I recently got this Duofold AF button filler which need to be resacced. Before I start on it, some guidance from the experts here would help. Thanks in advance. Pix below.

Is the section a friction-fit or does it screw into the barrel? The button came off with hardly any resistance - is that normal? Can the button collar unscrew (like Vacs)?

Anything I need to watch out for?

Hi Skundu,

The A/F is straight forward, the section unscrews, normal thread, gentle heat makes life much easier.

There are at least two slightly different forms of A/f pens in slightly different plastics, this is particularly noticeable in the black ones it makes no difference to how thay come apart

There are a couple of versions of A/F filler units, some are anodised a coppery colour some are plain, most will unscrew but they can be extraordinarily difficult to get out due to plastic shrinkage and or corrosion of the aluminium. There are a few fillers that don't unscrew and don't even have threads and are shrink or press fitted, I have found two of these in several decades. In general there is no need to remove the fillers and unless they are damaged I tend not to even try to remove them.

The button does not usually come out of the unit, the fact that it does means that you may need to do a bit of work to ensure that it doesn't, some delicate reforming of the bottom end of the button.

When you fit a new sac (size 16) make sure that you use French chalk/talc liberally and make sure that the pressure bar is snugged up against the wall of the barrel, it is easy to twist the sac.

Cheers and best of luck,

John