stupid ; Lumber question

[Zach England]

Sometimes I get lumber that has color on the ends of the boards. It is usually blue or green, but sometimes red. What is this? Is it from the sealer used in the drying process or is it just marking done by the mill or lumber yard for some other purpose?

Sorry for asking something that I am sure is common knowledge.

[Matt Ranum]

Most likely a sealer applied before its milled into boards to help prevent checking and cracks.

[Matt Evans]

Should be an identification paint. I can tell you right now that marking the ends of wood different colors is a great help in sorting and finding the lumber you need when you work in a commercial environment.

I don't know if the paint has a sealer property to it or not. I would guess that it does, even if it is regular paint it should help a little in preventing checks, but I don't know if they add anything else to the paint to help.

The one thing that makes me think that it isn't a dyed Anchor Seal product or something similar is that I still have checks in almost all the boards I use, even with the painted ends. I buy rough stock normally, and I generally waste 8" or more off each end just to deal with the checking. After planing of course. Why let good wood take the snipe?

[Gene Howe]

Is it anything like the white paint on the tops of steel fence posts? Always thought that was to tell which end goes up.

[Matt Evans]

Dunno. I can say that Inventorying a steel fabrication plant and a cnc milling plant we used different colored paint pens to count and identify different materials. The only end marked was the end that was visible in the rack, so it wasn't a directional issue.

Also, whenever getting a wood shipment in at the cabinet shop, pine was marked one color, poplar another, walnut yet another, etc. Depending on the company we ordered from, the colors might vary species to species.

[Scott T Smith]

Sometimes I get lumber that has color on the ends of the boards. It is usually blue or green, but sometimes red. What is this? Is it from the sealer used in the drying process or is it just marking done by the mill or lumber yard for some other purpose?

Sorry for asking something that I am sure is common knowledge.


Typically, end sealer - such as Anchor Seal - evaporates during the sterilization portion of kiln drying. If any part of it is visible post-kiln, it would be extremely faded.

Most likely you are seeing some type of identification paint used by the sawmill.

[David Freed]

I agree with Matt. It is for identification. Although many people say you should use endcoating, most large drying operations don't. It is cheaper to just trim any bad ends after drying. There actually is very little loss from endchecking. It was the same for me when I was running my kiln. Buying and using the endcoating cost more than I would lose if I didn't use it.

[Russ Kay]

I found these in my old photo collection:

[Matt Evans]

Russ,

I like the method you are using. If more people did that, or something similar, they would spend a LOT less time trying to locate the lumber they need for their projects. It looks similar to what the commercial places use, but more detailed.

Now, if only there were a national color standard for marking. . .

[Brian Kincaid]

I paint the ends of the lumber I buy from the sawmill with white latex. I do this as quickly as I can to help prevent checking (within hours off the saw).

End checking happens during drying because the endgrain moves moisture out more quickly and thus shrinks more rapidly than the rest of the board. The size difference will cause tension and the board will crack (check).

The paint, anchorseal, etc is to prevent moisture from releasing through the endgrain. The board dries more evenly through the long-grain.

-Brian