Friday, March 12, 2010

Log Log

My fire log drying research has been getting pretty technical, or to put it Kath's way - ridiculous

I found a web site giving details for lots of different types of wood and what their ideal burning condition should be in terms of moisture content. For Ash (type of wood, not the white stuff!), it seems that I should be aiming for a specific gravity of about 0.65.

Well, of course I needed to find out what my test logs were now in terms of SG, so after carefully wrapping them in cling film to keep them dry I floated them in water and measured how deep they sank when held vertically. The logs being roughly cylindrical, all I had to do was divide the immersed length by the total length and that gives me the SG i.e how heavy the logs are compared to water. OK so far?

It looks like they are currently at about 0.85 which it seems is typical for fresh cut Ash. The rest is easy. Assuming the volume stays the same I can work out the weight which would give an SG of 0.65. All I have to do is to weigh the log periodically until we get there.

Here's a pretty graph, which I will update from time to time.

Is all this really necessary? Naah! In any case my measurements are not strictly accurate. Also, apparently Ash logs will burn when fresh cut, but they use up a lot of their heat steaming off the water content so they burn hotter when dry.

But its fun.

If you like that kind of thing.

3 comments:

Halfie said...

Love it!

Extrapolating from your graph it looks like you'll have reached your target weight in another six weeks or so (your log, that is!). Let's see, that'll be ... the beginning of May. By which time the weather should (possibly) have warmed up enough not to have to burn it!

Rick said...

I am glad to see that you are keeping a log of your logs

VallyP said...

Haha Neil, it does sound very absorbing, even if not all that important in the over all scheme of things. I imagine once you get going on this kind of research, it's difficult to just leave it and walk away, isn't it?