Drum roaster restoration advice

[brendogs]

Hi there,

I got my hands on an old 10kg roaster for fairly cheap a while ago and have been slowly chipping away at restoring it back to life. I've got the entire machine in parts on a few pallets and I have just completed sandblasting and sanding it to get it ready to paint.

I have 2 questions.

1- I just dropped the drum off to get sandblasted inside because my small sandblaster couldn't fit it in there. It was caked with coffee oil's and residues so it was well needed. The advice I need is in regards to getting the inside of the drum coated in something or do I give it a couple coats of high temp paint or is bare metal fine?

2- Any idea's on remaking a chaff collector cyclone. I've been looking at the one I have, it need's a serious clean but I thought if I could make a new one I would have a crack.

Thoughts?

-Brendon

[TC]

You probably just unseasoned your wok...

Don't even think about paint! Would you like to consume the output?

[Vinitasse]

Thoughts?

-Brendon

What the....?!?!?!

My thoughts are that I wish you had discussed the refurbishment with someone who actually has a clue before getting started. It's obviously too late to do anything about the previously seasoned drum but please... for the love of coffee... stay away from paint of any kind on the roasting surfaces.

[chokkidog]

Methinks a 60kg bag of cheap Brasil going into the drum to get it back in season, 6-10 roasts should do, for starters.

Make sure your sandblasters don't put anything solvent or oil based in it to clean up when they finish.

[brendogs]

What the....?!?!?!

My thoughts are that I wish you had discussed the refurbishment with someone who actually has a clue before getting started.

Funnily enough, I did speak to a few roasters in regards to this. All had suggested to bring it back to bare metal since I was doing a full refurbishment on it, my question was purely only intended to try and assist in rust prevention. I would have thought that rust and coffee wouldn't mix overly well...

I intended the question to receive a response along the lines of, "new roaster drums are coated in X" or "new roaster drums are bare metal, they just require a few seasoning roasts".

Upon previous conversation with the guy who does my chrome work, he told me there are specially designed chemical dips that can be used to stop rust. He told me that in he's previously line of work at a surgical equipment manufacturer they used this method for anything that wasn't stainless steel. I was vaguely thinking that something along those lines may be an idea to stop rust. This conversation is what sparked the question I asked yesterday.

It seems the chokkidog's idea may be the most helpful so far. Thanks mate, I know new roasters need to be seasoned in so I will have to endeavour to get my hands on some cheap beans and run a number of roasts through it. I did tell him not to coat it or clean it with anything after the job was completed.

Vinitasse & Talk_Coffee; The drum is waiting in line behind a very long list of jobs at the sandblasters. If you think it's wise to just go an pick it up, I can still do this. The drum is heavily seasoned though it was used as an overload roaster at a roastery that was pushing out 1.5+ tonnes a week, so since it's last clean out it could have roasted a tonne of coffee. As I said there are significant signs of build up inside the drum.

[TC]

Coffee oils prevent rust.

[brendogs]

How good is coffee?!

We should start a car restoration business and line the rusting panels and chassis rails with coffee 😁

[chokkidog]

Do you have/can you get a photo of the inside?

[Trane]

Coffee oils prevent rust.

My urologist can confirm this. On a recent examination I had no rust at all

[MartyMac]

Hi,

I would of thought the drum would be made of stainless steel which means no rust prevention is needed, and leaving it bare would be fine. However if it is mild steel then you probably would need to protect it from rust with something. When mild steel is sand blasted, it needs to be coated with something within 4 hours to prevent rust, as it is in it's most vulnerable state with non of its natural scale to protect it.

I would suggest some kind of vegetable oil which could be burnt off once the roaster is up and running. But defiantly no paint, as it would wear off and contaminate the coffee.

Hope that helps.
Cheers
Marty

[MartyMac]

Oh and P.S.

If you are unsure if it is stainless or mild steel, then all you need to do is get a magnet. If the magnet sticks it is mild steel, if it does not then it is stainless steel.

[chokkidog]

Yeah, we haven't been told what material the drum is made of, being an older roaster it is unlikely to be stainless.

The two probable alternatives would be carbon steel or cast iron.

[TC]

I would strongly recommend against any other oil other than that which is found in coffee beans. Roasting #101- Seasoning your roaster.

[chokkidog]

I would strongly recommend against any other oil other than that which is found in coffee beans. Roasting #101- Seasoning your roaster.

Agreed, Chris, even if the sandblasting does eventuate and results in some surface rust............"oils ain't oils Sol" use coffee to remove the rust and reseason the drum.

[MartyMac]

Ultimately the sand blasting of the drum should be done once the roaster is ready to go so you can begin seasoning straight away. But if it's already sand blasted then maybe send it back for a quick whip blast when your ready to go.

Cheers
Marty