Pine Picnic table mould/mildew

[Coniferman]

I bought one of those cheap pine "picnic tables" from Argos, in the summer. I gave it plenty of coats of teak oil (until no more would be absorbed and it needed wiping off). It has now started to get black marks (mould/midrew?) on the top surfaces. I have tried mould/mildrew remover (the green bottle spray) and also diluted bleach but it is not having any affect.

I'm assuming its not just part of the natural graying process?

Presumably, a fairly light sanding will remove it (?) but what went wrong, is teak oil just no good for this. I was aware It would need regular re-coats but thought it would at least last a while?

The only thing I did not do with the teak oil was sand lightly, at least before the final coat.

Is it best to fix it now? I guess it will get much worse if I leave it over winter?

Just wondering what to do, the bleach might have have stripped the teak oil?

I'm thinking of giving it a sanding now and then add teak oil again but am I wasting my time? I'd rather stick with the teak oil is possible because I bought a big container of it. lol.

 

[geraldthehamster]

Softwood garden furniture isn't going to survive many winters outside, whatever you do with it. Can you store it under cover?

 

[Coniferman]

I brought this in over winter but it will be going back outside soon. Anyone know anything that will clean it up. I assume it is mould/mildew rather than just graying. As above, diluted bleach didn't do much and sanding looks like it would take a lot of work.

Anyone know if one of those "wet and forget" mould/mildew removers for any hard surfaces will have any affect, or a waste of time?

I appreciate it won't last forever but anything to clean it up for a while?

 

[geraldthehamster]

You could try an oxalic acid-based wood bleach. Despite its name, it's acidic, not alkaline like domestic bleach.

e.g.

http://www.amazon.co.uk/Liberon-WB500-500ml-Wood-Bleacher/dp/B000TAR6MQ

Cheers
Richard

 

[r896neo]

If bleach didnt shift it, a hard surface cleaner certainly wont. oxalic acid may but may also leave a very odd effect as it bleaches. try on a secluded spot first

 

[JohnD]

Oil is not moisture-proof, and outdoor oiled timber is prone to black stain, so is varnished if moisture gets under the film.

The oil will make it difficult to treat, but you can sand it and use oxalic acid. Lots of work now it is oiled, but if you use a spirit-based wood preserver such as Cuprinol it will discourage the fungal stain, and if you use a darker wood dye such as Colron, staining will not show.

 

[geraldthehamster]

At the end of the day it's a cheap product made from low quality material. If you manage to get it looking something like, I'd suggest keeping it under cover during autumn/winter.

 

[lostinthelight]

Use a pressure washer with a fan nozzle, start spraying with the grain at a distance and work closer till the crud comes off.If you start too close with too much pressure it can peel the surface of the wood if its very soft....it works like magic.

 

[Coniferman]

Thanks for ALL the replies and suggestions. I bought a tin of Cuprinol garden furniture stain, specific for Softwood in Mahogany. (Says on the tin good for pine and even has a picture of a picnic table on the tin) Went on quite well (has consistency like paint rather than shed/fence stain) and hides the black stain whilst keeping the wood grain. Looks great and looks like it should repel rain. Hopefully the teak oil won't cause it too flake off.

 

[geraldthehamster]

Thanks for ALL the replies and suggestions. I bought a tin of Cuprinol garden furniture stain, specific for Softwood in Mahogany. (Says on the tin good for pine and even has a picture of a picnic table on the tin) Went on quite well (has consistency like paint rather than shed/fence stain) and hides the black stain whilst keeping the wood grain. Looks great and looks like it should repel rain. Hopefully the teak oil won't cause it too flake off.

As long as you realise that stain won't protect the wood

 

[Coniferman]

Thanks for ALL the replies and suggestions. I bought a tin of Cuprinol garden furniture stain, specific for Softwood in Mahogany. (Says on the tin good for pine and even has a picture of a picnic table on the tin) Went on quite well (has consistency like paint rather than shed/fence stain) and hides the black stain whilst keeping the wood grain. Looks great and looks like it should repel rain. Hopefully the teak oil won't cause it too flake off.

As long as you realise that stain won't protect the wood

What does "long lasting water repellent barrier and weather protection" mean then???

 

[geraldthehamster]

it's a surface coating and will flake off, especially with the expansion and contraction of cheap softwood. You'd be better off with a coloured Osmo oil.