finishing cherry with soft spot/tearout

[Jake Helmboldt]

I'm turining a cherrry bowl that has a small area of old, somewhat soft "punky" heartwood that is giving me fits in getting a smooth surface. There is some cracking that I stabilized with Minwax wood hardener, but I can't go any further (turning) to try to eliminate some of the small cracks or tearout (without changing the shape and thickness of the wall). Should I just live with it as "character" of the piece or can I use something to fill some of these small voids?

I've seen the reference to coffee grounds and this heartwood is dark enough that it wouldn't look bad but I have no idea how best to go about any of this? What about a slurry from sanding? Thoughts? I'm in unfamilar waters here.

thanks

[Chris Padilla]

Do you have any pictures, Jake? In general, one should always try to repair wood using the same wood. This ensures "eveness" in finishing and in aging.

However, this sounds like it will add character to the piece. :)

[David Walser]

Jake,

Without a picture or two or a more detailed description it'll be difficult for us to give you specific advice. So, the following is a general description of some of the methods that can be used to fill cracks. Which method might be best for your situation, will be up to you.


CA glue. CA glue is nice to work with because it's fast, strong, and dries clear (assuming you didn't use accelerator). For thin cracks, you can simply pack some sanding dust into the crack and then apply some thin CA glue. The thin CA glue will wick down into the crack and between all the particles of sanding dust, gluing everything into a solid mass. With luck, the crack will all but disappear. For wider cracks, you might want to follow the application of thin glue with thick or medium CA glue. (The thin glue will help the thicker CA glues wick down into the crack.) However, a wide crack filled with sanding dust does not disapear. It just looks like a crack filled with dust or putty. Rather than hiding the crack, it may make sense to replace the dust with coffee grounds or some other decorative material -- such as brass filings or turquoise. Note: CA glue can sometimes stain or darken the wood surrounding the crack. It may also seal the wood, preventing the wood from taking a stain. This is usually not a problem if you still have some turning to do. Otherwise, you might want to carefully mask around the crack with painters tape.
Epoxy. Epoxy is nice to work with because it is strong and can fill reasonable sized gaps. You can mix a dye with the resin (before adding the hardener) and/or you can incorporate coffee grounds or some other filler into the epoxy. Unless the repair area is small, it may be best to use 60 minute epoxy rather than the 5 minute variety. Because your first application is seldom your last (as you sand/turn away the epoxy patch, you'll almost always discover a void or two that you'll want to fill) epoxy can take a lot longer than CA glue. Also, you'll need to thin the epoxy down with acetone to repair small cracks.
Sanding sealer. If you are dealing with hairline cracks, you can use sanding sealer to fill the cracks. Simply apply the sanding sealer (or lacquer) and start sanding before the sanding sealer has set. The slury of sanding sealer and sanding dust should fill the cracks and make them all but disappear.

Hope this helps.

[Jake Helmboldt]

Here is a picture of the spot in question. It really isn't that bad, but enough so to be annoying. The crack has been stabilized with the hardener so I'm not concerned with that so much as just getting a smooth, even surface.

The gap at the edge (left of picture) I'm not worried about either; that was an odd little inclusion from an old twig that never developed into a branch. I'll leave that alone. But you can see the main crack running the length of the heartwood along with a small section of tearout in the middle top of the pic. There are some much smaller areas of tearout resulting from the heartwood being somewhat dry and crumbly in spots. Those I'd like to be able to smooth over a bit, but perhaps not fill, other than with some wet sanding slurry.

Has anyone tried Ernie Conover's approach of using a nut oil or similar with sanding to fix minor tearout? I think I also saw where Bill Grumbine does this. What kind of oil is good to use? Will BLO work?

Thanks for the help so far; all good for the learning curve.

[Jeff Nicol]

Soak it with some thin CA and rub some fine dust into it, or rub the dust in and put the CA over the dust. It will work either way. Since the cracks are pretty tight, that should do it. Epoxy will work but not as fast.

Jeff

[Steve Schlumpf]

Jake - I have had good luck with a slurry mix using the final finish (Watco, Minwax, Poly, etc) and a 320 grit sanding disk. Sand the area to create a slurry and force it into the cracks. You may have to do this a couple of times to get everything filled correctly. The advantage of using the finish to create the slurry is that it will not stain the wood.

[scott schmidt grasshopper]

I have had a try at filling cracks with sawdust from the piece I am working on ( ie;walnut to walnut ) and find sometimes ca glue will darken or lighten the wood. now i keep three or 4 bags of differant wood sawdust and a sample of what they look like in a cured CA glue-up. this helps me match the finished bowl color with the ca fill, right now I have maple,walnut hazelnut, madrone which gives me med brown,dark brown,light brown and reddish. good luck

[Steve Mawson]

If you put some Watco or finish before the CA the CA will not discolor the piece.