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Re: Boka Time

PostPosted: Wed May 01, 2019 11:09 pm
by Rolls912
It’s Boka time alright. 4 inches of pure happiness.
Excellent build quality as always Andrew. Thanks :handgestures-thumbupleft:

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Sorry - couldn’t upload more pics...

First cleaning run with three copper rolls came in at 90% (adjusted).
Ran one element at 80%. Snap.

What’s everyone’s packing recommendations? This thing is huge - could take 8 or more copper rolls - $$$.

I was thinking two at bottom and two at the top with scoria in between. Any other suggestions? Should I pack all the way up thru the coil to the very top?

I’m sleeping in my shed tonight!! Lol.

Re: Boka Time

PostPosted: Thu May 02, 2019 6:13 am
by The Stig
Excellent :music-deathmetal:
2 rolls top , 2 rolls bottom and fill with stainless scrubbers or scoria and pack either scrubbers or copper around the coil in the head would be my recommendation.
Let’s see what bigger brains than me have to say :-B

Re: Boka Time

PostPosted: Thu May 02, 2019 7:28 pm
by bluc
Sweet as rolls would be interested to hear some details once you have it dialled in and pulling azeo :handgestures-thumbupleft:

Re: Boka Time

PostPosted: Thu May 02, 2019 7:35 pm
by Rolls912
I’m still very much a beginner so it will take some time before I figure out what works best. From what I gather, I should be stuffing it full of copper and scoria and running both elements. I’m also unsure as to what output rate I should be chasing... dribble with a drop, all dribble or just drops. Oh and how long to leave in equilibrium before I take off. Actually come to think of it, I’m way over my head... hehe.

Re: Boka Time

PostPosted: Thu May 02, 2019 7:50 pm
by bluc
I am gunna do my first boka run this weekend(2"). Ihave heard heat it as much as you can without overflowing out top to get it up to temp. Wait till temp stabilizes at about 70 hold it there half- 3/4hr then bleed off fores at drip drip per second then slighty faster for heads (broken stream) then open it up slowly till temp drops then back off till it stabilizes again and that should be good for hearts. When temp rises past 71.5 its the runs end... thermometer and voltage reg may help till you get it dialled in.. :handgestures-thumbupleft:

Re: Boka Time

PostPosted: Thu May 02, 2019 8:12 pm
by The Stig
Rolls , your doing fine mate.
Getting 90% with bugger all packing is better than expected, use the force brother

Re: Boka Time

PostPosted: Fri May 03, 2019 7:45 pm
by Rolls912
So.... I’ve decided to pack the main column with one copper coil, few kilos of scoria, and then another copper coil. This thing is HEAVY! I’ve then packed scoria up the top around the condenser. Some of it has fallen into the ‘dam’ or the collector. Would that matter?

Re: Boka Time

PostPosted: Fri May 03, 2019 8:14 pm
by bluc
I wouldnt pack scoria round condenser maybe pack copper mesh inside coil though :-B aaand wouldnt leave scoria or anything inside dam :handgestures-thumbupleft: would it matter though? Prob not...

Re: Boka Time

PostPosted: Fri May 03, 2019 9:15 pm
by Professor Green
Definitely put mesh up around the condenser not scoria. The mesh will help it condense and reduce the risk of vapour escaping from the vent.

Re: Boka Time

PostPosted: Fri May 03, 2019 10:02 pm
by dazzerthemighty
Hi 2 questions as just curious
1- Is there any reason to go from the 4" on boiler Milk can lid reducing to 2" then back to the 4" Collom?
2- Wouldn't that reduce the speed/efficiency of utilizing the 4" in the first place over a 2" boka?

Re: Boka Time

PostPosted: Fri May 03, 2019 11:04 pm
by Rolls912
1; only cause it’s easier to change over to my pot
2; don’t believe it makes any diff.

Cheers

Re: Boka Time

PostPosted: Fri May 03, 2019 11:09 pm
by The Stig
1 - Rolls a lazy c€*%<?? And can’t be bothered :laughing-rolling: :laughing-rolling:
2 - if anything it would speed things up, but realistically not that much to make a big difference

Re: Boka Time

PostPosted: Sat May 04, 2019 7:26 am
by scythe
1. Already answered so concisely... :teasing-tease:

2. Vapour speed will increase through the 2" diameter but then slow down through the 4" giving you a net 0 effect.

Re: Boka Time

PostPosted: Tue Jun 11, 2019 11:31 pm
by Rolls912
So I’ve been making out with this magnificent beast for a couple of months now... Now that the honeymoon is over I need this puppy to earn its keep.

At the moment I’m running;
    All bran / Wheatbix wash stripped.
    5 coils copper
    Scoria - changed every time I use it
    50l milk can with two elements
    Reflux for 40minutes before showtime

Output is a very light trickle at 92-93%/ 15mins for 250mls. I was getting the same output from my pimped t500 head.

So I’m keen to start to fine tune things a little. I have a couple of questions;
1/ where should I start to look to get the output speed up without sacrificing %?
2/ how do I get the output up to 95%? Simply more copper rolls?

Cheers

Re: Boka Time

PostPosted: Fri Jun 14, 2019 4:06 pm
by RC Al
The Stig wrote:
bluc wrote:Any ideas of power requirements?

Not yet but I’m guessing it’ll run on 3600 - 4800
And the lucky owner will be our tester
I’m not sure if he wants to be named yet or not


Are you running this much power yet?

more power - more reflux - more take off speed OR purity - up to a point...

Re: Boka Time

PostPosted: Fri Jun 14, 2019 9:17 pm
by coffe addict
@rolls912 your bio says 2m boka... Can I ask is that 2m from ground or 2m packed section?
2m from ground you'll struggle to get purity to where you want.
2m packed the only thing holding you back is reflux ratio.
Either way, There's three ways to improve the reflux ratio 1. More heat 2. Slower take off 3. Taller packed section. In no particular order.
A 4in packed column should be capable of 6kW at take off speed of 2.5l/hr. This heat input is usually too much at start up . So get everything full and working with full reflux for at least 30mins, then gradually up to the power. Ensure its not flooding, then adjust rc to control take off speed/purity.

Also higher abv in the boiler also helps but 40% maximum. So stripping before a boka run makes a big difference.

Re: Boka Time

PostPosted: Fri Jun 14, 2019 11:09 pm
by Rolls912
Great feedback thanks.

Running 4800 watts. I’m guessing the packed section is 1m.

Don’t think I can output any slower - my pimped T500 is quicker and almost equal purity.

I don’t have control of the rc, it’s either on full or off.

I always use stripped washes before the Boka is cranked.

So, I have a FSD milk can. How do I get more power into the boiler? Does this mean I need a third element? Not so keen on cutting another hole.

any other suggestions?

Re: Boka Time

PostPosted: Sat Jun 15, 2019 7:19 am
by The Stig
Change one of the 2400W for a 3600W
But you’ll need a 15AMP point to drive it.
Just a thought

Re: Boka Time

PostPosted: Sat Jun 15, 2019 11:16 am
by scythe
Longer packed section will increase the speed you can run at for a given %ABV

Re: Boka Time

PostPosted: Sat Jun 15, 2019 10:34 pm
by Rolls912
The Stig wrote:Change one of the 2400W for a 3600W
But you’ll need a 15AMP point to drive it.
Just a thought

Do you think I need it for the inch?