Yellow Chalk in my wood grains

[andrew whicker]

Sigh.

It''s hard to see in this photo, but I have yellow chalk stuck in the grains of my walnut and I can't seem to get them out with acetone.

Is there something else you would recommend besides sanding?

Thanks and cheers,

Yellow Chalk.jpg

[Doug Hepler]

Andrew,

Try to reproduce the problem on scrap.

I would try a stiff bristle brush or very gentle wire brushing. Often chalk residue becomes invisible when you apply finish. Chalk is calcium carbonate. It is not soluble in acetone, as you have learned, or in water. It is soluble in acids, possibly even soda water, surely dilute vinegar, etc. However, I do not know what the yellow pigment would be, or whether it would dissolve. It might actually penetrate deeper. If you can reproduce the problem on scrap you can figure out what works without endangering your piece.

Doug

[andrew whicker]

Thanks for your reply. All good ideas.

[Andrew Hughes]

How did you get chalk stuck in the walnut grain? Where you marking out parts?
I ask because I stopped using chalk on walnut for this reason
Good Luck

[andrew whicker]

That's exactly what I did. Lesson learned

[Paul Girouard]

Blow it out with compressed air. To simple?

[glenn bradley]

I still use chalk on walnut to mark parts on rough stock. I keep a spray bottle of mineral spirits by the sink. A spray of this and a wipe with a rag does the trick if I get it somewhere that won't be removed in the following milling steps. For parts that are closer to size I use white pencil.

[Rich Engelhardt]

Mix up a very stiff paste of vinegar & corn starch.
Put it over the chalk.
The vinegar will dissolve the chalk & the corn starch paste will allow the vinegar to evaporate & draw out the chalk/vinegar mix as it evaporates.

[Yonak Hawkins]

Mix up a very stiff paste of vinegar & corn starch....

Is this tried and true, Rich ? It seems like this is a recipe to add corn starch to the chalk.

I tend to agree with Paul .. taking it to a tank of compressed air to blow it out.

[andrew whicker]

compressed air isn't an option. I'll try the acid trick.

[Rich Engelhardt]

Is this tried and true, Rich ?

Works on concrete, no reason I know of for it not to work on wood.

As always though - - any and everything should be tried on scrap first.

[Jon McElwain]

If you don't have access to an air compressor, I'd go to an office supply store and get a can of compressed air for blowing out keyboards and such. I've had dust and such stuck in grain quite often and it comes out easily with air.

[Andrew Hughes]

Compressed air didn’t work for me. It blew the chalk in further from what I remember the solution is not to use it.

[Roger Feeley]

It seems to me that you can't sand your way out of this because some of the chalk will just dig in deeper. What if you blow/vacuum what you can and then shellac the wood to stabilize the chalk and then plane it away?

[Bill Dufour]

Speaking as a teacher wipe it with a damp rag. if it still shows when dry use damp fine bristle brush?