"Bruising" on Wood

[sanelko]

Hello,

So I took a large branch (about 3 inches in diameter) off the walnut tree in the backyard for a little cat tree project. Ended up cutting it into 3 pieces and debarked it by hammering on them quite hard with the back of the head of my hatchet. It made the removal fairly easy and it didn't seem like it was harming the actual wood underneath. However, it wasn't until after that I noticed all these marks that look like bruises show up on the wood itself (links to pictures below). It started off as green and then the next day have started to become more dark brownish. Anyone know if they won't be apparent once the wood has been dried out or will I have to sand them out? I'd prefer not to have to sand them out as they're about a mm deep so it would be a lot of sanding all around. Thanks in advance for your input.

 

https://ibb.co/y8t4j25
https://ibb.co/gvxqN83

[curlyoak]

The white  color of the wood is called the sap wood. Just below that surface is the brown beautiful walnut wood. I would remove most of the sap wood with a draw knife. Then finish it with mineral oil which is not toxic. The heart has so much more to look at...

[RichardA]

I'm not entirely sure that the cats would notice, or complain.  But by looking at what I can see of the ends, there doesn't seem to be much heartwood available for show. I'd let the wood dry for a couple of weeks, then pick a stain color you like, stain and finish it.   Who knows, the cats might salute your effort.

[sanelko]

10 minutes ago, RichardA said:

I'm not entirely sure that the cats would notice, or complain.  But by looking at what I can see of the ends, there doesn't seem to be much heartwood available for show. I'd let the wood dry for a couple of weeks, then pick a stain color you like, stain and finish it.   Who knows, the cats might salute your effort.

I agree, I wouldn't really want to remove any more wood than I need to at this point because I'm happy with the thickness. Also, I actually prefer the wood to be lighter on this project. Just two weeks? So the rule of thumb of 1 year per inch of air-drying doesn't apply here? Also, any opinion on the marks -- should I deal with them somehow or will they go away as it dries? My theory is that I may have forced some "juices" into the wood from the bark from the hammering. I'm new to woodworking so sorry for all the questions but I highly appreciate all the insight.

[RichardA]

If you are after perfectly "dry" wood, you'd best prepare for at least a year of drying. Depending on the thickness it could take longer for perfectly dry wood. Then, it's for cats, who won't have a clue if it's dry or not. If you are concerned about shrinkage after you build your cat tree, cut a few more branches, set them up to dry until the shrinkage does its damage, then replace the branches with the ones that have been drying. You can even set extra aside, so when the second set reacts like the first set. you should have "perfectly" dry wood by the for a second replacement.

The marks will likely dry darker than the surrounding wood. That's somewhat controible with a stain. Not completely, but somewhat. And why is that important? It's not as if you or anyone is going to critique the wood, the interest will be in the cats. The wood will not be a focus, the design will.

[sanelko]

1 hour ago, RichardA said:

If you are after perfectly "dry" wood, you'd best prepare for at least a year of drying. Depending on the thickness it could take longer for perfectly dry wood. Then, it's for cats, who won't have a clue if it's dry or not. If you are concerned about shrinkage after you build your cat tree, cut a few more branches, set them up to dry until the shrinkage does its damage, then replace the branches with the ones that have been drying. You can even set extra aside, so when the second set reacts like the first set. you should have "perfectly" dry wood by the for a second replacement.

The marks will likely dry darker than the surrounding wood. That's somewhat controible with a stain. Not completely, but somewhat. And why is that important? It's not as if you or anyone is going to critique the wood, the interest will be in the cats. The wood will not be a focus, the design will.

I see. Disregarding the fact that it won't stain as well, is there any harm if in staining and finishing the wood after just a week or two? Will the internal moisture content be an issue? Great idea with doing another set of branches. Another thing I'm thinking of doing is just building the tree as is and letting the branches dry out on their own indoors, then I can decide if I want to finish it at that point.

In terms of the marks, it's definitely for me not the cats . I consider the piece I plan to build to be a decoration as well and feel like all the marks give it a bit of an unnatural look.

[Chestnut]

If you can finish the branches with an oil, like tung oil or linseed oil, something that doesn't cure and form a film finish, a week or 2 should be fine. If you want a film finish to stay on then a longer drying period may be necessary as the internal moisture may impact finish adherence.

I'd suggest against a film forming finish regardless as cats will destroy it. A penetrating oil finish will be easy to repair. 100% pure tung oil is my recommendation as it's somewhat easy to find and the price isn't bad.

There are a lot of "oil" products that are not at all oil products, eg Teak oil as well as danish oil. They are called oil but are more often than not film forming finishes. It's confusing and dumb but marketing departments ran amock with buzz words and this is where we are.