Thread: CA Lifted on the ends

Amos
I have this problem fairly regularly with larger pens. A friend of mine has been working on the problem. You are right there are a few things .. over tightening , not letting the CA dry etc ...or maybe the end not being square to the bush.

I read on the forum that some make paper washers for coating which are then ground off using a pen seating tool when finished. I tried this .. I bought a set of hole punches and made some out of paper .. Seems to work but still had some issues .. A WIP as you say. I'm trying a higher number of thinner coats eg 20 using thin CA. ... Still a WIP .. I'll keep you posted.

One thing I do which might help is when I have finished the turning and sanding phase before CA is I take the barrel off and very carefully sand the ends on 400mm paper holding the barrel vertical and tight. I have a theory that during turning and sanding the ends get squashed a bit away from the barrel ... So when you apply CA it is uneven.

Another delamination on the ends issue I found was the overflow of CA between the barrel and the bush resolts in issues with the bush being stuck to the barrel. I use a blade to cut through or remove the excess for the barrel. Either way I usually get issues with Delam. An under sized bush or specially made stepped bush might sole this issue. Again a WIP


Randal

Randal, thanks for your input, I have tried all those variations,
As for barrel sticking to the bushings, I use Teflon Bushings for Between Centre turning, I got mine off Fred(BigShed), but you can make your own.
Also, with the larger pens I always square the ends after turning and sanding BEFORE applying CA;
I find that Thick layer of CA may give a deep look to the pen, BUT, very susceptible to lifting at the ends, I have even tried putting a score line between the blank and Bushing so that the CA would not lift-mixed results.
I found that using thin CA and no more than 3 coats and then remove the blank and the bushings works ok, and then there are some woods that are just a real pain-especially Red Gum- have to be extra careful.
The other thing is over tightening while putting together, however, if that is an issue then it is a potential problem if the customer happens to drop the pen, I have had pens that were quite ok, but just a drop on the desk and CA has lifted!? found that mainly with certain timbers. Ebony is another difficult timber for CA-very oily.Teflon Bushings (Large).jpgpicture of Teflon Bushings
Amos

Watching the work in progress.

Some thaughts on CA.

#1 I think people try to lay up too much at once AND fail to allow it to cure out properly between coats.

#2 I always seal the ends of the pen blank with CA at several stages ...... first after the initial end trimming ...... then lightly retrimming and more CA. make sure the ends of the timber are choked out with CA prior to mounting for rouging down.
After I have turned and prior to sanding I again sand & seal the ends before remounting.
This ensures the end grain is stabilised and it is surprising how far up the blank it penetrates sometimes.

3# I have begun to apply the first application of CA before any sanding ..... if the wood is soft or there is any question of the timbers stability, I will apply CA before the final cut

#4 I will as much as possible try to choke out the grain in the first stage of sanding ..... this allows the CA to penetrate into the timber before it is burnished.

I think much of the problem with CA finishes is the obsession with "coats" and the view of applying "coats"

The first goal should be to get penetration into the timber and achieving a bond to the timber and fully choking the grain before moving up in grits.

BTW I no longer use accelerator and use only thin CA for finishing.

I have never seen or heard anybody else doing so .... But I use cotton buds to apply CA and lately manually turn the lathe to do so.

I think a good CA finish is time consuming ..... but I don't see any way arround that.

cheers

Thanks Soundman, excellent advice given, I have also tried doing the ends as you suggested, I will also try applying CA first before any further sanding as suggested. True, many of my "liftings" have been because of impatience and trying to get it done FAST!! just love seeing the completed pen!!!! After reading Les's Miniwax Wipe On Poly, I realized that even that takes TIME and Patients!!!! so am resolved to slowing down somewhat---BUT---- still experimenting!!!! Amos

if ya want fast the only thing that will give it to ya reliably is friction polish

This is another blank from 3 years ago, was put aside in the too hard basket for a rainy day! The blank was overturned and therefore the fittings outside diameters were larger than the blank, to compensate I added extra layers of CA, but in so doing the CA lifted on the ends,. I have started this one now, and used "some" of Soundman's advice, I was especially interested in his application with a cotton bud!, my cotton bud immediately stuck to the blank and would have tossed me over like a judo throw had I not let go!, but I did let g, for the time being not using a cotton bud!
Next I used Soundman's advice about turning the blank slowly, and this did give me better results, I am still working on this blank as it needs many layers to get it to the correct thickness. Here are the pictures.-thus far-- Amos

I think adding lost thickness with CA is a big ask ...... it was never intended as a casting resin or a thick film finish.

I think there are inherant problems with laying up significant thickness of CA.

If using a cotton bud, you must make sure it is wet .. AND if you are to apply with the lathe running it must be running slow.

cheers

watching with interest as I don't us ca as a finish - I've never had luck with it

I'm about to do the slow method of using it - ie apply thin coats over a few days and wet sand at the end

Here is the Black Palm finished product, it actually looks better in the hand than the photos. Amos

Originally Posted by PenTurner

Here is the Black Palm finished product, it actually looks better in the hand than the photos. Amos

Nice
and it's good to see that you're still a better turner than you are a photographer!

[QUOTE=Sawdust Maker;1917282]Nice
and it's good to see that you're still a better turner than you are a photographer![/Q
I think that was a backhanded compliment!!!Amos

Worked out in the end Amos and looks great. CA will often lift if there is too much oil in the timber. A wipe over with metho first is handy. Also seal the ends of the blanks with CA as well. It doesn't matter if some gets into the tube as a craft knife or deburring tool will get it out and round off the end of the tube nicely as well so the kit fits in better. Always wipe the turned blank down with metho before CAing as it cleans it up and opens the pores on the timber for a better CA grip.

Originally Posted by plantagenon

Worked out in the end Amos and looks great. CA will often lift if there is too much oil in the timber. A wipe over with metho first is handy. Also seal the ends of the blanks with CA as well. It doesn't matter if some gets into the tube as a craft knife or deburring tool will get it out and round off the end of the tube nicely as well so the kit fits in better. Always wipe the turned blank down with metho before CAing as it cleans it up and opens the pores on the timber for a better CA grip.

Thanks Greg, Metho hint taken,!Amos