Restoring an Old Oak Table: How do you get the mold out?

Factual Questions
1

I was fortunate enough to pick-up and old Oak table this weekend whilst out at the Cape. (Brought it back on my boat, Mrs.P wasn’t too amused.

I have finished sanding it, and I have a problem. It has some mold spotage on it. Little flecks I can not sand out totally.

Anyone know how to get them out? I think I remember there is a bleach solution to apply that will get rid of it…Anyone know what it is? I’m not working on it again till tomorrow so I have some time.

Thanks!! Phlosphr

2

Oxalic acid is a good wood bleach. You can use it on oak to get out tannin stains (which is possibly what you are seeing). It’s widely available at hardward stores and is fairly safe, although gloves, mask and safety glasses are not a bad idea.

3

Bleach is used at half strength, but you have to watch it carefully & when it gets where you want you wash it off. Maybe a cup in a gallon of water would be a safer start.

Im not sure thats mold you have, as oak does usually have some grain stains like that.

4

Handy - grain stains? what do you mean? … This table was in a basement for nearly 5 years.

1 part bleach 2 parts water sounds about right…

Anyone else know the true facts???

5

[sup]BOLDING ADDED[/sup]

JFTR

6

So a cup in a gallon of water…then spray it on?

Watch it? And if oak already is prone to staining could I damage the table with bleach? Should I wash it off with a hose? We are rained out today so I have some time.

7

Turn the table upside- down and try it on the bottom side first, if you have concerns about the bleach concentration. Even if there is no mold on the bottom side you can try the bleaching to see if it stains the wood or not. Even if you get a “stain” from the bleach on the entire top side, you should be able to sand and stain it so it the effects of the bleach (if there is any) is minimized.

8

This is one of those times where a photo of it would be nice…
On some woods you want the grain to show up & bleach kinda takes that effect away.

9

Some hardware stores have “wood bleach”. Follow manufacturer’s instructions or dilute even further.

10

I’m wondering what kind of spots these are:
“Little flecks I can not sand out totally”

It is possible that the spots in question were caused by iron reacting to the tannic acid in the oak. If that is so, then oxalic acid is the best bleach. Otherwise, Jasco makes a two part wood bleach.

“How could iron contaminate the table?” you may be asking.
This sort of thing happens all the time. One example would be little bits of steel wool lodging in the pores, later wetted with water (as part of a clean-up perhaps), reacting with the wood’s naturally high tannic acid content.