nsfr1206
Member
Did my very best ca finish ever today. But when I took off mandrel and pulled bushings off it looks like the ca on end of tube has come loose. It is opaque and you can take your nail and scratch it off. What's up??? David
Got it but it cracked
- Thread starter nsfr1206
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toddlajoie
Member
I had similar problems with CA when I was using accelerator and was in too much of a rush to let the accelerator work and evaporate. I can't say that I'm correct, but my theory was that after putting on one coat of CA and then using accelerator on it, when there was still a small amount of accelerator on the pen and I hit it with the next coat of CA, the CA cured before it had a chance to bond with the previous layer, hence you have what amounts to 2 thin sheets of CA right next to each other, rather than a thicker bonded pair. Some of the CA around this area will have bonded, so it stays there and is just fine until some stress comes along (like trying to separate the bushings, or even pressing the pen parts together) and shifts the parts that are not bonded, taking some of the parts around it that did bond with is, and starts separating the layers...
I stopped using accelerator because of this, because I'm too impatient to be sure that it has all evaporated before moving on....
Now if you aren't using accelerator, you can ignore all the above...And all this is assuming that under the layer that has come off is more CA, If the CA is chipping off right down to the wood, then there are other issues at work...
I stopped using accelerator because of this, because I'm too impatient to be sure that it has all evaporated before moving on....
Now if you aren't using accelerator, you can ignore all the above...And all this is assuming that under the layer that has come off is more CA, If the CA is chipping off right down to the wood, then there are other issues at work...
Don't use bushings when you are finishing with CA unless it is the delrin ones, and sometimes the CA will stick to them as well. JohnnyCNC sells some conical shaped finishing bushings that are great for finishing on a mandrel.
Before I got Johnny's bushings to finish with I would finish without bushings with the pen directly on the dead and live center, that way there would be no overlap of the finish, which is prone to crack when you separate them or create those white spots (where the CA lifts off the wood when you separate the bushings).
Just my 2 cents worth.
Before I got Johnny's bushings to finish with I would finish without bushings with the pen directly on the dead and live center, that way there would be no overlap of the finish, which is prone to crack when you separate them or create those white spots (where the CA lifts off the wood when you separate the bushings).
Just my 2 cents worth.
Fred
Member
Forget the accelerator, clean the blank with each sanding, and don't touch the wood before applying the CA.
Accelerator ... why use if it you are using 5 second, or 30 second CA. Takes you longer to get the accelerator and spray.
Touching the blank can sometimes contaminate the surface with whatever is on your hands at the time. CA doesn't cater to some stuff and will not adhere properly.
White spots under the CA ... moisture, dust pockets
CA remaining soft ... how old is the CA, and/or, what is the temperature. Cold CA = bad news. Old CA = bad news ...
Bushings ... Either wax the ends contacting the wood before applying the CA, or, score around the blank/wood seam with a sharp razor prior to removing the bushing from the tube.
Accelerator ... why use if it you are using 5 second, or 30 second CA. Takes you longer to get the accelerator and spray.
Touching the blank can sometimes contaminate the surface with whatever is on your hands at the time. CA doesn't cater to some stuff and will not adhere properly.
White spots under the CA ... moisture, dust pockets
CA remaining soft ... how old is the CA, and/or, what is the temperature. Cold CA = bad news. Old CA = bad news ...
Bushings ... Either wax the ends contacting the wood before applying the CA, or, score around the blank/wood seam with a sharp razor prior to removing the bushing from the tube.
Last edited:
leestoresund
Member
I heard from one of our members that he sprays the accelerator first so that the CA dries from the inside out.
Tried it.
Seems to work.
Lee
Tried it.
Seems to work.
Lee
greggas
Member
I agree with Lee. Back in the fall a member turned me onto spraying accelerator onto the blank before applying the CA. Have done about 200 pens this way with no cloudiness or blisters.
Sounds like the initial problem listed in this post was caused by the CA being torn after pulling away from the bushings which is a common problem if you apply CA with bushings on and do not cut or part a line through the CA near the end of the bushing
Sounds like the initial problem listed in this post was caused by the CA being torn after pulling away from the bushings which is a common problem if you apply CA with bushings on and do not cut or part a line through the CA near the end of the bushing
nsfr1206
Member
I think that is the problem as Greg says. When I pulled off bushings it just broke the finish. Thanks for your answers. David