Builders Bog will be very suitable for these repairs. The thing to watch is that you don’t leave any spores from rot in the adjacent timber. If you do, and don’t take some action to kill them, the timber will rot again around the Builders Bog and the client will not be happy. So, either remove sufficient timber to ensure there is only sound timber left. Or drill some holes around the repair and implant anti-rot slugs and then fill the holes with more Builders Bog. The slugs are boron compounds usually, and will ensure no further problems.

The latter solution applies to large repairs where there is so much damage it is not feasible to access or remove all rotted timber. As part of our on-going development of Builders Bog we repaired, about 4 years ago, a large picture window (4 metres by 2 metres in 2 smaller and one large pane) which faced the sea and was so badly rotted it took 12 litres of Builders Bog, plus timber packing pieces, to fill and repair it.

We drilled holes afterwards and injected a solution of boron compounds in glycol. Then we plugged the holes with dowels and sanded them flush (Builders Bog would not have stuck to glycol-wetted timber), and painted the job (all on the same day). Quoted cost to replace the windows was $7500.00. Cost of the Builders Bog at retail would have been $240.00 at the time of the quote and time taken by one person (my son while I videoed it) 5 hours including painting and cleaning up. We fixed the header flashing which leaked and caused the rot and the repair is perfect and undetectable today. Bunnings are the major stockist in Christchurch, and you will have to get the price from them.

I cannot help ypou with amount needed since it depends entirely on the volume of the holes you create in hacking out any rot. But from your pics it looks like one or two litres would be ample. It comes in 250 ml, 500 ml, 1 litre and 2 litre cans. Some Acetone to clean up with would be good, though petrol can be used (less effectively) and a metal spreader can the be used to apply and then to to carve “(plane”) back the Builders Bog at the “cheesegrating” stage. – or a Surform file can be used. Use 80 grit paper to rough sand and 120 to finish.

A palm sander is handy, but finishing to shape is incredibly easy and quick with our product, even by hand using a sander block. The repairs you show are quite small an should not take long at all. You can finish-paint within a couple of hours of applying the Builders Bog if you use the correct hardener ratio to give about a 20 minute pot life.

Regards
Stuart Jordan
Managing Director