CA question

[vacca rabite]

On all the pens I have made with CA, save one, the glue has not made a clean break at the body of the blank, and I am left with a white line at the ends of the blank.



This pic was for another experiment (failed overall) but shows the issue I am having. How the heck do I fix this in the future.

Tonight I ruined an otherwise really nice body with this issue, and it is ****ing me off. HELP!

Zach

[Woodswood]

I have found when I only apply 3 coats it's not as bad, but have not completely found a solution yet, let me know if you do.

Nathan

[BSea]

Do you leave the bushings on to apply the CA? I'm guessing you use a mandrel. If you do, try removing the bushings and putting some wax on the bushings before applying the CA. Or If you have 60° centers, you can apply the CA between centers without bushings. This is the way I do it, and I've put over 20 coats of CA on a blank without a problem.

[Xander]

Newbie here and I've only done one CA finish (more on that in an other post, just let me say that I learned a LOT doing that pen) so I don't know all the answerts but...

Do you remove your blanks and put just a smear of vaseline on the bushings so the CA does not stick? Then put blanks back on mandrel and apply CA.

Also, before removing the finished blanks run a very sharp blade between the blank and the bushing. I found an exacto knife works.

Like I said, i'm no expert so please obtain more advice.

[Woodswood]

What is a 60 degree center?

[leehljp]

I use Turning Between Centers as mentioned above. But before I got there, I had the same problem and here is how I solved it most of the time. I have a set of mini chisels that I use for some small bowls similar to these:
Set of 8 Benjamin's Best HSS Micro Detailing Anniversary Set at Penn State Industries

I used the diamond and small parting tool to cut the CA down to the bushing just at the bushing/blank joint. This made separating them easier. This worked except when I was using oily woods such as ebonies, cocobolo and the like. I often had trouble with lifting and the "white" showing (because it lifted) when separating. Since I did quite a bit of those woods, and had the lifting of the CA a little too often to suit me, I changed to TBC and haven't had any problems since. That was back in '07 or '08.

[BSea]

Originally Posted by Woodswood

What is a 60 degree center?

60 Degree Live center that goes in the tailstock. You probably have this for your mandrel.


60 degree dead center for the head stock.

[leehljp]

Originally Posted by Woodswood

What is a 60 degree center?

60° centers are the live center on the tail stock ends that go into mandrels. Most lathes come with a center for turning wood. The mandrel is metal and the dimple in the end is made for metal lathe centers. The wood centers tend to wallow around inside the mandrels.

That is what a 60° center is.

Now Part 2 to that. In the last three or 4 years JohnnyCNC has made bushings with 60° cups in it for using in Turning Between Centers (not using a mandrel). In this case, 60° centers are needed on the tail stock end (use with LIVE center) and head stock end (Use with dead center).

However, if one has the bushings for mandrel use, these can be used with just about any live center. Contrary to what most people will tell you, you do NOT have to use 60° centers for standard bushings to turn without a mandrels (TBC).

AS a reference to this, here is the first dead center that I made and used and posted here back in '08 and it was NOT 60°.
IAP Home - Photos - Imported Photo from leehljp

IF you use custom bushings and they are MUCH better than commercial ones, you WILL need 60° live and dead centers.

[writeitdown]

Also, Delrin bushings might be another solution, CA doesn't stick to Delrin. Check with Hans at Bushings, he's a member here (hewunch)

[ALA]

I have the same problem with the glue coming loose near the edges. I just did a Cigar pen that turned out pretty good except for this problem, TBC is sounding better all the time!