Hi, I recently received a Conway Stewart Dinkie 550 which I purchased online; it was described as needing a new sac. I don't know much about casein, but read this on the CS website:
Casein is a protein derived from milk which following a 6-9 month pressure and curing process results in a beautiful, hard, lustrous material. This material was used extensively in pen making prior to the advent of modern resins and has been re-introduced by Conway Stewart on a range of models. Casein is a natural material and as a result has some properties that must be carefully handled. Firstly casein is water soluble - it can be wiped clean with a slightly damp cloth but if left submerged for any time it will begin to dissolve. Secondly the material contains pores which can swell and shrink when subjected to changes in heat and humidity. This can affect the fittings of the bands and so is best avoided in areas of extremes of temperature or humidity.
Firstly, if I can't apply heat to the pen, how am I going to unstick the barrel from the section, which appear to be shellacked (spelling?) together? I'll have to do this in order to fit the new sac.
Secondly, how does one clean the section of a casein pen without dismantling the nib and feed? I had intended to flush it out with a bulb syringe - if it will fit, the pen is so tiny - but wonder if this will affect the casein.
The nib is great, I've dip-tested it: it's flexy, which shocked me as I've never written with a flexy pen before. I may gently smooth the nib a little, I have lots of experience of doing this with very cheap pens, but this will be the first gold nib I've smoothed.
I would like to turn this pen into a good everyday writer and any advice you can give me about servicing and caring for this pen will be greatly appreciated. Thanks.