ok so i made a 50 gallon rocket stove/heater to heat 100ft of copper at the top inside of the barrel to heat my pool. on the inside of the barrel instead of using the usual vermiculite etc, i read that if the usual is not easily available you can use rockwool (roxul insulation ) which i happened to have. i wrapped the heat riser with it and wrapped some steel wire around it to hold it onto it. the heat riser is about 12" below the top. here's my idea. Being i had some extra roxul insulation i proceeded to place some inside the barrel around the heat riser to the same height of the heat riser leaving a channel down to my exhaust from top to bottom of the barrel where i have the exhaust. i had some sheet metal so i cut that out to fit on top of the roxul (act as a reflector). just above the riser i placed two pieces of solid copper in the shape of a X to hold my 100ft of soft copper coil. guess my question is should i take out the reflector and the roxul i put in to fill around the heat riser? i am wondering if it would get hotter in there. right now the water going through is from the pool is about 70 degree celsius coming out i am getting from 100 to 110. I admit its a good difference, but for some reason feel it should be hotter. I don't know how many gpm is coming out but its at a decent rate, and i know if i slow it down a bit more it would get hotter.
On a another note for my feeder/combustion chamber i used a tee. i seen somewhere on you tube someone using it, cant find it again for the life of me. which end of the tee would be best to use or does it matter? i can close one end with a cap, and i also like the idea feeding the fire from the top. also can someone recommend a good high heat sealant i can get say from a lowes, home depot, home hardware or canadian tire? i bought a fire barrier caulking from lowes, doesn't say any rating for heat on it. didnt work so well. Many many thanks on reading my wordy help question.