Drying out damp in saloon teak veneered ply and removing black staining

[Men a vaur]

Hi all

I have returned to my boat after a couple of months overseas to find one of the deck fittings has been leaking into the headlining and down into the teak veneered panel between the fore peak and the saloon. It has stained the top of the wall black. Having sealed the leaking through deck fitting I’m now trying to figure out the best way to dry out the wood and remove the black staining as best as possible. Does anyone have any suggestions for this? Would using a heat gun on a low setting to dry the wood out and then applying oxalic acid be the best option? Should I be concerned that the oxalic acid may bleach the teak to a different colour vs the rest of the panel and also if a heat gun may cause the veneer to delaminate?

thanks!

 

[dansaskip]

I think I am right in saying the Oxalic acid does not bleach the teak - it has not done so when I have used it. As for drying out I’d be loathe to apply heat with a heat gun anyway that would only dry the surface, best to be patient and let it dry out naturally and slowly, a warm cabin would help.

 

[howardclark]

Don’t use a heat gun - if you have mains available best to put a low power heater near the panel for several days- I have tube heaters I would use for this.

the black mark is going to prove very difficult. For any removal you can use 0000 wire wool - but don’t leave any bits behind because they will go rusty.

any bleach may help but go very gingerly to see what happens. If the teak gets too light then you can use a spirit teak stain to colour it down, but again try a very little piece to see what will happen.

I suspect you will not get rid of the discolouration completely and will then have to decide between putting up with it, possibly painting or if practical reveneering. I’m renewing the veneer on a panel atm but only because I can remove it to do it in the workshop rather than in situ.

 

[Refueler]

Basically any external applied heat such as Heat Gun .... radiant bars of fires .... fan heater direct to the area will create a problem in itself ... the outer laminate will dry - contract - leaving the damp expanded laminates inside ... this leads to that often seen split of outer laminate and even looking like onion skin/

Warming cabin and letting it dry naturally is what I did after my boat was flooded. Basically because of my spending so much time out of UK - boat stood and cockpit drains blocked. Rain water seeped in and then through engine bay into main bilge. Over months - it was substantial level in cabin.
That happened back in about 2004 - 5 .....
The black - I treated with oxalic based on reading up Furniture Makers advice etc. It removed some - but even today - you can still see a tide mark in places.

 

[Tranona]

Take it slowly. A dehumidifier will help as will a tube heater for background heat. you won't know whether you can get the stains out until it is dry, but the fact that it has gone black is not encouraging. often the veneer is extremely thin so there may be an issue with delamination of the top layer. Once it is dry then as suggested there is a range of techniques for getting the colour even to blend in with the rest of the panel. Much depends on the state of the existing panel and how perfect you want the end result.

 

[Concerto]

Further to Tranona's advice, once the veneer is dry, check it is still bonded to the plywood underneath. If not the you may have to let in a section of veneer. If still bonded then you will need to remove the surface finish. Then black staining can be be removed using a bleach solution. Use the cheapest supermarket bleach as it has not been perfumed. Dilute with 6 parts water to 1 of bleach. Brush on and keep damp for 20 to 30 minutes. Wash with fresh water and leave to dry. If still looking black, then increase the solution to 4 to 1 and repeat. This should remover the black discolouration. Lightly sand the veneer with 320 grit and refinish. It is probably been finished with a lacquer. What type of boat do you have.

You might find the presentation of mine worth reading.
https://wiki.westerly-owners.co.uk/images/2/25/Interior_Woodwork_Concerto_PowerPoint.pdf

 

[Refueler]

There are remedies for laminates that separate without cutting out / replacing ... but they are drastic and need slow and careful application.

The slow part is how you dry out the area affected. Note that internally - the moisture has probably penetrated further than exterior indicates.
De-humidifier / warming of cabin atmosphere combined as the moisture that evaporates out from the 'wood' needs to be extracted from the air.
Once its thought wood is 'dried' - then small holes are carefully drilled into the 'area' to allow internal to 'breathe' and for later access for penetrating adhesive. I think you start to see the idea.

Once the area is dried ... thinned resin can be carefully introduced then laminates pressed together while resin sets .... once completed - stained / lacquered.

Its also possible to remove the exterior laminate for an area ... impregnate inner after letting it dry ... then fix new exterior laminate in place ... stain / lacquer.

I cannot give actual links to suppliers of Ply veneers ... but they are available ... talk to a furniture repair shop ...
I used to buy veneers for covering foam model parts ... and it was sold in small or large sheets. They will also be able to advise on best adhesives etc.

 

[Wansworth]

Take a radicle step and once dried if it cannot be returned to original colour paint it

 

[dansaskip]

Some people have suggested using bleach - I am sorry but I strongly disagree. - Bleach does what it's name suggests and does bleach out colour. Use Oxalic acid, as you first yourself suggested - it is what most professional furniture restorers use.

 

[howardclark]

I agree that bleach will discolour the wood but I don’t think oxalic acid will remove the black mark.
In the workshop last year I addressed a ply cupboard front which was rather poor and patchy in colour. This is what would happen if you used bleach. Although I’m not a great fan of spirit stains, on this modest sized panel a teak stain gave a rather acceptable result. Don’t get me wrong- it doesn’t look new , but then if it were that good it would not match the rest of the interior.

 

[LiftyK]

I had the same experience when the boat was not visited during COVID lockdown measures. In the end I had to sand the veneer, a delicate process. I only cut through it once but at least the rest looks much better. Once sanded, I covered the wood with epoxy then varnish.