Hardener for MDF

[andrewm]

Not really woodworking related even though it concerns MDF so will stick this under off-topic. Mods, please move if you think fit.

Now, the wall between the bath and the airing cupboard in my bathroom is tiled on MDF (not MR just plain 12 or 15mm MDF). In general it is fine and was sealed with a couple of coats of PVC before applying the tiles. However on one edge there has been water seepage from the shower down behind the tiles and so the MDF has swelled slightly and is delaminating a little. I have removed the tiles but would like to stabilise the MDF behind as I otherwise suspect that the new tiles might be holding onto not much. Replacing the whole wall is not really an option at this stage. Would something like this do what I want?

Is there anyone out there who can point me in the right direction?

Thanks,

Andrew

 

[skipdiver]

I don't think it would.That stuff works on the fibres in timber,so i can't see it doing the trick with MDF.Bog standard MDF has no place in a bathroom,especially at the back of a shower.I would be inclined to get rid of the lot and retile.If that isn't an option(as you referred to earlier)could you not cut the offending piece out somehow and put something more suitable in it's place?Put in a patch as it were and put some blocks at the back to support it?

 

[RogerS]

I agree with Steve 100% re normal MDFin a bathroom but seeing as how you're not to keen on replacing it in toto (and until JasonB comes along) I am inclined to go down the route you suggest. If the MDF is really friable then to be honest I don't see wat you'vegot to lose.

If the delamination has come up through the edge of the MDF then you are in deep doodoo unless you can really seal things well....as in have someone stand in the shower tray while you silicone the bottom join ...and ideally have them stand there until it goes off The idea is to simulate daily usage. If it was a bath you'd fill it with water before siliconing.

If you've lost chunks out of the MDF then I'd be tempted to harden using that stuff and then fill with cellulose wood filler and sand flat. But you really are living on borrowed time.

 

[andrewm]

Agree entirely about MDF in bathrooms but this was done when I was young and innocent and didn't know any better (or at least had never heard of MR MDF) and in any case was done as a temporary measure as I was going to be letting the house out for a couple of years while I was working in the States. I’m reluctant to do any more than patch at this time because the whole lot is going to get redone in the not to distant future.

Obviously didn't quite explain the situation fully. This is a tiled wall with a shower on but it is over the bath. The water ingress is on the outside of the bath and appears to be where the shower screen has let water through so there should be no issue with the silicone sealant.

All I want to do at this stage it get to a point where I can replace the tiles that have fallen off. At least that will make it useable again until such time as I rip the whole lot out.

Think perhaps I will try this wood hardener - the sort of think I was looking for was some form of resin that would at least provide a sound surface for the tile adhesive.

Andrew

 

[RogerS]

two part wood filler will give you that

 

[skipdiver]

Was gonna suggest the same or car body filler.

 

[RogerS]

Was gonna suggest the same or car body filler.

Yup...brilliant stuff. Use it all the time now. Forget Polyfilla :wink:

 

[andrewm]

two part wood filler will give you that

What I was concerned about was that using a two part filler would give a goo surface for tiling onto but the filler would detach from the delaminating MDF. Hence the desire to find something to stabilise the MDF first.

Andrew

 

[RogerS]

two part wood filler will give you that

What I was concerned about was that using a two part filler would give a goo surface for tiling onto but the filler would detach from the delaminating MDF. Hence the desire to find something to stabilise the MDF first.

Andrew

Sorry didn't make myself clear in my first post.

Use hardener to stabilise the MDF then use the wood filler

 

[andrewm]

two part wood filler will give you that

What I was concerned about was that using a two part filler would give a goo surface for tiling onto but the filler would detach from the delaminating MDF. Hence the desire to find something to stabilise the MDF first.

Andrew

Sorry didn't make myself clear in my first post.

Use hardener to stabilise the MDF then use the wood filler

Ah, that makes sense. I will see if I can find some hardner locally.

Thanks for everyone's help.

Andrew

 

[RogerS]

You should get it in any DIY shed.