Help!!! Why did this happen???

[Jayman72]

Hey all,

I have run into a bit of an issue.

My process for finishing has not changed in the last 40+ pens I have made.

3 thin coats of medium - Accelerator.
6 thin coats of medium - Accelerator.
6 thin coats of medium - Accelerator.

Wet sand - 400/600/800
Wet sand Micro mesh - 1500-12K

Polish/Wax

It's only happened on this one pen but I am in the process of getting ready for my first "Show" and am in the process of making 80+ pens for it in the next month or so.

I found that this pen, after I finished it, had "spider cracks" in the CA finish on the cap and a little on the base.



View in Gallery


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My first thought would be age of the CA (If thats even a thing)
My second thought would be that the CA built up around the edge a little too much and when I put it together the CA had no place to go and cracked.

Any shared knowledge is greatly appreciated.

Thanks
Jay
Tampa, FL

 

[JimB]

Both your thoughts are possibilities. Another is the wood was not dry and continued to dry during turning and finishing and therefore moved and caused the cracks.

 

[liljohn1368]

Jay, did you sand the CA back flush with the end before pressing the pen together? If not that might put pressure on the CA and make it crack..

 

[jttheclockman]

15 coats of med CA with accelerator.

Not going to touch that with a 10 foot pole.


many things could have caused that. You left out alot of your process. You did not say how you do your finishing. Do you use delrin bushings? Did you sand the ends before assembling??? Did you ream the ends of the tubes before assembling??

fittings too tight because too much plating.
wood movement
ca in the ends of tube or burrs
went together on a slight angle and cracked
Had a hairline crack before assembly
Heat caused a crack
CA not dry before next coat (15 of them wow)
That is a few for now. Will let others add to the list and good luck.

Oh yea something about wearing the right colored socks for the right day:biggrin::biggrin:

 

[flyitfast]

I want to follow this one!
I've never seen cracks go the full length of a blank like that.
You mentioned that it might have happened when you pushed the parts into the blank - could be, but normally the cracks are at the ends of the blank.
Before I put the hardware into a blank, I usually ream out and slightly taper the ends with a plumbing reamer/deburring tool. This does help the parts to ease in before pushing them fully in.
Also, was the inside of the tube clean of any glue/epoxy?
Gordon

 

[Wingdoctor]

I had cracks like those at one time, and I attributed them to the accelerator. I changed cans and greatly reduced the amount of accelerator, eliminated it for thin CA eventually, and have had no additional problems. As I changed 2 things at once I cannot say for sure it was the accelerator. I have changed my technique so that if IU do use accelerator it is a mist from 18" or so away and I wait 10 to 20 minutes before adding another coat of CA. I let the CA dry overnight before sanding and polishing for the final shine.

There was another thread about a year ago. Maybe you can search and find the replies.

 

[Ted iin Michigan]

I, too, have had that issue. And I'm pretty sure mine was due to "old" CA. I did a number of trials and comparisons and the results pointed in that direction. When I pitched the "old" CA the issue resolved.

 

[farmer]

2nd choice

Looks like a stress crack to me ..< final answer..<<<
normally if its old CA or to much activator the crack will be all the way around and it will crack more and more even while you are holding it .

 

[edstreet]

Look in the search. I covered this topic and what causes it. Also for those who like to flame me I am unable to do the home work for YOU and look it up.

 

[jttheclockman]

It is funny but Ed gave the same answer here as well. He did get goaded into giving up his knowledge and opinion here as well.

But lots of good reading here. Now this only goes back one year but this has been going on since the discovery of using CA as a finish so there are plenty more threads on the subject.

Maybe we should bookmark or pin this thread for future reference. Weren't we doing that or something like this recently or am I imagining things again???


www.penturners.org/forum/f14/ca-cracking-135361/

 

[Imaginethat]

:biggrin:
What!!!! No one told me what color socks to wear and what days to wear them!

 

[Skie_M]

Don't ask me ... I don't wear socks while turning.


I wear flip-flops and leave the shavings on my living room floor, so socks would be bad for me, as the shavings would always stick to them and end up in the wash ... very uncomfortable.

One of these days, I'll have myself a nice little wood shop .... currently making plans for a 14'x14' shed that will go in the back yard which will be where I set it all up!


As for cracks in the finish ..... never used an accelerator and haven't seen cracks in my CA finish yet...

 

[leehljp]

Sorry, Off Topic to the Original Post - Helping folks with problems:

Let them learn, help them learn:
One of the things that makes a forum to continue on, and be a great forum is that it does not stop letting new members ask the same question over and over and over. And it does not criticize each new iteration of it.

Once a subject has been thoroughly, and thoroughly again discussed, a good forum will not chide each generation of new members for asking the same question again. Each generation (about 2 years here) needs to find out 1. from personal experience, 2. from research, and OR 3. from personal interaction with others, depending on their personality style and need.

Searches don't always work:
I have forever had trouble with "search" here (and on other forums). Sometimes I get direct hits and other times, it keeps giving me "no hits" for things that I know is there (and searching for my own years ago posts). No hits.
Searching is not the answer when a person doesn't know what key words to use. Shucks, "Turning between centers" had three different names at the beginning, depending on who was posting. (And I think I was the first one to post a photo of the TBC (under a different name) although the principle had been mentioned a couple of times by Frank (Rifleman) and one other.

Tired of this:
One thing I have noticed is that once a subject has been defined well and the answers throughly analyzed from every angle, it irritates some of us (I have been this way too) when someone doesn't listen or decides they can re-invent the wheel when the answers are already there. When I found myself in this position, I knew it was time for me to back away. Newbies learn from intermediates because the intermediates have just been there. I have watched forums give up the ghost, so to speak, because the experienced users not only quit interacting with the newer and intermediate ones, but told them to "look up" the solutions. Without the personal interaction on the same subjects over and over, a forum will stagnate and die. When I got irritated at the same question over and over, I learned that it was best for me to let someone else teach. I did change my tactic and started posting links to previous discussions (not just this forum.)

I did it on my own so let others do it:
I enjoy it when I find people who blaze their own path and discover thing for themselves. (That is one of the basic characteristics of my own personality.) However, I have learned that not all people are like me. I will never forget the beautiful picnic table my unskilled cousin created on his very first wood working project. He followed the rules (plans) to the "T". He didn't have the ability/experience to "create from experience" but he does know how to follow plans, and does best when he can interact with more experienced builders. I personally enjoy it when those I help advance the plans better than I possibly could.

More than one way to solve the problem or prevent the problem:
When I moved to Japan in '86, I quickly noticed that there was a whole new world out there that did things different and did it great. I may have the answers but there are other ways to get to the same results. I am a TBC advocate, but there are those that "must see" both blanks on a two blank pen. LOML told me that physically seeing is important. I have had psychologists/psychiatrist friends tell me that some people (artists in particular) "see" things that others can't. TBC is not a problem for me on two blank pens, but it is for others. Same for solutions. More than one way to fix, more than one reason for the problem - depending usually on the person's individual work methods/habits.

 

[edstreet]

Interesting to note some still does not help, they seem to be filled with hatred and like to attack others and share nothing constructive that is well researched instead posts are filled with attacks and hatred.


For the rest here is the info that I was posting about last night. I was unable to search and in a very limited capacity because A) I am not retired b) I have a busy life c) I have a demanding job and a function. So I take time out of my schedule to try to help share knowledge and info that I have gained in many years of experience and exposure and research and testing.

http://www.penturners.org/forum/f14/do-jd-blanks-need-stabilized-117947/#post1612723

For those who refuse to click links or do your own homework I will post it here.

Lets talk about cracks for a moment.

Cracks can be either active or passive.

An active crack, such as when the wood is drying or undergoing changes, i.e. drying/weather/humidity/saturation, will continue to crack until it's equilibrium point is reached then it will slow down but never truly stop as some changes can cause it to grow even more.

A passive crack is one that has cracked as a result of some traumatic event, i.e. drying, sudden drop in moisture content etc and is no longer growing. It is a weak point in the structure and should be addressed with some type of resin, bonding agent or similar.

Adding any type of glue/epoxy to an active crack will only break and damage the glue joint and cause more headache down the road. The only way to deal with active cracks is to rate limit lost of moisture in the wood by a controlled drying process, i.e. kiln.

Adding any type of glue/epoxy to a passive crack will strengthen the weakened area and build up the gap, UNTIL it turns active and grows more. Things like change in saturation point, humidity, weather, location and a slew of other things can cause this to happen.

Stabilizing helps greatly on passive cracks. It helps by securing the fibers with resin and allowing them not to absorb things like water, moisture, fluid and the like. This in turn removes the fibers need to move. Whatever is currently in the fibers will stay in the fibers forever and also hinder uptake of the resin. This is why tannins, waxes, varnishes, water and everything else needs to be out of the material before it is stabilized, else you are shooting yourself in the foot and causing more problems down the road.

When evaluating wood to be stabilized you need to look at several points and they are very vast to list every one of them but include weight of the final product, material harmonics, environment the product will be used, how hard/brittle/stable the wood is.

Hope this helps.

 

[leehljp]

Interesting to note some still does not help, they seem to be filled with hatred and like to attack others and share nothing constructive that is well researched instead posts are filled with attacks and hatred.

For the rest here is the info that I was posting about last night. I was unable to search and in a very limited capacity because A) I am not retired b) I have a busy life c) I have a demanding job and a function. So I take time out of my schedule to try to help share knowledge and info that I have gained in many years of experience and exposure and research and testing.

Ed, I get the same response at times and then a few days to weeks later, a comment on what it took to fix it, or discovery of the the cause - and that was what was presented at the beginning as a fix or cause. I just let it go. That is also when I back out. But I don't let it get me down.

Your second paragraph sounds like me and my three daughters at times. We get along great but there is a generational difference - sometimes they listen, and then there are those that I put forth lots of effort on deaf ears. LOML used to be totally on their side (I am too logical ). Now she is saying: "I guess they gotta learn on their own! They won't listen to reason or experience."

 

[edstreet]

There is also the value of something learned when it is given to you and when you bust your but and earn it the hard way. Huge difference between the two. However, that discussion is seldom proactive or assertive on a forum.

I do find that most new people need some basic guidance and a general point in the right direction and let them do the rest rather than give them everything. Some subjects, such as this topic, is one that has always been deficient in tech info and a more common problem than most topics. They also seem to devolve into something else and the main focus of what I feel the topic should be going towards is hijacked.

On this topic I have studied and have extensive info on cracking.

The problem is somewhat common and certainly not a new problem and I would also like to point out this article I wrote for Toni's site on the subject.

https://www.claypenblanks.com/what-is-polymer-clay/ca-finishing-101.html

It is also worth noting that this link, this info, is in my signature tag line on every post that I make. It is also a subject that I do know a good deal about.

 

[jttheclockman]

:biggrin:
What!!!! No one told me what color socks to wear and what days to wear them!

There is a chart somewhere. Very important to check the chart each day.:biggrin::biggrin::biggrin: