Window rot, raining doon, what to do?

[Marie_A]

This weekend I've sanded back and started to repaint this wood window. There's rot in this corner and small holes suggesting wood worm. I've taken away all the damp, soft wood and then treated with woodworm killer. Now what?

Does it need a new piece of treated wood put in? It's set to rain in the evening, as a temporary fix I'm thinking of ronseal wood filler? I was thinking Bondo when I next have the time but us that good enough? I plan to cover the frame with tarpaulin tonight.

 

[Notch7]

Ideally you need a flexible epoxy resin -try repair care international or timbabuild.

 

[opps]

From the images posted, I can't see evidence of woodworm.

As mentioned by Notch7, I too would recommend an epoxy resin filler. You mention Bondo, I guess you mean their 2 pack polyester resin filler. Bondo may well work but it is less flexible than epoxy resin filler.

I have only been using epoxy resin fillers for the last couple of years, prior to that I would have used the likes of Bondo, in many cases they worked but when it comes down to dynamic joins, such as the one in your photos, epoxy is more likely to last. It does however cost a lot more and is more difficult to sand.

You mention that you have removed the soft and damp timber. It may be advisable to use a wood hardener as well before filling.

Personally, looking at the window, I would remove enough timber to splice in a bit of new timber and use epoxy resin to glue it into place. However, as I said earlier, epoxy resin is expensive. If you can get a very flat section removed then you could use polyurethane adhesives to glue the new bit of timber ina. They (polyurethane adhesives) have gap filling qualities but not massive gap filling qualities. You would also need to find a way of locking the insert off. Polyurethane adhesives expand and left to their own devices will push the timber insert outwards

 

[Marie_A]

Thanks both for your advice.

I think I'm going to follow your advice, oops, and splice in a new piece of wood. I've done some basic woodwork before but not this, but it seems fairly straightforward? I think I will invest in the epoxy as I have a few more windows to repair. I plan to shape the gap so the shape is more regular and cut the new wood piece to it. Then apply some epoxy to bind the new piece in and fill any gaps, alongside screwing the piece into the existing wood to fix it whilst it dries.

I've applied ronseal wood hardener and its worked well, and I've covered it with tarpaulin to be on the safe side until I can finish it off.

 

[Harry Bloomfield]

I agree, not woodworm - that is wet rot.

 

[opps]

If you use epoxy resin, it will not be necessary to use screws. In theory, you could just use epoxy without the timber but it would be very expensive and it will slump out unless you use perspex to hold it in place as it cures.

RepairCare have some videos on their site. Be aware that they recommend using the wood "hardener" specific to the particular epoxy product (which bumps up the cost). Timbabuild only have two types of epoxy (1 hour cure and 4 hour cure), whilst they do sell an epoxy wood hardener (EWS) http://www.chemfix.co.uk/products/t.../timbabuild-epoxy-wood-repair/timbabuild-ews/ it can be used with either of their epoxy fillers.

If you shop around you can get the (well made) Timbabuild gun for about £25. The rubbish plastic RepairCare gun is about £30 and the decent quality one is about £50. The Timbabuild fillers are three to four times cheaper than the RepairCare ones but RepairCare is stocked by more local suppliers where I live in west London (actually, I have never seen Timbabuild branded products in any shops, ever- that's the power of marketing).

RepairCare might be the better option if you wanted epoxies that cure at very low temperatures (eg winter), in most other cases I would recommend Timbabuild (so long as you are happy to wait for delivery). There are other brands available, but I have no experience of using them.

As an aside, the 1 hour Timbabuild (ERC10) is much easier to sand and more flexible than the 4 hour EHB60 but the former is limited to 10mm thickness. If splicing timber I would use the ERC10. It slumps a lot though so splicing in the timber means that you have less sanding to worry about when compared to just using filler. BTW when I say easier to sand I use the term relatively, machine sanding with 60 grit paper (and dust extraction) would be advisable.

Oh, wear gloves and mix the products thoroughly (otherwise they will not harden). I use off cuts of wood/tile/laminate/etc to mix up on, alternatively I use the plastic board that was part of the overpriced RepairCare introductory kit (£125) and then use decorators wipes to clean the board and filling knives.

Please do provide feedback once you proceed with whichever product you go for- it helps other people that search for similar solutions.

Given the cost of the products, when splicing wasn't viable I have been known to use small pebbles to bulk out the filler, thereby reducing the amount of epoxy needed.