Kiln dried oak - stanless steel screws?

[michael pooley]

i know the tannin in green oak will turn a steel screw black and stain the wood but is this true of kiln dried oak ?

or would a good quality coated screw be ok?

thanks

Mike

[Kyle Kraft]

Welcome, Mike. I use plain old zinc plated screws in my KD oak projects all the time with no ill effects.

[John Keeton]

It is my understanding the staining process requires moisture to oxidize the ferrous material that in turn reacts with the tannins. So long as no moisture comes into play, stains should not appear. This is why the green wood shows stains.

[Ken Fitzgerald]

I sure hope it's not a problem with kiln dried oak. My wife's gonna be awfully disappointed.:(

[Terry Beadle]

Even if you start with a really dry oak, it will absorb moisture over time. Even in an air conditioned house, there is enough moisture fluxuations for the wood to absorb moisture. Therefore any iron exposed to it will stain the wood. Stainless steel will give you quite a bit more time before stain will occur. Predrilled and threaded holes with brass screws ( it's a lot of work ) would be the best.

[Howard Acheson]

As Terry said, there is ALWAYS moisture in wood. Kiln drying just means it was reduced at the time the wood was taken out of the kiln. As soon as the wood is brought into an area with higher humidity, it will absorb moisture from the air and and it's moisture content will rise.

The high tannin content in oaks will always cause staining where it comes into contact with a ferrous metal. Expect it. The best bet is to completely bury steel fasteners or go to stainless or brass if the fasteners have to show.

[M Toupin]

Lots of woods have moderate to high tannin levels besides oak, for example, chestnut, cedar and black walnut.

True enough, high moisture levels can cause problems, but in the average moisture levels in the average home, you will not have problems. Take a look around, there are literally millions of pieces of furniture made out of oak. I'll even go out on a limb and say that oak is one of, if not the most used domestic hard wood in the US. If there was really that big of a problem, then there would be a LOT of screwed up furniture around. Now, if you're talking soaking wet, as in exposed to rain and the elements, then yes, but not in the average home.

On the other hand, maybe it's just that me and a few hundred thousand other furniture builders have been really really lucky over the last few hundred years.

Mike

[John Keeton]

Like Mike, I must be one of the thousands of lucky ones. Most of the pieces I do are in oak, and I have never had a stain problem. I have also acquired, reworked, refinished several victorian oak pieces, and they are all assembled with iron/steel screws. Some of the pieces that have been exposed to moisture, perhaps in refinishing, will show some stain. Most of the others shown none. It's been awhile since they were constructed so, Ken, I think you are safe with your wife.

[michael pooley]

Thanks to you all for your help :)

i think i will chance it as i will be using very good quality coated screws.

thanks again

Mike