View Full Version : What will happen when I rip this timber?
06-20-2012, 09:24 AM
I've got some pretty big timbers to redo the deadwood and stern post on my Concordia. I also have some additonal smaller pieces for laminating frames and floor replacement. I was ripping the smaller pieces this week into 4" and then 1/4" so they could dry quicker. While doing the 4" rips, the pieces furthest away from the heart bent away from the heart as they were being ripped. This wont matter for the floors and lamination pieces because the lengths are short enough that I can cut the pieces square again. But I'm worried about the three 6" by 39" by 9' pieces. If I rip the heart out of them, are they also going to warp? If they warp enough, I may not be able to use them (at least in 9' lengths) fo rthe deadwood. These pieces are about 30% moisture content right now.
06-20-2012, 09:31 AM
06-20-2012, 09:32 AM
Oh sorry--White Oak.
06-20-2012, 09:49 AM
If I rip the heart out of them, are they also going to warp?
Yes, quite likely they'll bow away from the heart edge. The split in the plank is an indicator of the tension that's there. The heart should have been cut out when the log was sawn.
06-20-2012, 09:51 AM
Would it do any good to band it (with straps) to force the bend from occurring? I suspect it will not.
06-20-2012, 09:56 AM
You're correct. Nothing will stop it from doing what it wants.
06-20-2012, 09:58 AM
They will likely stay as flat as they are now, but might spring outwards as you cut the heart, but less than a thinner stick might. At 30% moisture content (on the surface) they will shrink a good deal as they dry.
06-20-2012, 10:05 AM
Oh yeah....... They're gonna move like Mick Jagger on stage in 1982.....
If you split them with a wedge now, not a saw, and let them relax a bit (A couple of cold beers, and the radio on a cool jazz station will help) before you saw them they'll spring less when the time comes to mill them to size.
06-20-2012, 10:10 AM
Think they will shrink less if I wait for the moisture content to come down? Again, I suspect not. This seem to me like it would be no more effective than strapping them to keep the bend from happening. In any case, I have no choice. I will go ahead and cut them soon. I may strap them just for giggles. Hopefully, there will be enough wood to plane them back square.
Any benefit to waiting as long as possible to cut the heart out? I can do the deadwood as the last repair and it might be a year before I get to it.
06-20-2012, 10:12 AM
Is lamination a possibility? If you've gotta make 'that piece' work, and if there's enough stock to resaw and glue up... May not work for your situation, though. Chip
06-20-2012, 10:18 AM
Any benefit to waiting as long as possible to cut the heart out?
The longer it drys, the more the tension will build up. Do what Lefty suggests. Split them with wedges and then let them dry.
06-20-2012, 10:33 AM
I would rough out the pieces oversize as soon as possible. The smaller the timber, the less tension develops as it dries. You'll want to slow down the drying by painting the end grain with thick paint or wax to keep checks from developing. It will be years before you see significant drying in these timbers.
06-20-2012, 11:31 AM
Whew! I love getting informed guidance. Thanks. That's the plan then. It looks like it will split like a ripe watermelon.
And Chip is right--It's just deadwood. I'll laminate it with resorcinol (or Gflex) if necessary to get the size.
My sternpost piece, I am hoping, does not have as much of these stresses as it is well outside the heart.
06-20-2012, 12:23 PM
I wouldn't count on laminating, Chuck. The timber is much too wet, and will probably remain so. In addition, the pieces involved are large and subject to a lot of cyclical movement, which would stress a glue joint to failure. As I said, cutting the pieces to rough size will reduce the stress dramatically.
Which dimensions are so close that you're worried about losing the necessary dimension? The six inch thickness? The width seems to provide a lot of wiggle room.
06-20-2012, 12:42 PM
The thickness is fine. Once I split it, and trim, the two seperate pieces are going to be not much wider than the 16.5" I need. Since the width tapers as it goes aft, I think I will be fine unless the warp is very significant.
Momentarily forgot about the moisture content. You are right.
06-20-2012, 12:51 PM
Also - if you choose to rip the piece instead of split it with wedges... I'd cut it with a bandsaw if possible. Safer.
06-20-2012, 01:32 PM
I bought a beam saw off Craigslist. Each piece weighs about 700 pounds.
06-20-2012, 01:46 PM
The 16" Makita?
06-20-2012, 01:53 PM
Thought I read that this was a year off, in terms of ageing/stabilization of the material?
06-20-2012, 01:58 PM
Yes Jim. It hasn't arrived yet. It was well-loved but promised to be strong.
Yes Chip--could be a year. Not sure a year will get me low enough though . . . maybe. Hopefully, it will all work out
06-20-2012, 02:31 PM
I bought one of those off Craiglist as well. It's pretty old, brown instead of the more-familiar blue. It will cut right through a 6x6 landscape timber, but with hardwood I use my regular saw to make the first cut, and then make successive passes with the Makita. Take it slow and you'll be fine.
If I was you, I'd invest in a gallon of CPES and paint the timbers as soon as they're shaped. It goes on like water and you can build up successive coats to make a good, stabilizing barrier coat.
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