Wondering what material to use when adding a heat shield to my Victory 2k.

Aluminum? Stainless? Looking to avoid a metal that gives off fumes when heated.

Thanks. I'll post photos and results when project is complete.

As far as fumes go you should be OK with any conventional material (aluminum, steel, stainless... titanium) as long as it's not galvanized. Beyond that it's a question of appearance, durability and cost. Plain carbon steel (1018 or similar) will do the job just fine, and very affordably but may develop some corrosion over time. Aluminum (6061 T6) will cost a bit more than mild steel, but do better with corrosion resistance. Also age hardening aluminum alloys (2XXX, 6XXX, and 7XXX series) lose strength with cumulative temperature exposure (not really a big deal in a non structural application) Stainless will be really durable and stay pretty, but is definitely the most expensive option (save for crazy stuff like titanium and inconel). Personally I'd lean towards mild steel with a hi-temp enamel

Soliloquy wrote:Wondering what material to use when adding a heat shield to my Victory 2k.

Aluminum? Stainless? Looking to avoid a metal that gives off fumes when heated.

Thanks. I'll post photos and results when project is complete.

Where are you installing a heat shield?

Between the drum and burners?

Like this?

Go SS
It stands up to heat the best..

When I need small pieces. this is the seller I go to..
http://stores.ebay.com/Frigo-Design/Raw ... 34.c0.m322

Steve, Yes, between drum and burners. The reason: to find a better balance between conduction and convection. Sub 6:00 dry times at 75% capacity result in slight scorching/ facing, which shows up in the cup ever so slightly. This is on washed coffees. Naturals are a real pain on this roaster. It doesn't seem to be a charge temp issue, as I've experimented with low charges. Not sure of my drum speed, but beans seem to be lofting nicely, when looking through the trier hole.

I can keep scorching at bay if I keep an eye on my MET and don't let it get above a certain temp, and keep airflow low, as airflow cools my ET even at very low levels. But, then I don't hit yellow till after 6 min.

All that said. I want to see what hotter air and a cooler drum will do for my coffee.

I went ahead and made a few modifications last weekend. In addition to the heat shield, I sealed off the burner area with a plate of steel just below the burner nozzles. There is a hole in the plate that directs incoming air across the flame bed before it enters the drum. The heat shield (for now) is 1/16in plate steel bent (crudely) to the shape of the drum. I mounted it as close to the drum as I could without rubbing.

The result: A cooler drum, and much hotter air! I turned 12 roasts on Monday and was able to achieve 5 min dry times with no scorching, not even a hint of it. I had to max out my BTUs for half the roast, however, to hit a 9 min first crack. Now there is not enough conduction. I'll cup the coffees tomorrow and go from there.

If I like the results I'm going to make a new heat shield out of 1/32 in stainless, and do a better job bending it for a closer fit to the drum. Thinner material and a closer fit should give me more heat to the drum, and (crossing my fingers) the perfect balance of conduction and convection.

Here's some pics

Here they are.

FYI:
My roaster is a San Franciscan SF-1
Sorry for the lack of a picture of my burner setup.
Two reasons: 1. I'm away from home; 2. I'd need to do a semi-teardown to show it.

I have two of the same burners as shown in the last post. My burners have a metal "roof" over them. The roof is simply a piece of mild steel angle iron cut to length and welded to two posts. The "ridge" of the roof faces the bottom of the drum. I don't get scorching on this roaster either.

Soliloquy wrote: The result: A cooler drum, and much hotter air! I turned 12 roasts on Monday and was able to achieve 5 min dry times with no scorching, not even a hint of it. I had to max out my BTUs for half the roast, however, to hit a 9 min first crack. Now there is not enough conduction. I'll cup the coffees tomorrow and go from there.

If I like the results I'm going to make a new heat shield out of 1/32 in stainless, and do a better job bending it for a closer fit to the drum. Thinner material and a closer fit should give me more heat to the drum, and (crossing my fingers) the perfect balance of conduction and convection.

I think you're on the right track, but I'd cut slots in the carbon steel one first. There's no functional difference between stainless and cold rolled in this application. Like Mr. Bill's pic?