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CA Finish on a Pen leaving pits and imperfections.

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Forum topic by Sunburned posted 07-02-2020 01:36 AM 271 views 0 times favorited 4 replies Add to Favorites Watch
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Sunburned

69 posts in 1326 days


07-02-2020 01:36 AM

Topic tags/keywords: lathe finish ca

Hey All,

I have been making pens for about a year now and i have recently been having issues with my CA finishes. They are just not coming out as smooth as usual. There are pits and imperfections no matter how much micromesh sanding i do.

I have been:

- turning my pen

- sanding in 5 stages from 150-600 grit

- Applying 5 coats of thin CA with a blue shop paper towel

- Applying 3 coats of med CA with a blue shop paper towel (occasionally hitting with accelerator but giving a few minutes between each coat)

- Applying 2 coats of thick CA with a blue shop paper towel (occasionally hitting with accelerator but giving a few minutes between each coat)

- Allowing the glue to dry for at least 15 minutes (this is way longer than the glue instructions say it needs)

- Wet sanding in 9 stages with Micromes from 1500 to 12000 grit (https://www.amazon.com/gp/product/B0756MT6X8/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1_)

When applying the CA i do a left and right motion with my lathe on the lowest speed (~500 rpm) with low pressure from my hand. I pull the paper towel away just after i feel the paper starting the pull from the rotation of the pen.

The theory I am working on right now is that I may need wait some hours between the sanding and the first coat of CA because it may be causing a few of the natural oils from the wood to sit on the surface of the wood and interrupting the adhesion of the CA.

Maybe it could also be the moisture in the air since we are now in the summer months and it has been raining in my area a bunch lately.

Does anyone have any experience with this? The strange thing is I never used to have this problem. The last pen I made was a hybrid redheart/walnut if that helps

-- Woodworking Forever


4 replies so far

View Lazyman's profile

Lazyman

5679 posts in 2197 days


#1 posted 07-02-2020 02:10 AM

CA polymerizes in the presence of water so it is is possible that humidity is affecting it. Using wood that isn’t dry enough could be a problem too. If you can check the moisture content of your wood that may help you determine if that could be a factor. When applying I make one pass and stop. I don’t got back and forth. If I feel a pull from the paper towel, I didn’t apply quickly enough. I use accelerator after each coat to make sure that it sets before I apply the next coat. I rarely use medium or thick CA because when I do, I almost always have ridges or pits that causes me to sand it back severely or have to start over. Even when I use a thicker CA, I sand (400 or 600 grit) and apply one or two last coats of thin to give the smoothest finish possible. After the last coat, I will lightly sand at 600 or 800 one more time to make sure that there are no pits or ridges before polishing. I have never found a need to use anything over 1000 grit (I have micromesh but have never used it). The polishing compound basically accomplishes a glass smooth finish.

BTW, I doubt that natural oils in the wood should be that much of a problem. Some people actually use a cloth or paper towel dampened with BLO as a lubricant to apply the CA. I have never tried this but I am sure that you can find examples of that online.

-- Nathan, TX -- Hire the lazy man. He may not do as much work but that's because he will find a better way.

View LittleBlackDuck's profile

LittleBlackDuck

5004 posts in 1630 days


#2 posted 07-02-2020 03:43 AM

I always use thin CA at 1800 revs… apply anything up to 20 coats which gives a decent layer. I then go through the acrylic polishing pads range starting at 600 (usually start with 400 then 600 sandpaper then move onto 600 pad) up through the supplied range.

No idea whether it may or may not be important, however, if old practices no longer work, have you considered the quality of the CA. CA has a limited shelf life, especially in the open. I keep my CA in a bar fridge and threw a heap out when I discovered their limited shelf life… just a thought.

-- If your first cut is too short... Take the second cut from the longer end... LBD

View Wildwood's profile

Wildwood

2879 posts in 2944 days


#3 posted 07-02-2020 09:07 AM

Never used anything other than medium CA glue for finishing pens. Never bought or used accelerator either! Both old CA glue and bad accelerator can ruin your finish. Know lot of pen turners over at IAP had lot of problems with using accelerator several years back no matter what viscosity CA used. Not getting rid of sanding dust from previous sanding can also cause problems or not wiping between each micro mesh sheet or pad.

I stopped buying cheap Abrasive rolls pen kit suppliers sell.
https://www.pennstateind.com/store/PKSPSET5.html

Replaced it with this sandpaper.
http://www.hutproducts.com/products.asp?dept=51

Item # 1120 Sanding rolls variety pack & item # 1130 Sanding roll variety pack. Could never find these pack at Klingspor’s Woodworking Shop
https://www.woodworkingshop.com/

Good turning with my skew or roughing allowed me to start sanding 320 or 400 grit and how many higher grits depended upon the wood. Those higher grits used for wet sanding polishing the finish. Then I found and started using micro mesh sheets to wet sand & polish the finish.

-- Bill

View Sunburned's profile

Sunburned

69 posts in 1326 days


#4 posted 07-03-2020 02:00 AM

Thanks everyone. First thing I tried today was doing the 20 coats of thin without the Med and thick and that produced a much better finish. I am also going to experiment with some of the other suggestions.

-- Woodworking Forever

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