White Spots under CA finish

[Alzey]

I have been tuning pens since October and almost all of them have a CA finish. I have made around 75 and still can not pinpoint what is causing white spots under the finish. It is very frustrating because you don't see them until you are almost completely done with the finish.

I normally sand to 400 grit then clean with CA Accelerator. On most woods, I apply 1 coat of BLO then Apply thin CA 15+ coats. If there are deep grains i will apply medium or thick CA to fill in. I then wet sand with 600 grit followed by MM.

 

[Ruby pen turning]

Looks like dust but it maybe the accelerator is turning the thin CA white as it will do when hit with accelerator. Accelerator and thin CA don't mix in my experience.

 

[leehljp]

Those white spots look familiar, although a few years ago. I would say that probably you either applied CA without a smooth build up, or sanded with too course of sand paper and created grooves. Even if you sanded with smoother sandpaper over the rougher, you probably did not sand all of the courser groves out. Then, when next sanded, CA dust got caught up in the little groves and balled up. When cleaned, it is not always easy to see these little pockets. But when CA is layered on top, the CA fuming or the left behind CA dust shows up about 15 to 30 minutes later - always after the fine job of a final smooth finish.

Three ways to get rid of them: 1. Sand down to level just below where the white spots are, or sand down to the wood and start over. 2. Use your chisel - skew or scraper and turn the finish off to below the spots or to the wood. 3. Soak in acetone . . . Not the best way, IMO, although I have done it.

I would definitely refinish it. That is a good looking pen!

This is "my" method only: I rarely go below 400 SP even on the blank before finishing. Rougher sandpaper allows more chances for deep scratches that show up later and have to be re-done. Not a single problem since I quite using anything below 400 a few years ago.

 

[Alzey]

I was wonder about the accelerator. Have had to use it from time to time due to the cold temperatures. Guess I will use a bit more patients and see if that helps.

 

[Ruby pen turning]

accelerator is fine for MED or HEavy CA but I would never use it for thin. Also, if you are sanding somewhere in between CA applications, try applying all your CA and then sand. I never sand between CA applications and have never had a problem. I also do not use this for anything other then filling in gaps between tube and blank or to soak soft woods as I am turning to shape.

 

[wouldentu2?]

It is CA dust from sanding. Don't apply more than a drop of medium or thick CA at a time and you won't have as much to sand down, and use thin CA the next coat after sanding.

 

[soligen]

I had this happen one time. I ran out of my usual paper towels and used the cheap ones from the kitchen. Turns out it was little specs of paper towel. Went back to my regular brand and the problem went away. If you recently changed brand of paper towel, perhaps that is it for you too.

 

[Ruby pen turning]

It is CA dust from sanding. Don't apply more than a drop of medium or thick CA at a time and you won't have as much to sand down, and use thin CA the next coat after sanding.

1 or 2 drops? It would take 3 nights to finish a pen at that rate. I put down 10-15 coats in less then ten minutes by laying down a fine line medium CA as I go with my paper towel. Then I sand out all ridges in the CA. Then I sand with finer paper and finally the micromesh (9) of them.

 

[gbpens]

After reading all the comments and taking a good look at the photo with the "white spots" I concluded that the problem is multifaceted. The wood you turned looks like black palm which is subject to tearout leaving small holes. Sanding will leave a dust build up in these holes. Try using compressed air before applying any type of finish and keep applying finish with sanding/cleaning untill the holes are filled. Then wet sand.

 

[ALA]

I had this happen one time. I ran out of my usual paper towels and used the cheap ones from the kitchen. Turns out it was little specs of paper towel. Went back to my regular brand and the problem went away. If you recently changed brand of paper towel, perhaps that is it for you too.

Looks like several good answers here...from dust in the grain to cheap paper towels. I've had problems with dust in the wood grain and it's been tough to get it all out. I'm working on one now that needs a "redo".

Speaking of paper towels, what is considered a good one to apply CA?