OK. Educate me. What caused this?

[Scruffy]

I was turning a blank. Camphor wood. Nice varied colors red, orange, black, brown. Wood works nicely. I put a CA finish. Same way I have in the past.
2 coat of thin. then 8 coats of medium. Sand down through 15,000 using MM.

After about 3 weeks, the CA finish cracked like a husk and most of the finish just came off. Some of it stuck tight.

My only thought on this is that the wood may not have been totally dry. If the wood was still somewhat damp and the wood still dried a bit more, I think the wood could have moved enough to part away from the CA. Do you think that could be the problem?

Otherwise, do you have other insights or possibilities?

 

[KenV]

Camphfor has an oily resin, that is the source of the odor.

Did you clean the resins off the surface with a silvent?

 

[Scruffy]

I used mineral spirits then DNA.

I always clean them that way. Got squirt bottles sitting within arms reach. But, if they were still a bit wet oil from the inside could have still spread outward; even if the outside was spotlessly clean.

... Now how do I test that theory.

 

[Marc]

It seems to me that there has been a ton of reported cracked CA finishes of late. I have seen a handful of reasons speculated but no real definitive answers. Those reasons have included a couple sited here, wet wood and oily wood.

I have also seen bad batches of CA and have myself reported the concept of putting the CA to thick and when accelerated, only the top portion really curing. I have seen others report that additional coats are added before the earlier coat(s) have cured.

I have also seen that sometime the blank is not milled all the way to the tube so that when the hardware is pressed into place, pressure is placed on the wood, and therefore the finish, instead of the tubes.

CA finish can also leave a bit of the cured portion extending over the wood, which needs to be carefully sanded off or it can crack the finish.

Just some thoughts here.

 

[monark88]

Oily/waxy wood. Amboyna is another one, although less oily. IMHO CA is going to fail somewher down the line, eventually, on most woods.
Russ

 

[Scruffy]

Ok. Then can I expect this to be potential problem

with any wood with the presence of any oil or wax or dampness. I guess I need to avoid CA finishes with such woods.

Should I expect potentially bad results with similar woods using other finishes?
What would be the best finishes for such woods?
Or do I need to stabilize (or avoid) any potentially suspect woods?

 

[healeydays]

Try sealing the wood with dewaxed shellac or a tung oil sealer first.

 

[ed4copies]

IF wood is oily enough (read cocobolo), you COULD just polish it (buff).

I agree with you when you say removing the oil from the surface will only delay it from rising out of the wood and affecting your CA "look".

CA was meant to be glue, not a plastic "finish". The preponderance of failures would lead me to look for a different finish, for all wood. Wood moves, plastic finish doesn't.

YMMV,
Ed

 

[monark88]

IF wood is oily enough (read cocobolo), you COULD just polish it (buff).

I agree with you when you say removing the oil from the surface will only delay it from rising out of the wood and affecting your CA "look".

CA was meant to be glue, not a plastic "finish". The preponderance of failures would lead me to look for a different finish, for all wood. Wood moves, plastic finish doesn't.

YMMV,
Ed

I agree. I always just polish and buff these type woods. One can rebuff at some future date, but I find some folks like the "patina" that the pen surface begins to take on.
Russ

 

[Crashmph]

I have started using a product called Call Coat. It is a water based product that is used for coating duck calls. Even though it is water based it has a very good finish on oily woods. I have started using it on some pens and have passed the pens around to clients for a "beta test" to see how the finish holds up. After about month now, all reports have been positive.

Just my honest opinion. Your mileage may vary...

disclaimer: One of my cousins owns a chunk of this company. I tested it as a favor to him. I am quite impressed with it, and I am trying to get some sample bottles to pass out on IAP for some honest evaluations.

 

[Scruffy]

Well, I guess I learned something today.

I have come to the conclusion that CA is only applicable in limited number of woods. And then it is risky to use as a finish for any project that is expected to last for a long while.

Sigh... and I like the finish. I wonder why no one else has observed any difficulties? Or customers?

 

[bjbear76]

I don't use a ca finish on my woods for 2 reasons: the possibility of cracking after it's in the customer's hands; and because I don't always get consistent results. However, I've been doing some decal and stamps pens (wood and acrylic) that I've been using a ca finish. So far the acrylics have cracked; the woods have not cracked yet. Trying to come up with a alternate finish for decal and stamp pens.

 

[kovalcik]

I have been using a CA finish on my wood pens for years without issues. All types of wood including Cocobolo and Rosewood. I have never had a finish crack. This includes my carry pens that I am always dropping, so don't give up on CA as a finish. I have used a few different brands (titebond, sattelite city, and now use Ez Bond from Exotics, always Medium) with similar results.

I don't know why your finish is cracking but here are some points that I make sure to follow. YMMV.

1) Always use dry wood. Burls that I buy from Woodcraft are notoriously wet and I have to let them sit for a long time before I use them. If in doubt, zap in the microwave for a few seconds.
2)After dry sanding, I always wipe my turned blanks down with alcohol before finishing. (also sometimes, depending on the wood I add some BLO to the wood just to make it pop a little. Buff in real well.)
3) I always use THIN coats of medium CA. Just 1 or 2 drops on a papertowel. 8 to 15 coats depending on the wood.
4) After putting CA on I go over and drill a blank, sort out a kit, clean the saw off, or something else for a minute to make sure that coat is dry before putting the next coat on.
5) I never use accelerator on my CA finish. If I feel I need it then refer back to #3 and #4. Just my opinion, but I feel accellerated CA can discolor and is more brittle.
6) Wet sand with MM to polish. I try to let the blank sit over night before starting with the MM, but not always.

As I said, this works for me. I am sure other people have methods that work just as well. Hopefully you will find something to help.

 

[bjbear76]

Thanks Tom. Sometimes it helps to have someone list the step by step details to see if there's something that's being done differently. I see 2 things that I will try this weekend. Use THIN coats of med CA - I have to admit I probably apply it too thick. Also, eliminate using accelerator.
Do you sand with 400 or 600 sandpaper before MM, or go straight to MM?

 

[kovalcik]

Not usually unless I get bad ridges. If I do get ridges or clumps, I sand those down between coats. Usually they are caused by going on too thick. I have read that the first MM pad is equivalent to 400 or 600 grit sand paper (have read both), so I usually just start with the MM.

 

[kovalcik]

One other point I forgot, I try to let the CA set overnight before polishing with MM. Not always, but I seem to get a better finish that way.

 

[ALexG]

I started a thread last week having issues with cracks on my CA finish, seems that the problem was that I was using accelerator between coats of Medium CA that was old, I stopped using the accelerator and letting 30sec between coats, after final coat I leave it to degas for one day then wet sand, this solved my problem so far

 

[Gary Beasley]

Was this regular CA or the newer wood finishing variety? I've done some experimenting when I had CA failure and compared regular medium to wood finish medium. The regular came out good, the wood finish cracked overnight. The wood finish bottle was fairly new, the regular was some I had stored in the fridge from a while back. This tells me some more intensive testing is in order for wood finish CA as well as new stock against older but properly stored CA. There is something in the formula not right that needs tracking down.

 

[bjbear76]

One other point I forgot, I try to let the CA set overnight before polishing with MM. Not always, but I seem to get a better finish that way.

That was the other thing I heard somewhere. You need to let the CA set awhile before polishing to allow it to offgas.

 

[mick]

Scruffy, when you say it cracked like a husk and came off in pieces,are you saying it turned loose in big pieces and just peeled off?
If thats the case I wonder what grit you sanded to before applying the CA. With oily wood it'd you and to high theCA has nothing to adhere to. Try sanding to 600 grit then apply your finish. Sometime this works and other times it just won't stick.

 

[mick]

Scruffy,I'm sorry but that sentence that made no sense I meant to say " if you sand too high the CA has nothing to adhere to"
Sorry bout that

 

[Cindylee]

I no longer do CA finish on any of my pens. I use the BLO/CA method. Easier, no sanding in between, and looks like the natural wood. No plastic look. I have had no issues with camphor using this method. But I still clean the camphor really well and I only sand to 220 so that my finish has something good to adhere to. Like another poster said. If you sand too much you start to actually start to polish the wood. Nothing will stick.

 

[robutacion]

with any wood with the presence of any oil or wax or dampness. I guess I need to avoid CA finishes with such woods.

Should I expect potentially bad results with similar woods using other finishes?
What would be the best finishes for such woods?
Or do I need to stabilize (or avoid) any potentially suspect woods?

Well, yes and no...! CA finish on properly stabilised wood "should" bypass many of the issues with CA adhesion however, you have to consider this;

*- The typical difficult woods to finish with CA, are also the typical woods difficult to stabilise, oils, density, etc., are their demise so, CA coating blanks that didn't stabilise properly, are not the solution...!

*- Finishing/coating stabilised blanks doesn't retract from the fact that, "contamination" of the exposed wood can happen quite easily if some care is not used.

*- Stabilised wood finished with CA, won't survive pressing the pen parts together if is glue inside the tube(s), the ends weren't cleaned and square properly.

- If pressing is done incorrectly, (parts not centered to the brass tubes).

- If bushings and brass tube sizes, don't match.

The number of "small" details that can create a "big" problem, are far too many to name them all however, one thing I do believe, if a wood blank was stabilised properly, the chances of any type of failure, are dramatically reduced...!:biggrin:

Cheers
George