Bumpy and Sometimes Bubbled CA Finish

[NewfoundlandLaw]

Hey All

So, some of my CA finishes are turning out perfectly. All I do is hit them quickly with wet Micro Mesh pads and a couple coats of polish, then they are like glass.

Other times the glue is not drying very slowly and leaving either a bumpy finish or sometimes has small white discolouration. (Sometimes both.)

(I am careful not to use much accelerator as it can cause problems.)

I'm thinking it is one of 3 potential problems:

1. Could it be the moisture in my garage or maybe it isn't warm enough for the CA to cure properly. (I keep it a brisk 15 degrees Celsius in there and it has been very humid lately.)

2. Could something be in the wood causing it. (High moisture, natural wood oils, etc.)

3. I do my finishing at my lathes minimum, (without swapping the belt around), which is 900 rpm

Any thoughts?


Pen Turning on the Rock

 

[MRDucks2]

I had real issues with consistency when using Stickfast CA and accelerator. Not sure if it was one, other or the combination. I have had better consistency with Titebond and Bob Smith CA.


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[1080Wayne]

Certainly high humidity and cool temperature can cause problems . Could you describe your application process in more detail and brand and viscosity of CA used . Problem with several woods , or just one ?

 

[KLJ]

All I have ever used is stickfast ca either medium or thin, I have not experienced the white spots and bumps except when I was trying to patch holes and put on a lot of ca and when I hit it with the accelerator watched it turn white bumpy, but have been able to either turn it or sand it off. I have experienced what I call a bumpy, finish more like lines on or in the finish,that appeared to be spiraling down the blank, that required more sanding when using the medium. What I think helped with this was using a lesser amount of ca like one drop, higher rpm, and apply the ca very quick and leave it be. I now apply more coats of thin and rarely use the medium. I am likely wrong for this but i apply at around 2000 rpm. Hope some of this might help.

 

[KLJ]

Just curious, have you received your Laguna yet and if so how do like it?

 

[NewfoundlandLaw]

Certainly high humidity and cool temperature can cause problems . Could you describe your application process in more detail and brand and viscosity of CA used . Problem with several woods , or just one ?

I use E-Z Brand CA and the problem seems to come up randomly.

I opened this tube of CA about 6 weeks ago... Could it be going bad?


Pen Turning on the Rock

 

[ebill]

I opened this tube of CA about 6 weeks ago... Could it be going bad?

- oddly enough, a while back I had a bottle of CA <Titebond thin> that was a few months old. I started to get some random results - small crackle finish area, spots, bubbles and the like. Purchased a new bottle and voila, no more issues. Back to my normal smooth and even finishes.

- so while we can argue how old is old, from now on if I get anything but my usual <expected> results, I am tossing the bottle. Probably not the most economical solution but it really is when you compare the CA cost vs time to re-sand and refinish several items.

- ebill

 

[TonyL]

When I first started, I did get bumps and ridges (regardless of the brand I used), if I did not apply the CA evenly and smoothly - especially if I "drooled" it on from above the blank. I apply at 170 to 200 rpms. I don't know if that is causing your issue.

 

[leehljp]

900 rpm is not the problem. I have and many have applied and finished at higher speeds. It is more a problem of technique and lack of experience. I had similar problems early on but overcame them with practice.

Just after about my 3rd or 4th pen, I cut up a small piece of 2x4 into a dozen blanks or so, and instead of making pens, I just spent a day practicing turning to size and apply CA finish. I had some lumpy ones.

I also used the scraper as I was not good with a skew. One thing I learned with the scraper: I had lumps on some but the scraper took them off and smooth up and down the blank. After that I occasionally got lumps and bumps but I never worried about it. The scraper leveled them off. Even today, I occasionally get uneven rings and the scraper will level them off quickly. An exceptionally smooth scraper and a skew can make them so smooth that sandpaper is only needed for polishing.

 

[NewfoundlandLaw]

So, I fixed the problem by changing to Mercury Adhesive's flex CA. (Thin and Medium viscosity.)

I also slowed the lathe to about 600RPM with my hand slightly right after applying each coat. (5-10 Seconds total.) My Revo 18/36 arrives tomorrow so I shouldn't have to worry about slowing the RPM by hand much longer.

My photography skills suck but here is an Electra Pen I made tonight:







Pen Turning on the Rock