CA finishing difficulties

[krap22]

I'm having issues getting a CA finish to cover completly. I always seem to have areas that don't get covered. My process is to apply my CA with one paper towel and then use another towel with BLO to spread it out. Wipe off the BLO and repeat. Is there something i should be doing differently?

I tried to get a photo, but i can't get one to show the issue.

 

[johnkofi]

Check out this thread, it was a tremendous help to me.

http://www.penturners.org/forum/showthread.php?t=39893

Here is how I have been doing ever since I read the thread above and the finish has come out nearly perfect every time.
When I am finished turning the wood to the correct size I quickly sand with 400 grit then I MM 1500 to 12000, with the 1500 & 1800 MM I stop the lathe and sand the blank side to side to remove any sanding scratches. After I finish the 12000, I rub in the BLO with a cloth towel and let it spin for a few minutes, I then remove any excess BLO. I then use the small rubber bags on my three middle fingers, and fold a paper towel until it is about 3 inches wide, I hold the paper towel with the hand with the fingers in the bags up to to the spinning blank and apply 5 coats of thin CA, lightly spraying applicator between coats. The CA drys within a few seconds between coats, I never have had any issues with ridges, so I can start out sanding with the 1500 thru the 12000 MM. I buff with the White Diamond and apply some REN polish after I assemble the pen.
Hope this makes sense. It works for me every time!!!

Thanks -

 

[JimB]

If I understand what you are doing correctly I think your problem is you are using the BLO to spread the CA. That is not the purpose of BLO. The BLO acts as an excelerant and will not let you spread the CA. Your first step of applying the CA is when you are spreading it. You should be moving the paper towel with CA across the entire length of the blank to cover it with the CA.

 

[leehljp]

In addition to the above, there are other possible reasons.

1. Sanding through - from Wobble: Bushing Out Of Round, or mandrel bent, non-60° live center for in tail stock, tail stock too tight,
. . . Wobble causes sanding force to be greater on one side or spot and results in sanding through.

2. Too thin on CA coats or not enough coatings. 2 or 3 coats are not usually enough. The amount of pressure in applying CA or sanding is something that must be learned from personal experience.
Not enough CA, too much sanding pressure or timing, can result in thin spots and sand through.

 

[george]

I have not worked with CA and BLO, since just CA works better for me.
But there is a video tutorial on this topic in the Library (by Russ Fairfield). If I remeber correctly, he first apply quite large amount of CA, followed by larger amount of BLO. Check the video, perhaps it will help.

I had some problems with full covering the blank with CA when applying at too high speed. Now I always apply it at cca 400 RPM or just turning the axe by hand.

Are you sure that you do not sand threw the finish, like Hank mentioned ?

 

[krap22]

I think i may have sanded through on parts of it. After looking closer at my finished pen, i think i have a bent mandrel. I used to apply way to much pressure with the tail stock. I didn't apply much pressure with it this time, but if it is already bent, that won't matter. I have some more slimlines i need to practice on so it looks like some more lathe time for me after i get a new mandrel.

Thanks for the help.