Why is this so?

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Tiger

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Feb 15, 2009
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245
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Melbourne, AUSTRALIA
I've had mixed success with CA finishes but am curious about a situation that keeps recurring with my finishes. I've noticed that I sometimes get a dull finish, it however only occurs at the ends of the blank and is usually a small patch that usually goes all around the blank or 3/4 of the way around. It is typically on one blank only (because I turn 2 blanks at the same time). I typically use thin CA and accelerator after every 2nd or 3rd application of CA and I apply the CA somewhere b/w 15 and 20 coats with a paper towel then MM, then Brasso and Swirl Remover. The photo is the best I can take at this stage and it looks similar to torn grain but I'm pretty sure that when I prepare the blank there's no torn grain. For the record I sand to 1000 grit and the blank is nice and smooth. I have been told that it could be from oversanding but why does this only happen at the end of the blank? I do use wax on metal bushings to separate them easily, not sure if the wax is contaminating the finish. Can anyone shed light on this?
 

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CREID

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Jul 23, 2008
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Vancouver, wa
Although I have not had the experience that others have here, I will give my 2 cents.
There are a few things I have noticed while finishing pens.
First, as I sand, I notice that the center gets more sanding than the rest of the blank due to action of going back and forth while sanding, and I do notice that if you do not get a good smooth surface, before finishing, you get a poor finish.
Second, I think the same thing applies to applying the finish as sanding, especially with CA, I tend to get more in some areas than others, usually one end or the other because of the way I apply CA, so if you don't get enough CA on one end or both ends you won't get the shine you do where there is more.
Third, this applies more to CA than friction polish, it is really easy to over sand as the CA finish is usually not very thick, for me anyway, and sometimes I get areas of no or little gloss due to over sanding the CA.
I am sure there are other reasons, like moisture, oily wood and such, but any of these or combination of these could be the problem.
Personally I suffered with CA for a long time and only recently have had consistant success, I haven't really been doing anything different, just constant practice and getting consistant. The more you do the better you get at it.
I think that was actually 2 1/2 cents, but keep the change.
It is also hard to tell from your photo, not complaining as I can't even take a photo to post, but you may be a little oversized on the end there, causing accidental over sanding on the edges.
Curt
 

cwolfs69

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Apr 24, 2011
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portsmouth, va
i have had a similar thing happen on occasion. it looks like you have gone through the CA at the point. it usually does happen on the ends as the sanding medium rolls over the edge. when i see that i immediately stop and re coat with CA and re-polish. you can usually get rid of it.
 

azamiryou

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Aug 14, 2010
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Silver Spring, MD USA
If your blank is proud of the bushings, or you aren't using bushings, it's really easy to sand through on the "corners".

If your turning has low or high spots, they can be relatively easy to sand through. High spots can sand through because the sandpaper is cutting them more, and low spots can sand through because during application, the CA can migrate to the high spots, leaving the finish a bit thinner there.

Either way, what's in the photo really looks like sand-through.
 

robutacion

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Aug 6, 2009
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Australia - SA Adelaide Hills
Hi Tiger,

You mention that, you turn the 2 barrels at the same time so I assume you using a pen mandrel, right...???

My question to you is, is the barrel that gets this dull ring, always the one furthest from the head-stock...???

If this is the case, there is a good chance that you have some wobbling at that end of the mandrel. This should be also noticeable when you turning your barrels, particularly the one furthest from the head-stock however, this out of balance movement should show on the non-roundness on the barrel's right bushing.

If the barrel is perfectly round after you turn it and that dull ring forms in the finishing stages/steps, one of 4 things can be happening;

1- The way you are applying the CA is not uniform, particularly at that end of that barrel...!

2- Your sanding technique is allowing for excessive CA removal/sanding from that barrel end...!

3- You are putting too much pressure at that end of the mandrel when sanding, forcing it to vibrate, therefore removing material in a wobbling motion...!

4- A combination of 1, 2 & 3

If the mandrel is not straight, even tough is not so noticeable when turning, a combination of some or all of the points I made above, are rapidly magnified by the out of balance mandrel...!

These are all "possibilities"...!

Good luck
Cheers
George
 
Joined
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Destin, FL
If you are using bushings, its also possible that one of the bushings isn't drilled on center. My cigar kit bushings are great except for the "nib" end. It's so off center I had to make my own to replace it.
 

Tiger

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Feb 15, 2009
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Melbourne, AUSTRALIA
Thanks guys for the responses, that really helps and gives plenty of food for thought. I'll need to take it easier on the ends.

George you're right I do use a mandrel and the end nearest the tailstock probably is the main one one where the dull finish takes place but I have had it happen at the end nearest the headstock just not as often. The mandrel is not out by much but that does explain why this is happening.

I wet sand with MicroMesh and usually don't realise that I've oversanded until I get to the 12000 MM, it certainly isn't visible before then. Is there any way of telling that there is not enough CA on the blank before sanding that far?
 
Joined
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Location
Destin, FL
Thanks guys for the responses, that really helps and gives plenty of food for thought. I'll need to take it easier on the ends.

George you're right I do use a mandrel and the end nearest the tailstock probably is the main one one where the dull finish takes place but I have had it happen at the end nearest the headstock just not as often. The mandrel is not out by much but that does explain why this is happening.

I wet sand with MicroMesh and usually don't realise that I've oversanded until I get to the 12000 MM, it certainly isn't visible before then. Is there any way of telling that there is not enough CA on the blank before sanding that far?

Yes...wipe the blank with a damp paper towel between grits. Make sure the blank is dry and you should see the place missing the CA.
 

keithbyrd

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Sep 2, 2011
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Mount Wolf, PA
I guess I am one of the fortunate ones. I had some trouble with the first 5-6 pens I finished with CA but none for the last year. (Knock on wood).
This is my process:
1. Sand the blank to 400 or sometimes 600.
2. Dust blank with micro fiber cloth and air compressor.
3. Use delrin bushings (from pen products)for applying CA, sanding, MM and polish. (Delrin lets me finish the blank without sticking to bushings)
4. Set speed to 500
5. Using thin CA (I have used 4 different brands with no trouble) I drop 5-6 drops on blank and wipe quickly from the bottom with a paper towel. ( I take 1/2 sheet paper towel, ViVa and fold it in half 3 times so I have 8 layers of PT)
6. Spray quickly 1-2 quick spurts of activator
7. Wait 4-5 seconds and repeat 5 and 6, 6-8 times.
8. Using Medium CA I fold a new PT the same way and now squeeze about 1/8 wide drop on towel and from the bottom wipe quickly and spread completely across the blank. Wipe back and forth 2-3 times - quickly.
9. Spray quickly 1-2 squirts of activator. I find the med ca cures slower so I wait maybe 10 seconds after spraying acvtivator before repeating steps 8-9, 6 to 8 times.
10. I wait maybe 1 minute and then sand with 400 until all shiny spots are gone. Leave speed at 500, clean sandpaper frequently, do not put too much pressure. I think if the CA gets hot it tends to get white or fuzzy spots in it. I do not wet sand.
11. After ensuring that all shiny spots are gone, clean all dust off with micro fiber and comporessor.
12. Increase speed to 2400. Using MM starting at 1500 I work my way through all the grits. I use just enough water to wet the MM and keep it from getting hot. I dip the MM in water then shake off all I can before putting to the blank. When the water dries off the MM I start seeing the shine coming through.
13. Light pressure and fast back and forth movements until the blank is shiny.
14. I follow the same procedure until I get to the last 3 MM pads. On these I use light pressure and no water.
15. Next I use a clean soft cloth and Huts Ultra and polish the blank.
16. I finish with a coat of ren wax polished at 2400.
17. Remove from lathe and assemble.
I have not had a problem with CA using this technique for the past year. I think speed and pressure are the culprits of bad finishes. Sand too fast and getting CA hot or using too much pressure and getting CA hot.
I ensure that my vac sytem is on so the CA vapors are pulled away from me or a fan is blowing over my shoulder to ensure I don't have to breathe the fumes.
Usually takes me 15-20 minutes to finish a pen.
I hope this helps some one get a better CA finish.
 
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leehljp

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Tunica, Mississippi,
One thing you can do to increase skill levels is to use calipers and measure the nib end, center band and clip end. Write these measurements down and turn down to the measurement sizes or about .005 less. Then apply CA, and measure your CA build up. Build up a little more than the size you need and sand back down. You will know at this point if you have CA on the ends or not, simply from the measurements, and also how much.

Bushings, as the sand paper touches them, or as the scraper/skew touches them, they will wear down over 20 to 25 pens and you will get inaccurate sizing unless you buy new bushings. Using calipers will eliminate this problem and let you know how much CA you have on the blank at any given time.
 
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Tiger

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Feb 15, 2009
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Melbourne, AUSTRALIA
Thanks Keith, there are countless variations of CA finishes and everyone swears by their methods, I think a lot has to do with how the CA is applied ie smoothly, consistently. Other factors outside our control such as climate and humidity will also affect results but will experiment with your method.

Thanks Hank, I do use digital caliper but probably not enough. My bushings have not worn away much as I'm usually careful about sanding away from them etc but I do agree that if you want precision, measure often.
 

NewLondon88

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May 15, 2008
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Location
Claremont NH
I dont use sand paper on my finish. micro mess get to hot

Try keeping the MicroMesh in a container of water. Put a drop or two
of dish detergent in it to act as a lubricant. MicroMesh doesn't get hot
that way, and you get a much more even finish.
 
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