I know that Frank Dubiel in Da Book suggests using baby powder as a cheap and readily available substitute for talcum powder when "dusting" pen sacs before reinstalling them into the section. But I've heard that veterans in pen repair disagree with Dubiel on this one. I guess my question is why.

James

It's one of many things on which we disagree.....

Do a search for "talc" for the full discussion. In short, baby powder contains other "stuff" that may shorten the life of a sac. Pure talc is cheap and readily available.

The "at hand" and "cheap" substitutes aren't the best in the long run. A little patience until you can get the right stuff is the ticket.

What is sold as Baby Powder is sometimes corn starch. You don't want that stuff in your pen. Interesting chemical reactions can take place involving sugars and other by-products. Pure talcum powder is the stuff. Available from
http://www.tryphon.it (among others)

Some baby powder is as mentioned corn starch... This makes a great pasty glue when it gets wet... So it'll glue the sac to the barrel, something that's generally not good.

The other kind is talc and perfume (or parfum) which is made from essential oils typically. They are volatile oils of various types. Probably not good for the life of latex sacs. You wouldn't dip them vaseline or WD-40 before installing them. This is basically the same, but at a much reduced concentration, so it takes longer to weaken the sac, but it will eventually.