No idea where you buy wood flour. I get the stuff I use out of the filter bag on my random orbital sander after using 240 grit sandpaper. Don't know if it's as fine as commercial stuff but it matches colloidal silica in workability. Belt sander dust is noticeably coarser, but still useable where the cometics are less critical (like jointing where the larger grains help prevent joint starvation.) Have never yet deliberately sanded wood just to create wood flour but if you did you could probably colour match pretty exactly.
Have learned it's vital to keep the flour absolutely dry in airtight container. Years ago we mixed a batch for the end block on a kayak. The weather had been humid and we'd kept the flour in an open topped tub in the workshop. As the epoxy heated and set it frothed up quite spectacularly. Less sensitive when filleting but still worth taking care.
Re sanding well, it's not like fairing compound or microballoons, it's tough stuff (as it should be to hold panels together) but is possibly a fraction easier to sand than colloidal silica.
Merry Christmas from me too!
Tim.
On 20 Dec 2013, at 14:44, Nesting Ray. [via UK HBBR Forum] <
[hidden email]> wrote:
> Hello each.
> But where to get the elusive stuff is the problem. Has anyone any idea's? Merry Christmas to all. Ray