A novice asking about knotty oak

[Pete Kurki]

I have an access to a fairly large amount of very inexpensive rough cut knotty northern red oak. I was just wondering is it possible or perhaps otherwise unwise to use knotty oak for building furniture. I don't have recollection of ever seeing knotty oak used in anything else but as hardwood floor. Is there a reason for that or am I just dreaming? Is there something different about oak knots vs pine knots for example? Do they fall off easily or perhaps make oak lumber fragile? What is the best use for knotty oak if it is not good lumber for furniture? :confused:

Pete

[John Keeton]

When I get knotty oak, I cut out the usable wood, and the knots make excellent firewood!

My limited experience would suggest that (1) the knots are very hard on blades, and (2) the area around a knot seems to be very stressed in red oak and tends to not stay flat and straight. Knots are evidence of branches, and if the oak has a lot of knots, I would guess that it was from branch wood or a smaller tree log. As such, the grain would be far from quarter or rift sawn, and would not be as stable.

Knotty oak has good "character" and burns well. Just my thoughts which are worth what you have paid for them.

[David Freed]

I agree with John about the problems that knots can cause. Even so, many people are after the "rustic" look these days. Several of the cabinet shops near me use different species of lumber, including red oak, with as many knots as they can get to make doors and faceframes. They simply remove any loose pieces from the knots and then fill the area with clear epoxy. It leaves a very smooth surface and you have to look very close to see the epoxy in the holes. I don't see why this process wouldn't work for any project you have in mind.

[Richard M. Wolfe]

It depends on the look you're after, but there are knots and then there are knots. :) Most well known for having desireable knots are pine and of course aromatic cedar.

Knots in oak, at least the red oak I've used, are of the ugly variety. The knots don't blend in well. When oak lumber is graded the number of knots reflects on the quality of the wood....the more knots the lesser the quality.

[Peter Quinn]

I'm seeing some kitchens here done in knotty alder that look nice, but I've never seen knotty red oak used for other than fire wood or character grade flooring. If your talking about #2 common (industry term) then the knots should be some what stable and may not fall out during milling, a little epoxy can help insure this. Knots are hard on tools. I've had them come out in the planer, some bang around and go into the chip hood, some come flying out like angry little cannon balls. Some contain bits of stone or grit that kills knives quick. Start with sharp knives, use light passes, and make extra pieces! You will likely lose some.

The most likely reason not to use common red oak is aesthetics. If you like that Little house on the prairie 1970's log cabin fever look with a pallid pink under tone that wont go away, then go for it. If it were common white oak going in the right decor I'd say great, but I've never found a way short of milk paint and glaze (ie totally obscure its color) to make any red oak appeal to me, and I've yet to see others do so either. It doesn't smell so good either, thus the nick name "piss oak".

That said it might be a great inexpensive project wood to work out your designs and practice with. Or, you may happen to like the look of red oak.

[Pete Kurki]

Thanks all for great input. At this point I am not worried about the looks or smell of the lumber, after all I can always use dark finishes so that the knots are less obvious. I am not going to be using it for heirloom pieces, but I figure there will be plenty of need to build more utilitarian pieces where I still want to use hardwood rather than plywood or MDF. So, my question was really primarily about the structural issues I may get from knots.

A couple of responses mention using epoxy to prevent losing the knots in milling. How is that done? A layer on all knots in the rough lumber?

Pete

[Peter Quinn]

So, my question was really primarily about the structural issues I may get from knots.

A couple of responses mention using epoxy to prevent losing the knots in milling. How is that done? A layer on all knots in the rough lumber?

Pete

Yeah, its not going to be as stable as say, pattern grade mahogany, but for simple pieces you should be fine. When laying out your stock, try to avoid cuts that place unstable knots on the edge of narrow pieces. This may compromise strength. Common lumber takes a bit more thought in the layout stage. I have purchased 14' X 14" X 2.25" common white pine for making windows as I am able to skim plane it, then cut clear grade pieces usable for rails and styles from around the knots. Saves me a fortune vrs buying clear grade in that thickness.

As for the epoxy, I'd closely inspect the knots before milling, give them a good poke to see if any are loose. You can tape one side of a questionable knot and pour a thin epoxy around the knot from the other side, let it set up over night, then mill as normal. For knots with voids I usually mix a bit of very fine saw dust into a thicker epoxy with a quicker set up time and spread it on with putty knife (which I make from scraps with a belt sander as epoxy is very difficult to clean from tools). Just experiment a bit, and don't sniff it too much!

Good luck and have fun. MPQ

[David Freed]

The cabinet shops I spoke of that use epoxy apply it after everything is assembled, and then run it through a wide belt sander before staining.

[John Keeton]

Pete, here is a thought. It is amazing how many things become heirlooms when you get "long in the tooth." The grandkids look at them and say PawPaw made that. I recall some of the crude items that my grandfather had laying around and how they were revered after he died.

And, the labor put into a piece is the far greater "equity" in a finished project, so I try to at least make my projects from presentable wood, even when they are utilitarian.

[Jacob Reverb]

FWIW, most unhardened epoxies can be removed with vinegar. It reacts with the amines in the epoxy and makes the whole mess somewhat water soluble, just be sure to wash it off your skin very well, because it also "liberates" the amines which can cause bad skin irritation and even allergic reactions. Gojo orange hand cleaner also works well.