Using CA glue to strengthen "punky" wood?????

[David Seward]

Seeing as their is so much wood turning experience here, I thought you could answer a question for me.



I have a few F.O.G. (found on good) bowl blanks about 8-8 1/2" in diameter and 6-7" thick that I thought were solid all the way through, well they are not! One side is actually quite punky, yet is still solid enough to turn. I managed to mount one of these blanks on my lathe using a screw chuck and it actually is holding it securely.



My question is this: If I were to use a small drill bit (1/4" maybe) to drill a few holes in the top of the blank in a circle around the chuck and then poured thin CA glue into the holes and let it dry, will that make the blank more solid, easier to turn, and less likely to fall apart???



Thanks in advance!

Dave Seward

 

[n7bsn]

I've used water-thin CA to harden punky wood. It's not a cheap way to do it. What I do is put the CA on the form, then cut away that layer, and then (usually) more CA.
I doubt the drill and fill would work. How stabilized wood is made is under pressure.

I've also used Minwax wood hardener, I think it works as well or better then CA. But again, you put some on, cut the hardened wood off, and repeat.

 

[MichaelMouse]

Nope, injecting isn't going to do it. Are we talking wet wood? If so, the tendency to peck out may diminish sufficiently when dry to allow you to do things without remediation. The white areas, as the articles say, represent delignified wood. Lignin is the glue that holds the wood together, so any steep pitch cut is liable to peck. With cylindrical gouges and bevel "riders" there is often a problem with crushing by that same bevel. The glue - ANY kind - will help with the pecking, but not with the crush, which is permitted by soft areas under a hard shell. Only solution there is to lighten the cuts and keep a clearance angle between the wood and the heel.

Solvent-based "glues" like shellac/lacquer can stiffen a surface to more or less the same depth as the CA for less money. Wood hardeners go a bit farther, but it's still going to require two applications to get to the bottom of the big pecks, and if you get a broken fiber crush, it'll show for some depth as well. Try the cheaper methods on cured wood first, and remember, your troubles are not over when you cut a clean surface. You still have to sand, and delignified wood sands pretty fast. Even if you still have some glue you may sand through, so keep the touch light and support the sander on something besides the work if you use something capable of being supported.

"Life's too short to turn crappy wood", as has been said. Sometimes the better choice is to pitch it.

Wet side down, delignified, and a PITA to clean up. ~13" http://i35.photobucket.com/albums/d160/GoodOnesGone/CantSellBirch-1.jpg
Can be done with no oil finish excluder.

 

[hockenbery]

David

You must have solid wood for your chuck or faceplate mount.
Pinky wood will not hold in a chuck or hold screws.

This is particularly dangerous. While some with lots of experience may work a pinky piece that has great potential- they know the rises and techniques to not stress the mount.

Don't turn it unless you have solid wood holding on the lathe!

Work safely
Al

 

[odie]

Seeing as their is so much wood turning experience here, I thought you could answer a question for me.



I have a few F.O.G. (found on good) bowl blanks about 8-8 1/2" in diameter and 6-7" thick that I thought were solid all the way through, well they are not! One side is actually quite punky, yet is still solid enough to turn. I managed to mount one of these blanks on my lathe using a screw chuck and it actually is holding it securely.



My question is this: If I were to use a small drill bit (1/4" maybe) to drill a few holes in the top of the blank in a circle around the chuck and then poured thin CA glue into the holes and let it dry, will that make the blank more solid, easier to turn, and less likely to fall apart???



Thanks in advance!

Dave Seward

Dave......

I've also used the Minwax wood hardener.......it works to some degree, but there is a point where the punky wood is just too far advanced to really expect your results to be acceptable. It's my opinion that the Minwax hardener is a little bit better than the CA for punky wood, but that point is left to discussion. Everyone will have to take each individual piece of wood and make their own judgement on that. With super sharp tools, if you just can't get a decent cut without the need for excessive sanding, it may be better to cut your losses and move on......as others have suggested here.

Spalting can be exceptionally beautiful, but there is a limit to what you can do with it, in an advanced state. In the early stages of spalting, the wood can be very useful, because the wood still has some solidness to it......it's all a matter of degree.

The point about not having a solid mount is wise to consider. When mounting the blank, this area must have some solidness to the wood......or, it will be a safety concern. You don't want it to disintegrate while turning......or, unexpected trips to the emergency room!

That's an interesting idea of drilling holes and filling with CA. Never tried that, but it seems like it could work for some applications.....don't know. If you do try that, be sure to let us know what your findings are.

Here is a bowl that had some major deterioration, due to spalting, but it was limited to one side of the bowl. The mount was solid, even though the worst of the punky wood did extend into the mounting area a slight bit. I'd say 80 percent of the wood in the mount was very solid, and that is enough to proceed without too much concern. (That is, as long as you don't get any catches that could knock it out of orbit!) The tool finish wasn't as good as I'd like, but sanding was able to bring the surface quality to something acceptable........although, the sanding did leave a somewhat uneven final surface. Couldn't help that, but the bowl finished out to something I could be satisfied with overall. There were also some voids to contend with on one side.......but, that's another story!

ooc

.

 

[MichaelMouse]

Looks like you had a good amount of lignin left, OD. Must be sound wood with David, too, or he would not be able to use a screw chuck effectively.

Couple extra bits of food for your thought, David. Use that tailstock to help you hold the wood in place as you turn the piece. Great advice always, but especially with wet and delignified wood. I even use it when hollowing inside, where the diameter of the piece permits. Cowardice coupled with the knowledge that having a good center to remount the piece after it dries makes regaining circularity easier.

Even if you don't have an artificially soft surface from rot, it's a good idea to make a shouldered dovetail-wedged tenon rather than try to chew wood. Or a dovetailed mortise, where you can cut with enough precision to get the full ring of metal in contact with the wood. Spreading the load broadly decreases the chance of a dismount.

Another thought for any who might want to encourage spalt. Note that the down side holds water longer than the up, and rots more extensively. Rotate your log to equalize. Made a LOT off of the directed spalting on this log. http://i35.photobucket.com/albums/d160/GoodOnesGone/Cultivated-Birch.jpg

Didn't make a dime off of this one, but I might have dried and tried if it hadn't ejected the mush you see balled up near its source. http://i35.photobucket.com/albums/d160/GoodOnesGone/You-Know-its-Rotten-When-1.jpg Had a LOT of peck-out.