Help with CA Finish on Cocobolo

[K-9 Man]

Hello,

I was hoping someone could tell me why the CA finish on the attached blank turned out the way it did. Some of it looks really nice and clear/dark other spots look milky/cloudy. I am new at the CA finish and until now have had good luck. I say luck because I am not sure exactly what I am doing applying CA as a finish.

The cloudy spot don't show up until I am using the mirco mesh to sand. I also noticed it when I applied the "one step platic polish" to the CA finish, which I had done before.

Thanks for any tips/help. By the way the wood used here is Cocobolo.

Ernie

 

[JohnU]

Others will probably have better answers for you but the way I see it, blame the wood. Cocobolo has oils in the wood that interfere with a good CA finish. Been there, done that. Try wiping the wood down real good with Denatured Alcohol or acetone before the CA. Just make sure you give it plenty of time to dry before the CA. Bocote and zircote along with others will give you the same problems. Good luck.

 

[RustySplinters]

There are several things that might be happening.

It looks to me as you are not applying enough ca and so it is all getting sanded off as you go through the mm.

If its not that then it might be because cocobolo is a very oily wood and so the clouds would be moisture from the oil or from other water that has built up under the ca.

Hope the info helps. I often had trouble with the first issue.

Michael

 

[micharms]

I would suggest that it is a problem because of the oils in the cocobolo. Did you wipe the blank with mineral spirits or something similar before applying the CA? I'm no expert on this so it is just a suggestion.

Michael

 

[anectine]

Cocobolo is an oily wood. Oils will actually disolve CA after long exposure. In this case the oils prevent the CA from sticking to the wood. One suggestion has been to tub the blank with acetone or denatured alcohol and allow to dry, just before applying CA. I like the DA better than Acetone, as acetone can discolor some woods. Sand this finish off and give it another go!

Adam

 

[mrcook4570]

You have sanded through the CA to the bare wood. It did not show up until you started sanding because the sanding dust will stick to the bare wood but not the parts that still have some CA.

It is true that CA is very oily, which can cause the finish to lift in some areas, giving it a cloudy look in those areas. However, I do not believe that is not the case here. Hit those dull areas with some sandpaper. Is the dust white or does it have a reddish brown (cocobolo colored) tint? If it is white, then those areas are still covered with CA and it has just lifted off the surface. If it is colored, then you have sanded through to the bare wood.

 

[keithbyrd]

I have never wiped the oils of any wood I turned. And have not had any spots show up since I quit used the CA/BLO method. Part of your problem I think is sanding as mentioned before and another part may be to much activator being sprayed on? I spray from about 6-8 inches and spray very lightly - just a spritz! Ok so now what is a spritz? A tiny spray? I also put on at 6-8 coats before I touch sandpaper.

 

[OOPS]

+1 on cocobolo oils causing the problem. A friend of mine places his cocobolo (and any other oily woods) into a bottle filled with denatured alcohol. After about 30 minutes, most of the oils have come out of the wood. Now, sometimes losing the resin and oils in the wood will affect the grain color in the wood. In those cases, wiping with DNA will remove oils and resins, but not enough to change the color of the grain. Cocobolo is one of the woods where turners get improved results through personal experience.

 

[Rodnall]

I haven't had any problems applying ca to my cocobolo blanks after sanding and I only wipe them with a paper towel. Are you sure the ca your using is good, or maybe your using to much activator like keithbyrd said.

 

[Alzey]

I use 1 - 2 coats coats of BLO before I start the CA.

 

[reiddog1]

Ernie,

I had the same issues when I would finish oily wood like cocabolo or paduak when I first started penturning. Here are the steps that have worked for me and I still use today:

-After sanding blank, put on delrin bushings and clean with accelerator and paper towel.
-Do not touch the blank with your hands after cleaning!!
-With lathe running, apply a small amount of BLO with paper towel and rub it in good.
-I then apply 6 coats of CA (medium) with a light mist of accelerator in between.
-Flip blank over only touching the bushings and 6 more coats of CA (medium).
- Finally 2 to 3 coats of CA (thin).
- Sand to 600 then buff with tripoli and then with white diamond.

People think that I'm a little crazy for putting oil on an oily wood, but i have pens over a year old that I finished this way with no issues. Anyway, not an expert, but works for me. Hope this helps.

Dave

 

[Ambidex]

blank

A different opinion here...I've had issues with different woods, some oily, some not...but micro meshing the ca can be a bit tricky. If you overheat the ca and don't let it cool a bit between meshes I think the ca clouds. I've had this happen numerous times and have fixd the probs by slowing down and letting the blank cool a bit. Not saying I'm right, just saying it has worked for me in the past, especially on multiples that I tend to try to crank out too fast. Good luck and let us know? We all still like to learn:wink:

 

[K-9 Man]

Thanks everyone for your help. I have a lot of ideas to try. I am back to work tomorrow so it may take me until this weekend to work on the blank.

I didn't use accelerator, or wipe the wood down with anything other than a towel prior to using applying the CA. Also, looking back, I didn't give the blank much time to cool down when using the micro mesh. I guess patience will help me out a lot with applying the CA finish.

Another question: When applying CA finish to the Bethleham Olive Wood is there any need to worry about wiping it down with alcohol or anything prior to applying the CA? Also what is BLO?

Thanks again.
Ernie

 

[reiddog1]

I wipe all my blanks down with something. Acetone, accelerator, alcohol, or naptha. Just watch it with woods like paduak, cause it will actually smear the color. On paduak, I will usually go with a dry paper towel folled by BLO. Obtw, boiled linseed oil.

 

[K-9 Man]

Thank you, I am trying to get a hang of some of the acronyms. I now understand BLO is boiled linseed oil and I have assumed BOW is bethleham olive wood.

I thought only the military used acronyms. Now I understand why civilians don't understand when I tell them about my job in the military.

Where can I find BLO?

Thanks again
Ernie

 

[reiddog1]

No sweat man. I got a small can at walmart in the paint section and put some in a small craft squeeze bottle. I've also seen it in the big box stores as well. I know what you mean about acronyms, Navy 19 years.

Dave

 

[raar25]

I definately think you sanded through the CA. The bushing kept you from sanding too much on the ends which is why the middle looks worse. Sand them down to bare wood and recoat; 2 coats thin and at least 5 coats medium. Then when you sand, knock the high spots down with 0000 steel wool, than very lightly with 400, 600 and I use EEE paste after. Depending on how gloss I want I use plastic buffers rouge after.

 

[Rodnall]

Are you using water when you micro mesh? It helps to keep the ca cool.

 

[pianomanpj]

I would not recommend using denatured alcohol as it actually absorbs water. Although you may not introduce any moisture into the blank with it, its not really worth the risk of compounding your problem. Play it safe; stick with acetone. YMMV

 

[OOPS]

That is precisely one of the reasons DNA is used. 1. It absorbs moisture out of the blank, and 2. it dissolves oils and resins from the wood. All of these are unwanted and they leave the blank and go into the solution. Once removed from the alcohol, the remaining alcohol on the surface of the blank evaporates quickly.

 

[dplloyd]

Thanks for posting this K9. I was about to ask the forum exactly the same question today. Lot's of good responses here. I have an order for several cartridge pens and my customer asked for cocobolo. Last time I CA'd a coccbolo it clouded on me in a few spots. Going to try a few of the suggestions this weekend.:biggrin:

 

[bitshird]

Thanks everyone for your help. I have a lot of ideas to try. I am back to work tomorrow so it may take me until this weekend to work on the blank.

I didn't use accelerator, or wipe the wood down with anything other than a towel prior to using applying the CA. Also, looking back, I didn't give the blank much time to cool down when using the micro mesh. I guess patience will help me out a lot with applying the CA finish.

Another question: When applying CA finish to the Bethleham Olive Wood is there any need to worry about wiping it down with alcohol or anything prior to applying the CA? Also what is BLO?

Thanks again.
Ernie

Ernie, Olive wood, or Cocobolo, Ipe, and a few other hard oily woods do need to be wiped down, with a good solvent, I prefer Acetone, it dries quicker than Denatured Alcohol, also let your CA dry over night, I know instant gratification is fun and fulfilling, (until you get fog like you did on the COCO) Ebony is another fun wood to hate, but most Rosewoods/ Dalbergia family of wood are pretty oily, and do need to be wiped down, And accelerator also works , but actually is slower to surface dry than Acetone, so it can give a bit of a hassle, on the first coat of CA.

 

[K-9 Man]

Are you using water when you micro mesh? It helps to keep the ca cool.

How do you use water when using micro mesh? Do you have it in a spray bottle and wet the blank when sanding?

I have never used water when turning or sanding.

Thanks
Ernie

 

[Lenny]

Are you using water when you micro mesh? It helps to keep the ca cool.

How do you use water when using micro mesh? Do you have it in a spray bottle and wet the blank when sanding?

I have never used water when turning or sanding.

Thanks
Ernie

I keep a small tupperware type container filled with water that I soak the MM pads in prior to sanding the CA finished blank. (replace the water frequently) I prefer to clean the blank with acccelerator before the first coat of ca. Always build up a sufficient layer of CA before sanding with the water and MM. I NEVER sand with MM dry! And NEVER let water get on a wood blank prior to applying CA glue.

 

[pianomanpj]

That is precisely one of the reasons DNA is used. 1. It absorbs moisture out of the blank, and 2. it dissolves oils and resins from the wood. All of these are unwanted and they leave the blank and go into the solution. Once removed from the alcohol, the remaining alcohol on the surface of the blank evaporates quickly.

You make a good point, sir - good call. (Dang it!)

I've always heard that when cleaning a blank (sanding residue, etc.) that DNA could introduce moisture and it should be avoided. But common sense would indicate that in the case of oily woods or those that have higher moisture content, it will draw more moisture than it will introduce - as long as the DNA has less water content than the wood in question. I would still follow it up with acetone for a final wipe down. (Or maybe I'm just trying to save face. )

 

[mmoncur]

I've been wiping mine down with Isopropyl alcohol (just because I had some handy) before the CA applications and that has worked pretty well. I'm new at this but I've had good luck with Cocobolo so far.

In this picture the three pens on the right are Cocobolo.



(Notice the first Cocobolo pen has a cloudy spot - looks a bit purple in the picture. Looks similar to yours. I think the problem was that I did a messy CA finish, sanded it off, then re-did it - a bit of the old finish was still there. I didn't notice it until after final polishing of course.)