE

Well-Known Member
Solly, the link won't load for me for some reason, but here in the colonies Cascade TEK makes quality ovens, including for NASA.
try the spanish one

http://www.grupo-selecta.com/es/catalogo

Any serious comapny in spain that need lab equipment with cee homolgation get it there, heck they offered a seminar if we get the rotovap from them. I find it hilarious when i show ppl the oven and they laugh and im the one laughing at them getting shitty yank ovens that if some day things do change theres no way in hell thats getting certified, you just got yourself a 3 grand barbie toy lol. I also think the circular type of oven is more precise than cubed shaped due to improved efficience in convection.
 
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Flagg420

Well-Known Member
I set my vac chamber on my seedling heat mat, on a towel, and purge for 3 days.... shatter every time :)

(Note, I winterize, so I am actually purging the alcohol rather than butane)
 

gwpharms

Well-Known Member
try the spanish one

http://www.grupo-selecta.com/es/catalogo

Any serious comapny in spain that need lab equipment with cee homolgation get it there, heck they offered a seminar if we get the rotovap from them. I find it hilarious when i show ppl the oven and they laugh and im the one laughing at them getting shitty yank ovens that if some day things do change theres no way in hell thats getting certified, you just got yourself a 3 grand barbie toy lol. I also think the circular type of oven is more precise than cubed shaped due to improved efficience in convection.
Those are probably autoclaves you are using. You are right the ovens sold to us yanks are basically ez bake ovens. Thats because they are vacuum assisted drying ovens. Not vacuum purge chambers.
They have been re branded re purposed and re marketed to people who think it a good idea , blasting butane through a tube and smoking what comes out. If you will buy that you will probably buy a barbie oven as a piece of scientific equipment
 

Eta Huinya

New Member
Contrary to popular belief most vac ovens like across international and such are nothing more than barbie's toys for prepubescent girls. I thought they must be the best cause its what everyone uses in america. Total bullshit, go to a lab supplier and tell them you use across international ovens and they will point and laugh at your face.
Look for a good national producer of lab equipment and get it propper.

I can vouch for the ovens made by these folks:

In fact anything they make is the tits, their heating plates are so precise a medal should be awarded.
Very good advice, I will definitely check them out.
 

Fadedawg

Well-Known Member
try the spanish one

http://www.grupo-selecta.com/es/catalogo

Any serious comapny in spain that need lab equipment with cee homolgation get it there, heck they offered a seminar if we get the rotovap from them. I find it hilarious when i show ppl the oven and they laugh and im the one laughing at them getting shitty yank ovens that if some day things do change theres no way in hell thats getting certified, you just got yourself a 3 grand barbie toy lol. I also think the circular type of oven is more precise than cubed shaped due to improved efficience in convection.
Your English is way better than my Spanish, so not able to appreciate the fine details shown.

Skunk Pharm Research did do an R&D project with Cascade TEK to refine their oven for our use, by which they supplied the oven and instrumentation including a MS on the discharge stream, with technician, and we asked AI to loan us an oven for similar testing purposes, but they declined. Their standard vacuum oven is cheaper than the Cascade TEK but their Elite is in a similar price range.

I know of one other experiment that we supported, by which an associate ran an AI Elite along side a Cascade that we had subsequently purchased for ourselves, and since the results weren't published, I infer they weren't favorable to AI, but have no details.

Pharmer Joe uses an AI convection oven as a basis for building a 20L short path distillation set up, which clearly works well, so they have their uses and shouldn't be ignored.
 
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