Castor oil
09-18-2024 | 08:18 AM
#2
I would advise against apothecary castor. It probably isn't de-gummed. Being less refined, it will produce more ash and is more likely to polymerize over time. I'm most familiar with the Sig product but any genuine castor should do.
09-23-2024 | 03:35 PM
#3
Senior Member
Brodak also has it. I’ve used Sig caster it’s the best in my book. Don’t know about this new company that bought out Sig. they moved it in the.zchicago area. I’ve also used the Brodak fuel. Kinda sounds like your doing own brew. But the stuff you buy at places like Walmart, and any of the drug stores is not good Caster for our purpose. You can get a gallon at Aircraft Spruce. I buy all my Dope from them and retarder and thinner also alcohaul. Keep them lines tight!
10-30-2025 | 08:17 AM
#6
My Feedback: (18)
Although some have reported that Apothecary castor works well, my experience was not good.
About a year ago, I mixed up some fuel using castor from Bulk Apothecary and then delayed using it for several weeks. When life settled down enough to resume flying I had forgotten all about the fuel mixing. I went out to the field and immediately had problems. None of my engines would run a whole tank of fuel without dying nor would they idle reliably. I got pretty darn good at deadstick landings though!
I struggled for a month or two trying different things like different glow plugs, tank position, foam around the tank, and different propellers. Finally I remembered that I had mixed the fuel. I drove to a hobby shop 100 miles away and bought a gallon of Omega 10%. Suddenly all of my engines ran perfectly. Now all I use are Klotz oils in my home brew fuels and have not had any problems since.
By the way, I should have known something was wrong with the Apothecary castor because the exhaust did not have that familiar castor smell we all love. It smelled vaguely familiar but not right.
In this hobby it’s often risky to use off the shelf stuff and assume it will work as well as stuff intended for our hobby. Fuel components not intended for internal combustion engines can be a hit or miss experiment. Off the shelf paints can be a gamble as well.
About a year ago, I mixed up some fuel using castor from Bulk Apothecary and then delayed using it for several weeks. When life settled down enough to resume flying I had forgotten all about the fuel mixing. I went out to the field and immediately had problems. None of my engines would run a whole tank of fuel without dying nor would they idle reliably. I got pretty darn good at deadstick landings though!
I struggled for a month or two trying different things like different glow plugs, tank position, foam around the tank, and different propellers. Finally I remembered that I had mixed the fuel. I drove to a hobby shop 100 miles away and bought a gallon of Omega 10%. Suddenly all of my engines ran perfectly. Now all I use are Klotz oils in my home brew fuels and have not had any problems since.
By the way, I should have known something was wrong with the Apothecary castor because the exhaust did not have that familiar castor smell we all love. It smelled vaguely familiar but not right.
In this hobby it’s often risky to use off the shelf stuff and assume it will work as well as stuff intended for our hobby. Fuel components not intended for internal combustion engines can be a hit or miss experiment. Off the shelf paints can be a gamble as well.
Last edited by 049flyer; 10-30-2025 at 08:23 PM.
