Problem removing pens after applying a CA finish

[Bob Ellis]

I like the smoothness and shine I get using a CA finish, but I am having a problem when it comes to removing the blanks from the mandrel because the CA glues them to the bushes. I have tried snapping them off and I have tried using a parting tool to cut through the CA that builds up on the bushes. Whichever method I use, when I smooth off the ends of the blanks by gently rubbing them in a circular motion on fine abrasive paper laid flat on my work table, either a small piece of the finish breaks off or, more frequently lifts a bit so that the finish becomes milky (see the cap end of the photo below).



The white line along the pen cap is not a blemish - it is a reflection off the finish. The fault is next to the cap finial.

I saw a Barry Goss video in which he advised applying a small amount of CA carefully to each end of the blanks after removing them from the mandrel to stop the CA finish from lifting or breaking loose when the ends are smoothed down. This seemed to make sense, so I tried it on my latest pen (the one in the photo). It worked well on three of the ends, but part of the finish lifted on the cap end of one of the blanks, so I will have to either find a way of repairing it or take the finish off that blank and start again.

Any ideas of how I can overcome this problem? I have tried other finishes, but I prefer CA and want to make this method work more consistently for me.

Since it might be relevant, here is a summary of the way I apply the CA finish. Having shaped them, I smooth off the blanks using Micromesh pads down to at least 4000 grit. Then I clean them with acetone and leave them to dry for a few minutes. I apply a dozen coats of thin CA glue using small pieces of kitchen roll and spraying with accelerator between each coat. After leaving this to harden for about an hour, I use Micromesh 1500 to smooth out irregularities in the CA finish and then stop the lathe and work laterally along each blank until all shiny bits have been removed, which ensures that the surface is completely smooth. Then I take the Micromesh all the way up to 12000 grit until the finish is very shiny and finally I polish the blanks with Silvo. Thus far everything works perfectly.

The problem comes when I remove the blanks from the mandrel. The CA sticks the bushes to the ends of the blanks. I have tried snapping them loose and I have tried using a parting tool against the bushes to break through the CA. Both methods leave some CA proud of the end of the blanks. As I mentioned earlier, I rub the ends gently in a circular motion on a piece of fine abrasive laid flat on my work table to smooth them off. More often than not this works, but sometimes it just appears to do so and when I assemble the pen I end up with the situation in the photo, which means that I have to disassemble it. Since I don't know of any way of repairing the finish, I have to spend time removing the entire CA finish down to the wood and reapplying it.

I shall hold off trying to repair this pen until I hear from some of the wise and experienced turners who offer their advice so generously on this great forum.

 

[Gizmo3k]

You could try using delrin (or something similar) bushes for finishing - the CA shouldn't stick to that at all.

Buy a cheap rod off ebay or somewhere, and turn your own bushes, you can drill them out if you are using a mandrel, or turn a cone in the end to fit on a centre.

I don't tend to use bushes when turning, so don't really have this issue, although cleaning my centres can be a pain!

 

[TK woodman]

I agree with Gizmo with the delrin just a thought for you to consider - why put 12 coats on when 2 will do?

 

[stevenw1963]

Why put 2 coats on when spray lacquer will give just as good a finish without the smell.

But, As Alan says, shape & sand down to your bushes then take the bushes away and use cones or delrin or similar that the CA wont stick to.

 

[rayf6604]

As the others have said, make yourself some cone shaped bushes out of nylon or delrin, available off eBay, and use these in place of the metal bushes. When applying the ca I find it works best to use thin ca, and let a few drops drip in the blank while it's spinning and use paper towel (i use 3 sheets folded up and cut into strips) to work the ca quickly back and forth. It needs to be a quick operation for each coat using accelerator between coats. Don't be tempted to run the bottle of ca along the length of the blank to distribute the glue, just let a few drops in the middle while working it back and forth. This way I find, doesn't get too much glue over the ends of the barrel making it harder to remove. When I've built up the layers I use 800 by hand, not spinning, to smooth out any ridges then use plastic polishing compounds, Farecla works great, to get the shine then I remove from the lathe and use the 800 grit again to remove any residue glue from the ends. That's my method and I find it works well.

 

[TK woodman]

Why put 2 coats on when spray lacquer will give just as good a finish without the smell.

But, As Alan says, shape & sand down to your bushes then take the bushes away and use cones or delrin or similar that the CA wont stick to.

Yes there are a lot of different ways to finish a pen - But i thought the question was about CA

 

[Jim]

I would agree that 12 is far to much to be honest Bob, i have good results placing wax paste on the tube ends before placing them on the mandrel. It helps stop the blank sticking to the bushes ..

 

[bellringer]

I use a sharp knife and cut around it

 

[paulm]

As said 12 is too many coats. The white line is where the ca is thick and been pushed out by the fitting when pushing it in. sand the top so that the ca isn't above the top of the tube othewise it gets squashed when you push the fitting in and you get that white.

 

[bassethound]

Another one that uses Jim's way with a little wax always works for me..

 

[Bob Ellis]

I'll have to get some wax paste by the sound of it. In the meanwhile, I'll make some non-stick coned bushes. I don't have any delrin at the moment, but I have some tufnol rod of sufficent diameter. Any reason why that wouldn't work, if I turned it to shape?

The reason I have been using 12 coats is because a saw that recommended on a YouTube video. Another video even recommend 20! I tried cutting it down to 6 coats, but I found the micromesh cut through it. I will experiment with some different methods of application to see whether I can reduce the number of coats without breaking through it when I polish the finish.

 

[Penpal]

Bob I would find it a pain in the bum to stop and remove exchange bushes etc also you encourage out of round that way I undercut my bushes and try not to overload the CA in applying. Before the CA I rely on accurate measuring not the bushes.

Peter.

 

[bigbob]

Paste wax as Jim said works for me

 

[Bob Ellis]

When you say paste wax, do you mean as in furniture polish?

 

[Neil]

Bob,

I think it probably a fair assessment to say that I make more than the average number of pens, and my methods are more commercially orientated, ie if it isnt perfect it doesnt get fixed it gets binned. I put three, sometimes four coats of CA, neat, on to a blank sanded once with 240 grit rotating as the lathe slows and then with the grain. I dont use cones, I dont polish bushes or put wax on them. Because I only put three or four coats on the glue doesnt get excessively thick across the ends of the blanks. Many here would disagree with me but CA glue isnt very good, it doesnt stick to metal very well at all. I simply hold the bush in a pair of pliers and a slight , very small bit of presure cracks the glue over the bushes. The only wood that I dont do this with is Cocobolo, being very oily the adhesion to the blank is not as good and the glue is not as consistent breaking over the bushes, on this occasion I use a knife blade to score the glue and that works.

Polishing with Silvo after micromesh is without doubt a retrograde step. Silvo has a grit value quite course relative to the top micromesh grades, which incidentally are not graded on the same scale as normal sandpaper so never sand to 1200 with wet and dry and then start out with 1500 micromesh, you are going backwards, 1500 micromesh is somewhere between 400 and 600 grit sandpaper scale.

Paul is spot on about the delamination near the top, the likely cause is incorrect alignment when assembling the pen.

You Tube should come with a public health warning, literally. Theres some really good stuff but also a lot of crap.

 

[wm460]

Bob,

I think it probably a fair assessment to say that I make more than the average number of pens, and my methods are more commercially orientated, ie if it isnt perfect it doesnt get fixed it gets binned. I put three, sometimes four coats of CA, neat, on to a blank sanded once with 240 grit rotating as the lathe slows and then with the grain. I dont use cones, I dont polish bushes or put wax on them. Because I only put three or four coats on the glue doesnt get excessively thick across the ends of the blanks. Many here would disagree with me but CA glue isnt very good, it doesnt stick to metal very well at all. I simply hold the bush in a pair of pliers and a slight , very small bit of presure cracks the glue over the bushes. The only wood that I dont do this with is Cocobolo, being very oily the adhesion to the blank is not as good and the glue is not as consistent breaking over the bushes, on this occasion I use a knife blade to score the glue and that works.

Polishing with Silvo after micromesh is without doubt a retrograde step. Silvo has a grit value quite course relative to the top micromesh grades, which incidentally are not graded on the same scale as normal sandpaper so never sand to 1200 with wet and dry and then start out with 1500 micromesh, you are going backwards, 1500 micromesh is somewhere between 400 and 600 grit sandpaper scale.

Paul is spot on about the delamination near the top, the likely cause is incorrect alignment when assembling the pen.

You Tube should come with a public health warning, literally. Theres some really good stuff but also a lot of crap.

Very interesting Neil.

 

[Penpal]

I bow to the person you Neil who is directly responsible and careful in making pens for a living and always try to help us mere mortals with our making. Thanks .

Peter.

 

[Vic Perrin]

Interesting read Neil. Although I don't use CA I can value the points that you raise

 

[Bob Ellis]

Following some of the advice received here, I have successfully repaired the damaged pen pictured in my first post on this thread.



Having removed the damaged finish, I applied a fresh CA finish whilst turning the blank between centres so that the CA did not stick to the bushes when removing the blank. I also employed a different method of applying the CA and applied fewer coats. This worked well and required less time smoothing out and buffing up the finish.

Thanks to everybody who offered advice. I feel that I now have a better way of applying the CA and finishing my pens.

My next task is to turn down a piece of steel rod to to the correct diameter to fit inside the tubes of a gel writer I need to disassemble because it has a similar problem.

 

[turnaround360]

Rub the bushes with wax first.