CA Finish Dulling?

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RandalG

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I've just started turning some Clairo walnut blanks. The wood is dry, 7 to 8 percent. I put a CA finish on it and sanded to 12,000 with MM and had a glass like finish on it. However overnight it has dulled like the finish has come off, or maybe there is oil coming out of the wood? I put 2 coats of thin CA on it to seal and fill the grain, sanded it smooth and then 3 coats of medium CA. I would think this would be enough to seal it but apparently not.

On another pen I used Mylands sanding sealer before the CA and had the same problem. Is there much of a difference between the Mylands and the Zinsser sanding sealers?

Any suggestions appreciated.
 
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My guess is you're sanding through the finish. I have a 200watt light bulb over my lathe and when I finish going through the MM, I get down at a low angle to the mandrel and slowly rotate the blank. It will really show up any area where I sanded through the CA. This is not an uncommon problem and drove me nuts when I was first learning to do a CA finish. I quite using medium and switched to thick, and I'm better at it now, so it rarely happens.

Welcome to the IAP.
 
If a number of things are not just perfectly right, it can set up a very small and almost undetectable out-of-round that will cause a sand through on one side or end. I am talking about .007" or .008" out of round. That is almost 1/100 of an inch o.o.r. which will produce the problems with sand through. A tad too tight on the mandrel, out of round mandrel, bushing o.o.r., unsquare end milling and a few other things can cause this.

The result is that it can cause sand through on one side or end very easily.
 
Randal,

Also, if you are using a CA finish there is no real need for a sanding sealer. Use thin CA to seal the wood prior to using the medium or thick as a finish.
 
Everyone should go back and read Randal's post. He used CA as sanding sealer and it WAS glass like when he finished.

To answer the question it may have some oil to it but i doubt it. I have not been doing CA long enough to have gone through all of the trials and tribulations of CA. Some say if you sand it down through the MM before you put on the CA that it does not stick as well as there is less surface for it to stick to, so if you did that, then you might look at that being a possibility.

Mike & Linda
 
I had a few that this has happened to. Next time I will investigate to determine if I am sanding through. It hasn't looked to be the case, but sometimes looks is deceiving. In the past I have sanded all the finish off and started over.
 
On this particular pen, Jr. Gents, I turned the blanks between a dead and live center to avoid the out of roundness. (I've had some that were a little egg shaped) Maybe I did sand down too far but I only sanded down enough to smooth it out. When I got through with the MM it did look wet it had so much gloss.

My hands looked like I had been handling a brownish purple stain at the end of the day so that's why I'm thinking it's an oil coming out. I have a good moisture meter and it actually reads a little less than 6 percent. How can the moisture content be this low and the wood still be oily? This is why I'm puzzeled.

I'v only been turning pens for a short time comparitively, but I do have a few dozen that I've done a CA finish on that are still like glass. One of the first pens I turned out of this wood did this but I used the Mylands Friction Poish on it. After finding this Forum and learning about the CA finish I refinished it. I carry it every day without a case and it still looks great. Maybe this wood needs to set a few days after turning, then be cleaned with alcohol or mineral spirits before finishing?

I have been lurking around the Forum, learning as much as I can. This is my first time to step out, so to speak. I do appreciate the sharing of knowledge that goes on here.
 
randal, i'd do a search of 'ca problems' or something similar to that in our search tool. russ fairfield has addressed the many possible CA pitfalls a few times and i always go back to that when i have a problem like the one you indicated. he pretty much covers all the possible problems one will encounter with ca finishing.
 
Originally posted by MLKWoodWorking
<br />Everyone should go back and read Randal's post. He used CA as sanding sealer and it WAS glass like when he finished.

To answer the question it may have some oil to it but i doubt it. I have not been doing CA long enough to have gone through all of the trials and tribulations of CA. Some say if you sand it down through the MM before you put on the CA that it does not stick as well as there is less surface for it to stick to, so if you did that, then you might look at that being a possibility.

Mike & Linda
Click to expand...

Gee, since I appear to be "everybody" I was referring to his mention of using Myland's SS and asking the question about other SS. Thanks for the clarification.
 
Sorry Cav didn't mean to upset you. Someone else mentioned sanding through the finish, which makes no sense if it was glass like when he finished it. So no Cav you are not everybody, in fact if you ask Ed quietly he will say nobody! [:p]
 
I think you have several questions here, so let's start with the one you explicitly asked. There is a MAJOR difference between Myland's Sanding Sealer and Zinsser's Sanding Sealer. Zinnser's is a shellac based sealer and Myland's is a lacquer based sealer. Both can be used effectivvely, but you need to remember to let each sealer cure. If you put CA over top of either before they have cured, the remaining solvents willmigrate to the surface, beneath the CA. Over a period of months, these solvents will work their way about, but the best choice is to avoid the problem by letting your sealer set for 24 hours. If the blank still has ANY solvent odor, let it continue to cure until all of the odor is gone. BTW, trying to smell solvents during the time when you are using CA is probably a waste of time. In terms of the pen where you sealer with thin CA, it is VERY easy to sand through both the sealer and the top coat. To avoid this problem, I user a set of 4X Mag-eyes and, when in doubt, a 10X glass. That's the best way to examine a finish that I've found.
 
Originally posted by MLKWoodWorking
<br />Sorry Cav didn't mean to upset you. Someone else mentioned sanding through the finish, which makes no sense if it was glass like when he finished it. So no Cav you are not everybody, in fact if you ask Ed quietly he will say nobody! [:p]
Click to expand...

As, my old boss from Alabama used to say: "Good 'un, Mike!"
ROTFL!!
 
My guess, with walnut (oak is another) brownish purple stain on hands is tannin.

If you have tannin on your hands after sanding your CA finish may have been breached. I've never experienced oil escape in relation to turning walnut.

With proper coverage I’ve never had tannin interfere with my finish.

Curious, what grits and how much sanding are you doing after you apply your finishes?
 
I believe I did sand through the CA. I've been using a Norton 800 grit pad to start with first, then on to the MM. What is still puzzeling is how much gloss was on it when I got through with the MM, but it didn't stay that way.

I put 2 more coats of CA on then started sanding with 2500 to make sure I didn't go through it again. It sure is shiny now!

This was the first Jr. Gents I've turned, thus the largest diameter also. That larger diameter may have contributed some.

Thanks for the help! I've read about everything I can find here about CA finishing, but I guess I've missed some things.
 
Originally posted by RandalG
<br />I believe I did sand through the CA. I've been using a Norton 800 grit pad to start with first, then on to the MM. What is still puzzeling is how much gloss was on it when I got through with the MM, but it didn't stay that way.

I put 2 more coats of CA on then started sanding with 2500 to make sure I didn't go through it again. It sure is shiny now!
Click to expand...

This was quite common for me at the beginning. It is surprising how well the wood could "shine" for a few hours or so before it became evident that something was amiss. Glad you discovered the cure. In the future, it might crop up again a few times on other pens. But at least you will be able to recognize the problems early on.
 
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