CA Finish and Plastic Polish

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DRB4381

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Joined
Apr 12, 2010
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128
Location
Floyds Knobs, Indiana
Having some issues with my CA finish after using Plastic polish. I basically follow William Young's method of applying 6-8 coats of med CA, I then wet mm to 12000. At this point the blank usually still looks OK. I then use Mequiers PlasticX or Novus 2 to bring out the final gloss. However, I often end up with very dull looking spots on the blank, usually near the ends, but not always. When inspected with a 10X magnifying glass it looks like very distinct patches where the finish has many tiny scratches. Finish still feels very good to the touch. I apply the plastic polish with a paper towel on the lathe. Seems to happen on variety of woods so I don't think that is the issue. Anyone else had an issue like this? Am I pushing too hard with the PP? Not letting CA cure properly? Poor quality paper towels? Thanks for any help.
 
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Daryn, I have had that same thing happen at times. It is always fine after 12000 and appears after the Novus2. I have never figured out what is causing it though. I usually end up running across it with 600 grit, adding a coat of CA and doing the MM again. Sometimes I get brave and do the Novus2 again and other times I just leave it off. (When I do repeat the final Novus step about half the time the problem pops back up).

I would like to know what is causing it as well. I'm pretty sure I'm not getting down to bare wood.
 
Just a thought

If you examine the wood where the spots occur could they be "softer wood" then the rest of the blank? I know if I sand a somewhat spaulted blank or even one with sap wood, I end up sanding flat spots in the blank. So when I go to finish the blank, the CA/BLO goes on unevenly in those areas.... and even before finishing this could cause the sanding to be uneven where the finer grades of sand paper just sort of skip over any flat spots.... leaving the coarser paper sanding scratches. Like I said.... just a thought.

also use Bill Young's BLO/CA finish technique. Never had a failure or even a need to sand further after the final coat has been applied. Obviously if you want a lot more gloss you can additionally MM, polish and wax.

Good Luck
 
I don't think it is an issue with soft wood, as several of the times it has shown up with solid woods such as tiger maple and rosewood (among others). I'll try to take a picture later tonight, but I think it will be difficult to get it to show up very well, as the light has to hit it just right for it to be obvious. Thanks.
 
One thought that came to mind...

People new to CA finishes might have experience with friction polishes.
A friction polish can get pretty hot on the blank as you pinch.. hot enough
to burn your fingers. If you are tempted to do this with the plastic polish,
you can soften the CA finish. Different formulations have various melting
temps, but it wouldn't surprise me if holding some tee shirt material with
an abrasive paste on it against the spinning blank could generate enough
heat to reach it's softening point or it's distortion point. Either one would
pretty much trash your glossy finish..
 
MLKWoodWorking said:
Sounds like you are going through the ca to the bare wood.
Click to expand...


I agree. Sounds like you are burning through the CA. It doesn't take much to do so and if you are going through the MM and using polish, it is likely. It will depend on how long you use each grit as well.
On a CA finish, I usually go over it very lightly with 600-800 grit wet, then cut and color it quickly.
 
I had that same problem. Then I stopped using BLO and the problem went away. I only use BLO on the bare wood after I clean with acetone (to pop the grain), after that it's CA only with a spray of accelerator on each coat (6) total, Micro mesh thru to 12000 then the plastic polish. Glass like shine every time no dull blotches.
 
HI
THIS NEVER ENDS DOES IT? :):):)
I KINDA THINK IT IS THE ACCELLERATOR CAUSING MY DULL SPOTS, I GAVE UP USING IT. AND I HAVE BETTER RESULTS IF AFTER FINISHING WITH THE COATS OF CA, LEAVING IT OVERNIGHT THEN FINAL SANDING.
SULLI
 
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