# Fixing cracks with CA and what makes it cure?



## Quickstep (Apr 10, 2012)

I'm making a pen out of some old mesquite. As I was turning it round, I noticed a crack, so I dripped on some thin CA and let it wick into the crack until I thought it was full, then I gave it a shot of accelerator. As I turned it smaller, the crack I thought I had cured blew out and a chunk came off. Luckily, it came off in one piece an I saw where it went. It broke cleanly and seemed to be a good fit, so coated both surfaces with medium CA, put it back in place and wrapped it tightly with electrical tape to hold it in position. Since it's covered in electrical tape, there's no opportunity to spray accelerator on it. So, I put a drop of CA on the surface of another piece of the same mesquite, figuring it would be a good "control"; knowing that once it was cured, the other joints should be cured. 12 hours later, the drop on top of the test piece is still very liquid. So I'm wondering,,,, what makes this stuff cure? (other than accelerator) How can I know when the CA inside the repair will be fully cured? Lastly, what are my chances that this piece is solidly stuck? It's a gift that I plan to give on Friday, so if this repair doesn't work, I need to start developing a plan "B"..........


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## Itchytoe (Dec 17, 2011)

Moisture will cure it. The humidity in the air should have cured your drop long before 12 hours. It should be as cured as it's going to be by now. CA is very brittle though, so the stresses of turning it may jar it loose. If I were you, I'd sharpen my tools, and take light cuts until I got it where I wanted it, then I'd finish it with CA and be done with it.


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## john lucas (Sep 18, 2007)

Did you use Thin CA? It sounds like it didn't wick into the crack very well. If the crack is large at all I start with thin and then add medium over it to fill the crack. My glue usually dries in a hour or less if I just put a drop out on something like you did. If I use accelorator the outer surface dries fast the but inner surface always takes a lot longer. Look at my glasses and you can see the results of being impatient. If your glue is taking overnight to dry I think you need new glue.


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## blondewood (May 17, 2009)

OK, time for the dumb blonde question. ;0)
What is the difference between Superglue type glues from hobby and hardware stores and the 2 part CA glues from Penn State or Woodcraft? If you don't use the accelerator will it still harden and just take more time? What would happen in penturning if you used Locktite or Superglue?
TIA,
Vicki


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## Quickstep (Apr 10, 2012)

I think it wicked into the crack well, but was absorbed by the surrounding wood and there wasn't enough left to fill the gap like in a starved joint. When it came apart, both sides seemed to be nicely coated with glue. 

I was wondering about the sample piece not curing, but the glue still bonds to skin instantly! Might be that the air is just to dry for a glob with no exposure to moisture other than in the air?


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## duncsuss (Aug 21, 2009)

blondewood said:


> OK, time for the dumb blonde question. ;0)
> What is the difference between Superglue type glues from hobby and hardware stores and the 2 part CA glues from Penn State or Woodcraft? If you don't use the accelerator will it still harden and just take more time? What would happen in penturning if you used Locktite or Superglue?
> TIA,
> Vicki


Hi Vicki,

Some terminology ...

CA = cyanoacrylate = superglue = Krazy Glue

CA is not "two part" -- that suggests you're thinking of epoxy-resin glues which typically have one bottle labelled "resin" and one labelled "hardener".

CA comes in different "thicknesses" -- thin, medium, thick -- which are often labelled "gap-filling" or suchlike.

You can get "activator" (sometimes called "accelerant" because it speeds up the cure rate) for CA but it isn't normally essential.

I just got a bottle of "odorless medium" CA but haven't tried it yet.

CA is usually brittle when cured, so I use epoxy-resin glue to hold the brass tubes in pen barrels (it remains slightly flexible), but I know folks who use medium CA for pens.


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## Adillo303 (Dec 20, 2010)

Depending on what effect you ar looking for. Sometimes, I take some of the fine wood dust from the sander and poke it in the crack then dampen it with thin CA. I have also ordered powdered aluminum, copper and brass from Woodcraft. You can get some really nice effects.


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## Foresta Design (Dec 26, 2011)

I've posted this elsewhere but it seems relevant to this thread. A cheap alternative to accelerator is to mix half and half of water and rubbing alcohol. Water is what makes Ca/superglue/krazyglue cure. the rubbing alcohol helps the water evaporate faster. put it in a mist bottle and go to town. old pump action hairspray bottles work great but remember that the rubbing alcohol will evaporate if the bottle isn't sealed so you may want to check your levels after you use it and then make sure on your next go around that the liquid is at the same level. I sometimes will just dab water from my micro-mesh bowl that I use later on the pen on the ca and turn on the lathe, the speed will dry the water and only a little water is needed to get the ca curing. as others have mentioned ca is brittle so too much heat will cause it to break so watch for that. Hope this saves some people some money. have a great day.


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## STAR (Jan 1, 2008)

I do not know much about CA and Accelerator. But I have very close friends who work in this industry at an Engineering level and they both have University Degrees. One is a Composite Engineer which deals in this, fiberglass etc type industry.

The information you have been supplied is right on the money, so no need for me to add any more to it.

You are in good hands here.

Pete


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## blondewood (May 17, 2009)

Then I can just use Locktite or superglue and don't have to buy the ones from the wood stores? And the accelorator would be optional?
I want to turn a few pens and want to be sure and use the right product.
Thanks again.


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## duncsuss (Aug 21, 2009)

blondewood said:


> Then I can just use Locktite or superglue and don't have to buy the ones from the wood stores? And the accelorator would be optional?
> I want to turn a few pens and want to be sure and use the right product.
> Thanks again.


Well, as I wrote earlier ... I don't use CA for sticking pen tubes in drilled blanks. I was taught to use epoxy-resin, and nothing I've read since has convinced me that CA is as good for this task.

If I'm gluing-up just a couple of kits, I normally use the "5 minute" stuff. If I'm gluing up a larger batch of kits, I use the "overnight" variety. It can be purchased at the home stores or the woodworking stores, I don't think there's any real difference between brands.


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## john lucas (Sep 18, 2007)

I personally don't use CA for pens. I prefer epoxy. It's easier to work with, cleans off your hands easily and will fill gaps better than CA. It's also far stronger and most think it last longer. You do have to mix the 2 parts but I buy some Dixie Cups and some stir sticks and keep them handy in my shop. That way I always have something to mix the epoxy in. 
CA can be finicky. It won't bond quickly when you want it to and it will bond too quickly when you don't want it to. One of our club members was doing pen demo Monday night and got the tube part way in and the CA bonded on him. I've had that happen also. Then I've have the opposite happen where you glue it and it never seems to harden. 
Thin CA is handy for filling hairline cracks. I sand the joint line to fill it with sawdust and then apply some thin CA. I let is set for about 5 seconds or so and then smear it with sandpaper. then I use a clean section of sandpaper to sand away all evidence of the CA. Many times you can't even see the joint or crack if I do it correctly.


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## Quickstep (Apr 10, 2012)

I recently found some 10 minute epoxy at my local hardware store. The extra time before it starts to kick is very welcome and it's still ready to turn in about an hour. I can't imagine using CA to glue the tubes. Seems like you'd have to be real quick to get the tube in and centered before the CA kicked off.


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## Quickstep (Apr 10, 2012)

Just a follow up on my original post. My test drop of CA finally cured after bringing the test piece from the shop to the living room where there's a bit more humidity. I unwrapped my electrical tape clamps on the pen blanks and finished turning the pen. All went well.


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## duncsuss (Aug 21, 2009)

Quickstep said:


> All went well.


That's what we like to hear :thumbsup:

_*However*_, the rule around here is "without pix, it didn't happen" ... :no:

:laughing:


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## Quickstep (Apr 10, 2012)

Here's a picture of the pen and some other stuff I made from the mesquite. The mesquite is from my friend's ranch. It had many cracks and bug holes which made it really interesting, but also challenging to stabilize enough to turn. I made a pen for him, one for his wife and a peppermill.


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## Adillo303 (Dec 20, 2010)

Really nice work. Congratulations.

What kit was that first pen?

Thank You

Andy


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## Quickstep (Apr 10, 2012)

It's the European Soft Touch Stylus from Craft Supplies. Twist pen on one end, stylus tip on the other. 

http://www.woodturnerscatalog.com/p/1/-/1/1/-/4976/Artisan-European-Soft-Touch-Stylus-Pen-Kit/stylus


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## STAR (Jan 1, 2008)

blondewood said:


> Then I can just use Locktite or superglue and don't have to buy the ones from the wood stores? And the accelorator would be optional?
> I want to turn a few pens and want to be sure and use the right product.
> Thanks again.


I have looked at all the replies and unless I am wrong I think the answer needs expanding. I guess that the us of the CA was for gluing the brass barrel into the blank.

But, what was not mentioned is the fact that if you do use a CA finish for your pen then it is important which type you use. For gluing, I have used CA and epoxy. Sometimes I make the decision depending on the wood and how hard or soft it is and how much play the barrel has in the hole.

Pete


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## Quickstep (Apr 10, 2012)

My original post was about using CA to fix cracks in the wood. I don't think I'd use it to glue the barrel in especially give what I've learned from fixing cracks. CA seems to readily get absorbed by porous woods, so I think there's high possibility of starved joints since what goes on inside the hole can't be seen. I also don't think I'm quick enough either. If that CA kicks before you get the tube fully inserted you're cooked. Sometimes I feel like I'm barely making it when using 10 minute epoxy.


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## Adillo303 (Dec 20, 2010)

**** Correction ***

I got the powdered metal at Woodturners catalog, not Woodcraft. Sorry for my error. Here is the link.

http://www.woodturnerscatalog.com/search?term=powdered+brass


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## Burb (Nov 30, 2012)

duncsuss said:


> Well, as I wrote earlier ... I don't use CA for sticking pen tubes in drilled blanks. I was taught to use epoxy-resin, and nothing I've read since has convinced me that CA is as good for this task.


Would you please post a link and/or photo of a typical epoxy that you would use? The more readily available the better. I am newer to penturning and I was taught to use CA; however, I would like to look at using the epoxy,

Thank you for your help!!


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## Dave Paine (May 30, 2012)

Burb said:


> Would you please post a link and/or photo of a typical epoxy that you would use? The more readily available the better. I am newer to penturning and I was taught to use CA; however, I would like to look at using the epoxy,
> 
> Thank you for your help!!


Not difficult to find examples.

Craft Supply example.
http://www.woodturnerscatalog.com/p/1/-/3/15/-/1152/System-Three-BarrelBond-5-Minute-Epoxy/epoxy

Epoxy resins are normally two part, a resin and a hardener. The mixing ratio varies among the brands.

Some brands require exact measurements. Some brands are "non-critical" measurements. I like to use this type, since I do not want to mess with measuring.

Typically the non-critical are 1-1 mix ratio. If you get the tube product, I just lay a bead of the resin on a 2in wide piece of masking tape and then match the bead length for the hardener.

I use the masking tape and remnants as an indicator to confirm the epoxy has set. Should not be an issue for new product, but the products have a finite shelf life.


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## Quickstep (Apr 10, 2012)

I've been using MAS epoxy and I bought the pumps. Even though the startup costs seem high, it's cheaper in the long run. With the ones where the ratio doesn't seem to matter, you'll often run out of either resin or hardener before running out of the other. Perhaps more importantly, getting the proportions exact makes the cure time more predictable. MAS resin comes in both thick and thin. The thin is great for soaking into crevices whereas the thick is the perfect consistency for glue; no additives needed. I still use the stuff in tubes for small jobs though, like gluing brass tubes in pen blanks.


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