old growth pine

[Keye]

I am making a fairly large table out of old growth pine. This is virgin pine without a single knot.

I have had problems with sap with old growth pine with knots. No knots this time but the odor is very strong. This was rough cut and had to be planed and dimensioned. I am concerned about both sap and odor. Should I seal the wood and then apply a finish. If I should seal the wood what should I use. I do not have spray equipment.

 

[KenOfCary]

How dry is this wood? Sealing it if still wet might be a mistake. Otherwise sealing it might be a good idea after glue-up. What other finishing are you planning to do with it? I've not done a lot with pine so am really only speculating here.

 

[gritz]

How wide are the boards? How were they dried? How are you joining them?

 

[Keye]

This wood was cut in the 1800's. I have a paper trail that verifies this. I have had this wood for many years and it has been stored in a dry barn.

The boards are 4" wide and I am gluing them.

 

[Keye]

This wood was cut in the 1800's. I have had it many years and it has been stored in a dry barn. Not sure what finish I am going to use.

 

[CDPeters]

In that case, the sap should be long ago "set". It should not be a problem. You may want to do initial dressing on the material, and then let it acclimate in a controlled shop environment, just to be sure the moisture content is not too high.

Scott Smith is probably the expert here. I seem to recall him mentioning a some thread somewhere on drying that pine takes an extra higher temperature cycle at the end of the kiln process to "set" the sap, but that would be on newly felled and milled lumber.

 

[CrealBilly]

In that case, the sap should be long ago "set". It should not be a problem. You may want to do initial dressing on the material, and then let it acclimate in a controlled shop environment, just to be sure the moisture content is not too high.

Scott Smith is probably the expert here. I seem to recall him mentioning a some thread somewhere on drying that pine takes an extra higher temperature cycle at the end of the kiln process to "set" the sap, but that would be on newly felled and milled lumber.

Yep talk to Scott Smith about getting the wood dried, sterlized and pitch set...

 

[scsmith42]

Keye, pine sap typically has a "memory" where it will crystallize at around 15 degrees below the highest temperature that it has ever been exposed to. A few weeks back we did a sterilization run in one of our kilns that included some very old, reclaimed heart pine boards. The boards felt extremely dry to the touch, but after they came out of the kiln there were little beads of crystallized sap on about 5% of them.

As old as your boards are, you will *probably* be ok with respect to sap bleed. If you want to be sure, you can either do them yourself in a home sterilization chamber that you can build using foam board and a space heater, or send them to a kiln operator to heat them up.

If you send me a PM with your e-mail address, I'll send you a copy of an article that was in FWW a few years back about a simple home sterilization chamber. I will not post it on a public forum due to copyright reasons.

Scott

 

[Jeff]

I'll send you a copy of an article that was in FWW a few years back about a simple home sterilization chamber. I will not post it on a public forum due to copyright reasons.

Two of our members have used the idea for sterilization (powder post beetles and other critters, etc) but slightly higher temperatures are required for setting pitch. Scott can tell us the temperature range and time needed.

If I closed the around the bottom it would run up to between 175-180 degrees and hold. No fiddling...It worked perfectly ( I turned it on yesterday at 4;00 and off at 11:00). It took about 45 minutes or so to get up to temp.

http://www.ncwoodworker.net/forums/showthread.php?t=58639

...and a much larger version...

http://www.ncwoodworker.net/forums/showthread.php?t=59847

 

[scsmith42]

160f or higher should suffice. Time at temp depends on material thickness but I would recommend at least 4 hours.