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After staining a piece of poplar a series of subtle, regularly spaced cross-grain markings appeared on the factory cut faces (I've attempted to make markings more visible with the green indicators):

enter image description here

It was not on every board, only a few. I sanded the wood smooth first (and put down a probably-inappropriate coat of shellac), and the markings were not visible to my eyes prior to staining or when the stain was wet. They appeared as the stain dried. There are 4 markings every 1-1/8".

I tried applying a second coat but it still did not hide them.

My question is: What are these from and how can I either hide them, prep the wood before staining to eliminate them, or determine if a board will have them ahead of time so I can avoid using it?

I am assuming they are artifacts from how the board was cut at the factory. My only thought is perhaps as a rule I could trim all factory edges off all boards on the table saw ahead of time, but this seems cumbersome.

Jason C
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1 Answers1

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What are these from and how can I either hide them, prep the wood before staining to eliminate them, or determine if a board will have them ahead of time so I can avoid using it?

These look to be leftover striations from the planing process. As you probably know, a planer is just a rapidly-rotating knife on a cylinder with a board being fed through it. Minor differences between the different knives in the planer cutting head lead to these striations.

The only truly effective way to get rid of these marks is to remove the wood that carries them. Therefore, you have to plane/sand/scrape to a level of wood that does not have them.

There is no staining or finishing process that will really be effective in removing the marks since they are a defect in the grain of the wood. Removing the "bad" wood is the only way to get rid of them.

I don't know that there's a very fool-proof way to avoid boards that exhibit these markings. Usually, if you buy rough-planed stock, you can clearly see the marks and plane them yourself to remove the marks. If you buy the stock pre-planed, you might try looking down the board using a raking light to see if you see the patterns left by the planer cutting head. Also, as @keshlam pointed out, you can give the board a quick wipedown with a rag soaked in mineral spirits to "preview" what the finished grain will look like (don't worry, the mineral spirits will evaporate away pretty quickly).

and put down a probably-inappropriate coat of shellac

I would not consider a coat of shellac "inappropriate" unless you were planning to stain before finishing and didn't sand it back to bare wood. Shellac is a good sanding sealer and will help make a smooth finish in the end. Also, shellac can help with splotchiness in some woods that exhibit it.

grfrazee
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  • These marks are often called "scalloping", and are basically high spots (or low spots, depending on how you look at it), albeit with a very minimal height. – Eli Iser Oct 26 '15 at 15:37
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    Agreed, motorized planing effect, where each lighter area is where one psss of a cutter came across.. I've actually sought those boards out, on occasion, when I though tthat effect might look nice in a project, as a poor man's version of figured grain. Fastest fix might be to hand-plane. Useful trick: you can often preview what a board would look like under a clear finish by giving it a quick swipe with a rag dampened with mineral spirits. (Dries out again fairly quickly, doesn't raise grain much.) – keshlam Oct 26 '15 at 17:03
  • @keshlam, good point about the mineral spirits. I was thinking about checking at a lumberyard and how one probably wouldn't have mineral spirits to use - didn't even think about once the boards are in the workshop! – grfrazee Oct 26 '15 at 17:05
  • Might affect which board you use where in the project, or help you fecide how much additional work they need...... (I'm still more carpenter than woodworker, but I hope to tackle some serious projects soon.) – keshlam Oct 26 '15 at 17:10
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    Yes these are often referred to as "planer marks". I've found a belt sander or random-orbital disc sander is the best way to get rid of these. Basically you need to remove a reasonable amount of material as these are actually small lumps/scallops in the timber. – WhatEvil Oct 26 '15 at 17:11
  • @JasonC, whoops, thanks for pointing that out. – grfrazee Oct 26 '15 at 22:52