Super-spalted maple

[Robert Marshall]

The two bowls pictured here are from a batch of maple half-rounds that I left too long in a plastic bag, resulting in extreme spalting. That created very interesting figuring, but also made the wood very "punky," very hard to cut cleanly on the lathe.

I treated both bowls with wood hardener after rough-shaping them, which helped, but there is still a lot of tear-out, despite frequent sharpening, high lathe speed, and very light cuts. The long-grain portions of the bowls are mostly smooth, nice to the touch, but the end grain is rough.

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My thinking at this point is that I will finish them with WOP, multiple coats, and just live with the tear-outs. I thought about epoxy-filling them, but I'm afraid that would look weird, because of the color variation, and the large number. I think they are destined to be "shelf-bowls", something to look at but maybe not too closely!

I welcome your comments or suggestions.

Robert

[Bruce Page]

Wow! That is some beautiful wood.

[Fred Belknap]

About how long did you leave them in plastic bags? I have some blanks that I am trying to spalt and don't know how long to let it cook.

[Barry Richardson]

I have had good luck soaking the punky spots with poly, giving it a couple days to cure, re chuck it, then carefully use a negative rake scraper for a smooth finish. Also, I use epoxy all the time for repairs and it disappears and is unnoticeable once the finish is applied IMO, either poly or lacquer is what I usually use for finish. If you use something like danish oil, the epoxy will show as a shiny spot....... fantastic looking wood BTW

[Damon McLaughlin]

Beautiful wood!

[Robert Marshall]

Fred Belknap asked about how long I "cooked" the maple half-rounds that spalted so spectacularly.

Honest answer is, I don't know. Wasn't deliberate, more a matter of forgetting about them for a while. Probably six months or more in the plastic bag.

[Richard Dooling]

Fred, you might find this FWW article helpful.
http://www.finewoodworking.com/2009/04/14/spalt-your-own-lumbe (http://www.finewoodworking.com/2009/04/14/spalt-your-own-lumber)r

[Fred Belknap]

Thanks for the link and information.

[Olaf Vogel]

Lovely patterns. Its exactly the type I prefer to work on, but can rarely achieve - deliberately.
For tearout, wood hardener helps.

Or,

Get epoxy resin, thin it with alcohol and soak it. Surprisingly, the epoxy soaks in pretty well.
Let it harden for a week or so, then finish cut it. There should be zero tear out and hard as a rock.

Or,

Power sand aggressively while the lathe is running at a decent speed. Which I did here. Messy and stinky though.

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Lovely piece BTW.

[Robert Marshall]

Olaf,

Regarding epoxy resin technique, a couple of questions:

1) You mention epoxy resin; would this also include the activator (the usual two-part mix)?

2) "Thin" with alcohol -- about how much? Equal parts epoxy and alcohol? Or what?

Thanks!

[Olaf Vogel]

Olaf,

Regarding epoxy resin technique, a couple of questions:

1) You mention epoxy resin; would this also include the activator (the usual two-part mix)?

2) "Thin" with alcohol -- about how much? Equal parts epoxy and alcohol? Or what?

Thanks!


1 - yes, mix them together as per instructions. I use Art Resin, because my wife bought a ton for her paintings.
2 - add about 10% alcohol, that thins it a lot. You loose some strength supposedly, but I can't quantify how much, and for punky wood, it can only add strength.

Then paint it on with a brush - use a cheap one cuz its going in the garbage.

[Robert Marshall]

Thanks, Olaf!
Robert

[Dave Fritz]

Olaf, do you use denatured alcohol? Have you ever tried other types of two part epoxy? I wonder if other brands might work too.

[Olaf Vogel]

Olaf, do you use denatured alcohol? Have you ever tried other types of two part epoxy? I wonder if other brands might work too.

From my research it seemed to be fine with any type of epoxy resin.

(sorry forgot the various sites I cruised - I was looking a "wood stabilizing" without requiring the Minwax "wood hardener" which is no longer available here. There are other options, such as cactus juice etc. It seems that many are really thinned down epoxy. So why not mix your own? Lots of material, easy to get)

All types I've played with are 2 part, mostly 50/50 mix.

The cheap stuff for car repair is 95% resin, with a small tube of hardener. Haven't tried it, since I've invested enough effort to justify slightly better stuff. But it might work. The issue there is the super fast hardening time might prevent soaking.

The Art Resin has UV filtering to prevent yellowing. Might be good for really light woods. Most of mine are darker, so it doesn't really matter. It was cheap and my wife had a few gallons extra.

All my attempts had a drying time of ~8 hrs and a few days til fully cured and turnable.

There are many possible thinners, but I wanted the least toxic, which in my case is normal rubbing alcohol.
Due to the 8 hr drying time and the possibility of picking up dust, flies etc, I do this in a spare bedroom.
We don't want this stinking up the house. Since my wife is epoxying paintings in the next room, she can't complain. :)


My next attempt is to build a vacuum chamber. I picked up a couple of 10G chambers last weekend for $50 used. Will use the pump from my vacuum chuck.

Drop the epoxied piece in there, wet, suck out the air to draw the epoxy deep into the wood grain. Its supposed to force out the air and possibly water: https://www.youtube.com/watch?v=kIH5lpwOBdM

Haven't tried it yet, we'll see...

[Dave Fritz]

Thank you for the reply. Will you use Art Resin with the vacuum or something else. Some years ago I stabilized corn cobs in a pickle jar using old polyurethane. It seems to work pretty well.

[robert baccus]

As Olaf replied epoxy resin works well. Also fiberglass resin (polyester) works as well and is cheaper. Mix with the hardener as instructed & Thin with acetone until it drips off of a stirring stick. Add your roughed out piece and a quanity?? of the resin mix together into a VINYL bag. Play shake and bake every time you walk by and leave overnite. In the AM it will be hard and the fibers hard and the pores will be open like new wood. There is no discoloration of the wood and it cuts and finishes like new wood. Works every time.

[Robert Marshall]

Robert Baccus,

Can you provide a link or a product name for the vinyl bags you use for 'shake and bake'? I haven't been able to locate something via Google, described as a vinyl bag.

Is this a one-time use for the bag? Seems it would be.

[robert baccus]

I use yard trash bags--look for vinyl--acetone dissolves many plastics but not vinyl.

[Olaf Vogel]

I use yard trash bags--look for vinyl--acetone dissolves many plastics but not vinyl.

From my reading, I couldn't find a functional difference between using alcohol and acetone.
However, acetone is much more volatile, stinky and aggressive. I was also a bit concerned that it might dry/harden too fast.

Which is why I went with rubbing alcohol.
OK, i've been told many times, by a chemist, that acetone won't harm you.....but it gives me a hell of a headache.

(and gets me kicked out of the house)

[robert baccus]

I haven't tried everything but acetone is the standard thinner in fiberglass work--boats ect. and I know it works well.