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checks and flakes in white oak causing problems9/6
We are a high-end furniture company and we use white oak solids and veneers in our furniture. We consistently have the problem of surface checking as well as ray flecks in the wood - both solid and veneer believe it or not. We keep chalking it up to the wood, but i'm starting to think that i am missing something. Is my lumberyard not drying the wood properly? Am i not storing the lumber properly? Regardless of the cause, any suggestions on how to fix the checks/flakes when they do present themselves? Right now we fill with either epoxy or CA glue, then re-sand - very wasteful and time-consuming!!! Please help.
Sorry Dan, that's a big, "who knows?" The only advise that I can give, is to become familiar with the moisture content of your materials at various stages. Buy a moisture meter, and use it. If you find that you are laying up veneers at 10% MC onto cores at 5% MC, and they check in a couple of days, then you have an answer. Everything else is just conjecture.
Ray flecks are normal in white oak and your not going to easily get around them if your buying in large quantities of random boards. It has to do with the angle of the wood grain, i.e.. quarter sawn has a lot of rays, rift a bit less, and plain sawn is usually pretty clean.
Surface checks do have to do with the lumber and how it's dried. White oak seems to be more prone to surface checks than other lumber I've worked with. Hopefully Gene Wengert will chime in as he us very knowledgable in this area!
As far as a solution I would think trying to cut around the defects at the beginning instead of fixing them down the line would be the best bet. White oak is relatively cheap so you may be better off tossing the defects when you compare the material costs to the labor cost to repair?
Ray fleck is normal, and it is often considered to be desirable, as it is a type of figure. This is one of the key attributes of quarter sawn oak. Medullary rays in oak generally appear in quarter sawn oak. However you may see them on edges of plain sawn oak. A pile of of plain sawn oak, will also usually have a quarter sawn board, or two mixed in as well.
I am not sure what you mean by flaking, as I have never encountered anything like that. A little tear out at times is unavoidable, and that is easily fixed with filler.
Also. White oak tends to have a coarse open grain, compared to most woods. I am wondering if you may be confusing this with checking, as the pores can be quite elongated, and large compared to other hardwoods. Standard practice is to apply a grain filler to achieve a flat surface prior to applying a film finish. Or you can leave it as is, especially when applying a finish with little to no build, such as "danish oil"
Actual surface checking (obvious cracks) is a major red flag, and it generally indicates poor drying. I have encountered this in maybe 1 or 2 pieces of white oak. I reject material with obvious cracks, and other indicators of serious drying stress.
You need a new lumber supplier. This is definitely a sawmill/drying issue. In years past, not a single piece of white oak furniture would leave the shop without a grain filler being used. Some shops would use this to also color the wood, others used natural colored filler to just make it glass smooth for the finish. This method has fallen out of favor in relation to speed to get the piece out of the shop. You may want to implement that into your work, AFTER you get a new wood supplier.
rich is right.
White Oak is hard ($$) to dry correctly, especially the thicker sections. The most prominent drying defect is checking which is separation along the medulary rays - the same rays that are desired/exposed in Quartersawn material. When they are loose, they are hard to repair.
I have a Qrtrd and Rift W Oak supplier that also supplies Stickley Furniture - and their competitors - with QS W Oak. The largest QS supplier in the US. They don't advertise here, so write me privately, and I'll tell you who to contact.
They know how to dry the material to minimize the defects you see.
Much of what you are describing is inherent of White Oak , especially QSWO . Since the WO log is so much harder and denser it will season for more years than say Red Oak before it may be milled in some cases .The wood looks shiny when cut on the chop saw closed grain so the moisture can't escape through the end of the logs well so it sneaks through the length where it may .
I think this may cause the checks , I see them in the white colored wood so closest to the edge of the log maybe .
Another issue that can cause extensive surface checking is circle mills pushing their blades when they are very dull. Not sure if your material is circle sawn or band sawn but when a band dulls it simply stops cutting but when a circle mill dulls it will still cut for some time. At that point, rather than cutting the wood fibers it actually tears them. The fibers wrap slightly around the tooth and tear back away from the cut similar to pulling a weed. A bit of this would be dealt with in surfacing but if the checking is substantial it may not be completely removed in average/normal surfacing.
If this is the case (can be tough to know unless your supplier is having a lot of complaints) there isnt much remedy for you. As I recall the only remedy is to pre-surface the green material before it goes into the kiln.
As far as the "flaking", Im wondering if your seeing a shaggy surface or if your actually having flaking like the trees suffer from shake? Hard to say. If the surface is shaggy it would be interesting to know the humidity of your shop. If your shop is damp it can really make oak shaggy in my experience.
I am agree with david r sochar message, above.
I am not going to repeat the correct and valid comments made by David and others. I would strongly support that you need a different supplier. Indeed WO, especially q-sawn, is hard to dry, but a good yard will dry it without much defect at all.
I do believe that what you are calling flaking is actually the end result of honeycomb (deep surface checking) on q-sawn oak. It can be controlled by proper drying.
Thanks everyone for all of your responses. As it turns out, i have switched my vendor and have not seen the issues arrise. I had extensive conversations about their process for drying the lumber and they assured me of their sound practices. Now i just have to wait and see that they stick to it!