A thought on what may cause dullness to CA finishes

After reading every single post on finishing with blo without blo ca only etc etc etc.....I have a theory on why my latest pen is shinny in some areas but dull in others.

I apologize ahead of time if this was already brought up by someone but...I think my pen is very slightly out of round Probably due to a too much sanding. I keep putting multiple coats of CA that look great dry, but after MM ing down, I get inconsistent shine. So after working on this one pen for literally 8 hours of finishing then sanding back to start over again, I think I've found what's going on. The only issue now is how to fix this....

..and thanks Curtis for the idea on using the skew to get the old ca off....a bit scary but it worked like a charm.

Still looking forward to a X-Mass present from Curtis on his ca finishing video

There are three things working against most of us when we apply a CA finish.

Our biggest problem is that we too often use CA glue for the wrong reason - because it is fast, and then we try to make it faster. We should be using CA glue because it is better, and then taking the time to do it right.

It is almost a universal fact that oils are what destroys the gloss of a finish, and CA glue behaves no different from other finishes. The oils can be those from the wood or those that we introduce into the process.

CA glues cure by a chemical reaction, and any foreign matter that is introduced into the mixture will influence that chemical reaction. We change that chemical reaction whenever we use an accelerator to make the faster curing finish even faster. Who else but a penturner would want to improve on "instant"??

If anyone is haveing problems with their CA glue finishes, the best solution is to eliminate the oils and the accelerator, and let the chemical reactions happen by themselves. The worst that can happen is that we will have to start sanding with a coarser grit to get rid of a rough surface.

I read this forum every day...

.... and I am going to have to conclude that I am the luckiest penturner around... I never have any of these problems!

I'm afraid to change any part of my regimen now! ... I wear the same socks even!

Sorry...

I use accelerator.... a tiny spritz a few seconds after applying a coat of CA... and have been doing it for years and never have the blushing or dull spots... Wish I had a clue why not, but I am not going to argue with success...

I just wanted to add that once in a while I will either leave the paper towel on too long, or not use enough CA and will get a dull spot... which disappears after a quick sanding between coats and another coat of CA.

Hope this helps....

Mark, you answered your own question about the reason for your success when you used the words "wait" and "tiny". Most people subscribe to "if a little is good, a whole lot is better" when it comes to using an accelerator. For them, not using the accelerator is the best solution to their problems.

So, finally success. Trying to prove my hypothesis that out of round caused my dull spots, I "squeezed" the MM between my fingers to polish instead of holding it in one spot behind the pen and going back and forth (therefore coming in contact with all sides of the wood.) All the dull spots went away. Not that I will do this every time, but next time I am out of round and get dull spots, this will be the first solution I try....

Russ, great article on your website by the way about typical causes for finishes gone bad.

Your description of the problem you are having sounds like the major problem I had for a while. My problem was I was sanding through the finish in certain places (dull spots) while others (for whatever reason, maybe it was OOR.) still had a very nice CA finish.

I began checking the thickness of my CA finish. Measured blank when prepped to begin applying ca then measured again after applying all CA. Went through the sanding routine and measured one last time. Discovered I was nearly back to original diameter.

That really surprised me.

I've learned how much of the finish I will take off when I sand. I make sure the CA I apply is built up to about double that amount.

I haven't had a dull spot since.

My fit has improved as well. I now know the diameter of the kit pieces I'm using and I build my finish up so after I sand it will be nearly perfect. I try to err on the side of a couple thousandths larger than the kit.

Dull spots in finish!

I sand and finish with the lathe spinning, and have had both the dull spot in the finish, and out of round problems. when I see the dull spots in the finish, I add more CA to that area of the blank, and refinish, (rebuff). When I see out of round it is usualy at the tailstock end. The I simply reverse everything on the mandrel and turn out the OOR blank and then finish. I have two mandrels, and both are OOR somewhat although I cannot see it when I roll them on a flat machined surface. I can always tell when I lay a tools on the spinning surface near the tailstock end and feel the tool vibrate. Damkit
WS (Bob)

Hi
I don't have a problem with being out of round but I do get dull spots on Ebany wood,
I do like to use ca with linseed oil,as I put on 4 to 6 applications but what do you do after that ,as I have heard that there is a 10 step finish to it?
Terry

Bob,
Two things can be done for the vibration.
1. Spend time - quality and quantity time learning the lathe. Before TBC became well known, users either accepted the vibration or spent time knowing their lathe to the point that - from a little observation and deductive reasoning - they could quickly figure out what caused the specific problem and how to make adjustments to fix it. I do think that learning and knowing how to fix problems is a good thing.

2. TBC does away with the mandrel/live center problem and learning curve and quickens the process of turning pens concentric to the pen fittings (no high / low spots of opposing sides). Unless you have Off Center bushings or Tail stock out of alignment, the vibration will for the most part be gone.


Terry,

Concerning Ebony, most ebony is oily to begin with and while CA does stick OK to ebony, it does have a tendency to lift. Applying BLO to ebony will often enhance the tendency to lift or separate from the wood.

Russ Fairfield has mentioned many times that BLO can cause dull spots in CA finishes. In addition to that, if sand through occurs, it will cause dull spots.

10 Step process?: I never count the steps, I go for the finish. If it takes 4 or 5 coats of medium, I am happy. If it takes 7 or 8 and it looks good I am happy. It is not necessarily the number of steps but the results. Keep adding until you get there.

Forget the BLO on Ebony. The wood already has enough oil to cause finishing problems without adding more to it.

My experience is that Ebony is a species that will turn anything finish we can put on it into a flat matte gloss if we wait long enough. If you want a glossy finish, you should be using African Blackwood because there is less oil and a glossy finish will last longer.

I polish the wood to whatever gloss I get from the 12,000 Micro-Mesh and that's it. Most people like the softer gloss on Ebony. If the pen is used, the gloss will improve with age. If it isn't used, it will never get any worse than it is.