Treatment of Old Wood

[Joe Kelly]

Recently I was given some Yellow Heart Pine that, according to the owner came from a house that was constructed in 1890. Needless to say it is dry. He wants me to make some pens from this wood for gifts to be given this Christmas.

I attempted to turn a blank and it came apart while on the lathe. I turned it down to approximately 1/8" when my tool began to take chunks out of the blank. I sharpened my tool and tried another blank. I got the same results.

Please advise me of a method of treating this 114 year old Yellow Heart Pine so that I can turn it into pens.

Joe Kelly

[Steve Cox]

Joe,

What type of pen are you making? When I turn pens I make one of three sizes, slimline, comfort (medium), or Mont Blanc (large). With some woods if I can't get it to turn down to a slimline because of the wood coming apart, making a Mont Blanc style with it works. Another question would be as the "chunks" are coming off, do they expose the underlying brass tube? If this is the case, you might want to re-examine your glueing process to make sure the tube is glued solidly to the blank along its' whole length. Just a couple of thoughts, need more info to be definitive. It may also simply be the wood. I have yet to be able to successfully turn a pen in Doug Fir no matter what I try.

[Chris Padilla]

Joe,

It might not be the best thing but consider ripping the SYP into strips and regluing and turn a SYP laminated pen. The glue should be enough to keep everything together but I dunno how it'll look. If you are careful ripping to get clean glue lines, I bet it turns out nice.

With straight-grained douglas fir, I bet you can hide the glue line pretty effectively if ripped in the right spots.

[Hal Peeler]

I have had the same problem. I think it is due to the grain. I got a piece of heart pine from my father in law that had very tight, very straight grain and have not had many problems getting pens out of it. BTW, the piece I got from him was cut off of a log from an old log house that he disassembled and rebuilt on his property, so I make the pens out of the log for him to give to his visitors.
Hal

[John Szarek]

If you precut and drill the blanks, then soak them in Rotted Wood Hardener (Lowes) overnight, you should be able to turn them no problem.

If you have the ability to develop a vacuum, that is even better as it will pull the air out then push the Hardener in. You will be turning plastic, but it will not come appart, and finishes very nice.

[Bob Smalser]

Dunno how tight grained your pine is, but I'll presume it's 15 rings/inch or better because of its age. Sungrown, 4-rings/inch softwood is less dense and more prone to problems in machining.

Old wood seems to lose some lignin over the decades....don't really know why, but expect its got to do with seasonal movement as boat planking that is bound tightly literally wears itself out and shrinks badly, given enough time.

Loss of lignin, the glue that binds the cellulose together, means the wood gets brittle.

Boatbuilders and old house rehab types use an epoxy product called CPES made by Smith Enterprises in South Carolina that'll soak deep and harden your wood right up.

[Steve Cox]

CPES or Smith's Penetrating Epoxy as I know it is great stuff but be aware that it can cause quite an allergic reaction worse than most other epoxies I'm aware of. One instructor of mine used the stuff all the time and had no problems, another had to post signs on his shop that it wasn't to be used anywhere in the vicinity because it would put him in the hospital. Always use PPE when using epoxy because the effects are cumulative.

[Steve Cox]

Bob,

On the boat planking shrinking over time, I saw an interesting study a number of years ago in WodenBoat about that subject. The gist of it was that if wood is allowed to fully expand and contract over time it loses nothing in size or strength. However, in a boat, the planking is constrained from swelling to its full size by the other planks. The net effect is that if not allowed to swell to its full size the wood then shrinks to less than its original size. I don't remember all the technical details but the conclusion stuck in my mind. No solution for it that I remember but an interesting read.

[Bob Smalser]

Bob,

On the boat planking shrinking over time, I saw an interesting study a number of years ago in WoodenBoat about that subject. The gist of it was that if wood is allowed to fully expand and contract over time it loses nothing in size or strength. However, in a boat, the planking is constrained from swelling to its full size by the other planks. The net effect is that if not allowed to swell to its full size the wood then shrinks to less than its original size. I don't remember all the technical details but the conclusion stuck in my mind. No solution for it that I remember but an interesting read.

Repaired a few of them....especially flatsawn Doug Fir which has a relatively large amount of seasonal movement compared to cedar...and especially riftsawn cedar.

But it happens to all carvel hulls. To make the boat watertight, you drive cotton or oakum into the planking seams....more to tighten the planking than to add a gasket. If you do this real tight with dry, 9% wood, it promptly expands to 13% when it hits the water...whether painted, CPES-treated or nothing at all...and the edges of the planks crush slightly as they swell, damaging both lignin and cellulose.

Then the next time the boat comes out for months of summer repairs, the planking dries back to 9% and the wood shrinks to its original size, less the 32nd" or so of damage. So the planking is now open and the owner drives in more cotton to tighten it back up...

...and the downward spiral of that planking wearing out continues. You can't stop it, just slow it down by paying careful attention to the EMC of your planking stock, maximizing the hull's time in the water and making a damp environment for the hull when it is on the dry...no concrete floors...tented outdoors on dirt or gravel....wet burlap ground cover beneath the boat.

Also depends on where you are. In the cool, wet NW, carvel trailer boats have few problems when planked with riftsawn cedar. The same boat when moved to San Diego will have to live in the water.

Lapstrake hulls aren't immune, either...move a flatsawn NW one to San Diego and leave it in the hot sun and the laps may split at the rivets from shrinkage.

All that is why rift and q-sawn wood is so important....riftsawn being preferred because it is less likely to split from fasteners than qsawn, but doesn't move much more seasonally.

[Steve Cox]

Yeah, but even up here it helps if the boat stays in the water. I saw an example of a boat in Portland that was in the water but when I went down below, the hull was tight but I could see through the sides above the waterline. It just hadn't been used much and really needed new caulking.

[Bob Smalser]

The planking seam is only beveled for the top two thirds of the edge, the bottom third of the edge a tight fit. If you can see thru the planking, it may need more than just caulking.

Old boats with worn planking do that above the waterline. So do new boats where the builder either didn't get a good tight fit or used wood that was either too wet or too dry.