CA and delron bushings

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navycop

navycop

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I was doing a CA finish on some pens the other day. I used the plastic bushings from Woodcraft. The blanks were sticking to my mandrel. It appears the ca was leaking down between them and the blank. I use the regular bushings as spacers and didn't want to crank down to hard on them. I got a Shopsmith and maybe can get the other ones (that CNC used to sell) to work between centers.
 
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I believe that the bushings were not the issue, but rather that amount of CA being used. The bushing are made out of delrin and CA won't really stick to it. But the blanks being glued to the mandrel implies that you used so much CA that it seeped between the bushing and the blank, which did get glued to the mandrel. One thing that you can do is clean off your mandrel and put a tiny amount of paste wax on it and let it dry then buff it out. CA does not usually stick to a waxed surface.
 
Wax the delrin bushings too. Ca will stick to them, although less so and it will come off much easier. I don't see how ca could get between the bushings and the tubes enough to get down to the mandrel as the bushings are tapered and go inside the tubes.

Unless it was really loose.
 
Dan Masshardt said:
navycop said:
I don't know either Dan. But I cracked alot of acrylic blanks by trying to tap on them to loosen them..
Click to expand...
so once it was loose there was actually glue on the mandrel? Are these slims? On most pens the tube isn't even on the mandrel.
Click to expand...

There was a little bit of glue. Yes they are slims. I think the glue might of ran down the slope of the bushing and settled on the mandrel.
 
From your first comment, my thought is that your whole assembly needs to be tightened up. You said that you were cautious about making it too tight.

Don't use more than one extra bushing on each side of the delrin. Bigger comfort type bushings if you have them.

Shorten the mandrel.

Or just get a dead center and apply ca in the centers directly.
 
I think you are applying too much CA, you should only wipe on enough to cover the blank. there really should not be enough to run. good luck, watch some of the youtube videos on applying a ca finish.

good luck
 
navycop said:
I don't know either Dan. But I cracked alot of acrylic blanks by trying to tap on them to loosen them..
Click to expand...

any reason you were using CA on acrylic blanks for finishing?

come over and I'll make you a good set of delrin bushings that will work for how you want to do things
 
This is a minefield of a post and I am not sure where to start.

Since not all CA is equal I would have to ask what brand CA are we talking here? Yes there are CA brands that CAN and WILL bond delrin. Just because it's delrin and you use CA does not mean it will not stick to it.

The using 'to much' is a bandaid approach. I suppose I used way to much in this project http://www.penturners.org/forum/f56...-conversion-114232/?highlight=gent+conversion when I build up 1/32" of CA on the tube. Oh and it did not stick to the bushing.

As for tightened up on the assembly there is some truth to this yes but also I will take it a step further and ask, is the ends flush? If they are not they will produce gaps where glue can drip down and cause this to happen.

Also if you are going to wax then use regular bushings as CA will not stick to waxed metal, does not need special bushings for that.
 
Last edited:
edstreet said:
This is a minefield of a post and I am not sure where to start. Since not all CA is equal I would have to ask what brand CA are we talking here? Yes there are CA brands that CAN and WILL bond delrin. Just because it's delrin and you use CA does not mean it will not stick to it. The using 'to much' is a bandaid approach. I suppose I used way to much in this project http://www.penturners.org/forum/f56/dragon-sceptre%3B-gent-tube-conversion-114232/?highlight=gent+conversion when I build up 1/32" of CA on the tube. Oh and it did not stick to the bushing. As for tightened up on the assembly there is some truth to this yes but also I will take it a step further and ask, is the ends flush? If they are not they will produce gaps where glue can drip down and cause this to happen. Also if you are going to wax then use regular bushings as CA will not stick to waxed metal, does not need special bushings for that.
Click to expand...

Ed,

I think you may have hit on the real problem in the midst of that post. :-). Uneven ends. That would do it.

Remember the core issue here isn't ca sticking to delrin but ca getting between the inside of tube and the mandrel.

Also with slims, there is not much of the busing inside the tube, it's more butted against it.

Which leads to my solution - stop turning slims! Time to move up. Lol.
 
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