The best way to fill defects is with an epoxy filler. Water based putty is certainly easier to use, easier to clean up, and cheaper. However it is not strong and not waterproof. Two part expoxies can be messy to mix but when set provide a substance stronger than timber but easily cut and sanded. Epoxies can also be dyed to colour (I've used shoe polish in the past to fill black defects, sealing the timber with shellac helps prevent dye penetrating the wood) or mixed with wood dust.
I've used Shelley's brand epoxies in the past with good results. I'm trialling West System Epoxy at the moment. However, it comes quite watery and you need a filler substance to mix with it. West System sell a cotton microfibre/silica powder mix. Just need a supplier...
|A close up section of Mrytle Burl. A thin layer of water helps to show what it will look like oiled.|
|This piece has some sapwood and burl, but will probably be hidden as the centre leg.|
|The vertical line is actually borer hole. It is superficial and will fill nicely.|
|Some sapwood but mostly clear.|
|This piece is interesting. Probably the most questionable. Lots of filling required to stablise it.|
|Clear with some sapwood.|
|Clear with some small burl patches.|
|The plan. I'm still debating a stretcher beneath the seat.|