Repairing External Rotted Window Frame At Mitred Corner?

[WhiteVanJack]

Hi,

I have a window frame to repair that has rotted at the external mitred corner and have just sanded it back to bare wood. There is a gap of approximately 7mm between the mitred end faces and also some of the wood is rotted. It looks as though there has been a previous repair at some stage as there was what appeared to be a powdery white softish filler in parts of the corner.


My thoughts on the repair are as follows:

1. Let the wood dry out then give it a wood treatment with something like a wood hardener or all in one treatment such as Cuprinol Wood Treatment.

2. Fill the gap and other crevices with an epoxy resin filler for exterior use.

3. Prime, undercoat and topcoat the area.

However, would anyone please be able to advise me if epoxy filler or something similar for exterior woodwork can be applied after the wood has had a wood treatment applied. For example. would the filler still get a good adhesion and remain in place in the areas to be filled if the wood had been previously treated with something like Cuprinol Wood Treatment. Or, is the filler likely to "float" out of the filled cavity after a year or so?

Also, I have not attempted this type of repair before so if anyone can offer any advice or propose an alternative process for the repair I would be most grateful. I am aware that I need to keep the "rain drip groove" on the underside of the frame but am not sure if I may need to apply the filler in stages to build up a fill in the gap?

I have uploaded a photo of the window frame below.

Untitled

• WhiteVanJack
• 24 Oct 2010
• 1

Rgds
Jack

 

[TheDec]

Jack.

Many within the trade will have differing opinions with regards to such things as filler, of late I have turned to Ronseal High Performance. This is a two pack application and has excellent flexibility, I am sure that others on here will offer you with a wider choice. Yet I have found this one performs very well.

Dec.

 

[WhiteVanJack]

TheDec,

Thanks for the reply.

I have a tin of "FillTite Wood Filler" which is a 2 pack application that I bought from Brewers a while back so I though that I would use that as the filler. Alternatively, I also have some Tetrion which may also be suitable?

On reflection, the gap between the mitred faces is the full depth and width of these faces. I might be better off trying to cut an undersized wedge shaped piece of wood to insert into the gap then apply the filler to the remaining gap on the top, bottom and corner edge. That way, the filler has some internal support.


Rgds
Jack

 

[joe-90]

I'd cut the corner off completely and then make a similar triangle size piece to go back on - screw and Araldite.

 

[WhiteVanJack]

I'd cut the corner off completely and then make a similar triangle size piece to go back on - screw and Araldite.

Hmmm, I have to admit, I had not thought of that and it does offer a more robust solution. Out of interest, how far back along each piece would you recommend I should cut, 2cms beyond the last rotted bit?



Rgds
Jack

 

[joe-90]

Whatever you can do neatly - or you still have a problem.

How about putting your saw against the absolute corner of the frame at 45 degrees and literally sawing the corner off? Then you'd get a very neat line.

 

[WhiteVanJack]

I have just been outside to have another look in connection with sawing off the corner and realised that the tile clad part of the bay window underneath the corner comes out more that the frame above the corner. There is more visible "land" on the upper part of the corner compared to the underside of the corner due to the tile face coming out. If I saw vertically downward when I get through the wood on the corner then I am not hitting air but going into the tile clad frame. If I saw very carefully, it should still probably be OK but I am not sure of the structure of the frame behind the tiles etc. Hmmm !


Rgds
Jack