Thread: How to dry hoop pine quickly

xbgthardtop - you are probably going to get quite a few different bits of advise here, too, but here is my 2c worth.

Drying small pieces of wood very quickly is always a hit & miss affair, in my experience. Sealing the end grain & taking it slowly is the safest though even that is no gaurantee because internal stresses/faults can upset even the best procedures. Having said that, most softwoods are pretty forgiving. Getting the 'free' water out is the easy step. You can dry as fast as you like until the wood reaches what's called 'fibre saturation point', which is around 25-30% moisture for most woods. After that it needs to be taken carefully because that's when the water starts leaving cell walls, which shrink, setting up the stresses which do the damage.

The trick is to get water to diffuse out evenly, so as to minimise the difference in shrinking between any two spots in your billets, & that's the hard part - the more rapidly you get the water to move by heating it, or placing it in a very low-humidity environment, the more likely the 'outside' will get much drier than the 'inside' & surface splitting or 'checking' occur. The reason for sealing the ends of the wood is to prevent the much more rapid loss of water through the open vessels, which allows very rapid drying of the ends, while the inside remains 'wet'. If this happens, the outside cells dry & shrink, setting up stresses that can usually only be relieved by splitting.

Microwaving heats the water & gets it moving faster, but it will be hard to control for a big solid billet. Turners use this trick successfully, but usually rough turn so that the piece is even thickness, and no section is very thick, meaning water doesn't have to travel far.

So there you go - it can be done, but it's a fraught process with such a thick chunk however you decide to sped things up.

Cheers,

Or you could have put it in 's shed any day this week.

Thanks for the advise it had been hot and humid here (mind you not as hot as vic) and have had a couple of 400mm diameter x 100mm high pieces crack while in the shed. But these ones were stacked on top of each other. so far I'm thinking of just painting the ends and making some type of rack. But I have some green pieces coming soon and would like to use them a bit sooner then normal.

Originally Posted by xbgthardtop

........ But I have some green pieces coming soon and would like to use them a bit sooner then normal.

Yeah I used to be like that, once, but nowadays the problem is to get to them before they turn to dust!

I forgot to mention before that the degree of "dryness" required will depend on what you are going to use it for. If the job doesn't require dimensional stability to any great extent, you can hop into them a bit sooner, but if you are going to make musical instruments, then much patience is called for.

Cheers,

I'm actualy just turning them in to solid shapes like bowls and plates without the middle being hollowed out.

Originally Posted by xbgthardtop

I'm actualy just turning them in to solid shapes like bowls and plates without the middle being hollowed out.

In which case you can probably get away with turning them once they hit around 18% MC or so. The circles will go a little oval as the last of the drying takes place, but that may not be a big deal.

Cheers,

A little bit of ovalising would not be too bad. I would be more concerned about cracking. I will giving the finished piece a few coats of polyurethane.

Thanks for the help Ian.