Silvia grouphead PID heater rope mod - Andy made me do it!

[miKe mcKoffee]

After talking to Chris today and determining he'll probably likely time will tell don't count your chickens before they hatch when it happens it is then a reality come out with a PID dual boiler Quick Mill '06 and calling and failing to get WLL to budge from the current $1699 Brewtus II price and once again deciding I don't want an HX so Vetrano not an option and S1 just too big for our kitchen decided to push on with Silvia grouphead PID heater rope mod for now. Parts on order, will post Thermofilter temp tests once done. Does it really make sense to dump another 2 bills into Silvia when contemplating upgrading Rhetorical question, this about espresso after all.

[AndyS]

decided to push on with Silvia grouphead PID heater rope mod

Hey, that's very cool. Let me know if there's anything I can help with. If you're using the water soluble heat conductive putty, BE SURE to let it dry completely before turning on the power (24-48 hrs). Otherwise, you may hear a very loud BANG when you first turn it on!

[miKe mcKoffee]

Hey, that's very cool. Let me know if there's anything I can help with. If you're using the water soluble heat conductive putty, BE SURE to let it dry completely before turning on the power (24-48 hrs). Otherwise, you may hear a very loud BANG when you first turn it on!

Yeah, I'd read about that particular putty curing experiment Rather than order a "little" gallon container from McMaster I first called Lowe's plumbing dept. They have 4oz plumbing epoxy <$5, don't think it's exactly the same stuff though but believe it'll work. Plan to call around other places locally and see if something actually called heat conductive putty available while waiting for the parts.

[hbuchtel]

Say- thanks for posting this! I hadn't seen mention of this idea before (thanks Andy!) and am thinking it'll be just what my Presso is looking for!

I ordered the part and it has arrived at my parents' place, now just another 2 months for it to arrive here . . . (sigh).

Henry

[Kristi]

It's on my list!

--->>>>Let me know if you find any suitable epoxy stuff locally... I need a gallon like a hole in the head - I could imbed the entire Silvia and create a sculpture...

Andy, what temp do you run your a) boiler, and b) rope heater to get 199F(93C) at the shower screen (or whatever you shoot for)? I seem to be down to 206F on the far side of the top of the boiler, and don't know if I'm kidding myself or what...
tia
Kristi

[miKe mcKoffee]

It's on my list!

--->>>>Let me know if you find any suitable epoxy stuff locally... I need a gallon like a hole in the head - I could imbed the entire Silvia and create a sculpture...

Andy, what temp do you run your a) boiler, and b) rope heater to get 199F(93C) at the shower screen (or whatever you shoot for)? I seem to be down to 206F on the far side of the top of the boiler, and don't know if I'm kidding myself or what...
tia
Kristi

Not Andy and I haven't done rope heater Silvia mod yet (rope heater arrived yesterday, waiting on PID, TC & SSR ETA 12/12) With just boiler PID, TC left screw of boiler tstat, I keep coming back to 227 boiler for 200f measured via Thermofilter for first shot from idle with 2oz flush before shot and filling PF, shot (or temp measuring shot) started just us PID coming back up to 200 (227) after flush.

I'll post what I come up with locally for the heat conductive epoxy.

[Kristi]

Thanks Mike!

[AndyS]

Andy, what temp do you run your a) boiler, and b) rope heater to get 199F(93C) at the shower screen (or whatever you shoot for)?

I've typically been running both the boiler and the grouphead at around 212F to get brew temps ~200F. But I wouldn't take the grouphead temp too literally, it depends on where you measure it.

[Kristi]

I've typically been running both the boiler and the grouphead at around 212F to get brew temps ~200F. But I wouldn't take the grouphead temp too literally, it depends on where you measure it.

THANKS Andy!!!
Kristi

[miKe mcKoffee]

I've typically been running both the boiler and the grouphead at around 212F to get brew temps ~200F. But I wouldn't take the grouphead temp too literally, it depends on where you measure it.

Your 212F boiler temp right in line what I find with superheating grouphead via a dozen of so back to back blanks. But fascinating, where did you mount the grouphead TC? I expected to be running the grouphead closer to shot temp. Since parts ETA for my grouphead mod not due 'til the 12th, and will have just gotten the Bricoletta the 9th, and Christmas and related insanity already decending, likely won't get to Silvia's grouphead mod 'till end of the month after Christmas.

[miKe mcKoffee]

Andy, do you have any idea how well this coil around Silvia's boiler inlet preheat method compares to your thermoblock method? I suspect it should work quite well but have no data or input to back it up.

[Kristi]

I wonder what the capacity in oz is of the 10 turns of copper tubing...

I wonder what would happen if I put a heater in the reservoir and controlled it to 170F or something...

[barry]

I wonder what the capacity in oz is of the 10 turns of copper tubing...

10 x (pi x diameter of coil) x (pi x (inside diameter of tubing / 2)^2) x whatever the conversion factor is for cubic inches to oz.



--barry "use centimeters and milliliters, it's easier"

[AndyS]

Andy, do you have any idea how well this coil around Silvia's boiler inlet preheat method compares to your thermoblock method? I suspect it should work quite well but have no data or input to back it up.

Mike, I've thrown a fistfull of modifications at the Silvia, and for all I know, some of it may have been counterproductive. Now that I have a Scace device, I can more easily sort things out. But lately, with this GS3 on my counter, I haven't been doing anything with Silvia. Maybe in a few weeks I'll get back to Silvia.

The inlet coil is, of course, purely a passive device, so there's only so much that it can do.

[AndyS]

I wonder what the capacity in oz is of the 10 turns of copper tubing...

I wonder what would happen if I put a heater in the reservoir and controlled it to 170F or something...

Depends on the tubing of course, but for typical 1/4" OD, probably around 30 ml, maybe half the volume required for a double.

Vibe pumps aren't designed for hot water. I think there's a max temp listed right on the pump. It's pretty low, IIRC.

[miKe mcKoffee]

The inlet coil is, of course, purely a passive device, so there's only so much that it can do.

Passive yes, but a fair length of copper tubing in direct contact with the hot boiler. And if affixed/covered with heat conductive epoxy likely even more efficient heating of the water in the coil before entering the boiler. And if insulated...

Dang, I'm gonna talk myself into doing it just to find out Bric' or no Bric'!

Depends on the tubing of course, but for typical 1/4" OD, probably around 30 ml, maybe half the volume required for a double.

You're guesstimating 30ml for volume of water in 10 coils of tubing around Silvia's boiler?! Somehow me thinks that's way way low.

What's the diameter of Silvia's boiler? I'll do the math...

But lately, with this GS3 on my counter, I haven't been doing anything with Silvia. Maybe in a few weeks I'll get back to Silvia.

And who can blame you. Why drive a VW while you have use of a Ferarri!

[AndyS]

You're guesstimating 30ml for volume of water in 10 coils of tubing around Silvia's boiler?! Somehow me thinks that's way way low.

What's the diameter of Silvia's boiler? I'll do the math...

coils = 8
tubing od = .25"
tubing id = .15"
dia boiler = 3"
ml/cu in = 16.4

I get ~24ml

[miKe mcKoffee]

coils = 8
tubing od = .25"
tubing id = .15"
dia boiler = 3"
ml/cu in = 16.4

I get ~24ml

My sincere apologies! Ran the math and you are of course correct for copper tubing with ID of 0.15". Never imagined over six feet of 1/4" copper tubing had such a small actual volume.

Did a little googling on copper tubing and found one 1/4" OD with 3/16" (0.1875) ID. Even that somewhat larger ID only comes out to 34ml.

[miKe mcKoffee]

The inlet coil is, of course, purely a passive device, so there's only so much that it can do.

Which leads to the question of "how much can it do"!? Given total coiled tube of 25ml volume flowing through the HX heated tube, during a 75ml 24sec shot 25ml of water would transverse the tube from beginning to end in 8sec. So the cooler water entering the tube would work to cool the copper tube while the heat transferred from the boiler would be heating the tube while the copper tube is heating the water flowing through the tube. I don't know where to begin calculations to determine if at idle boiler @212F with tube temperature equalized 212F, with first a flush to equalize tube temps during a flow versus idle, and water entering the tube say @60F what the tube exit water temp entering the boiler during flow would be! I have no idea how efficiently the relatively large mass of over six feet of HX heated copper tubing would heat the 25ml of water flowing through every 8 seconds... I could probably do the mod and measure the temp faster than researching to figure out the math!

[Kristi]

Depends on the tubing of course, but for typical 1/4" OD, probably around 30 ml, maybe half the volume required for a double.

Vibe pumps aren't designed for hot water. I think there's a max temp listed right on the pump. It's pretty low, IIRC.

Andy, I didn't see this post till now... THANKS!!! So about a shot's worth of preheating... And for the stability factor that may be just about right...