BudDryer v2.0

[Al B. Fuct]

Having buds hanging around drying in free air for a couple of weeks is a bit of a security/scent problem for me. The place started to smell like a dope factory. Had to work out a way to dry quicker and with less scent, without sacrificing quality.

 

I investigated using commercially made food dehydrators but some quick research indicated that their usual op temp of ~38-70C (100-160F) would break down THC, which begins to degrade at 29C. Food dehydrators are also often rather small unless you buy the most expensive units. None but the very most expensive dehydrators for commercial kitchens (~$5000) had sealed doors and flanges for exhaust air ductwork.

 

One could modify a commercially made food dehydrator by putting a heavy-duty incandescent light dimmer in series with the heating element, but the unit's original thermostat might be useless at 29C and below. However, I decided there's enough work and cost in buying and modifying a new food dehydrator that I may as well start from scratch and get exactly what I need from the get-go.

 

BudDryer v1.0

 

BudDryer v1.0 was built in 2000 from junkbox parts and remained in use in working yet rough form for many years.

 

BudDryer v2.0

 

I've recently rebuilt it but found there's some more R&D in the temp control than I'd anticipated. v2.0 still needs tweeks... but v1.0 did the job in an even rougher form for 7 years!

 

Started with a common plastic storage tub and made some wire racks to hold the buds, hung those by small chain from the lid.

 

airflow diagram for v1.0, nearly identical for v2.0 except for component detail notes

 

I put one fan exhausting air out of the box on one end, up near the lid, as warm air rises. The intake on the other end is down low, pumping warmed air into the lower part of the box.

 

Air is warmed by aluminum body resistors bolted to a heatsink, which is in turn bolted to the intake side of the inbound fan.

 

BudDryer v1.0 wiring

 

BudDryer v1.0 had a pair of 470 ohm, 25W resistors being fed by an incandescent light dimmer. It had a 4" intake and a 5.25" exhaust fan. The 25W resistors could take 50W each as they were bolted to the fan cooled heatsink. v1.0 had no trouble making enough heat to raise cool, 10-13C air up to 29C as the 4" fan was a bit of a bottleneck.

 

BudDryer v2.0 wiring

 

v2.0 has four 2.2k ohm 25W resistors bolted to the heatsink but wired straight to 240V in parallel with no dimmer. Temp control will be by a Jaycar Super Simple Digital Thermostat which simply switches the resistors on and off as temp rises to the setpoint.

 

240V across 2.2k ohms is 26.1 watts, dissipated across each 25W resistor. However, fans were both replaced with new 5.25" units. They work a little TOO well. With the much increased airflow of the new, matched fans, the v2.0 dryer doesn't get warm enough to come up to 29C when ambient air is very cool. I need to drop the resistor values to push a little more current through them.

 

 

I've duct-taped over one end of the heatsink to reduce airflow so the temp will come up a bit until I can fix the problem. The exhaust fan is also temporarily disconnected.

 

The 25W resistors can dissipate a lot more than 25W when they are bolted to a forced-air cooled heatsink. I should have used 1.5k or 1.2K ohm (std value) resistors. 1.5k's would dissipate 38.4W per resistor; 1.2's will dissipate 48W each. I've ordered four 1.2k, 25W resistors to replace the 2.2k resistors. Hopefully, being able to dump 192W into the heatsink will make it get warm enough for cooler times of the year.

EDIT: I've poked around with a voltmeter and found the maximum voltage the dimmer will supply to my load is 208V though the mains is 240V. If I want to drop around 200W across the 4 paralleled resistors, they would each ideally be 865 ohms. However, I'm stuck to the available standard values. The nearest std values are 1k and 680 ohms. I'd rather shoot below the ideal resistance because I can always dial them down with the dimmer. 208V across 680 ohms is about 63 watts per resistor.

 

v2.0 heater, intake spacer and intake fan

 

The heating system in 2.0 looks like it has two intake fans in series. The first 'fan' is actually an old fan body with a burnt-out motor cut out of it using a Dremel. The body makes a perfect sized spacer. If the fast moving fan blades pass too close to the stationary heatsink fins, it makes a hell of a whizzzzzzzzzzzzzzzing racket. Spacing the fan off the heatsink made it much, much quieter.

 

The all very temporarily placed (like the ockie straps? ) 200mm exhaust duct is housing a UV ioniser to gauge effectiveness.

 

Bubble wrap is used as a spacer to force all air to flow through the ioniser. If this works, I'll gut the ioniser unit and permanently build the innards into the exhaust ducting.

 

The lid on the storage container bought for v2.0 not only did not seal but had ribs under the lid edge to create a gap to allow air to circulate. No good in this application. Used a Dremel with a sanding drum to remove the ribs. Cut some strips of foam and hotmelt glued them under the lid edge to provide a decent seal so that air passes only through the fans.

 

With the present (too high) value resistors, v2.0 takes about 4-5 days to dry a load of buds. However, the inline ioniser mockup is working out very well to reduce scent.

 

There's a few typical questions I get about this thing. Let's see if I can cover them and save you the time.

 

* Don't the buds come out fragile/crunchycrispy?

 

No, if the dryer is minded reasonably closely. I take buds out of it when the outer part of them is quite dry, nearly crisp, but there is a slight bit of flex due to water content left in the stems. They go in a storage tub for a day or two to allow moisture to wick out of the core of the buds and rehydrate the outer material. Nice and springy, ready to smoke. If I neglect to remove buds and do accidentally overdry them, no big deal. A teaspoon of water on a paper towel nested in with the buds in the storage box for a few hours puts enough water back in to make them pliant and springy again. If ambient humidity is high, just disconnecting the heater and leaving the fans to run will rehydrate buds too.

 

* Don't you get a chlorophyll scent/flavour with such a short drying time?

 

Never. I leave zero bud leaf when I manicure and I grow good genetics (at present, Sweet Tooth #4, Spice of Life Seeds). ST4 has a sweet, perfumey flavour, very nice to smoke, whether dried for 3 days or 3 weeks- make no difference whatsoever. None of the bud from various strains I've put through the dryer has ever had so much as a trace of chlorophyll scent or flavour- but I've never grown anything but good DNA, including White Widow, Skunk #1, a few varieties of NL and some I've been too stoned to recall.

 

'Curing' is a process applied to cannabis as it was harvested years ago, with all bud, leaf and stems being bagged up or bricked. You old bastards will remember the bags of seedy, greyish-green, half-mouldy bricked shit we got in the 1970s. Leaf is harsh to smoke because it has a lot of chlorophyll and cellulose plant matter versus the amount of resin on leaves. Curing, or aging in a humid environment, does break down and deplete chlorophyll, making a leafy mull much smoother to smoke. However, if you're only harvesting buds, the curing process isn't really needed as bud has a very high resin to chlorophyll/cellulose ratio.

 

The dryer would work even if it did not have the air warmer- just not as well nor as fast. It's especially nice when I have to get buds dry when ambient RH is high, like when we get a solid week of rain. Moisture is removed quickly and there's tons of airflow, guaranteeing that my buds never can mould.

 

'Smaller' amounts of buds (up to about 10-13oz) dry in 3 days, rain or shine. I've dried up to 23 oz in one whack in the dryer in about 5 days in v1.0 form, v2.0 should be able to do it in 3.

 

The dryer has become a trusted and invaluable appliance in this op. Nice to be able to know exactly when the just harvested buds will be ready to go.

Edited July 1, 2007 by Al B. Fuct

[loylty gets u nothing]

got 2 plants here

cmin round to check it oput...

ive always been a bit sus on these machines

personally i lay mine on a screen,manicured

for 5 days then into a jar for 2,back onto rack for 3

then just do the cure process in the jars

thanks for sharing bet ya fingers are numb...

bil

[Al B. Fuct]

Yeah, numb fingers and real bad eyestrain every 2 weeks.

 

There's actually very little difference between your process and mine; a warm, drafty day at your place is identical to what this low-temp dryer does. The dryer just does it with sustained, controlled conditions.

 

I don't intentionally cure, but buds may sit around in a storage tub for awhile before I use them, so some moisture equalisation happens. My moisture percentage would have to be about 3-5% at the end of the day. Wish there was a convenient way of measuring that.

 

For those who would like to make a dryer, cut the holes in the storage tub with a hot soldering iron. Hammer the tip flat to make a hot knife if you like. Saws and drills will crack the cheap plastic.

[Al B. Fuct]

One note on the thermostat; it really is super simple. As its actual temperature sensor is internal to the unit, the thermostat would have to be placed inside the drying chamber- if not modified.

 

I intend to open up the tstat unit, remove the sensor and put extension leads on it. I'll mount the sensor in the airflow from the inbound fan. I'll then be able to mount the tstat housing unit on the front of the dryer, making temp adjustment and tstat battery replacement much easier, as well as getting a constant visual display of the current temp.

Edited July 1, 2007 by Al B. Fuct

[mull]

Nice work once again Al B, you're an ideas man

[Al B. Fuct]

Nice work once again Al B, you're an ideas man

 

And I love the smell of two-stroke.

 

We're goin' ta Bonnie Doon...

 

heh, thanks

[MongyMan]

* Don't the buds come out fragile/crunchycrispy?

 

No, if the dryer is minded reasonably closely. I take buds out of it when the outer part of them is quite dry, nearly crisp, but there is a slight bit of flex due to water content left in the stems. They go in a storage tub for a day or two to allow moisture to wick out of the core of the buds and rehydrate the outer material. Nice and springy, ready to smoke. If I neglect to remove buds and do accidentally overdry them, no big deal. A teaspoon of water on a paper towel nested in with the buds in the storage box for a few hours puts enough water back in to make them pliant and springy again. If ambient humidity is high, just disconnecting the heater and leaving the fans to run will rehydrate buds too.

 

Where I live atm the humidity is lucky to be 10% most days, especialy in summer. In 3 days my buds are dry and crispy on the outside while still having flexible stems as you described. Bagged up at this stage I find is perfect but as you said, if they are a little dry or damp it's easily fixed over the next couple of days. Personaly I like to dry them out a bit more and add moisture. THC has a molecule of water bonded to it when it is in its raw state straight off the plant and it isn't phsyco-active. Drying breaks this bond and leaves active THC. Once the bond is broken it will not rejoin again. My theory is that buds dried to near 0% humidity and then rehydrated will have more active THC present than the same bud dried to 10-15% then bagged.

 

* Don't you get a chlorophyll scent/flavour with such a short drying time?

 

Never. I leave zero bud leaf when I manicure and I grow good genetics (at present, Sweet Tooth #4, Spice of Life Seeds). ST4 has a sweet, perfumey flavour, very nice to smoke, whether dried for 3 days or 3 weeks- make no difference whatsoever. None of the bud from various strains I've put through the dryer has ever had so much as a trace of chlorophyll scent or flavour- but I've never grown anything but good DNA.

 

I'd agree Al. Having grown from good, crap and plenty of in between genetic pools over the years I'm of the opinion that although manicuring obviously plays a big part in the finnished bud it is mosty the genetics.

 

'Curing' is a process applied to cannabis as it was harvested years ago, with all bud, leaf and stems being bagged up or bricked. You old bastards will remember the bags of seedy, greyish-green, half-mouldy bricked shit we got in the 1970s. Leaf is harsh to smoke because it has a lot of chlorophyll and cellulose plant matter versus the amount of resin on leaves. Curing, or aging in a humid environment, does break down and deplete chlorophyll, making a leafy mull much smoother to smoke. However, if you're only harvesting buds, the curing process isn't really needed as bud has a very high resin to chlorophyll/cellulose ratio.

 

Although not necessary with better quality genetics in order to get an enjoyable smoke, I do think that cured buds are definatly better than uncured. Just like fine wines and whiskeys, both can be drunk straight from the fermenter but are better cured. After picking and drying there are alot of chemical reactions taking place inside bagged buds that ballance out and change many of the chemicals other than THC present. These give cannabis its almost unbelivable number of tastes and smells. The THC level in properly cured buds remains unchanged but the taste and smell definatly mellow with age imo.

 

Great post by the way Al B

 

Peace MongyMan

[SukonmiSkunk]

i hang mine on a clothes rack.. in front of the wood heater.. 3-4 days.. its coming off the stalk.. works well.. the smaller branches are ready within just hours.. around 6-12...

 

and yes... you will have a green/fresh taste from these buds because theyre dried so quickly.... but regardless of how long you dry the buds for.. you will still need about 4 weeks to get rid of that green/fresh taste...

 

usually about 6-8 weeks for real nice cure..

 

good work again al.. ive been thinking of building a drying wardrobe fitted with a carbon filter or something..... certainly has given me some ideas...

 

damn it boy.. stop posting is fuckin sunday.. get in the chat and have a bong... :peace:

[Al B. Fuct]

Thanks Mongy, SS.

 

I'll nose into the chat and see wot's on.

[jimbojones5678]

Respect.

Excellent thread, top comments, some great tips and experience showing there!

 

Jimbo