Hey all,

Long time Behmor roaster and decided to have a go at making my own gas roaster. The main reason being the cost of a commercial unit, those things cost a heap of money as we all know. Originally I was put off by the idea of making one, simply because I wasn't sure I could do it. But that's no reason to not have a go. The added kicker for me is I live on an island with my partner, shopping is every 3-6 months by plane. So i'm relying on scrap and help from you kind souls!

I've being reading up on DIY roasters the past few weeks and found some great ones, the biggest issue for me was the drum. Stainless seems like the best option and safest, but stainless scrap isn't hard to come by here! I love the drums made in the USA, and long term will buy one of theirs if I can! Fatboy on the forums here has a great word document for building a roaster too.

Scrap available:

-I found the following scrap; two stainless drums from washing machines, as many 44 gallon drums as I need, plenty of gas burners and fittings, a small beer keg already setup as a crayfish boiler, stainless banding, stainless flue (Thanks Mal for that idea!), what I think is stainless mesh, an old BBQ, a cut down and welded solid 44 gallon drum, 2 wiper motors (1 likely no good), 2 bits scrap stainless.
-I have any tool you can think of including ARC welder and oxy cutting kit. Not much experience in these but eager to teach myself here.
-We have scrap galore, nearly anything you can think of. Old air compressors, steel, RHS, building supplies etc. Plenty of old power supplies. Some solar panels.

Ideas:

-My current idea is to use the top pictured stainless washing machine drum as the drum for the coffee. The issue is then the roaster housing as the drum is large. To give you an idea, the top pictured is a 44 gallon drum on it's side and the washing machine barrel only just fits inside and would be able to rotate. The thing I like about this washing drum is it's lightweight and has vanes on the inside which would help with the coffee roasting. it's also huge, I could roast 5kg in this thing! However, this makes it hard to mount the gas burners. I could potentially make a bigger housing from other 44 gallon drums once I cleaned them out. The second photo with the newer stainless washing drum doesn't show how big it is! It's even bigger and heavier than the other one.
-I want to keep it 12V, maybe even solar powered later on. Got one spare solar panel here which could charge a battery bank. Got some old remote power solar AGM batteries lying around too. But I also have plenty of old laptop power supplies lying around, electronics ain't my strong point but have had no problem wiring in basic things like car stereos/radios, lights etc.

Questions:

-Does anyone have any input on internally mounted gas burners VS externally? Obviously with the washing drum internally would be an issue with the current housing drum. I've seen many different types online and no idea what's better!
-I could try and make my own drum from the scrap stainless but from reading up on it it seems I need a machine brake, it's too thick to do by hand. Also I may struggle with welding stainless considering my lack of experience in general. I could also try to cut down the stainless drum and make a smaller drum, that seems hard to me too.
-What's the best way to test the wiper motor? The larger unit is from a series 3 steel fgp landrover, it was in the elements for god knows how long and the wiring plug has corroded from the unit.

Thanks for taking an interest, if I can make a roaster anyone can! Feel free to get involved as much you want to, everything here has being a learning curve and this is no different.