Well I spent 2 hours trying find dry ice and failed.
So I used regular ice and a heat wraps and heat pad.
Only got about 2lb to move and I recovered 1.8lb so i lost a little bit.
But look at this giant cookie 
7 Likes
Nice cookie Some grocery stores sell dry ice they usually keep it upfront close to customer service in a locked freezer for safety reasons. Where I live there’s Fry’s market and Safeway that carry it.
5 Likes
We can only get it here at the liquid air / welding supply stores. Best to call ahead first to make sure they have it in stock.
6 Likes
Well I found some today but holy crap is it expensive
I thought the closed loop was going to save me money because I wasn’t buying butane every time but I’m not to sure 
I think butane may be cheaper then dry ice 
Hopefully I just got way more then I need.
I’ve got the column loaded to run again when I get home, this time with dry ice.
8 Likes
How much did you get? Was it in chip/pellet form or blocks
3 Likes
I guess I’d call it blocks. 6"x6" squares roughly 2" or so thick.
It was $70 total and if I remember correctly, it was like $2.60 a pound.
Roughly 25 pounds worth if my math is correct.
4 Likes
So this 2.5cfm single stage harbor freight vacuum just isn’t cutting it 
I can’t get below -27 "hg and heres what the first run useing regular ice and heat is looking like at 72hours keeping the temperature set at 100f.
I think I need a 2 stage 5cfm
5 Likes
That means you probably have a leak somewhere.
When I operate my vacuum pump, it’ll run for a solid 8-10 minutes, and then the tone will change when there’s no more air left. I’m able to pull a -30hg.
Upgrading to a larger pump will pump it out faster, but if there’s a leak, it’ll still leak and never pull a full vacuum.
6 Likes
This was in my mind
Now how do I troubleshoot for leaks
6 Likes
I would recommend using an air compressor. Pressurize the system, to a certain pressure, and use soapy water to look for bubbles when sprayed on all of the gasket areas.
If it can hold a vacuum, it’ll hold pressure. I wouldn’t go over 20-30psi, not much pressure is needed to find a leak.
9 Likes
This was my intention testing method and it holds the -27 hg for hours (i turn the pump off when i go to work)
According to Chat GBT,
"It depends on a few factors, but in most cases, a 2.5 CFM vacuum pump should be able to pull a 5-gallon chamber down to -30 inHg (inches of mercury) if the pump has a deep enough ultimate vacuum rating.
Considerations:
-
Pump Ultimate Vacuum Rating – Most rotary vane vacuum pumps can reach 29.92 inHg (which is a near-perfect vacuum at sea level). If your pump has an ultimate vacuum rating of 25 microns (0.025 mmHg) or lower, it should be capable of getting very close to -30 inHg.
-
Chamber Size vs. CFM – A 5-gallon chamber (approximately 0.67 cubic feet) is relatively small compared to a 2.5 CFM pump. The pump should be able to evacuate the chamber quickly and reach maximum vacuum in a reasonable time."
I couldn’t find my exact model “single stage 2.5CFM”, but heres a 2-stage 3CFM same brand that rated at 22.5 microns which is below the 25 microns AI says is needed.
I’d assume my smaller single stage has a rating even lower then 22.5 microns.
The “test” of leaving it under vacuum doesn’t take the hose confections into consideration as I close the valve on the pot so I could have a leak in the hose maybe
5 Likes
Possibly, I had one. I replaced it.
The speed at which it pulls a vacuum doesn’t matter, it’s the very end, that takes the longest of evacuating all of the air out.
Try pulling a vacuum on different parts of the column, by shutting off valves, and this will section off the leaks where they’re coming from.
6 Likes
So i think you are correct my friend 
I can see tiny bubbles at the condition to the pot.
Theres a bit of oil in the line just enough that I can clearly see teeny tiny bubbles moving.
You can see one there.
6 Likes
What is it that you have a hose clamp on
5 Likes
There should be no hose clamps anywhere in this set up.
6 Likes
Exactly stainless braided hoses only. Not the red and blue hoses with brass ends either. My vac only pulls -29 but I put mine under 50psi pressure test overnight before pulling a vacuum then I leave that for a few hours before packing dryice in the dewaxing column and packing the base in a bucket full of ice and dryice it then sits under vacuum while everything gets cold. Then I check the vacuum pressure again to make sure that the freeze didn’t cause a leak somehow. Then I add butane. I found leak once right before I ran it. It wasn’t a gasket but a bad hose that didn’t start leaking untill I put it in a bucket and packed in the ice. I had to pull it all out and repressurize it to find the leak.
6 Likes
The vacuum pump and chamber is what I was talking about right now.
However when pulling vacuum on the exterior, it is useing the same condition with hose clamps.
I had thought this could be a weak point, but it’s how it came 
I used the braided stainless lines for the vacuum chamber also. Although it’s not critical to get down to a full vacuum when venting off the extract.
5 Likes
That’s good information man 
I knew elevation play a role but i didn’t know how much.
I am roughly 1000ft above sea level so I lose 1"hg
4 Likes