Black spots on old desk

Snowshoe Sam

I have an old desk which I was going to refinish, as the top is quite scratched and also has some white drink rings on it.

I have noticed that the wood is covered with little black dots of varying sizes but no bigger than a felt tip pen mark.

It looks as if someone took a fountain pen and shook it, leaving drops of black ink everywhere. There are also a few marks which almost look like they were drawn with a pen - a cm or so long.

Afraid I have no idea what sort of wood this is - possibly mahogany?

Anyone any idea what this could be?

kadman

I,d say you have answered your own question.......ink. Any pictures.

kadman

tabby aspreme

what kind of finish is on the desk now, and what are you going to refinish with

Snowshoe Sam

I,d say you have answered your own question.......ink. Any pictures.

No, definitely don't think this is ink. All sides and surfaces of the desk are covered and there's hundreds of marks, not just a few accidental ones.

I think you can make out the dots in the pic below:

what kind of finish is on the desk now, and what are you going to refinish with

That was going to be my next question!

Am a complete newbie to all this -- looks like maybe a laquered finish but is badly scratched and damaged. This is a pic of some of the marks left by mugs etc, I think:




Any suggestions on the best way to proceed with this?
Thanks,
Sam

S.L.F

The wood is definitely red oak.

I have the same problem with a table I own, I believe the marks are a fungal growth from not being finished correctly (although I'm open to correction on that).

As soon as I have a few spare hours I'm going to strip the table top of finish and the sand the top lightly then clean it with bleach, let it dry for a few hours then coat it with danish oil, again then buff with fine sand paper the use a satin heat resistant varnish.

***Edit*** or you could take a belt sander to it but you'll lose the lovely colour

kadman

Snowshoe Sam wrote: »

No, definitely don't think this is ink. All sides and surfaces of the desk are covered and there's hundreds of marks, not just a few accidental ones.

I think you can make out the dots in the pic below:






That was going to be my next question!

Am a complete newbie to all this -- looks like maybe a laquered finish but is badly scratched and damaged. This is a pic of some of the marks left by mugs etc, I think:




Any suggestions on the best way to proceed with this?
Thanks,
Sam

I,ve just seen the pictures, and I,d say S.L.F. is on the button, with the fungal growth. Looks like blue sap stain, fungal staining that occurs when the surface of the wood is exposed to moisture. Normally seen in fresh sawn wood like beech, where the timber is allowed to have a higher moisture content than 22%.

Similar type of staining is also seen on oak windows and doors ect, that have metal parts in contact with them, pins , nails ect, that are exposed to water. Chemical reaction causes staining.
Blue sap stain removal is virtually impossible, without sanding. Metal oxide staining would require an application of an oxalic acid solution , WHICH IS A DEADLY POISON< AND SHOULD NOT BE USED BY AN AMATEUR< AND I WOULD STRONGLY ADVIZE AGAINST ITS USE HERE.

I would go with S.L.F. on this one.Its more like fungal staining.

kadman

S.L.F

Also oak is an acidic wood so it rusts nails and screws that are in them.

Which is why you should use brass screws in oak.

Snowshoe Sam

Oh well, looks like sanding is the way to go then....

Thanks for the help guys, much appreciated!

Sam

S.L.F

Snowshoe Sam wrote: »

Oh well, looks like sanding is the way to go then....

Thanks for the help guys, much appreciated!

Sam

I'd have big reservations about sanding an old desk or table top because you lose the wonderful colour which makes it what it is.

In order for you to get the fungal marks out you will have to sand in quite deeply as oak has an open grain.

I'm not sure when you plan to do this but I plan to do my own table top in the next couple of weeks and am determined to remove the fungal marks either by using bleach or maybe one of those restorer solutions (get in a boating shop like Viking Marine).

The very last resort for me is to sand the good colour out of the top and staining never looks right.

I'd rather leave it, just remove the finish and re-varnish.

Of course I also just hate sanding

Snowshoe Sam

I'm not sure when you plan to do this but I plan to do my own table top in the next couple of weeks

It's not an urgent project....have plenty to keep me going at present!

When you get round to having a go at your table perhaps you'd be kind enough to stick up a quick post letting us know how you got on?

S.L.F

Snowshoe Sam wrote: »

It's not an urgent project....have plenty to keep me going at present!

When you get round to having a go at your table perhaps you'd be kind enough to stick up a quick post letting us know how you got on?

That was my thought process, I'll be stripping the table first regardless.....then trying all sorts of things to solve the fungal problem...from bleaching (domestic bleach) to cellelose thinners to white spirit to wood revivers.

I'll probably end up sanding the stupid thing

Made a phone call to my old boss and he reckons (he's not totally sure though) that the reviver should work.

Needs stripping apply the stuff then power spray off.

tabby aspreme

lads before you start sanding or striping try this , get 1/2 pint of linseed oil add 1 tablespoon of turpentine, methylated spirits, and white vinegar give mix a good shake ,get some 000 or 0000 wire wool and rub with the grain into the wood dont rub too hard as you dont want to remove all the old finish ,this is also suitable to clean french polished surfaces that have become scruffy

kadman

Any chance of a full size picture of this desk. thanks

kadman