Image help!!! Perfect to Crap when barrel trimming

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Jeepmiller09

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So I casted 2 images today and they came out perfect!!! Then I barreled trimed them and it looked as if air bubbles showed up. Possibly the tube breaking lose a bit from the alumilite??? I attached a pic after turning.

My process
CA GLUE IMAGE ON TUBE
4 coats of CA thin to seal image
Waited 7 hrs
Poured Alumilite (5 min open time) / placed in pressure pot 60psi for 4 hrs
Pulled out looked amazing
Barreled trim and what looked to be airbubbles next to tube
Turned got worse

Help!!!!!!!
 

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Another problem could be, and maybe more likely is you put too much pressure on the tailstock, causing the alumilite to separate from the blank. You have to be very light with these types of blanks.
 
Sanding the barrels (on a lathe) is the only way to go in my opinion.

There are several different ways to do this. Find the one that works for you.
 
A barrel trimmer wont normally cause tiny air bubbles to appear next to the tube, it can cause de-lamination (a ghost effect at the end of the blank)

I think you didn't wait long enough for the CA to de-gas, now if you had said 7 DAYS then that sounds more like it... but 7 hours is just too soon to then cast.
 
In addition to what has been mentioned above is a technique issue. You can rough turn them when you want, but it is better to trim the ends BEFORE you rough turn them, IMO. And you did turn them too soon after casting. You can get away with turning that quick but your percentages of failures increases significantly.

Bladed Barrel trimmers are iffy. If the blank is hard enough, if the trimmer is sharp enough, if you don't have any chatter, if you don't apply a tad too much pressure. . .

I like to CA over some ebony and other oily woods. From experience, I do not use a trimmer, but rather a sander. I KNOW what is going to happen 50% of the time with a barrel trimmer, and I have 3 carbide trimmers, sharpened by professionals.

Success is accompanied by patience. Part of the success is to enjoy the journey, not rush to the end.
 
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I noitced you waited 7 hours after coating with ca glue before casting. I wait 3 days. This is a debated topic but I've never heard anyone casting that soon after applying c.a.
 
Jeepmiller09 said:
So I casted 2 images today and they came out perfect!!! Then I barreled trimed them and it looked as if air bubbles showed up. Possibly the tube breaking lose a bit from the alumilite??? I attached a pic after turning.

My process
CA GLUE IMAGE ON TUBE
4 coats of CA thin to seal image
Waited 7 hrs
Poured Alumilite (5 min open time) / placed in pressure pot 60psi for 4 hrs
Pulled out looked amazing
Barreled trim and what looked to be airbubbles next to tube
Turned got worse

Help!!!!!!!
Click to expand...

How long after printing your images did you wait to seal with ca ?
 
m4skinner said:
Jeepmiller09 said:
So I casted 2 images today and they came out perfect!!! Then I barreled trimed them and it looked as if air bubbles showed up. Possibly the tube breaking lose a bit from the alumilite??? I attached a pic after turning.

My process
CA GLUE IMAGE ON TUBE
4 coats of CA thin to seal image
Waited 7 hrs
Poured Alumilite (5 min open time) / placed in pressure pot 60psi for 4 hrs
Pulled out looked amazing
Barreled trim and what looked to be airbubbles next to tube
Turned got worse

Help!!!!!!!
Click to expand...

How long after printing your images did you wait to seal with ca ?
Click to expand...

I waited about a week after printing them... Just because my work schedule became crazy
 
I'm not trying to start a debate on who's right and who's wrong just saying what works for some and not others. As far as sealing goes part of the purpose for sealing is so the resin doesn't attack the ink or glue. I've done a process for a while then things would happen so I would change the process. Things would go well then I would have to change again. If things are going well then great if not maybe something needs to change.
 
Barrel trimming advise needed :))

I'm curious to know if a barrel trimmer is required for wood blanks? Is it acceptable to just use a belt sander on the ends to square things up?
 
The problem with barrel trimmers, is that the shaft spinning inside of the tube creates friction, which creates heat, and with the thin walls of the tubes, heat is created very quickly. The tube expands and then cools.

This leads to de-bonding. It happens to tubes that are just glued into a blank. So when there is a clear blank involved, it shows the spots that come loose.

Sanding the ends will help alleviate this issue, but if the end of the blank gets hot, it can cause the same thing at the ends. Sand lightly to prevent heat.
 
As mentioned, sanding the barrels square is the way to go. I also let Alumilite cure for at least 3 days, usually a full week, poly gets 2 weeks minimum. I think they polish better with the extra cure time as well.
 
If I may I will weigh in here as well and say I use my barrel trimmer alot. In pen turning as with most hobbies and sports and jobs and in life you need to work at it. because one thing goes wrong do you call for divorce. Do you call the boss and say I quit, and so and so forth.

To the person who revisited an old thread the answer and it is my opinion as well as all others that have answered is just an opinion. You can use a sanding disc on wood as well as a barrel trimmer. That was the only question you asked. But I will give a little more info that is not mentioned. A 4 cutter head is better than a 2 cutter head. Carbide cutter is better than steel. But in all cases care must be taken not to create heat from the cutter cutting into the ends. Also care must be taken to not force the cutter into the ends because if they grab they will rip the casting away from the tubes. Good quality glue and a liberal amount is needed when gluing the tubes in. Time for the glue to set and not just become dry is a key and most glues will have this on the package. What was show in the very first post can happen with a trimmer as well as a sander so just be aware. Heat is your enemy when casting. heat is your enemy in most parts of pen making. Good luck.
 
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