Wierd spots left on a ca finish

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Benelli6

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Joined
Aug 27, 2019
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8
Location
Rockford michigan
I am relatively new to pen turning and I'm having a issue with my CA finish. For some reason I have big splotches left that look dull. At first I thought I might have sanded through the ca into the wood but that's not the case. There is still plenty of ca on the wood. I've attached some photos of what the wood is looking like. One came out well but the other has the big splotches I have mentioned. I use denatured alcohol to clean the oils off the wood but I make sure to let it completely evaporate before I apply the Ca. I also sand the CA with micro mesh and apply a plastic polish.

Thanks for the help!!!
 

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Looks like you sanded through your finish. Have you checked if your mandrel is straight? Last time I had this issue I had a bent mandrel.
 
Looks like you sanded though the finish. Once I put ca finish on, i start with 3200 micromesh. Very light pressure
 
When I see spots like that on my work, it usually represents the CA separating the the wood. I remove all and start over ensuring the wood is dry and allowing more time between coats. I usually only get that on the ends after assembly.
 
I agree from the photos it looks like CA has been sanded off. But with that said, other things can cause the same look. First is if you did the CA finish and and took the blank off to sand the ends because of CA build up on those bushings (which I do not like when finishing) It make have cracked the end of the CA. Also if wet sanding and you do not seal the ends of the blank, water can get under the CA and cause lifting. We do not have a good read on your method of applying and sanding and finishing so hard to make a true assessment. We are guessing here. I highly suggest you do not finish with the same bushings as you turned with. Make or buy some finishing Delron bushings. There is a ton of info here if you do some searching and even check the library. Just so much to cover when it comes to properly doing a CA finish and there re many methods used. But those bushings have to go.
 
jttheclockman said:
I agree from the photos it looks like CA has been sanded off. But with that said, other things can cause the same look. First is if you did the CA finish and and took the blank off to sand the ends because of CA build up on those bushings (which I do not like when finishing) It make have cracked the end of the CA. Also if wet sanding and you do not seal the ends of the blank, water can get under the CA and cause lifting. We do not have a good read on your method of applying and sanding and finishing so hard to make a true assessment. We are guessing here. I highly suggest you do not finish with the same bushings as you turned with. Make or buy some finishing Delron bushings. There is a ton of info here if you do some searching and even check the library. Just so much to cover when it comes to properly doing a CA finish and there re many methods used. But those bushings have to go.
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Thanks! The bushings in the pics are not the ones I used. I have nonstick bushings. I just used these so you could see the wood better. Any advice on how to deal the end of the pen to prevent water from getting in when sanding?
 
Benelli6 said:
Thanks! The bushings in the pics are not the ones I used. I have nonstick bushings. I just used these so you could see the wood better. Any advice on how to deal the end of the pen to prevent water from getting in when sanding?
Click to expand...

After you trim the excess CA off the ends of the tube, lightly coat the ends of the tube with thin CA. To do this, I take a folded piece if paper towel and dampen it with thin CA and then dab the blanks on that. Work quickly - it WILL stick!
 
In addition to sand-through from bent mandrel, sand through comes about from different reasons:
1. Not thick enough layers of CA. Anyone can apply 10 to 15 layers of thin CA with paper towel and I can apply one layer with medium that is thicker. The point is, It is NOT the number of coats that make a success, it is the thickness and build UP of layers. If you want to know how effective your coats are, use a set of good calipers (metals ones) to measure the diameters Before Appling CA and after applying CA. That will give you the thickness. VERY Thin layers will/can be sanded through in SPOTS.
2. Too much pressure in Sanding will cause the mandrel to give and flex just enough that you will sand more on one side than another.
3. soft woods will sand more on the soft portion between bands of hard grain.
4. Using a stock wood lathe endpoint/live center in the tail stock - in the little cup in the mandrel. The mandrel requires a 60° live center for proper use. The wood lathe live center is made for WOOD, not mandrels. This will cause the tip of the live center to bend a tiny bit and introducer minuscule wobble and sand through on one side.
5. Too Tight on the tail stock with mandrels - Again forcing a minuscule bend in the mandrel - maybe imperceptible to the naked eye but results in sand through in spots.

You mentioned that "you can see the CA but you see flat spots". This is a description that many "new to turning" say. Because the CA can be seen easily - that does not mean that it is everywhere. It has been sanded off in the dull areas. One other item that hides this is if a wax is applied AFTER turning, the shiny wax may hide the sanded spot for a few hours to a few days.
 
It is amazing when you stop and think how much effort and care needs to go into making a pen. Then people wonder why they cost so much. You are paying for the skill and knowledge, not just a pen. Just this post there are some very good tips here and they do not even touch or scratch the surface. On top of that the many ways to go about these methods. what can be learned here is so valuable if you are truely serious about pen turning so do not take for granted. What Jeff and fore runners thought of when this forum started started has developed into what it is today. I bet they never envisioned this.
 
Water is used to keep the heat down. Friction creates the heat. So, if you don't create friction, you don't need water. If your blank is getting hot, you should change your procedure to eliminate the heat or stop periodically to allow the blank to cool.
 
jttheclockman said:
It is amazing when you stop and think how much effort and care needs to go into making a pen. Then people wonder why they cost so much. You are paying for the skill and knowledge, not just a pen. Just this post there are some very good tips here and they do not even touch or scratch the surface. On top of that the many ways to go about these methods. what can be learned here is so valuable if you are truely serious about pen turning so do not take for granted. What Jeff and fore runners thought of when this forum started started has developed into what it is today. I bet they never envisioned this.
Click to expand...
very true. A lot of people overlook how complex the process can be.
 
leehljp said:
In addition to sand-through from bent mandrel, sand through comes about from different reasons:
1. Not thick enough layers of CA. Anyone can apply 10 to 15 layers of thin CA with paper towel and I can apply one layer with medium that is thicker. The point is, It is NOT the number of coats that make a success, it is the thickness and build UP of layers. If you want to know how effective your coats are, use a set of good calipers (metals ones) to measure the diameters Before Appling CA and after applying CA. That will give you the thickness. VERY Thin layers will/can be sanded through in SPOTS.
2. Too much pressure in Sanding will cause the mandrel to give and flex just enough that you will sand more on one side than another.
3. soft woods will sand more on the soft portion between bands of hard grain.
4. Using a stock wood lathe endpoint/live center in the tail stock - in the little cup in the mandrel. The mandrel requires a 60° live center for proper use. The wood lathe live center is made for WOOD, not mandrels. This will cause the tip of the live center to bend a tiny bit and introducer minuscule wobble and sand through on one side.
5. Too Tight on the tail stock with mandrels - Again forcing a minuscule bend in the mandrel - maybe imperceptible to the naked eye but results in sand through in spots.

You mentioned that "you can see the CA but you see flat spots". This is a description that many "new to turning" say. Because the CA can be seen easily - that does not mean that it is everywhere. It has been sanded off in the dull areas. One other item that hides this is if a wax is applied AFTER turning, the shiny wax may hide the sanded spot for a few hours to a few days.
Click to expand...
Thanks for the advise! Really helpful to me as a beginner. Thanks!!!
 
I will disagree with the not using water and the reason is CA is plastic and plastic needs a lubricant to sand and water is that lubricant. If you seal the ends of the blank water does not get into the CA. I do this all the time. If you do not use a lubricant when sanding with MM you wear those pads out real quick especially the real fine ones. Now if you are talking sanding bare wood then that is obvious you never want to introduce water into wood. We fight to get them dry.
 
I wet sand the CA finish as John does for the same reason . However , occasionally I sand through the coating , causing a dull spot , and re-introducing the wood to water . That is the point at which the blank gets set aside , and returned to another day when it is totally dry .
 
Personally, I've never wet sanded a blank, and I've never ever had an issue with my CA finishes. I sand all of the blanks I turn, But, without water and very lightly. And my pens always look nice and shiny, with a smooth no flaw finish.

Len
 
Plastic does NOT NEED water. I have made and sold thousands of "plastic" pens=PR, Acrylic Acetate, inlace acylester, alumilite-and never used water to sand. In fairness, I only sand with 400, 600 and 1000, then go to a buffer with tripoli and white diamond. This regimen does not get the pen blank hot.

Regarding the sandpaper, I cut my sheets into strips about 1-1.5" wide. Use them once then throw away. I get 3-4 pens out of each strip, so I'm not trying to save sandpaper.
 
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CA and other plastics need a lubricant when sanding more for the longevity of the sanding material. I have clogged a lot of sand paper with melted plastic and had to trash the paper. While you can do it without a lubricant your sanding materials will last longer with one.


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ed4copies said:
Plastic does NOT NEED water. I have made and sold thousands of "plastic" pens=PR, Acrylic Acetate, inlace acylester, alumilite-and never used water to sand. In fairness, I only sand with 400, 600 and 1000, then go to a buffer with tripoli and white diamond. This regimen does not get the pen blank hot.
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ED that is your method and you do not use MM. When they sand a finished piece of furniture they use an oil to lubricate. Now I have never made thousands of pens an never will in my lifetime but have done my share to see the difference in using a lubricant and not. I suggest this because there are so many ways to finish a pen is try different methods and choose for yourself. Because we are all adamitt about our methods that work for us. No right or wrong.
 
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I too use a plastic polish after micro meshing. You do have to be careful with some of those that are marketed as a plastic polish for pens. If you get to aggressive and build up to much heat, you end up with splotches exactly like you have shown. Speaking from experience here. Can't say that was what happened, but it has happened to me.


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