Cocobolo specks

[Tiger]

Turned some cocobolo and applied a CA finish, however there are small specks of glittering light, some in a ring formation, others scattered nearby. I wiped down the blank after sanding with acetone, i did use a little accelerator. I sanded some of the finish off, could not see any glittering specks, reapplied the finish and the specks came back. I can't get a decent picture, has anyone had this happened before.

 

[Bean_Counter]

Sounds like you got some brass shavings on the wood and when you are putting the finish on it is highlighting them. Try wiping the coco with DNA, let dry and then reapply finish

 

[BSea]

Pictures would help.

 

[1080Wayne]

A ring formation around the tube suggests not quite enough sanding .

 

[GaryMGg]

Coco tends to have large pores and can also be multi-colored; I've had coco blanks which are orange, red, black and golden.
Back to the pores--the CA can reflect light differently on those areas where there are large pores compared to those areas where it's on the surface.
Sometimes, it's necessary to fill the pores to obtain a nice consistent looking finish.

 

[Tiger]

Difficult to get a photo but they are almost microscopic specks, not sand-through as i stripped it back and re-applied the CA, the specks came back in exactly the same position though. Gary you might have something there with the pores as you can only really see the specks when the blank catches the light in a certain angle.

 

[Tiger]

Here's a photo.

 

[toddlajoie]

From the photo, I would think it were dust or some other "stuff" embedded in your CA... However, if what you are saying is you sanded off the CA and re-applied, and they are still there in pretty much the same place, that would be very unusual...

Based on the previous comment about the pores in the wood, what are you using for CA (thin, medium, thick)? I usually do 2 or 3 coats of thin to start, which wicks into the pores very well, and prevents me from getting air pockets in the larger pores when I do the rest (I use medium for the majority of the finish...)

 

[Tiger]

I just use 10 or more thin ca.

 

[Tiger]

I did yet another strip back and re-application of CA, this time i found very faint scratches at the trouble spots, my best guess is that i was collecting ca/sanding dust and it was trapped in these scratches. I thought i was cleaning them out with a rag dampened with Acetone but maybe not. Looks okay now but i realise that there's a couple of spots on the other blank where dust may have been caught.

 

[Chatham PenWorks]

I did yet another strip back and re-application of CA, this time i found very faint scratches at the trouble spots, my best guess is that i was collecting ca/sanding dust and it was trapped in these scratches. I thought i was cleaning them out with a rag dampened with Acetone but maybe not. Looks okay now but i realise that there's a couple of spots on the other blank where dust may have been caught.

Your cleaning may be where your problem is. Open grained wood can pull tiny fibers off of paper towels and rags when you do the acetone wipe. They often aren't easily seen until after you put some ca on. It's been a while since I've turned any open grain woods, but I recall using air, and a close inspection, between the acetone and ca.

 

[toddlajoie]

The Acetone could also be the culprit...

To be honest,from my experience, CA dust SHOULD re-disolve in a new application of CA over it, at least it always seems to have with me. I have never wiped off CA dust when sanding between coats, and never seen anything like those specs...

I believe Acetone can act as an accelerant for CA, and I know from experience that Thin CA can have a somewhat energetic reaction to it :biggrin:, often foaming, smoking, and getting very hot. I'm wondering if small amounts of acetone left on the blank caused small pockets of the thin CA to have this type of fast reaction, causing small foamed specs...

Whenever I use Acetone to clean off a blank before doing a CA finish, I give it PLENTY of time (probably WAY too much, but I'm cautious that way) to evaporate off before I apply the CA....