Blotchy CA finish

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azimmer1

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Oct 1, 2007
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Location
San Diego, CA, USA
Hi. I am new here and a new turner. I just finished a Statesman and my CA finish has a blotchy section. (3-4 coats of Med CA, Sanded level between coats when necessary.) Despite MM to 12K and buffing. I didn't like it so I sanded the finish off to wood and started over. I still get a blotchy part. It is still very smooth, but won't sand or polish to a high gloss despite the rest of the pen being like glass. I know there is CA in that spot because when I sanded I got the typical white CA sanding dust.
Any suggestions
Thanks
Andy
 
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Welcome to the IAP. What kind of wood is it? There are some woods that just don't like a CA finish because of the oil content. Without know what kind of wood it is, my guess is that you're sanding through the finish. Did you seal the wood with thin CA? Most people here, if not all, who use a CA finish seal the wood with 2-3 coats of thin CA before applying thicker stuff.
 
I am a luthier so I have a lot of left over guitar woods. This was mostly african ebony.
I sealed with 1 coat of thin CA
I don't think I sanded through the finish since I was getting white CA dust in that area. Also, I thought I might have sanded through at first, so I sanded the entire block back
down to wood and started over.
Thanks
Andy
 
I've never used African Ebony, only Asian Ebony, but I believe most people around here say that CA doesn't work very well on it. I used to have a lot of trouble sanding through even several coats of medium CA. After I switched to thick CA, it hardly ever happens.
 
Make sure you get a even coat on the wood. Wipe it blo and let dry before you start sanding. I had the same problem. I was not letting the ca and blo dry before sanding. Use just a little accelerator, if not sure run your finger over the blank. Check in the library for the demos, they reall helped me. Hope that helps.
 
You are not going to buff out the blotch. I have tried, and I have all sorts of buffing compounds and sanding media. Nothing--- absolutely nothing--- will work.

The problem isn't on the surface. It's in the CA film. I don't know how, why, or what, but something causes the CA to get milky.

Sand the CA to a nice, smooth surface and finish up with 400 grit sandpaper. Spray on a coat of lacquer, it will bond to the CA just fine if the CA is sanded with 400 grit (don't sand with heavy force, just enough to scuff the surface). For whatever reason, this always works for me and the haze goes away. Does't seem logical, but it works for me every time. I seal every wood pen with CA and spray with lacquer.


To totally remove the CA, you need to take a cloth soaked with Acetone and put the lathe on low speed. Use the Acetone to remove the CA. Will take a while but is quicker than sanding.
 
Also, you can try system 3 bartop epoxy. That stuff goes on thick, sticks to anything, and is much harder than CA finish in my opinion. It will take more patience, as you'll have to wait a couple days before sanding down and polishing the blanks, but patience has it's rewards. There sure won't be a milky problem. You do have some dust settling to worry about in the first 6 hrs...but I just rest a board over the top of the lathe and that makes a big difference keeping dust off it.
 
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