How to alleviate horizontal scratches in CA finish

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Nickfff

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Hello,
I have been doing CA finish and I like it overall. However, I still see horizontal scratches. Does anyone have any tips on avoiding/retting rid of this?

Thanks in advance for replying,
Nicholas Frederick
 
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A few thoughts.....
Use a skew for your finishing cuts...
NEVER use anything lower than 400 grit...
NEVER skip grits...
ALWAYS stop the lathe and sand lengthwise with EVERY grit...
I follow these rules when sanding bare wood and CA finishes and it works FOR ME.
 
Nick,
You didn't give your sanding protocol so I'm assuming you MM through 12000. Some say it is necessary to sand the barrel length wise to eliminate the circular scratches. I have found this not to be necessary. I use an automotive antiswirl compound, like Meguier's, after 12000MM on both my CA finished wood pens and my acrylic pens. Some use the Novus polish and get the same great results. After the antiswirl, I follow with pure carnuba was and TSW.
 
Nick,

Also of importance is trying to determine if your horizontal scratches are in the pen blank magnified by the CA or if the scratches are in the CA finish itself.
 
Originally posted by Nickfff

Hello,
I have been doing CA finish and I like it overall. However, I still see horizontal scratches. Does anyone have any tips on avoiding/retting rid of this?
Click to expand...

Nicholas; I would add to the suggestions by others.

Between each grit, wipe down the blank with denatured alcohol. This removes sanding debris and any sandpaper grains left on the blank.

You *DO* want to determine whether the scratches are in the finish or in the blank.
 
When I'm sanding the lathe is on slow and I move the sandpaper as quickly as I can left to right and right to left. By keeping the lathe turning and the sandpaper moving I get a crosshatch pattern of sanding marks rather than horizontal lines. Yes, I then turn off the lathe and go lengthwise to get rid of the crosshatch marks. Then I switch to the next grit. I repeat like this all the way down to my final grits.

You have to be careful of everything in your shop, though. I've had "the perfect finish" and gone to put on that final coat of wax and had a hard spot on the microfiber cloth where the wax from previous uses had dried. I ended up with a bunch of teeny tiny scratches. Now, I use clean cloths for each pen.

GK
 
In my opinion we have lots of turners on this forum but few wood workers! That is not meant to be an insult, just a fact in my opinion. I've met many fellow pen turners who have only made pens and nothing else, have little to no knowledge of wood working basics other than what they pick up on this forum.

Sanding is an acquired skill just as using a router, jointer or applying a nice hand rubbed finish. I have heard a thousand methods of sanding but seriously doubt if half the people even stop to think what sanding really is.

When you sand with one grit, say 400, then follow up with 500, the 500 should be removing the deep scratch marks made by the 400. Then the 600 should be removing the scratches left by the 500 and so on. If you need to start with courser grit than 400 I would seriously consider having a look at your turning skills and choice of tools. A skew will leave a smooth finish needing little sanding, often only requiring a light touch with 600 grit then 1000 before buffing.

I have seen people sand so quickly that they are not removing the scratches left by the previous grit and by the time they are using 1000 grit, they still have heavy scratches left by the 400 and 600 grits. You can spend a day with micromesh and will rarely remove heavy scratches left by the courser grits.

My method......... TAKE YOUR TIME AND SAND CORRECTLY! You'll have better finishes stopping at 1000 grit then buffing than poor sanding followed by going all the way through the micro mesh series then ten polishing compounds!

Nicholas, I would start with 400 grit then look at your blank. Are there outstanding scratches more prominent than others? NOW is the time to deal with those not later. Don't leave a grit before you have fine uniform looking swirl marks.
 
Originally posted by Texatdurango


Nicholas, I would start with 400 grit then look at your blank. Are there outstanding scratches more prominent than others? NOW is the time to deal with those not later. Don't leave a grit before you have fine uniform looking swirl marks.
Click to expand...

George; To join the thread; I have and use a jeweler's loupe (sp?) to examine pen blanks. Cheap ones can be had for $10 or so....

I think mine cost $20 or so and have several loupes of different magnifications.
 
Tex... Is right about the basics of sanding. I used to do lapidary work and you sure get used to sanding/grinding to remove the previous grit's scratches before moving on to the next finer size. If you don't, you will be there all day long.

I happen to turn with a gouge, then a skew, then rough sand with 180 grit to level off the blank. I do this with the sandpaper streched tight. I then go to 320, 600, and then MM to whatever grit the wood needs to get the shine. I always stop the lathe between grits to inspect for scraches. I then use CA and start sanding that with 1500 MM lightly to smooth it out. I rarely sand CA past 4000 MM before buffing out with novus polish.
 
Originally posted by Texatdurango

In my opinion we have lots of turners on this forum but few wood workers! That is not meant to be an insult, just a fact in my opinion. I've met many fellow pen turners who have only made pens and nothing else, have little to no knowledge of wood working basics other than what they pick up on this forum.

Sanding is an acquired skill just as using a router, jointer or applying a nice hand rubbed finish. I have heard a thousand methods of sanding but seriously doubt if half the people even stop to think what sanding really is.

When you sand with one grit, say 400, then follow up with 500, the 500 should be removing the deep scratch marks made by the 400. Then the 600 should be removing the scratches left by the 500 and so on. If you need to start with courser grit than 400 I would seriously consider having a look at your turning skills and choice of tools. A skew will leave a smooth finish needing little sanding, often only requiring a light touch with 600 grit then 1000 before buffing.

I have seen people sand so quickly that they are not removing the scratches left by the previous grit and by the time they are using 1000 grit, they still have heavy scratches left by the 400 and 600 grits. You can spend a day with micromesh and will rarely remove heavy scratches left by the courser grits.

My method......... TAKE YOUR TIME AND SAND CORRECTLY! You'll have better finishes stopping at 1000 grit then buffing than poor sanding followed by going all the way through the micro mesh series then ten polishing compounds!

Nicholas, I would start with 400 grit then look at your blank. Are there outstanding scratches more prominent than others? NOW is the time to deal with those not later. Don't leave a grit before you have fine uniform looking swirl marks.
Click to expand...


This is good but if your turning skills have not reached this level you will get the same thing if you start with 60 grit then 80, 120, 150, 180, 200, 220, and so on until you get to the 400 and go on as quoted and it will turn out just as good, make sure that the scratches are gone before going to the next grit. No you should not have to start with 60 grit.
Bob
 
Originally posted by randyrls

Between each grit, wipe down the blank with denatured alcohol. This removes sanding debris and any sandpaper grains left on the blank.
Click to expand...

This tip made the biggest difference in my finishes! If you are grinding away with a bit of grit from the previous step or the material itseld, you are just cutting more scratches into the wood!
 
Originally posted by Nickfff

Hello,
I have been doing CA finish and I like it overall. However, I still see horizontal scratches. Does anyone have any tips on avoiding/retting rid of this?

Thanks in advance for replying,
Nicholas Frederick
Click to expand...
Nick, are you sanding with the lathe turned off and going back and forth?? This could be the reason for the horizontal scratching. I rarely do this, only when doing acrylic and I see some build up from dirty MM in ring form, or so. Then I sand horizontal with the lathe off. But I also follow with the next grit and the lathe spinning. As far as speed, I sand with the lathe full speed, I don't see the need to run a low speed for sanding. I use a low speed only for application of CA, Enduro etc.
 
Start with as low a grit as you feel your turning skills require. For some, that may be 600. For others, 60. I only sand up to 600, wiping with a dry paper towel between each, for the reasons mentioned by others. I used to MM it all the way up to 12000 but stopped - I believe (could be wrong) that some woods were absorbing some water and releasing it _underneath_ the CA finish when I applied it - causing a cloudy appearance. Not to mention, take a look at a woodworking magazine sometime. I don't think any of them will recommend sanding up to 600, let alone 12000MM! They seem to get some amazing finishes without going that high, so we should be able to also, right? I also only MM the CA to 6000 - I actually don't care for the super smooth finish you get if you go much higher than that - especially with buffing. But, that's personal preference.

The one thing that remains: if you keep sanding and just can't get the deep scratches out... you're probably using too fine a grit. Go back to a larger grit (either the one you started with, or perhaps even lower depending how bad it is) and go through all the grits again... no cheating!
 
All,
Thanks for the replies.

Here are answers to some of the questions raised...

-I have historically sanded to 12,000mm then novus
-I don't see scratches in the wood, I see scratches in the CA

I tried sanding with the lathe turned off going back and forth now the finish looks alot better.

Thanks for thoughts and replies,

Nick
 
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