Hairline Celluloid Crack

[tmenyc]

S, good start! Walk away from it until tomorrow. As Ron notes, it needs to cure.

 

Tim

[Ron Z]

Should I add another wicking of MEK, or just leave well enough alone?

 

Leave well enough alone. Add more only if it opens up again. If the sides have touched and fused, you have little to gain by trying to apply more.

 

Let it stand for 24-48 hours. Data I've seen on other solvent weld chemicals indicate that the initial bond is fairly strong, and it reaches something like 80% strength in 24-48 hours, with the curve flattening after that, but getting stronger over several weeks. This in particular is a case where letting it cure longer is a good idea. Rush putting the pen back together before it has cured and hardened is a good way to insure that the crack opens up again.

 

After its had a chance to harden, use a pick, or a tap smaller tap with the same thread pitch, and chase the internal threads so that what has oozed into the threads doesn't cause the section to stretch the barrel. It won't hurt to chase all the way around to remove any residual crud. Warm the barrel when you screw the section in so that the celluloid softens a bit, reducing the chances of the crack opening up again. Be gentle.

[sugna]

Figured I owed you all an update considering everyone's generosity with their advice. I applied MEK twice, with a space of 48 hours between each application. I then waited another 48 hours to reassemble the pen, and it seems to have held! Thanks again!

 

[praxim]

Congratulations Sugna. In the photo that looks very clean.

 

Apropos, I completed a celluloid crack repair today. It was in part of the section of an Onoto 1332, just enough not to leak evidently but to wick ink onto your index finger, unnoticed or even unnoticeable until then without magnification.

 

My approach after some reading was MEK on a slightly blunt or furry toothpick, drawn along the crack, then three weeks of perfect rest.

 

A long water test has shown no wicking through that point. Inking will come later today.

[SMG]

Ron is the master at these repairs. I have seen his work up close on many occasions and often could not point out where the flaw had originally been.

 

Cheers

Sean