White threads in purpleheart

[mgatten]

I finished a pen in purpleheart and was disappointed to notice a few little white "threads" in the grain when I was done.

I assumed that I must have overheated the CA glue a little bit.

Annoyed, I sanded all the finish off. I was very aggressive about it because I needed to make sure there was no CA left. I sanded with 100 grit until ALL hint of CA was gone, including making sure there were no white threads. I figured I might make it too small past the bearings, but nothing that a ridiculous number of coats of CA wouldn't fix.

I then cleaned it with denatured alcohol. It looked perfect. No white anywhere.

Then I started sanding with 150, 220, 320, 400, 600 and then 800.

But the white threads came back with a VENGEANCE!! Now they are all OVER the thing, and LONG! The tube pictured has had no CA finish. There is no superglue there to have overheated.

What the heck?

Is this normal for some purpleheart? Is there a way to avoid it?


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[ivel]

Maybe put some fire to it ? ? ?

 

[leehljp]

Different people have different opinions on sanding grit and that is OK, however, no real need for 100. Pens are not furniture size and don't need that; the 100 sanding grit leaves deep enough scratches that only requires much MORE sanding to get those out. I NEVER use anything less 240 at the lowest number on pens. Now, as to furniture, that is different.

The white can be ANY sanding dust and usually "CA" sanding dust. It is the symptom of the pores not being sealed. Oak, walnut and many others have open grained pores that catch the sanding dust. Sealing with more coats or medium to thick coats of CA before sanding will do it; Blowing it off with air from an air compressor - this will probably be the best help; wiping it down with a dry cloth, or very lightly damp cloth/paper towel will usually remove most. Caution, using a damp cloth, even denatured alcohol can/will introduce moisture into the wood that will cause cloudiness in the finish in some cases.

 

[randyrls]

Marshall; The white streaks are almost certainly CA sanding dust caught in the pores of the wood. Sand the blank finished. The best way to get the white out, is to scrub the blank with a brass bristle brush using denatured alcohol before sanding, wipe thoroughly and allow to dry, then apply CA without further sanding.

I have had the streaks show up even during the CA finish process.

 

[Woodchipper]

I sand a blank and then wipe off the blank with a microfiber cloth or a gentle blast of air from compressed air as used to clean off computer keyboards, etc. I also use a very gentle and quick blast from my air compressor.

 

[jttheclockman]

Hank, Randy, and John summed it up perfectly and gave you the exact answer to your question. So what I am about to say is more or less repeating. Sanding a pen blank with 100 grit any time is asking for problems. To progressively get sanding scratches out that deep would require so much more unnecessary work. It is sanding dust in the grain of the wood. Blowing it off with compressed air can dislodge it all or most of it. Using a tack cloth can also help but nothing is guaranteed. I preach this so many times here I am beginning to hate myself. But learn to use the skew and stay away from sandpaper. We make such small round objects that the need for heavy sandpaper is absurd. Yes sandpaper can be looked at as a tool but a tool that can change the outcome for the bad of a pen as you see. A skew will get the shape and feel to a point no sandpaper can touch. Remember you are top coating so it does not have to be baby bottom smooth.

 

[BRobbins629]

Try wet sanding with a drop or two of CA on 220 grit. Do this a couple of times and the pores will be filled with purpleheart saw dust. Just did a demo on this for our club. Makes a world of difference.

 

[mgatten]

I normally start at 320, go to 400, then 600, then sometimes 800. Often I can even get away with starting at 400.

This was a special case because I had about ten coats of CA to remove.

 

[Woodchipper]

John T. has it- learn to use the skew. I'm still working on it. I have seen skews that are so effective that sanding isn't needed.

 

[greenacres2]

Unless I screw up, which i'm known to do...after my skew chisel 800 grit would roughen the blank. When I do it right, it's straight from skew to finish. When I do have to sand it's pretty much always my fault.
earl

 

[RogerC]

Marshall; The white streaks are almost certainly CA sanding dust caught in the pores of the wood. Sand the blank finished. The best way to get the white out, is to scrub the blank with a brass bristle brush using denatured alcohol before sanding, wipe thoroughly and allow to dry, then apply CA without further sanding.

I have had the streaks show up even during the CA finish process.

^This