Wavy CA Finish: A Hypothesis?

[dachshund1]

After having initial success producing a smooth, professional CA finish on my pens, I've been recently plagued with issues of "waviness" - sometimes ever so slightly discernible to the touch, but often not. As a result, simple projects that used to take 45 minutes have become marathon sessions in futility. :frown:

There's nothing special or proprietary to my technique: I apply the finish at slow speed (~600 rpm) on a pen mandrel between Stick Fast Non-Stick synthetic bushings. I use only thin CA, applied sparingly using craft foam, with a short spritz of aerosol accelerator from approximately 12" away. I wet sand with MicroMesh and finish with PlastiX. This part of my process has not varied - which is why I'm baffled.

I realize there's a boatload of potential factors, but I'd like to think most of those environmental or technique-related are relatively controlled. Moreover, I've tried sanding lightly every 2-3 coats (I generally put on 8-10) - which seems to help - but nothing completely corrects the problem. For whatever reason, I suspect the problem lies in the application of the CA - not the finish sanding.

Then it struck me: While I've been using the Stick-Fast bushings throughout, I had to replace the first set due to CA buildup from extended use (even with a coat of paste wax, they're not entirely non-stick). :wink:

So, wanting to keep this new set a bit longer, I peel off what CA I can after each use - and promptly plop them into a shallow cup of acetone. Then, prior to use, I take them out and thoroughly wipe of the thin layer of CA (evidently, acetone does not really dissolve CA; it merely makes it pliable).

Hence, my hypothesis: It is possible that some residual acetone (or the resulting fumes) on the synthetic bushings could be having this rippling effect on the CA finish? Or, conversely, the acetone that I wipe on the sanded blank prior to finishing? I know it dries immediately; does it also completely evaporate - or is a residue left behind?

When it works, there's nothing (IMHO) classier than a deep CA finish. However, the lack of consistent results about has me ready to look for another option.

Any thoughts? Recommendations? Alternatives? Anyone have other experiences - similar or different?

 

[jttheclockman]

I say you need to try the things you mentioned one by one to zero in on the problem. Acetone does not completely dry right away even though is seems to. No it does not leave a residue. Why not clean the bushings way ahead of time to start with.

To me it is in the application. Thin CA dries rather quickly but I would let it seek its level and not use the accelerator. If you started having any waves in the first couple coats it will only pile on and not go away. When you use the acc. you immediately freeze the coat and any imperfections is there to stay. Just my thoughts. I do not use that stuff.

 

[thebillofwrites]

If you are always using the exact same methods and products/supplies, I'm not sure why you would be getting varied results.

But in my experience, whenever I used the craft foam as an applicator, I would almost always get the wavy corkscrewing effect that would take lots of sanding to eliminate.

My best results have always been achieved by using the Scott's Blue Shop Towels from the Depot or Lowes as my applicator. Always a very smooth finish that needs minimal sanding.

To me, the foam just kind of pushes the CA around, whereas the shop towels tend to absorb the excess and deposit only the amount needed for that coat.

But I do know quite a few folks that get good results using the foam. I just never could.

Bill

 

[edstreet]

There are so many red flags in your post that I'm going to ask for photos of the bad finish.

 

[lhowell]

Never used the craft foam but I found that if I didn't wipe off any excess CA Accelerator prior to applying the next coat of CA I would get uneven layers of CA as the residual Accelerator on the blank would cure the CA layer being applied before I was able to wipe the entire blank down.

If the CA finish is not soft and is curing properly I would doubt that it has anything to do with the bushings. Just my two cents as it seems CA needs the right conditions or else you can end up with cloudy, wavy, uneven layers due to humidity, too high of ambient temps, etc. Hope you find the issue and can absolve your frustration!

 

[flyitfast]

Have you changed brands of CA lately?

 

[CREID]

Pictures would be a first step to being able to help you.

 

[farmer]

To thick

After having initial success producing a smooth, professional CA finish on my pens, I've been recently plagued with issues of "waviness" - sometimes ever so slightly discernible to the touch, but often not. As a result, simple projects that used to take 45 minutes have become marathon sessions in futility. :frown:

There's nothing special or proprietary to my technique: I apply the finish at slow speed (~600 rpm) on a pen mandrel between Stick Fast Non-Stick synthetic bushings. I use only thin CA, applied sparingly using craft foam, with a short spritz of aerosol accelerator from approximately 12" away. I wet sand with MicroMesh and finish with PlastiX. This part of my process has not varied - which is why I'm baffled.

I realize there's a boatload of potential factors, but I'd like to think most of those environmental or technique-related are relatively controlled. Moreover, I've tried sanding lightly every 2-3 coats (I generally put on 8-10) - which seems to help - but nothing completely corrects the problem. For whatever reason, I suspect the problem lies in the application of the CA - not the finish sanding.

Then it struck me: While I've been using the Stick-Fast bushings throughout, I had to replace the first set due to CA buildup from extended use (even with a coat of paste wax, they're not entirely non-stick). :wink:

So, wanting to keep this new set a bit longer, I peel off what CA I can after each use - and promptly plop them into a shallow cup of acetone. Then, prior to use, I take them out and thoroughly wipe of the thin layer of CA (evidently, acetone does not really dissolve CA; it merely makes it pliable).

Hence, my hypothesis: It is possible that some residual acetone (or the resulting fumes) on the synthetic bushings could be having this rippling effect on the CA finish? Or, conversely, the acetone that I wipe on the sanded blank prior to finishing? I know it dries immediately; does it also completely evaporate - or is a residue left behind?

When it works, there's nothing (IMHO) classier than a deep CA finish. However, the lack of consistent results about has me ready to look for another option.

Any thoughts? Recommendations? Alternatives? Anyone have other experiences - similar or different?

You are applying the CA thicker then you use to.....

 

[leehljp]

For me, in the early days of CA use, 2nd and 3rd year, I would get this on occasion. It would be from too thick of an application partially and also in cooler temps - below 70° or 75° F. I don't think that the temp is the problem at this time, unless you are doing it in the evening times with an AC on.

Regardless, when I recognized this, I let it cure overnight, and then used my sharp scraper to smooth it out, then sand with the upper end of MM.

 

[dachshund1]

Thanks for all the input, folks - it's very much appreciated. I'll try to post some pictures, but I have no idea whether or not the effect will be clearly captured. It's subtle and seems to be most visible in a certain light/angle. I'm hardly a perfectionist (or so my wife tells me), but like you, I want my work to look good from any perspective.

I use EZ Bond thin CA - and have since the beginning. I switched from the EZ Bond pump accelerator to the Satellite City aerosol - but this was prompted by (and not the cause of) the waviness issue. I just couldn't get a fine, even coverage with the pump applicator.

I'm most intrigued by Bill's comment re: the craft foam merely "pushing the CA around." I originally used wax paper to apply the finish (ala Dave Bell) - which spreads it on similarly; however, in his tutorial, he (Dave) builds the finish up and then turns it down smooth to the desired size - which may negate any "swimming" effects. There may be something to the absorbent properties of paper or fabric (i.e., it wicks up what the wood doesn't want) - which, ironically, has been one of its major complaints (wasted CA).

I'll give the Scott's blue shop towels a try. If the problem persists, I'll try a new set of "uncontaminated" non-stick bushings - and test this theory further. Per JT's comment, I may also try to apply the finish sans accelerator.

I'll keep everyone updated. Thanks again.

 

[TonyL]

I have used about 4 or 5 brands including EZ Bond with very good results. As you may have noticed, even thin CA will thicken overtime (not much time depending on the conditions). Perhaps, in addition to the applicator (I use paper towels or craft foam depending on what I applying the CA to), your waves are caused by the thickening CA.

When I use craft foam, I do use less CA than when I use paper towels for the reasons mentioned above.

In my case, it was a lot of trial and error (mostly error ) that improved my results. And I am not afraid to admit that I still produce waves every now and then, but no 10 foot seas like I used to .

Despite using several good brands of pump CA, I cannot get it right. I am sure it is me given the success that others have with it.

FWIW

 

[thebillofwrites]

I switched from the EZ Bond pump accelerator to the Satellite City aerosol - but this was prompted by (and not the cause of) the waviness issue. I just couldn't get a fine, even coverage with the pump applicator.

Here is something I posted a few years ago about accelerator use.

I apply mine by using a fairly inexpensive airbrush. I can adjust it so that I am applying just a very fine and even misting of the kicker. It works very well for me. I also bought an adapter so that I have it hooked up to spare tire for air pressure. No compressor noise or issues. Just have to pump up the tire every once in a while.

Bill

 

[jcm71]

It could be you are using too much accelerator. In my opinion you don't need it between coats. I apply about half a dozen coats of thin one after another without using accelerator, and then follow that with a half dozen or so coats of medium, again with no accelerator until after the last coat. Works for me. BTW, I use a nitrile glove to apply. Much better results than with the craft foam.

 

[TDE]

When my micro mesh needs to be replaced I get a little wavy looking finish. Don't know if that is your problem or not but is something to watch for. Hope you get your problem solved. Ted

 

[jsolie]

Do you start off right away with the micromesh, or do you first sand with 400 & 600? I use craft foam and don't usually get much of the wavyness you're describing. Would it be possible to post a pic of what you're describing?

 

[dachshund1]

I sand to 600 prior to beginning the CA finish - and will sometimes sand again (prior to MM) if a high spot needs to be removed. Generally speaking, if it's discernible to the touch, MM isn't likely to have the desired effect.

I've attempted several pics, but the problem just doesn't photograph clearly - and my guess is that most folks would remark, "The guy's nuts. I don't see anything." I'll keep trying.

Here's the best description I can offer: You know how if you examine a nicely-finished pen under a desk lamp - the reflected light forms a sharp, crisp line down the length of the barrel? Lately, mine don't - the reflection wavers and appears to swim over the finish - like a camera lens slightly of focus.

You've generated some good ideas to try. I hadn't considered worn MM might be another possible culprit.

 

[duncsuss]

Try sanding with a hard backing block (such as an acrylic pen blank) behind the sandpaper to make sure it's flattening the surface and isn't simply polishing the ripples.

After putting the CA on, but before starting with Micromesh, wet sand with 400 grit against the hard block. Rinse off the slurry and dry the blank -- if the surface is perfectly level, it will ALL be scratched up at 400 grit. Any bright shiny spots mean you've got an non-level surface (i.e. ripples) and you have to get those peaks flattened out before starting on the Micromesh.

 

[CREID]

What your describing sounds to me like an uneven surface. Now without actually seeing it, the unevenness can come from an uneven coat of CA or an uneven surface before CA. The CA will usually apply an even coat over the blank leaving you with an uneven surface if the surface underneath is uneven. It is hard to shape a blank by sanding CA as it is not that thick of coating and you will sand through.

 

[dachshund1]

I appreciate all the responses - including those on addressing the issue during the final sanding process. I still believe my issue lies somewhere in the CA application - so I'd much rather avoid the problem than continually have to correct it.

My tentative plan is to implement, incrementally, the following changes in this order:

(1) Applying CA using Scott's blue shop towels rather than craft foam. I use the small extender tips - so I don't think over-application is an issue. I usually do only 1-2 drops.
(2) Eliminating the accelerator. While I've switched to the aerosol - and apply it sparingly - I have been using it after each coat of CA. I'm more than willing to experiment with just letting it dry on it's own.
(3) Replacing my MM pads. I don't think they're particularly worn, but it's a potential variable. I'll try this last.

Thanks again for all the input. I'll update this thread in a week or so with my results.

 

[efrulla]

I had those issues on a couple of pens when I started out. I changed to using 2 coats of thin to seal the surface and then complete the finish with an additional 9 or so coats of medium. I found that mentally I was trying to build up the finish with thick layers of thin which I believe was causing the issue. By switching to medium CA I cured the mental problem I was having during application. Also, ditch the foam and use paper towels.

 

[farmer]

Micro mesh

I appreciate all the responses - including those on addressing the issue during the final sanding process. I still believe my issue lies somewhere in the CA application - so I'd much rather avoid the problem than continually have to correct it.

My tentative plan is to implement, incrementally, the following changes in this order:

(1) Applying CA using Scott's blue shop towels rather than craft foam. I use the small extender tips - so I don't think over-application is an issue. I usually do only 1-2 drops.
(2) Eliminating the accelerator. While I've switched to the aerosol - and apply it sparingly - I have been using it after each coat of CA. I'm more than willing to experiment with just letting it dry on it's own.
(3) Replacing my MM pads. I don't think they're particularly worn, but it's a potential variable. I'll try this last.

Thanks again for all the input. I'll update this thread in a week or so with my results.

Meguiars Polishing creams dump the Micro Mesh ..........................
Heavy cut
then fine cut
then swirl remover
then show glaze wax ...

Most of my finishes I rub out by hand ....