Cracked CA

[Jmaxcy]

I am..... frustrated

I batched out about 20 pens and at least 8 of them the CA has cracks. None of the cracks are on the surface, all layers under.

I am using stickfast flex. I've read some threads here where people say that might be the culprit. I used a brand new bottle for the batch. Did it in my garage that is rather cold. About 3 coats of thin, 8-10 coats of flex. Accelerator after the flex coats. I have used stick fast for 60+ pens and never once had this issue.

Pissed I wasted so much time to get that close to the finish line just to likely throw them out now.

Any thoughts? Probably going to ditch stick fast and go to mercury. Can't have this happen again!

 

[JohnU]

Sorry to hear this. I've had that happen with most CA glues over the years. Sometimes it happened quick, other times it showed up a year or two later. I been told it's the accelerator that causes the cracks. I made the switch to Gluboost which is made and advertised as a finish and not just ca. I haven't had any problems with it over the past few years. Rather than toss them, you can always sand the finish off and reapply the new one.

 

[egnald]

Greetings from Nebraska.

Only a few weeks ago I found about a half dozen or so of my pens with cracks/crazing in the CA finish. I too use Stick-Fast CA and have done so successfully for 5+ years. I think my culprit was that my initial thin coats were from a bottle I procured in 2018, so it was quite old.

I tossed it and got a new bottle and so far things have gone great. A few things that I do that may or may not make a difference:

- I use Non-Stick bushings and before I start applying the finish I clean the blank with denatured alcohol just to make sure no oils or contamination are on it from my handling it. I give it plenty of time to evaporate. In my heated shop I wait about 10 minutes - that seems to do the trick.

- I use Stick-Fast Wood Finish. I don't know if it is the same thing as Stick-Fast CA, but I always make sure that what I buy is labeled "Wood Finish". I use both the Thin and Medium viscosities. I apply it in thin coats with a small applicator made from a folded piece of Viva Signature Cloth paper towel. By thin I mean very thin - more CA soaks into the paper towel than goes onto the blank.

- With the lathe running at about 500 RPM, I apply 4 coats of Thin and wait 90+ seconds between coats to let them dry. (I have a 90 second hourglass timer that I use). My presumption is that the thin coats soak into the surface of the wood and adhere to the wood fibers acting as sort of a primer layer.

- After the 4 coats of Thin, I apply 12 coats of Medium, giving it one or two short bursts of Activator/Accelerator from about 1 foot away. I have a fan running at floor level to help disperse the overspray. I let the last coat dry for 5 to 10 minutes before removing the blanks and re-installing the metal turning bushings in prep for wet sanding with MicroMesh. I have heard that CA cures from the inside out, so I give it plenty of time before hitting it with wet sanding.

For the time being, I will be continuing to use the Stick-Fast Wood Finish for my CA regimen.

Oh, as for the ones that I found were cracked, I knocked them apart with a rubber grip and a set of punches, then sanded them down and re-applied the CA finish as described above. That was 3 or 4 weeks ago and so far no cracks have re-appeared and there have been no cracks in any of the new pens I have made since then.

Good Luck with finding a solution. Cracked finishes can be very frustrating! - I feel your pain.

Best Regards,
Dave

 

[NJturner]

After having various failures with CA, I also switched to GluBoost same as John U states above. I had used Starbond and Mercury CA interchangeably for some time, often doing a boiled linseed oil and CA finish on most of my pens. The CA finishes required lots of coats to get to a deep look that I liked. The GluBoost gets there in under 5 coats - usually 2 coats of thin (1st and last) and at most 3 coats of thick (middle). I go as light as I can with accelerant with either product, as I prefer the finish to level and dry most of the way without the accelerator. The finish seems really durable and handles well.

I wouldn't throw that many pens away - especially if they don't have a pressed in transmission. Disassembly is relatively easy with a set of pins to match the tube diameters. A little light taping with a small hammer and usually everything comes apart. Sand off the finish and recoat after cleaning the body with a good wash of denatured alcohol.

Good luck!!
Kevin

 

[MRDucks2]

I started out using StickFast and experienced the same issues. I know there are folks on here who never have. I am guessing environmental conditions during the build likely play a part. As noted above, take them apart and remove the ca finish. They can be saved.

 

[Jmaxcy]

I started out using StickFast and experienced the same issues. I know there are folks on here who never have. I am guessing environmental conditions during the build likely play a part. As noted above, take them apart and remove the ca finish. They can be saved.

thanks

Does temperature effect the curing process? I swear I saw somewhere temperature doesn't effect it only humidity.

I applied this in my garage which was probably below 50 degrees.

 

[Jmaxcy]

Sorry to hear this. I've had that happen with most CA glues over the years. Sometimes it happened quick, other times it showed up a year or two later. I been told it's the accelerator that causes the cracks. I made the switch to Gluboost which is made and advertised as a finish and not just ca. I haven't had any problems with it over the past few years. Rather than toss them, you can always sand the finish off and reapply the new one.

Thanks

Checked back on my pens today and lost a lot more. I'm thinking the problem was likely with the thin I used prior to applying the flex as all of them are cracks below the surface. Probably going to bail on stick fast and move to glu boost, since I finished my bottle of thin with this batch. Going to try my best to salvage the kits and turn down the blanks.

Can't recover the hours spent in on these, which is by far the most frustrating part, way more than the potential financial loss.

 

[fernhills]

Well i have been away from doing pens for awhile and things do change. I never heard of gluboost before. When i have a spunky or burl blank i just sand it to get the sawdust going and douse it with thin c/a and sand it in. It works, i let it sit all day or overnight before i work it again. I don't think i can bring myself to spring for $30 for a 2 oz bottle of glue, but then again, i may change. Carl

 

[Jmaxcy]

Greetings from Nebraska.

Only a few weeks ago I found about a half dozen or so of my pens with cracks/crazing in the CA finish. I too use Stick-Fast CA and have done so successfully for 5+ years. I think my culprit was that my initial thin coats were from a bottle I procured in 2018, so it was quite old.

I tossed it and got a new bottle and so far things have gone great. A few things that I do that may or may not make a difference:

- I use Non-Stick bushings and before I start applying the finish I clean the blank with denatured alcohol just to make sure no oils or contamination are on it from my handling it. I give it plenty of time to evaporate. In my heated shop I wait about 10 minutes - that seems to do the trick.

- I use Stick-Fast Wood Finish. I don't know if it is the same thing as Stick-Fast CA, but I always make sure that what I buy is labeled "Wood Finish". I use both the Thin and Medium viscosities. I apply it in thin coats with a small applicator made from a folded piece of Viva Signature Cloth paper towel. By thin I mean very thin - more CA soaks into the paper towel than goes onto the blank.

- With the lathe running at about 500 RPM, I apply 4 coats of Thin and wait 90+ seconds between coats to let them dry. (I have a 90 second hourglass timer that I use). My presumption is that the thin coats soak into the surface of the wood and adhere to the wood fibers acting as sort of a primer layer.

- After the 4 coats of Thin, I apply 12 coats of Medium, giving it one or two short bursts of Activator/Accelerator from about 1 foot away. I have a fan running at floor level to help disperse the overspray. I let the last coat dry for 5 to 10 minutes before removing the blanks and re-installing the metal turning bushings in prep for wet sanding with MicroMesh. I have heard that CA cures from the inside out, so I give it plenty of time before hitting it with wet sanding.

For the time being, I will be continuing to use the Stick-Fast Wood Finish for my CA regimen.

Oh, as for the ones that I found were cracked, I knocked them apart with a rubber grip and a set of punches, then sanded them down and re-applied the CA finish as described above. That was 3 or 4 weeks ago and so far no cracks have re-appeared and there have been no cracks in any of the new pens I have made since then.

Good Luck with finding a solution. Cracked finishes can be very frustrating! - I feel your pain.

Best Regards,
Dave

I follow almost the exact same process except for using DNA before application and I use CA rather than wood finish. Probably going to bail on stick fast, not sure that's the problem but also not sure it wasn't and can't afford losing another batch of 15+ pens to a faulty product.

 

[Jmaxcy]

Sorry to hear this. I've had that happen with most CA glues over the years. Sometimes it happened quick, other times it showed up a year or two later. I been told it's the accelerator that causes the cracks. I made the switch to Gluboost which is made and advertised as a finish and not just ca. I haven't had any problems with it over the past few years. Rather than toss them, you can always sand the finish off and reapply the new one.

Is the blue gluboost the same as medium in terms of viscosity? I see a thin and a blue bottle that isn't defined at rockler. Fill n finish I assume is the right type? Thanks again

 

[grpass]

Now I remember why I quit using CA

 

[JohnU]

Is the blue gluboost the same as medium in terms of viscosity? I see a thin and a blue bottle that isn't defined at rockler. Fill n finish I assume is the right type? Thanks again

Yes, the blue label fill and finish is the medium and the orange label is the thin.

 

[Mortalis]

I never use Denatured alcohol before applying CA. If you do use DNA then I would recommend letting the blanks degass for quite some time or use an oven to drive off the residual.
I use Bob Smith CA (BSI) exclusively after having issues with StickFast and other popular 'off the shelf' CA's. I dont use Accelerator hardly at all.
I have never had cracks form in my CA that wasn't caused by the wood moving. I've used "old" CA and all it ever does is not harden.
IMO it is the DNA that has some effect to the process.
Just my 2c

 

[Jmaxcy]

I never use Denatured alcohol before applying CA. If you do use DNA then I would recommend letting the blanks degass for quite some time or use an oven to drive off the residual.
I use Bob Smith CA (BSI) exclusively after having issues with StickFast and other popular 'off the shelf' CA's. I dont use Accelerator hardly at all.
I have never had cracks form in my CA that wasn't caused by the wood moving. I've used "old" CA and all it ever does is not harden.
IMO it is the DNA that has some effect to the process.
Just my 2c

Thanks. I don't use DNA either. I was responding to someone who does.

There has to be something with the fact the cracks are all layers below and none cracked on the surface. Thinking it was something to do with the thin coat prior to applying the flex coat on top.

Probably not Wood movement because it happened across a lot of different blanks.