Could the sandpaper be causing hazy CA finishes?

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redfishsc

redfishsc

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As many of you know, I spray my pens with a catalyzed varnish, and I hope to work up a tutorial on it soon.


However, the main reason I use this is b/c I cannot get a consistent sheen on CA finishes. I do use CA as a sealer before spraying, but if I try to build a CA finish and buff a shine on it (micromesh), I ALWAYS get haze. I have tried two brands of CA, with and without BLO, with and without the aerosol activator, with my mouth open, halfway open, and shut, and it always has hazy spots.


Now, the other day I was reading some info on an industrial woodworking forum warning NOT to use stearated sandpaper (ie, "non-loading") when using a waterborn finsih because it can cause similar problems.

Now, I know CA is NOT a waterborn chemical, but could it be that the zinc stearate that is added to so many brands of sandpaper be causing the blotch?
 
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You should do a search about finish or read Russ Fairfield titorial, lots of dicussion here on IAP but you can find here

http://tinyurl.com/yojg5o

Hope this help
 
Just curious, what method do you use after CA application?? I use straight CA and after 4 coats it looks NASTY. However, left to dry overnight, I then wet sand with 400 wet until it is knocked back smooth. Now a light hand sand followed by MM, polish, and Ren-wax will bring it to glass and perfectly smooth. I was not able to get the film thickness to sand and polish when I used the BLO, I always went thru the CA. I use those derlin strips and med. CA for mine. Btw, I have bought tubes at WAL-MART and applied nice finished once when I ran out of CA. I keep a 2-pak of that glue on hand in case I run out still.

I for one, could never get a CA/BLO that was perfectly line free and glass smooth without burning thru. I could get the finish with some sprial lines, but that is not what I wanted from a finish. My major turning point was the derlin strips, what an improvement! No CA on the finger, no mess, no CA loss on the paper towel.... [;)]

EDIT: Oh.. and shame on me!!! TURNING BETWEEN CENTERS for putting on the CA! That is a major help, just pop them off the centers and mill the overflow nice and flat and you will never "chip" the edge again!
 
My experience is this: The only time I have ever had haze on my Ca finish is back when I use to apply it with the lathe on... I have been applying the CA with the lathe off, nice thin coats using a paper towel, for over a year now and have not had a single incident of haze....

That's my guess anyhoo... and also why I don't try to apply thicker coats any more...
 
Originally posted by Firefyter-emt
<br />
EDIT: Oh.. and shame on me!!! TURNING BETWEEN CENTERS for putting on the CA! That is a major help, just pop them off the centers and mill the overflow nice and flat and you will never "chip" the edge again!
Click to expand...
DUUUH. That would eliminate my problem of the CA chipping and separating from the wood when I remove the bushings.[B)][B)]
 
Originally posted by Firefyter-emt
<br />Just curious, what method do you use after CA application?? I use straight CA and after 4 coats it looks NASTY. However, left to dry overnight, I then wet sand with 400 wet until it is knocked back smooth. Now a light hand sand followed by MM, polish, and Ren-wax will bring it to glass and perfectly smooth. I was not able to get the film thickness to sand and polish when I used the BLO, I always went thru the CA. I use those derlin strips and med. CA for mine. Btw, I have bought tubes at WAL-MART and applied nice finished once when I ran out of CA. I keep a 2-pak of that glue on hand in case I run out still.

I for one, could never get a CA/BLO that was perfectly line free and glass smooth without burning thru. I could get the finish with some sprial lines, but that is not what I wanted from a finish. My major turning point was the derlin strips, what an improvement! No CA on the finger, no mess, no CA loss on the paper towel.... [;)]

EDIT: Oh.. and shame on me!!! TURNING BETWEEN CENTERS for putting on the CA! That is a major help, just pop them off the centers and mill the overflow nice and flat and you will never "chip" the edge again!
Click to expand...


I have not tried the "cure overnight" method, I may have to give that a shot. I was sanding and buffing immediately when it was cured.
 
Originally posted by Monty
<br />
Originally posted by Firefyter-emt
<br />
EDIT: Oh.. and shame on me!!! TURNING BETWEEN CENTERS for putting on the CA! That is a major help, just pop them off the centers and mill the overflow nice and flat and you will never "chip" the edge again!
Click to expand...
DUUUH. That would eliminate my problem of the CA chipping and separating from the wood when I remove the bushings.[B)][B)]
Click to expand...

Monty, that is the very reason I went to turning between centers instead of the mandrel. Not a single problem on about 40 pens since I started in the summer.
 
Originally posted by redfishsc
<br />
Originally posted by Firefyter-emt
<br />Just curious, what method do you use after CA application??

I have not tried the "cure overnight" method, I may have to give that a shot. I was sanding and buffing immediately when it was cured.
Click to expand...

Another question is how thick do you put the CA on? Thicker takes longer. I always give a good coat time to cure. Thin coats and paper towel applied, - they harden and cure quick but more than just a thin coat needs a few minutes of curing. I use Monty's CA and haven't had a problem. So far, I have used three 8 oz bottles in a years time and haven't had the problem.

In the past, a few did have problems like that and all used DNAlcohol to clean. Russ warned against using DNA because of those problems.

I JUST REREAD your post and get two different readings:
1. Is it haze in the CA finish as in cloudy finish?
2. Or is is nice and shiny with dull spots/blotches in places?

Those are two different problems.
Click to expand...
 
Here are a few things i have notices when using CA as a finish.
It seems to me that the haze is caused by the CA getting to hot while it cures. I have actually watched it appear as the blank smokes. adding more coats or basically anything that will cause the ca to be thicker increases the risk of it clouding. of course thinner coats risk getting sanded through.
thin CA cures faster than thick also increasing the chance of over heating.
Accelerator also increases the chance of clouding and old Ca (over a year old)is nearly impossible to keep from clouding, at least the thick stuff. I have done 10 Ca finishes with old thin CA in the past week with no clouding problems. was a bit suprised I might add.
 
For my method, using those derlin strips, I apply a line on the edge of the strip side to side and about 2mm wide. You can kind of tell if you have too much on a coat becasue it wants to build on the edges and "flare out" in a bead. If this happens, I wipe the strip clean and "scrape" the excess off. The strips are really something else, you can go back and forth to smooth them out and the CA will just lay flat. I am not going for a perfect finish at this time, I want it smooth so there are no "divots" or "lines" in the CA that need to be filled or sanded out. I apply four coats which seems to be about perfect. I tried three but I burned thru too many times. I turn slightly undersized (In fact, I now make my BCB bushings slightly smaller than they should be so I can sand better.)

When mine are dry like this I do get dull spots but theY sand right off the next day and polish up like glass when done. No lines, no rings, no bumps, pretty much just like a fine lacquer job. However, it's not done "in minutes" but I can spare the time for perfection. [;)]
 
Originally posted by leehljp
<br />
Originally posted by redfishsc
<br />
Originally posted by Firefyter-emt
<br />Just curious, what method do you use after CA application??

I have not tried the "cure overnight" method, I may have to give that a shot. I was sanding and buffing immediately when it was cured.
Click to expand...

Another question is how thick do you put the CA on? Thicker takes longer. I always give a good coat time to cure. Thin coats and paper towel applied, - they harden and cure quick but more than just a thin coat needs a few minutes of curing. I use Monty's CA and haven't had a problem. So far, I have used three 8 oz bottles in a years time and haven't had the problem.

In the past, a few did have problems like that and all used DNAlcohol to clean. Russ warned against using DNA because of those problems.

I JUST REREAD your post and get two different readings:
1. Is it haze in the CA finish as in cloudy finish?
2. Or is is nice and shiny with dull spots/blotches in places?

Those are two different problems.
Click to expand...

Sorry it took an eon to reply.

#2 is the correct answer-- shiney in some places, cloudy in others.


After reading this thread I am going to try the overnight-method.

Has anyone tried buffing with tripoli/white diamond instead of micromesh? At the moment my finishing methods don't require micromesh, so I don't buy it (I do have some handy but only almost-wore-out pads).
Click to expand...
 
In my experience, it seems to happen when I sand before the CA is really dry. Doesn't happen when I use BLO, but lately I'm just using thin CA with no BLO and getting better results. But I do need to let it cure for a few minutes. Sometimes I hit it with a blow dryer.
 
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