Fine tuning a CA finish?

Signed-In Members Don't See This Ad

Woodchipper

Member
Joined
Mar 15, 2017
Messages
5,138
Location
Cleveland, TN
I just finished a Slimline pen with a Spectraply blank. Really two questions here: 1. I put seven coats of thin CA on the blank, Still looks, to me, a bit rough. What do you do to smooth out the CA? Applied with a paper towel and a shot of Accelerator between coats. I have a bottle of Shellawax. Will that work? 2. How do you keep the CA from making a "lip" on the end of the blank? Any way besides applying with the bushings? Thanks.
 
Signed-In Members Don't See This Ad

Kenny Durrant

Member
Joined
Sep 11, 2012
Messages
2,480
Location
Sachse Tx. 75048
I still struggle with CA at times but here's what I've found. I've switched to Mercury Brand Flexible CA instead of the regular brands. Glue Boost works well also. First thing is to sand the blank as if you were finishing it. Any scratches on the wood will show through the CA. Slow the lathe down for this. I run about 650-700 rpm's. I'll put a couple coats of thin to try to penetrate the wood as much as possible. Between each coat I use steel wool or fine sandpaper to knock down the rough spots. The guy that helped me called it leveling. Also all accelerators aren't the same. Most will cause bubbling or the glue to turn white. Glue Boost or Mercury brands don't. After a couple of coats of thin I put 4-5 coats of med flex. Still "Leveling" between coats. Once I feel comfortable with the CA buildup I start wet sanding with micro mesh at the slow speed. Then I polish with Hut Plastic Polish. I use a bright light to watch for shiny spots while leveling. Good Luck.
 

Woodchipper

Member
Joined
Mar 15, 2017
Messages
5,138
Location
Cleveland, TN
Thanks. I have Hutt and MM. Will try it. Accelerator is Titebond and never had it bubble ot turn white. I sand by turning manually and sand with the grain. Will experiment.
 

AllanS

Member
Joined
Jun 13, 2022
Messages
81
Location
New Mexico
2. How do you keep the CA from making a "lip" on the end of the blank? Any way besides applying with the bushings? Thanks.

I don't. I sand off the excess before assembly. It was one of the bits of advice I heard early on - you sand it down because that extra CA on the end could cause the finish to crack when you press things in.

And I'm not quite certain if, by "applying with the bushings" you mean with the turning/metal bushings or with CA/plastic ones. But just in case, you might want to look at CA/plastic bushings for this stage, it's much easier to get the blank off of these - here's one example and here's another.
 

Woodchipper

Member
Joined
Mar 15, 2017
Messages
5,138
Location
Cleveland, TN
I make my own bushings from a piece of HDPE I got at the recycling center. I lightly sand the ends. This is the buildup on the edge, looking like the end of a trumpet.
 

Kenny Durrant

Member
Joined
Sep 11, 2012
Messages
2,480
Location
Sachse Tx. 75048
Sorry I forgot to mention the glue and bushings. As mentioned you can make your own with HDPE or Delrin. Anything the glue won't bond to. You can also buy them. I use HDPE cones from Woodcraft. They're actually called finishing bushings.
You mentioned turning the lathe by hand. That's fine but when applying the glue you need to wipe it on and get off. The longer you play with it the more you leave streaks If you can slow down the late and apply the glue with a paper towel or small pen kits parts ziplock bag. Be careful with the bags. Some have red printing on them and CA will dissolve it and transfer it to the blank. If your using an accelerator that might cause foaming be sure to use ligh squirts from a distance and try not to get too close.
 

gbpens

Member
Joined
Jul 1, 2011
Messages
821
Location
Homer Glen, IL
Spectraply can be problematic for a CA finish. Fine sand the wood, let the first coat of medium CA soak in and then continue with additional coats. Use accelerator on the third coat. If I apply too much CA in one coat then a revert to 240 grit sand paper to get rid of the ripples. One coat of accelerator will usually be good for a six or seven coat finish.
 

JohnU

Member
Joined
Jan 31, 2008
Messages
4,925
Location
Ottawa, Illinois
CA never goes on without needing work. Once you finish applying your layers, use 400 grit sandpaper and a very light touch at a lower speed to knock down the ridges. Then turn the lathe on high and hit it with #OOOO extra fine steel wool. Then wet sand with all 9 grits of micromesh and polish. I use this process with Gluboost and get spectacular results every time.
 

Woodchipper

Member
Joined
Mar 15, 2017
Messages
5,138
Location
Cleveland, TN
Again, thanks to all. I would like to cut-and-paste the replies when everyone is done here.
I assembled the pen (need better QC). I can push out the top and remove the clip. OK for that. The twist assembly is another thing. Suggestions are welcome.
 

greenacres2

Member
Joined
May 2, 2017
Messages
1,686
Location
Northwest IN
Sanding the blank after turning has been mentioned a few times here--i typically don't sand the wood, espceially SpectraPly (or contrasting segments). Sanding dust discolors the lighter layers with darker dust that never comes out. I normally turn the bulk of waste material away with carbide (or lately a 1" roughing gouge), then my finish turning is with a skew or spindle gouge. High speed steel leaves a finish that can't be achieved with sandpaper. And--the HSS leave Red White & Blue SpectraPly looking Red White & Blue!! Takes learning to sharpen HSS, and practicing--but if you can get a smooth finish on poplar with a skew or spindle gouge--you can get a smoother CA finish over the top of SpectraPly.
Good luck!!
earl
 

Fangar

Member
Joined
Apr 27, 2005
Messages
1,837
Location
Wilton, CA, USA.
Some great suggestions! As for bushings, I would suggest getting some delrin rod and making bushings to use when applying CA. The CA won't bond to the delrin bushings. CA can be a fickle finish, but it has worked well for me over the years. Haven't turned a pen in a while though, so what do I know! šŸ˜…
 
Top Bottom