Stuck Screw In Pfm V Blind Cap, Help!

[jzara]

I am trying to get the screw out of the blind cap of my PFM V and it just won't budge. I have tried soaking it for a day in water and using WD-40. Does anyone know another trick to try? I have all of the parts and really would like to do this overhaul myself.

Thanks,

Jason

[viclip]

Have you tried dry heat?

[jzara]

Have you tried dry heat?

 

Would a hair dryer do that?

[viclip]

I use a hair dryer for all of my pen work. They generally won't heat beyond about 140 degrees F. which is about the max temp that you'd want to use. It's a good idea to use a thermometer until you get the feel of how hot your hair dryer blows an inch or two from the nozzle or preferably the concentrator if your unit has one. Heat the blind cap gradually while attempting to loosen the screw every so often.

[jzara]

I use a hair dryer for all of my pen work. They generally won't heat beyond about 140 degrees F. which is about the max temp that you'd want to use. It's a good idea to use a thermometer until you get the feel of how hot your hair dryer blows an inch or two from the nozzle or preferably the concentrator if your unit has one. Heat the blind cap gradually while attempting to loosen the screw every so often.

 

Thanks for the tip, I will let you know if it works

[fountainbel]

Besides applying heat, I've experienced that spraying a small amount of WD 40 in the plunger pipe and let it soak overnight helped a lot (barrel vertically , filling knob down)

Francis

[Gary1952]

Hi,

 

I had the same problem with a PFM IV.

 

Tried heat and WD 40 to no avail.

 

Turned out the the slot in the screw head had been burred off by a previous repairer.

 

Eventually got it out by persisting with a screw driver in conjunction with much cursing.

 

Regards,

Edited May 16, 2011 by Gary1952

[pieemme]

I had the same problem and ended up cracking the blind cap🥲.  I used section pliers but the screw was much more stubborn.  Now I keep checking every day if a replacement one comes up (at a huge price, I fear), but still I would need to get the screw out.

[Ron Z]

I have seen cases where the screw head has rusted to the point where there is no slot.  In that case you may have to sacrifice the  plunger tube.  I don't like it, but it's cheaper and easier to find than a PFM V blind cap.  But try the WD-40 or PB Blaster soak first if there is a slot.

 

Cut the tube with a Dremel cutoff wheel down near the blind cap, then use a burr to cut a new slot.  If you get the screw out, you're good.   Use a stainless screw, and put a little silicone grease on the threads before you screw it back in to prevent corrosion from fusing screw to blind cap.  Actually, replacing the screw is a good idea.  IIRC the thread  is 4-40.

[pieemme]

Sadly I'm learning this too late.  I didn't realise that replacement blind caps were so difficult to come by. I have often wondered if 3D printing might not offer a solution.  I bought my pen as "serviced" and it did work well for about a year. But now I'm almost certain that my filling issue is related to the plunger seal, which was obviously not replaced.  

 

By the way, I eventually succeeded in removing the blind cap screw. I should never, ever have used section pliers to apply the necessary force. As there is a square metal end to the blind cap, I should have set it against a spanner in the appropriate size or openinng,  working metal against metal, rather than plastics.

 

Now, if I can't get hold of a PFM V blind cap I am considering machining a blind cap of an earlier PFM in order to fit the metal tip on top. But maybe I would incur into some problem like unmatching sizes.