San Fran SF6 Owners! Advice needed.

[Mr.GreenBean]

Hi. I have been roasting on my SF6 now for a month and cannot seem to dial in a profile for dark roasts without little "potholes" on my beans. I found the following article, and after toying with 6 more batches, still get the holes. Any potential solutions would be EXTREMELY appreciated.

Roasting Problems - Coffeetime

 

[Mr.GreenBean]

Additional info you may want is that I am charging to 400f and aiming for 1st crack between 9:30-10:30m, and have mainly attempted with 5 & 6lb batches.

 

[CoffeeTec]

That's usually associated with too much energy within the bean (bean mass) during 2nd crack. You might be finding those little caps choking your cooling tray screen as well?

You don't mention either the position of your air control damper or what is registering on the gas gauge??? Use those controls to lengthen the time between first and second crack.

Charging your beans at 400F is fine, but I'm also curious what time and temp you are dropping your beans at?

Hi. I have been roasting on my SF6 now for a month and cannot seem to dial in a profile for dark roasts without little "potholes" on my beans. I found the following article, and after toying with 6 more batches, still get the holes. Any potential solutions would be EXTREMELY appreciated.

 

[Mr.GreenBean]

That's usually associated with too much energy within the bean (bean mass) during 2nd crack. You might be finding those little caps choking your cooling tray screen as well?

You don't mention either the position of your air control damper or what is registering on the gas gauge??? Use those controls to lengthen the time between first and second crack.

Charging your beans at 400F is fine, but I'm also curious what time and temp you are dropping your beans at? Also, my 1st cracks are not as consistently timed as I'd like. Ranging from 9:45 up to 11 at times.

One thing that also makes me wonder is why it took my gas guy dialing up the propane pressure on the external tank to about 13.5WC to reach my 11WC on my roaster's gauge. The heads are clean, and the pressure was right on input and output of the Honeywell part.

Will installing a damper change things dramatically?

Thanks again.

Hi. I have been roasting on my SF6 now for a month and cannot seem to dial in a profile for dark roasts without little "potholes" on my beans. I found the following article, and after toying with 6 more batches, still get the holes. Any potential solutions would be EXTREMELY appreciated.

Hey! Thanks for the reply.

I have no damper on my crossover tube, which is odd. Can't wait the month it will take to have one installed by San Fran. They don't think that is the issue with this challenge, but I wonder if they are not taking into account that they roast at 5000ft altitude vs my sea level.

I am dropping at about 15:30 at 440-450f.

 

[Mr.GreenBean]

(Reposing this because something chpped up my reply on the last post)

Hey! Thanks for the reply.

I have no damper on my crossover tube, which is odd. Can't wait the month it will take to have one installed by San Fran. They don't think that is the issue with this challenge, but I wonder if they are not taking into account that they roast at 5000ft altitude vs my sea level.

I am dropping at about 15:30 at 440-450f.

One thing that also makes me wonder is why it took my gas guy dialing up the propane pressure on the external tank to about 13.5WC to reach my 11WC on my roaster's gauge. The heads are clean, and the pressure was right on input and output of the Honeywell part.

Will installing a damper change things dramatically?

Thanks again.

 

[CoffeeTec]

(Reposing this because something chpped up my reply on the last post)

Hey! Thanks for the reply.

I have no damper on my crossover tube, which is odd. Can't wait the month it will take to have one installed by San Fran. They don't think that is the issue with this challenge, but I wonder if they are not taking into account that they roast at 5000ft altitude vs my sea level.

I am dropping at about 15:30 at 440-450f.

One thing that also makes me wonder is why it took my gas guy dialing up the propane pressure on the external tank to about 13.5WC to reach my 11WC on my roaster's gauge. The heads are clean, and the pressure was right on input and output of the Honeywell part.

Will installing a damper change things dramatically?

Thanks again.

Yes, installing the damper will have a great effect on your roasting times, temps, profiles. Without the damper that also tells me you purchased a used SF6?

Don't hold your breath waiting for SFR to flip that in a month for you. Rumor has it they don't even make the SF1 and SF6 in house anymore? Mass produced outside and then only assembled at home base?


So a few more questions/comments come to mind...

- What does the flame look like (color). Are you sure it's set up for propane?

- Who is your "gas guy", and is he dialing up the pressure on a 5 gallon propane tank or whole house storage tank?

- What is the Honeywell part you speak of. Gas valve or regulator? And how are you measuring pressure at the input/output sides?

- If you're roasting that dark you're going to have to be on top of your cleaning game.

- First crack at 9:30 is not unusual (8:30 to 9:30 quite common).

- Your drop time and temp is OK but I suspect you'll achieve a shorter roast time as you experiment?

- What are your different gas levels "WC" throughout your roast?

 

[Mr.GreenBean]

Yes, installing the damper will have a great effect on your roasting times, temps, profiles. Without the damper that also tells me you purchased a used SF6?

Don't hold your breath waiting for SFR to flip that in a month for you. Rumor has it they don't even make the SF1 and SF6 in house anymore? Mass produced outside and then only assembled at home base?


So a few more questions/comments come to mind...

- First crack at 9:30 is not unusual (8:30 to 9:30 quite common).

- Your drop time and temp is OK but I suspect you'll achieve a shorter roast time as you experiment?

- What are your different gas levels "WC" throughout your roast?

Answers below:

- What does the flame look like (color). Are you sure it's set up for propane? Blue. No orange

- Who is your "gas guy", and is he dialing up the pressure on a 5 gallon propane tank or whole house storage tank? 120 gallon tank outside the building. Gas guy is the guy who installs propane for Perico Gas Co.

- What is the Honeywell part you speak of. Gas valve or regulator? And how are you measuring pressure at the input/output sides? Gas guy is the actual propane company guy. He took readings on the input behind the drum that feeds the gas to the burners.

- If you're roasting that dark you're going to have to be on top of your cleaning game. I have a daily/weekly/monthly/quarterly maintenance log that I check off.

I have attached a sample profile where my beans pop holes. Generally starting at 10-11WC to make first crack. Back off when I hit about 350f to a 3 sec interval rise per degree.

 

[Mr.GreenBean]

Won't let me upload a picture of my profile notes.

 

[Musicphan]

Do your beans look like this - see Tipping: https://coffeecourses.com/coffee-roasting-mistakes-photos/

And what is your 'average' FC temp?

 

[CoffeeTec]

Answers below:

- What does the flame look like (color). Are you sure it's set up for propane? Blue. No orange

- Who is your "gas guy", and is he dialing up the pressure on a 5 gallon propane tank or whole house storage tank? 120 gallon tank outside the building. Gas guy is the guy who installs propane for Perico Gas Co.

- What is the Honeywell part you speak of. Gas valve or regulator? And how are you measuring pressure at the input/output sides? Gas guy is the actual propane company guy. He took readings on the input behind the drum that feeds the gas to the burners.

- If you're roasting that dark you're going to have to be on top of your cleaning game. I have a daily/weekly/monthly/quarterly maintenance log that I check off.

I have attached a sample profile where my beans pop holes. Generally starting at 10-11WC to make first crack. Back off when I hit about 350f to a 3 sec interval rise per degree.

Yeah, I guess this platform can be a little finicky? I almost didn't respond because the first time I tried the system logged me out when I hit reply and the second time it "timed out" while typing. So I'm composing elsewhere... then cut and paste.

That's great the gas guy is willing to check some things out for you. Big plus. Where your gas supply line (120 gal) connects to the pipe at the rear of the roaster there is a regulator mounted on the pipe itself... correct? So basically the regulator is between the main supply and the gas input pipe to roaster. Might be a Dwyer regulator?

The gas tech can pop the cap on the top of the regulator to see if he can dial the pressure up anymore via the regulator while dialing down the pressure on the big tank. However...

- If the big tank has to be at 13.5" for you to achieve 10-11" at the roaster that is likely pretty normal. A lot of people run their SF6 off a 5 gallon propane tank. Those have a low pressure regulator on the tank which is rated at 14" max. You should actually try running off a small tank to see if there is any difference? But before you experiment make sure (again) there is a gas regulator on your roaster separate from what's on your supply tank.

- Another common issue that is seen more with natural gas is that when the supply line is too small in diameter and a sustainable pressure cannot be maintained. It's like putting a straw in your mouth with your finger on the end. Poof, release your finger and that pressure is gone because there is no volume or mass to sustain that pressure. People that have a gas line 2" diameter and larger usually have no issues.

- I've worked with a shop on the east coast who got their roaster all set up, then started to experience low gas pressure issues weeks later only to find out that their city makes seasonal pressure adjustments to the cities gas supply in their building.

Blue flame... great!

Do you have a copy of the updated SF6 maintenance guide? The last tech guy at SFR put together a pretty detailed 2018 version before he jumped ship. They might send you a copy for the asking?

And while your asking, see if SFR would be willing to send you a new hopper/cross over pipe assembly with the air-flow control? Then when it arrives you can just send your existing one back with minimal downtime for you. Just make sure the hole pattern measurement is the same on the mounting flange (4 bolts) because I suspect it is slightly different on the older roasters? I'd be curious what they would charge you on a trade-in?

 

[Mr.GreenBean]

Yeah, I guess this platform can be a little finicky? I almost didn't respond because the first time I tried the system logged me out when I hit reply and the second time it "timed out" while typing. So I'm composing elsewhere... then cut and paste.

That's great the gas guy is willing to check some things out for you. Big plus. Where your gas supply line (120 gal) connects to the pipe at the rear of the roaster there is a regulator mounted on the pipe itself... correct? So basically the regulator is between the main supply and the gas input pipe to roaster. Might be a Dwyer regulator?

The gas tech can pop the cap on the top of the regulator to see if he can dial the pressure up anymore via the regulator while dialing down the pressure on the big tank. However...

- If the big tank has to be at 13.5" for you to achieve 10-11" at the roaster that is likely pretty normal. A lot of people run their SF6 off a 5 gallon propane tank. Those have a low pressure regulator on the tank which is rated at 14" max. You should actually try running off a small tank to see if there is any difference? But before you experiment make sure (again) there is a gas regulator on your roaster separate from what's on your supply tank.

- Another common issue that is seen more with natural gas is that when the supply line is too small in diameter and a sustainable pressure cannot be maintained. It's like putting a straw in your mouth with your finger on the end. Poof, release your finger and that pressure is gone because there is no volume or mass to sustain that pressure. People that have a gas line 2" diameter and larger usually have no issues.

- I've worked with a shop on the east coast who got their roaster all set up, then started to experience low gas pressure issues weeks later only to find out that their city makes seasonal pressure adjustments to the cities gas supply in their building.

Blue flame... great!

Do you have a copy of the updated SF6 maintenance guide? The last tech guy at SFR put together a pretty detailed 2018 version before he jumped ship. They might send you a copy for the asking?

And while your asking, see if SFR would be willing to send you a new hopper/cross over pipe assembly with the air-flow control? Then when it arrives you can just send your existing one back with minimal downtime for you. Just make sure the hole pattern measurement is the same on the mounting flange (4 bolts) because I suspect it is slightly different on the older roasters? I'd be curious what they would charge you on a trade-in?

So funny how spot on you are with all of this post...

Yes. My gas guy is cool. Each time he has been by to install the 120 tank. I do a poor over for him. He's pretty fascinated with the roaster never having seen one before. So he has taken extra time to check pressure all around the machine. He even checked the regulator.

I did run off a 20gal tank while waiting for propane delivery. Similar results.

I am not sure on the supply line diameter and will check today. But this roaster was converted from Nat Gas to Propane 2-3 years ago.

That shop on the east coast saw as probably Boston. That same adjustment made a bunch of homes explode recently. Was in the news.

Dimitri the SF sales guy emailed me the most recent maintenance guide. Following it to the letter, and broke out this maintenance onto my monthly log clipboard.

Funny you mention the bolts lining up, because I asked if they could send a replacement hopper with valve, and that was why they were reluctant to do thisZaza telling me that he thinks the valve would not be the issue. Not sure if my issue is just too small for what is presently on their plate, or if there is something we are missing in our troubleshooting conversations.

Now... I understand that welding is an art, and I know an artist welder. I was thinking of just ordering the valve & parts from San Fran and having my own guy put in this part since they are too busy for me. Thoughts?

 

[CoffeeTec]

Honestly, if you're able to hit 10 or 11" off the 120 gallon tank I wouldn't even be concerned with that. Move on to perfecting your roast!

Dimitre is a good guy and I would bounce your questions off him while he is still an available source. I don't think SFR has a tech person anymore from what I hear. You fill out a form online and I guess they collectively see what answer they can come up with. Too bad.

That was my next question... so you know anyone that welds or can do metal fabrication? That would be a super easy upgrade for anyone comfortable with metal. It's basically the same thing as a damper within your flu pipe on a wood burning stove. You will have a shaft that goes all the way through the cross over pipe, inside the cross over pipe a round disc is attached to the shaft. On one end of the shaft is a spring to keep tension on the assembly and other the other end is your handle. When the disc is laying horizontal air flow is open 100% and when the disc is vertical air flow is closed. So you only need 90 degrees of rotation. Attach the handle so that it reflects the position of the internal disc and you'll always know the position of the disc by your handle position.

If you have that new manual in hand there are probably enough good images within to use as a guide.

I'd go for it.

 

[CoffeeTec]

Like so...

 

[Mr.GreenBean]

Like so...

View attachment 9738

Coffee Tec... you are the bomb. Thank you. I mean it.

Matt

 

[CoffeeTec]

You're welcome.

I think that's pretty self explanatory?

And I believe SFR just welds the disc to the shaft, but I think it would be worth while to drill and tap two holes for screws for future ease of maintenance.

I also show a nut on one end which means that would be threaded, so you could potentially start with a 6-7" long bolt...

or...

If you just use a piece of straight rod you could drill a hole and put a cotter pin in place of a nut.