Resin for replacing rotten wood

Thanks for that :)

Agreed

That looks dark enough that you could get away with a multitude of repair sins if required :-)

Yup that sounds like the best option - just do a large ish bit of new wood rather than worry about making a patchwork of small filled bits.

Sepele is a good grain and colour match, not to mention being fairly easy to get hold of.

I would opt for :

It is for the polyesters. Epoxy which is a two pack mix is different I wouldnt recommend epoxy: its harder to use - need to get the two amounts very equal and very well mixed to avoid areas that never set properly. Polyester once it sees a whiff of catalyst goes off properly everywhere.

Oh ok. Car body filler it is then. I personally didnt biother to stablise rot last job I did - just pulled off the loose stuff and drove some screws into the solid bit for a key and made a whole new lower door frame section for the garage doors!

use polythene sheet to form a moulding surface. It doesnt stick to poly

Ah

I was thinking about popping some screws in - to the 3 or 4 different members that meet at the joint, then dripping some wire or coarse glass fibres into the hole as I filled with the filler, just to tie the joint.

I should be careful that I choose to do whatever external splice at the same time, if I do - otherwise I'll end up with a bit that's impossible to cut.

Might be best as John mentioned, to commit to a heavy splice - I'll be able to assess the damage better in a big external hole and I will at least end up with the corner post properly supported at least on a lump of 2x3 or 3x3 sapele. The rest of the bodgery is reduced to saeling the mush to prevent it collecting more water in the next winter and hopefully putting a stop to further rot.

I'm curious - did they pick this for a reason? vs say a thin resin?

Ease of use, obviously. It's just, in my mind, I assumed that if it were saturated in resin, the result would be more solid?

Wood filler is far more expensive than car body filler but is supposed to flex when the wood expands and contracts with heat and humidity.

I waterproofed mine on the outside and cut holes through the inside so they would dry out over time.

Yes screws for the filler to set around is a good idea