Fizzy walnut? To the mystery machine!

[Elvee61]

Never seen this happen before. I'm hoping somebody can give me some insight into this mystery...

I was turning bottle toppers last night, and grabbed some walnut out of the big box o' blanks. Everything seemed fine until I started putting on the CA finish.

There were some small dark holes in the Walnut where the CA would bubble, making nice craters in the CA. I thought I had overheated the piece with dull chisels, so I scraped the finish off and re-sanded and let the piece sit and cool while I re-sharpened.

Refinished with CA, but those same craters formed over the black holes. CA refused to stick to those spots. The CA that did manage to dry over the spots had bubbles under it.

Scraped it all off again, finished with BLO, EEE and shellawax. Looks terrible, but no craters.

What the heck?

 

[leehljp]

There will be some other good responses I am sure but I will give you my opinions.

First my experiences. In the MS delta area, we had one walnut tree that we harvested from our farm and I have some of the wood from that tree just waiting for me to make something. This walnut is dense, somewhat heavy and very small capillary tubes. Mine finishes fine and does not soak up lots of finish.

A few years ago, I got some walnut from dryer climates and found that it sucked up finish. This is probably what you have. As a second note on my walnut tree, it was located just beside a small stream (bayou) that never dried up. Not far from it was a natural spring. The water table was close to the level of the ground at that point. The reason I say this, is that I have found other walnut lumber in the general area to be much lighter in weight than from this tree that we harvested 50 years ago. From the walnut that I purchased from a dryer climate, it had noticeably larger capillary holes.

There are two ways that I know about to go about fixing your problem.
1. Use thick CA as a first coat to seal.
2. DeWaxed Shellac is often used as a first coat to seal wood, even on pens and stoppers. But recently I tried de-waxed shellac on my first ukelele kit (two coats and lots of sanding) and it did not do as well as I was expecting. Subsequent lacquer layer finishes (6) still left dimples.
3. Sanding sealer. This also does OK in some cases. Not sure how well it works on bottle toppers though.


I would go with thick CA. Let it set for an hour or two to cure.

 

[Elvee61]

Thanks. I'm going to try both the sanding sealer and thick CA and see which keeps the bubbling under control.

I was going to run down to the basement to try it out on several different pieces tonight, but apparently the girlfriend has some crazy ideas about going out somewhere tonight. Her priorities are all out of order. :biggrin: