Repairing patches on walls

[LoneWolf]

There are a couple of patches on my walls where the surface coating has gone (due to condensation i think) and the wood is darker.

See pic

 

 

How do i fix this?

 

I believe the wood is maple if that makes a difference

 

thanks in advance

[bag 'o' bones]

There are a couple of patches on my walls where the surface coating has gone (due to condensation i think) and the wood is darker.

See pic

 

 

How do i fix this?

 

I believe the wood is maple if that makes a difference

 

thanks in advance

 

Check that your windows are not leaking. One of our windows began to leak from the outside and created similar symtoms as you have described.

[BEngo]

There are a couple of patches on my walls where the surface coating has gone (due to condensation i think) and the wood is darker.

See pic

 

How do i fix this?

 

I believe the wood is maple if that makes a difference

 

thanks in advance

 

 

How is the boat insulated? This looks more like the effect of condensation behind the panel dripping onto it and causing discoloration from the rear. The only way to cure that would be a new panel (or if you are a better chippy than most to let a piece in) with an effective vapour barrier between that and the steelwork where the condensation is occurring.

 

Looking at the relationship between the dark patch and the porthole it may actually be one of the porthole or porthole surround fixings that is the drip point.

 

I would be inclined to look and see if the porthole surrounds and panel can be removed without destroying the fit-out.

 

Regards

 

N

[LoneWolf]

Thanks for your replies. I think i can get the porthole surround off.

 

Any ideas on what to do with the patches; can i rub them down & treat with something (what?) and re-varnish?

[alan_fincher]

I also think this could point to the panel getting wet from behind.

 

As someone has asked, what is the insulation type, please ?

 

If you can get the porthole surround away, is it possible to reach in and see if whatever is behind there is getting wet ?

[nb Innisfree]

Insulation needs to continue right up to the porthole trim, you can do this by removing trim and wrapping it snugly in clingfilm, then squirt expanding foam behind the panel and quickly replace trim, leave for a couple of days or more depending on outside temp then remove trim and cut away any extra foam. Don't overdo the foam injection, better to do it in stages rather than have it squirting out all over the show.

[LoneWolf]

I also think this could point to the panel getting wet from behind.

 

As someone has asked, what is the insulation type, please ?

 

If you can get the porthole surround away, is it possible to reach in and see if whatever is behind there is getting wet ?

 

I dont know Alan, but i'll let you know when i've had a look

 

Insulation needs to continue right up to the porthole trim, you can do this by removing trim and wrapping it snugly in clingfilm, then squirt expanding foam behind the panel and quickly replace trim, leave for a couple of days or more depending on outside temp then remove trim and cut away any extra foam. Don't overdo the foam injection, better to do it in stages rather than have it squirting out all over the show.

 

Thanks Innisfree, that's very helpful. I see some types of expanding foam are 'fire rated'. I guess it would be a good idea to get this type.

I'm guessing the colder the day the longer to leave it but i'm sure the instructions will say

 

 

 

So thats help with future prevention. Can anyone assist with how to repair the wood?

[alan_fincher]

So thats help with future prevention. Can anyone assist with how to repair the wood?

I think you need to isolate what's happened first. In the worst case, namely that it is penetration from behind, the damage might be significantly worse than a bit of apparent staining on the front implies.

[nb Innisfree]

I dont know Alan, but i'll let you know when i've had a look

 

 

 

Thanks Innisfree, that's very helpful. I see some types of expanding foam are 'fire rated'. I guess it would be a good idea to get this type.

I'm guessing the colder the day the longer to leave it but i'm sure the instructions will say

 

 

 

So thats help with future prevention. Can anyone assist with how to repair the wood?

 

If possible it's best to try and cover the back of the wall panel with clingfilm as well to stop foam sticking to panel, will allow removal of panel if necessary.

[LoneWolf]

I think you need to isolate what's happened first. In the worst case, namely that it is penetration from behind, the damage might be significantly worse than a bit of apparent staining on the front implies.

 

I need daylight to investigate. I shall be worrying about penetration from behind all night now

 

If possible it's best to try and cover the back of the wall panel with clingfilm as well to stop foam sticking to panel, will allow removal of panel if necessary.

 

ok thanks. humm maybe i will investigate taking the panel off to have a proper looksee

[WotEver]

Just a quick note to point out that it's possible that once you remove the source of moisture and allow the panel to completely dry out that the stain may become much less noticeable or even disappear completely.

 

Tony

[jelunga]

I shall be worrying about penetration from behind all night now

 

 

Oh eer missus

[alan_fincher]

Just a quick note to point out that it's possible that once you remove the source of moisture and allow the panel to completely dry out that the stain may become much less noticeable or even disappear completely.

I know I'm sounding like the harbinger of doom here, but in my experience, usually once this kind of damage has occurred, it's usually hard to eradicate all trace.

 

Mind you, I'm assuming this is a veneered ply with one of those really nastily thin veneers that can hole through if you just look at them too intensely!

 

I don't think the actual material has been stated. Another possibility, increasingly replacing faced ply, is a faced MDF, which I'll freely admit I have no experience of, (either damaged or undamage). I'm still guessing this has a micro-thin vaneer that is easily damaged, though.

 

Sorry about "penetration from behind" - didn't spot I'd managed to say that!

[LoneWolf]

Just a quick note to point out that it's possible that once you remove the source of moisture and allow the panel to completely dry out that the stain may become much less noticeable or even disappear completely.

 

Tony

 

yay optimism thanks Tony

 

I know I'm sounding like the harbinger of doom here, but in my experience, usually once this kind of damage has occurred, it's usually hard to eradicate all trace.

 

Mind you, I'm assuming this is a veneered ply with one of those really nastily thin veneers that can hole through if you just look at them too intensely!

 

I don't think the actual material has been stated. Another possibility, increasingly replacing faced ply, is a faced MDF, which I'll freely admit I have no experience of, (either damaged or undamage). I'm still guessing this has a micro-thin vaneer that is easily damaged, though.

 

Sorry about "penetration from behind" - didn't spot I'd managed to say that!

 

no apologies needed Alan, it was funny & i appreciate the help.

I'm afraid i dont know what 'veneered ply' is. My understanding (ie someone told me) is that the wood is maple (i think i said that under the pic)

 

screwdriver time now...

[alan_fincher]

I'm afraid i dont know what 'veneered ply' is. My understanding (ie someone told me) is that the wood is maple (i think i said that under the pic)

Most boats fitted out in "sheet wood" materials, (as opposed to say in "joined planks"), will be based on a material that is 90 something percent just structural, but to which a very thin layer of the wood giving the finish has been glued. Thus though it may be described as an "oak", "maple" or whatever finish, perhaps less that a millimetre will actually be of this wood, (it usually is just a very fine layer indeed!), and everything beneath will be something else.

 

There are various choices for the "something else"....

 

Plywood is the wood itself constructed of multiple layers of wood bonded together with glue. The middle layers will be thicker than that veneer, and if you look at a cut edge of it, (as you will see with the trim removed), you should clearly see those layers if it's a "ply". If ply gets repeatedly wet the glue layers can break down, and it "de-laminates" - i.e. falls aprt into it's constituent layers. It is (unfortunately) possible to have damaged ply that looks not a lot worse than your picture, but where the "behind layers" are falling apart.

 

Alternatively the backing to the veneer can be MDF. This is a very hard substance, man made, and will just look like a solid brown sheet - no visible layers or joins of any kind. Some prefer MDF to ply, other's loathe it!

 

There are other less possible materials that can be used with a veneer, (block-board, even chip-board), but I think one of the above two is the most likely for an upper cabin lining.

[WotEver]

I had some sheets of ash veneered MDF delivered a while back and on the truck was a large-ish piece of veneer that had come loose from another panel. The driver let me have it as it would otherwise have been thrown away. I thought it might be useful for patching, or covering some edges.

 

It was so thin (I didn't have a micrometer but my guess would be less than half a millimetre thick) that I actually found it unusable - it fell apart every time I picked it up. It's like a thick piece of paper.

 

Tony

[LoneWolf]

Thanks Alan, the learning never stops. I see what you mean

 

behind the metal bit

 

 

 

and in close up

 

 

I didn't expect it to look like that. Sadly no insulation visible. The layered wood type stuff looks and feels dry but i can see from the screws that there has been water there.

 

I should add that this was the porthole where the curtain was closed all winter & i was somewhat slack with checking it & condensation did build up and take off some varnish(?) directly under (ie at 6o'clock) that you can see in the picture. I expect it some did leak through.

I polished the walls recently but did not polish the 6o'clock bit but did do the 4o'clock bit where i didn't notice that the surface was gone. I'm wondering if i introduced a darker colour with the polish.

 

There's a patch on the other wall not near a porthole which is similar to the 4oclock one which has gone dark since the polish. on investigation the surface has gone here too.

It was tesco furniture polish with beeswax (came with the boat so i assumed it was the thing to use)

 

I've been very slack with wall maintenance it appears but i'm trying to get on top of it now.

[WotEver]

Looking at the pics and the description it's quite possible that if the varnish was very thin (quite common) and had subsequently worn away, possibly by rubbing when opening the curtains, that your polish has soaked into the wood and darkened it that way.

 

The moisture 'damage' evident on the screw head looks nothing more than minor condensation to me.

 

Tony

[alan_fincher]

Looking at the pictures, the plywood is in first rate condition, with no exidence of water damage at the cut ends.

 

I now think it's likely this is just surface staining, and that no damage exists beyond that.

 

Whatever you try, don't be tempted to put even the mildest sandpaper on the staining, as with some venerrs just a few rubs, and you'll be through the maple into something else.

 

We need David Schweizer, I think - he is very good on matters of wood-care and restoration IIRC.

[RLWP]

Looking at the pictures, the plywood is in first rate condition, with no exidence of water damage at the cut ends.

 

I now think it's likely this is just surface staining, and that no damage exists beyond that.

 

Whatever you try, don't be tempted to put even the mildest sandpaper on the staining, as with some venerrs just a few rubs, and you'll be through the maple into something else.

 

We need David Schweizer, I think - he is very good on matters of wood-care and restoration IIRC.

 

The second image above would suggest that the veneer is a reasonable thickness

 

Richard

[LoneWolf]

phew, no penetration from the rear then!

 

 

thanks guys, much appreciated. I'll wait for some woodwork experts to advise on how to treat the surface... to sand or not to sand, how to revarnish etc

[WotEver]

phew, no penetration from the rear then!

 

 

thanks guys, much appreciated. I'll wait for some woodwork experts to advise on how to treat the surface... to sand or not to sand, how to revarnish etc

Not to sand. That's a given.

 

First thing I'd try is a cloth dampened with White Spirit. Dampened, not soaking. If it's polish that's soaked in then that might dissolve it. Just try the centre of the stain to begin with, don't rub it all over the place. If it goes a little darker when you rub, don't worry, that's just the spirit soaking into the wood and it'll lighten as it dries back out.

 

Tony

 

If your cloth gets brown as you rub, then it's working.

[LoneWolf]

Not to sand. That's a given.

 

First thing I'd try is a cloth dampened with White Spirit. Dampened, not soaking. If it's polish that's soaked in then that might dissolve it. Just try the centre of the stain to begin with, don't rub it all over the place. If it goes a little darker when you rub, don't worry, that's just the spirit soaking into the wood and it'll lighten as it dries back out.

 

Tony

 

If your cloth gets brown as you rub, then it's working.

 

thanks Tony, i'll post results when i've found the white spirit. I know i've got some somewhere...

[WotEver]

thanks Tony, i'll post results when i've found the white spirit. I know i've got some somewhere...

If it works, then we know that you need to re-varnish

 

Good luck,

Tony