Hi
I must respectfully dissagree with johnyb about the repair care being better.
I think the repaircare slow setting one may be very marginally better for forming corners and mouldings etc but its silly money. The "quick" one they do for splicing is rubbish.
The timbabuild ERC 10 is the sweet spot.
The speed of the ERC 10 enables you to get much more done more efficiently , even if you need to do a splice followed by a smaller fill you can finish it and get it painted in the time it takes the thicker EHB 60 or repaircare to go off.
You will need a mixing gun.
If you dont have any relevant stuff they do a starter kit with the gun a tube of each resin some stabilizer and some extra bits which is actually a good deal.
Pro tip the cheapest supplier is called direct brick.
If there is any rotten or soft wood left in the repair area you should prime it with the 2 part liquid epoxy leave it about 30 minutes. However I prefer to try and remove any soft or suspect timber completely and replace with a timber splice, using the epoxy as a glue and filler. As mentioned don`t make the joint super tight so you can "surround" the repair.
As with all epoxy, temperature is a factor its very slow when cold and will go off in about 2 minutes in July. We used to put some tubes in the cab of the van on the way to site on winter mornings.
Another tip is if you catch it at the right time as it cures (after it gels so not sticky, but before full cure ) you can use a plane or chisel to cut and shape it very nicely this leaves only very minimal sanding to do. If you leave it too long this becomes more difficult and sanding is the best way if you have left it more than a couple of hours. This doesn`t really work as well with the ehb 60 as it cures quite differently.
I personally think the timbabuild stuff is the best value and is a product that has been around a very long tome (used to be called VR90 and was developed by Chemfix for Ventrolla).
Ollie