Metal barrel chemicals

Hey there people. This question might be answered somewhere else. Feel free to link to the topic.

Im going to start building a  rocket mass heater outside to practice. I wanted to know which are the No-go chemicals that barrel could have contained that I should use. I thought I could just burn and clean them to be sure but I read somewhere even if I burned them this might still be dangerous with certian chemicals. Is this true ? If so could you guys list me the most common chemicals to avoid in 5gal and 50ish gal metal drums. Or if it easier, the top common one that are okay to burn up the barrel and use.

Any other advices will be welcome! ( yes I will be planning my  burn / riser ratios accordingly )

Also if any of you know if the pricks on the picture are usable for a manifold, I would appreciate

here is what I planned to use

Kyle Prescott wrote:

here is what I planned to use

Well . .   what size of RMH are you planning on building ?  Planning on welding the steel pails together ? Need more details too give advice . ..  

will no be wielding anything. I just wanted to use free materials I found around to start practice on a smaller scale RMH. I would use the metal bucket as is, respect the ratios and all.

I just need to know if the bricks will support the heat ( if they are clay ) and what are the chemicals the drum might have contained that I should stay away from. Or can I just go ahead burn it and then use it.

thanks

Are those modern 3-hole bricks?  They look like they might have the holes filled with mortar, do they?  If so, the mortar in the holes may not stand up to the heat.  I like using old, solid bricks, the ones you can tell have a vitrified surface, for the burn tunnel.  I got some used bricks that were salvaged from a 100-year old school that was being torn down.  They made a nice burn tunnel.

As far as the paint cans, whatever is on the interior surface will flash off in the first few burns.  You might want to try really hot initial burns (like burning fatwood or paraffin coated cardboard) to speed up the flash-off process.  

Is the exterior of the paint can going to be covered?

Are you thinking of the 5-gallon cans (stacked) to contain the heat riser insulation? I believe those would work fine. You would probably want to burn them off outside first, as the outer skin of the riser will mostly not get hot enough to burn clean without long hot fires, if then. I would not try to use them as the outer barrel in a scaled-down J-tube system, as such small-scale systems are supposed to be much harder to get working well than larger systems. I would try a 6" system for starters, as that will work if you get close to a correct build.

Glenn Herbert wrote:Are you thinking of the 5-gallon cans (stacked) to contain the heat riser insulation? I believe those would work fine. You would probably want to burn them off outside first, as the outer skin of the riser will mostly not get hot enough to burn clean without long hot fires, if then. I would not try to use them as the outer barrel in a scaled-down J-tube system, as such small-scale systems are supposed to be much harder to get working well than larger systems. I would try a 6" system for starters, as that will work if you get close to a correct build.

I wasnt going to stack them. I was going to use them as the outer barrel of the J tube and go 4 or 5 inch and get all ratios to follow.  They dont work as good you say ? Well if it works a little, its good enough for me as it would be a practice for an official in door 6 inch.

Let me know what you think

It's not so much that they don't work as well as that they absolutely don't work adequately unless you do everything right the first time. If you are okay with discarding all of the first trial, you could probably build a thinner riser (6" ID, 8" OD) to fit inside the paint cans. You need the height of at least two 5-gallon cans to get a decently tall heat riser. For a test, I would think you could tape the cans together with aluminum foil high-heat tape available in hardware stores. I used a 30-some gallon barrel (15" diameter if I recall correctly) as the outer shell for a demo 6" RMH, and that worked fine.