Scratches in CA Finish and Other Problems

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I've been noticing some scratches appearing in my CA finishes lately. I decided to buy some new Micro-Mesh pads to see if that would fix the problem, but nothing seemed to change. Is there something I'm missing?

For my CA finish, I apply 2 coats of thin CA to fill any open grain in the wood, then sand back to 600 grit, polish with wood shavings, and remove any dust with DNA. Then, I apply 10 coats of thin CA, using accelerator between every two coats (then wiping off any excess with a blue shop towel). Then, I speed the lathe back up to 1500 rpm and wet sand with Micro-Mesh, starting with 1500 and going up to 12000. Finally, I speed the lathe up to 2400 rpm and polish with plastic polish.

Another problem I've been having is with my plastic polish. On two separate occasions, I've had my polish melt completely through the finish. I'm not exactly sure what's causing it, but I think it might have to do with the blue shop towels that I use to polish my blanks (it also might just be from the heat created when polishing). Is there any way to counter this? I've been thinking of purchasing a buffing wheel, which might help.
 
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KenB259

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You have to be careful with some of the plastic polishes. One that I had a terrible time with was called "one step" I ruined a lot of finishes before I gave up on that one. I'm guessing you got it to hot while applying the plastic polish. As far as the CA finish, it all comes down to technique and there seems to be hundreds of techniques.
 

sorcerertd

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I've had these same problems. CA is essentially plastic and will melt if there is too much friction. Maybe that is part of the trouble. Polishing should be done with light pressure or the grit (no matter how fine it seems) will gouge the finish.

That being said, I do have trouble with those micro scratches, too. They often are not noticeable until you are a couple grits beyond the one where the inconsistency occurs. I end up going back a couple grits and trying to even it out and progressing back through the grits again. The last one I did has an awesome shine, but those tiny scratches are still present. Guess it takes a lot of practice.
 

jttheclockman

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A couple things here. Start with CA. 2 thin coats and you are sanding after. I can tell you with all certainty that you are sanding the finish away in a heartbeat. Not nearly enough to start sanding after 2 coats. Now you are introducing surface scratches back into the wood blank and if you do not remove they will show all the way through to final finish because CA is like a magnifier and it will deepen the look. Even using all thin layers and using 10 coats is just not enough. I do not care how thick you think you are putting it on. If you insist on thin instead of going with med, then increase layers to 20 or at least 15. As mentioned there are 10000's of methods to apply CA and finish so all I will say is I will mention mine and you will see the comaprison. I will always start with about 4 coats of thin CA. That is to seal the wood not to build a finish with. Never touch that CA with any type sandpaper. Should not be a reason to. I then apply 5 to 8 coats of med depending on my infill needed to build blank back up and allowing for sanding. My sanding is always wet sanding and if need be I will never start with anything less than 600grit and usually start with 800 and switch to MM after 2000 grit. I alwways stop lathe to sand with the blank after sanding with lathe running. This gets all scratches out.

As for top coats and polishing, there are a ton of polishes but you need to be careful with is they will have some sort of grit in them and the finer the better. I use MM polishes. Good luck. Wet sanding will eliminate the heat portion where it could melt your top coats.
 

studioseven

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You polish with wood shavings? I've never heard of that. Could you explain the process? I prefer Ultra Gloss or Novus for polishing but there is a host of other finishes just as good. Also at some point you should try using Glu Boost instead of CA. Hope this helps.

Seven
 

jttheclockman

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Burnishing wood with wood shavings is done all the time. Many turners do this when making bowls and spindles and things. They grab a handfull of shavings they turned off and by hand apply while lathe is spinning. Not so safe way to do things but it is done all the time. You do not do this on a finished piece. Some people use paper bags as the substitute for shavings.
 

Kcimdrib

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I use CA on wood all the time and have not seen this problem my method is as follows.
1 Sand down to 600 grit stopping Lathe and sanding along blank between grits.
2 One coat CA thick Lathe slow.
3 Eight coats CA thin all coats applied with Blue Roll
4 Micromesh Lathe speed 600 rpm stop between grades and sand along blank.
5 Burnishing Cream fast speed light pressure applied with Blue Roll.
Hope this helps.
 

jrista

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Another problem I've been having is with my plastic polish. On two separate occasions, I've had my polish melt completely through the finish. I'm not exactly sure what's causing it, but I think it might have to do with the blue shop towels that I use to polish my blanks (it also might just be from the heat created when polishing). Is there any way to counter this? I've been thinking of purchasing a buffing wheel, which might help.

When I first started using plastic polishes, I polished with the lathe on and had similar problems (mostly melting acrylic, though). I now polish with the lathe off, both circular motions, then strait motions along the blank, to polish out remaining scratches.

Note that, for a polish to work, you need to have very fine scratches already. If you are trying to polish out large, deeper stratches, the polish is usually of such a high grit that all you'll do is make a sharp-edge scratch into a rounded edged divot or ditch, but you won't get rid of it. You will need to effectively polish the blank with high grit wet sanding (MM goes up to 12000 grit, and I spend a little time wet sanding with that one to polish the blank up as best I can first). Your blank (CA in your case) should look shiny and glass like with a sharp specular highlight, until you get the light at an angle...you'll then see remainder scratches. Its THOSE scratches that polish is intended to remove.

Finally, keep in mind that, ultimately, there is no "total removal" of scratches. Polishes are still a grit, just a finer grit than the sandpapers (papers may go up into the thousands, polishes are usually in the tens of thousands, so you may find wet/dry papers up to 2000 grit or so, MM up to 12000 grit, polishes can be 30000 grit, 45000 grit, etc.) You will still have scratches after polishing...its just that those scratches are ultra fine, so they are very hard to see, and most people will be looking at the blank itself, the wood underneath the CA, not looking for ultra-fine scratches.
 

Kcimdrib

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Be careful when using Buffing wheels you can generate more heat with this method.
 

jrista

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One thing I am curious about is what the best polish for plastics is. I've been using plastic polishes you can find at woodcraft or from PSI, which are somewhat expensive. I've heard of people using metal polishes and the like, though, and I think even car clearcoat polishes. I'm curious what works best. Even with some effort, I am sometimes still not able to reduce my scratch level on plastics down to what I would consider acceptable. I wonder if the polishes I'm using are just not quite sufficient...

Another thing I am curious about is, does anyone use another kind of finish on top of plastics? I turned a couple of pens that used segmented blanks I found on Etsy. They were wood, plus resin (alumilite I think) with metal honeycomb in them. I used Pens Plus, and I was actually blown away at how good the resins looked with the pens plus on it. Anyone else ever try that? With the microcrystaline wax, I wonder if that might help fill in fine scratches? Not sure about durability and longevity, though...
 

Kcimdrib

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I use a Burnishing Cream from Chestnut or a paste from Axminster Power Tools which resembles T Cut
I have used Tooth Paste very fine abrasive.
 

Bstrauch

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Another thing to consider is how long you let the CA cure. I usually let it cure for at least 24 hours to fully harden. CA is still somewhat soft even with an accelerator until some time has passed (at least that has been my experience).
 

Kcimdrib

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Another thing to consider is how long you let the CA cure. I usually let it cure for at least 24 hours to fully harden. CA is still somewhat soft even with an accelerator until some time has passed (at least that has been my experience).
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mmayo

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Save yourself some work.

I think sanding before you are done applying CA is an issue unless you see a major need. I apply 4 coats of thin, spray, apply 8-12 coats of pen finish 50 cps with light spray after each. I let cure for at least an hour THEN I sand with 400 grit. I buff on the Beale buff and press together. It works every time.
 
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