Creostote Buildup on Copper Lines

If you apply varsol to the creosote you should be able to dissolve it unless it has crystallized. It should not matter that much but if you do get it clean then keep the fire breathing since creosote is 90% caused by poor combustion. Moisture of wood is only 5% factor.

GA for a great and accurate answer - wrong/bad combustion and relatively cool copper = large amounts of creosote!! Simple!!!

They should try a smaller, but hotter burning fire with plenty of air and therefore COMPLETE combustion....

By creosote I presume you are referring to the tar left from burning wood or coal. In my understanding, true creosote is a liquid derived from such tar.

If the copper is a continuous coil, then you may periodically drain the water from the pipes and allow them to get hot enough to burn the tar. If it is copper pipes with soldered elbows, that would likely melt the solder, so I wouldn't try it.

You don't say where you are or what fuel you are burning. If you are burning mostly softwoods, you might have to use hardwoods for the burn-out.

Depending on the design, it might be possible to add a catalytic grid to burn the tar before it reaches the copper. This would increase the efficiency of your entire system and reduce or possibly prevent the tar build-up. It would not remove existing tar.

Thanks for the info, as for what kind of wood it was quite the mixture this past winter but what caused the large buildup was some very sappy green wood (yes i know, stupid... was -35 C and ran out of wood). The majority of the elbows are outside the box for obvious reasons and no i don't like to heat up the lines without the water going through them, would be a disaster if we had to replace the lines inside the box (theres 75 ft of copper coiled up inside the fire box). I have used a torch on the lines and scraped and brushed the lines when they were scorching hot and that has removed a great deal put there is the final remaining coating on the copper lines that we need to get rid of.

You can try a number of organic solvents, xylene, acetone, hexane,,, all kind of nasty. If the tubes are continuous you may be able to burn much of it off if you leave the tubes dry. If they are soldered with lead you can't do this, If they are silver soldered you may be able to.

I have the same problem with a stainless steel heat exchanger in a wood burning stove. The problem is caused by the cold (relatively) surface being in the actual combustion chamber, the creosote condenses before it has a chance to burn.

Cheers

Martin

Makes sense, i'm just afraid to torch it too much without the water going through as i don't want to wreck the pipe by overheating it. How hot can you let copper pipe heat up? I use a blow torch to do the heating.

Maybe this would help? http://www.chimneysweepinglog.com/

I'll caution you up front to be very careful and make sure you have water circulation at all times if you use this method. I used to use cardboard to clean heating coils in fireboxes however when we installed them they were iron pipe and not copper. Cardboard burns VERY hot so be very, very careful if you try this.

You can buy special logs or a chemical from any big box store. put this in the fire box when You build the next fire and it should keep the buildup to a minimum. Don't know if this will get rid of what You have now but worth a try.

oilcan13

As I mentioned on my reply incomplete combustion is culprit. Go to this site to see how modern high efficiency furnaces operate. http://wooddoctorfurnace.com/converter.html There are several companies making these furnaces and they all have one thing in common a ceramic fire box for high temperature burn. solves the problem of creosote.

If possible, I would remove and replace the copper tubing. With the old tubing out of the firebox, you will be able to chemically remove the creosote and save the tubing for future replacement. I don't think you will be able to remove the creosote with a clean fire unless you overheat the tube. FYI, many firebox designs keep heat exchangers out of the flue gas - now you know why.

You have a better than 70% chance of being correct!!