CA Finish Problem - HELP!

[kf4knf]

I have been trying to perfect my CA finish over the past few days but I have run into a problem...

I apply a thin coat of CA and harden this with with some accelerator. I do about 3 coats before I begin sanding with 600/800 grit paper (wet). After advancing a few grits into the process I have noticed a dull area may develope, sometimes in the middle of the blank, sometimes at the end.

I think this is this because I have sanded through the CA? Do I need to apply more that 3 coats? What is a good way of preventing this in the future?

The problem here is I cannot simply apply more CA and start over as it will still appear on the finishing product. In most cases I have to sand the entire blank back down to wood and start over. Could some of you experienced CA guys lend me some knowledge? [:I]

If you need a picture I might be able to get one posted later tonight...

 

[its_virgil]

Try using medium CA. There are a few excellent tutorials on CA finishing, but I suppose you've read them. Is is happening on all blanks, or just on a certain species. There are times when I just sand off the CA and use another finish. I think it may be the CA not sticking to the wood for some reason, or as you say, you've sanded through the CA into the wood. That should be easy to check out and see if the dull spot is CA or wood. I suggest you read the tutorials (if you haven't) and see if you can find what you are doing to cause the problem. I do not wet sand so I can't help you there. Good luck on solving your delima. Don't give up. You will figure it out.
Do a good turn daily!
Don

 

[JimGo]

Some have reported similar problems because of the use of the spray accelerators. If you're using thin CA that's still good (i.e. hasn't expired), you shouldn't need accelerator. Mine sets up in at most 15-20 seconds. I find I get similar speed with medium, too, but I use BLO with my CA most of the time.

If you really think it's from sanding through the CA, the problem may be a misalignment/bowing in your mandrel or headstock/tailstock setup. Try stopping the lathe before you start sanding and rotating the blank on the bushings by 180 degrees (i.e., hold the bushings still with respect to their location on the mandrel, or at least try to reposition them close to the same place after you're done). Touch up the shape with your tool of choice again. Do your first sanding pass, repeat the blank rotation step. Do this again on your next sanding pass, too. That should give you a pretty cylindrical barrel with fewer high spots, thus reducing the likelihood that you'll only sand through the CA at certain points on the barrel.

Good luck!

 

[gerryr]

I've experienced the same thing and it is definitely that you have sanded through the CA. I apply 2 coats of thin, then 2 coats of thick, then I start sanding. I never use accelerator because it can, and eventually will, cause the CA to turn white in which case you have to remove it completely. To use only thin CA, you would probably have to put on 6-7 coats to have enough thickness that you won't sand through it. Don't try to rush the process, let the CA cure on its own. Remember, this is a finish that can be done in a matter of minutes, rather than days or weeks if you're using lacquer or enduro.

 

[wudwrkr]

I have also been plagued with the "dull spots". I have been trying to perfect the CA finish and the last few pens I have done have come out great. I examine the blank after each application of CA and check for problem areas. If I see an issue, I sand it all off and start again. I use to use BLO with every application of CA, but I don't do that any more. I still use BLO, but only a couple of drops prior to the first coat of CA. I think it really helps make the grain "pop", but IMHO too much causes problems. Another thing that appears to help is to wait 10 to 15 minutes before sanding. I do not use accelerator. After sanding with the first grit, I wipe the blank with DNA and look for any problem areas. There are times that I have seen dull spots on the finish, but they are on top of the finish, not below. I have been able to sand these off by hand with the lathe off. I also let the blank sit overnight before I do any buffing.

I have also found some woods that I can't get CA to apply properly. For those I am using Enduro. In fact, I just completed my first Enduro finish. I think I like CA better, but at least it is another option.

I can empathize with you. Good luck!

 

[jtate]

okay - newbie here.

What's Enduro?

Where is it obtained and how is it applied?

Julia

 

[gerryr]

Enduro is a polyurethane finish. Wayne is the resident expert on it and if you do a search you will find his method. You can get a relatively small quantity to try it out from Ernie at Beartooth Woods.

 

[Jerryconn]

Fanger has a CA finish that is beautiful and I follow almost to a tee. The one thing I read is that you use ACC on the thin CA that is something that is not recommended. Then you need to put a coat or 2 of thick CA on top of the thin, then you can start sanding.
I hope he won't mind but here is a link to the thread on his finish

Hope this helps

 

[kf4knf]

Yea I have heard that thin CA is best for the first few coats because it's well, thin, and therefore able to be absorbed better by the wood. I think tonight I will try 2 coats of thin CA, no accelerator and then a few thick coats like you all are telling me...

I am glad I am not the only one with this problem. [] One step I take that is not listed in any of the articles is applying a thin coat of way to the wood before applying CA. I think it helps do two things, clean the wood and bring out the grain much like the BLO method others have mentioned. The wax is throughly removed from the blank surface and does not affect the aplication of CA. I think wax is great, it can really make a dull grain look priceless.

 

[Ligget]

Is it not the wax that is causing the problem?[]

 

[JimGo]

that was my thought too, Mark.

 

[gerryr]

Wax, holy smokers!!!![:0] I don't see how the CA can pentrate and seal the wood if you do that. I tried putting Tru Oil on a couple before the CA when I was first learning to do a CA finish and every one of them was a problem. I ended up using lacquer after a ton of sanding to get all the whitish spots out. The CA seals the wood, that's all you really need.

 

[kf4knf]

Actually, I tried it again last night using the wax and just adding more coats of CA. Works great! I thought the wax would cause problems too at first but as I began to use it I found that was not the case.

 

[davidrei]

In addition to skipping the accelerator, consider trying a different applicator. I started out using paper towels, with and without BLO, but I couldn't get rid of the 'ghosting'. I think that a big part of my problem was that here in Houston, the hot humid weather helped the paper towel to accelerate the setting of the CA much faster than I wanted. I now apply with a nitrile gloved finger and I'm getting good, consistent results. Some other use wax paper or the little plastic bags the pen kits come in. Also, make sure you are applying even coats. I use 1 coat of thin and 3 coats of medium, but when applying, I run my finger up and down the blank to smooth it, until the CA starts to get a little tacky (begins to slightly pull on the nitrile glove)

 

[rfreeouf]

I think the main thing is to give each coat of CA time to dry between coats. I usually wait about 10 minutes after the last coat to sand and polish the CA to a nice shinny finish. I have never used accelerator and I have never had any white or dull spots. I also use a egg timer and set it to 2 minutes between my coats.

 

[Dario]

I will go out of the limb here...but will share my experience which may contradict a lot of posts.

It is probably due to the heat and humidity of San Antonio, TX but whenever I let CA cure by itself, it turns white on me! [:0][!] It doesn't happen when I let it sit a minute then hit it with accelerator. [B)]

I am only sharing this to point out that what works for others, may not work to you.

BTW, If you are applying CA evenly enough...one coat of thick is sufficient. If you have deep ridges, it doesn't matter how many coats you applied, you will have to sand to the bottom of the deepest one anyway. As much as possible apply from one end to the other, avoid multiple passes or worse going the opposite direction as this may lead to trapping air and create voids (air pocket).

Using the nitrile gloves is one that I've been planning on doing for a while now (like more than a year [B)])...just too lazy to actually order the gloves. []

 

[kf4knf]

I agree Dario, I have had better luck keeping air out if you only apply 1 coat.