Refinishing pens - Dull spots

[mpex]

I've got a couple questions. I've read a few other posts that I think might have some answers, but I want to double check and expand.

1.I'm getting a few dull spots in my CA finish. It is not the whole pen that is dull, just a couple areas. What strikes me as strange is that on this last pen, there was a dull spot, around 3mm in length that ran the whole length of one of my sections. I'm wondering if that was just a high spot from turning. This may be further enforced by the fact that the same pen also has dull spots in the area around an intentional high spot on the other section. You all think I've diagnosed properly?

2.How do I solve this problem going forward? Are more coats of CA needed? Below is my method.

3.How do I correct this problem on this pen? Do I have to sand back down to wood or can I just apply more coats of CA?

Method:
Skill: beginner
Wood type: Lacewood
Style: Slimline
Pre-finish: turn, sand 120,200,320,400,600
CA: Satellite City Medium (have had the same issue with SC Thin) (no accelerator is used.)
Process: Apply a total of 9 coats of Medium. Lightly sand with 600 between coats if there is unevenness or rough spots, usually every 1-3 coats.
Let dry for a few minutes.
Micromesh wet using the entire MM series.
Dry with paper towel.

Thanks for any help!!!

 

[JasonM]

I've run into similar problems before. In my case it was where I had not evenly applied the CA and parts of the blank beneath were poking through after sanding/polishing.

 

[Akula]

Sounds like high spots or your sanding areas back to the wood

I don't sand between CA coats. The point of CA is to build up a protective finish, sanding the coats off defeats that reason (IMO), faster with pressure while sanding.

I would check and make sure everything is round if this is happening often (I'm thinking your using a mandral)

 

[Randy Simmons]

I agree, If you are using a mandrel it may be bent, especially if you are getting consistent sized and placed spots. I would probably buy a new mandrel shaft, they are fairly cheap, or you may look into turning between centers. I would recommend not sanding between coats, and spending less time with the tougher MM grits and more with the finer ones. Just IMO

Cheers,

Randy

 

[mredburn]

If your wood blank has hard and soft areas from knots, burls, or grain patterns it may turn, as well as sand unevenly. When I have this problem I build extra coats of ca up and sand lightly trying not to sand through the ca. If its bad enough you may have to go back and turn the high spot off.

 

[mpex]

So do I need to take it back down to the wood and build the ca up from scratch? Or can I just add more coats as it is?

 

[mredburn]

You can try and build it up and if it doesnt work then take it back down.

 

[JD Combs Sr]

I too have had the problem in the past and generally speaking it was just too thin of and application of CA and also generally speaking it was predominantly a problem on Slimlines. On most of my Slimlines I sculpt a grip shape next to the nib which creates an intended very "high spot". Any sanding would really work on that spot plus during the CA application the CA spreading action over this spot would tend to make it thinner probably due to higher pressure at that point under my finger. I corrected the problem with a few changes in my process.
1st absolutely no sanding between coats unless I screwed up a coat some way and if I do sand that automatically means an extra coat of CA.
2nd I significantly lightened up my finger pressure when applying the CA. This probably made the biggest improvement. I was actually pressing too hard and squeegeeing off most of the CA I was trying to apply. Now days a very light application pressure is the order of the day.
3rd Could be considered part of no.2 but I make sure that I am extra light over any raised areas like beads to insure they get sufficient CA thickness.

With these changes I rarely have a re-occurrence of the problem.

Edit - As to refinishing a blank with the problem, if I had already applied wax I would wipe the blank down with a solvent then lightly re-sand using my finest grit the start applying CA as normal. If no wax has been applied yet I would make sure the exposed area was dry(I water wet sand) then apply additional CA until I was sure the area was well coated.