Alternative to CA for hairline cracks?

[Aaron Craven]

I regularly use thin CA (usually along with sanding sawdust) to fill hairline cracks in some of my bowls. But I've found that it often absorbs into the wood and creates a stain that I can't do anything with other than a) try to sand through or b) hope my finish hides the stain. Since one of my favorite finishes is a plain walnut oil finish, the latter is hardly a guarantee and the former sometimes just doesn't happen (especially if the CA absorbs quickly into the wood).

Is there some alternative that would work better? Epoxy doesn't seem to stain like CA, but the cheap two part epoxy I'm using is far to thick to flow into hairline cracks.

[Alan Heffernan]

Thin your epoxy slightly with acetone and use a palette knife or paddle to push it into the cracks.

[Barry McFadden]

I finish my turnings with WOP and if I have any small cracks to fill I put the first coat of WOP on then fill the cracks before I put the remaining coats on. That way none of the CA soaks into the wood.

[David Gilbert]

I also use CA to fill small and sometimes large cracks in my bowls. If the CA is applied to the raw wood it fills the crack but also fills in the area around the crack and usually results in a lighter area that stays forever. As soon as I see a crack my process is the put Minwax Antique Oil (MAO) in the crack and around it and then use a fine dental tool that is dipped into the CA to add small drops to fill the crack. Since CA cures by reacting with water in the wood and MAO doesn't it usually works well. The entire process takes me about five minutes. I don't wait for the MAO to cure.

I have filled gaps with sawdust but find that it looks sort of muddy and doesn't match the rest of the wood. I like to use regular coffee grinds to fill the bigger cracks. These will often look more like bark inclusions. I start by adding MAO around the area, fill the crack with coffee grinds, and then add CA. This usually gives a filling with some variations in color. I tried grinding the coffee very fine but it also gives the muddy and flat appearance that I don't like.

Cheers,
David

[Aaron Craven]

I also use CA to fill small and sometimes large cracks in my bowls. If the CA is applied to the raw wood it fills the crack but also fills in the area around the crack and usually results in a lighter area that stays forever. As soon as I see a crack my process is the put Minwax Antique Oil (MAO) in the crack and around it and then use a fine dental tool that is dipped into the CA to add small drops to fill the crack. Since CA cures by reacting with water in the wood and MAO doesn't it usually works well. The entire process takes me about five minutes. I don't wait for the MAO to cure.

I have filled gaps with sawdust but find that it looks sort of muddy and doesn't match the rest of the wood. I like to use regular coffee grinds to fill the bigger cracks. These will often look more like bark inclusions. I start by adding MAO around the area, fill the crack with coffee grinds, and then add CA. This usually gives a filling with some variations in color. I tried grinding the coffee very fine but it also gives the muddy and flat appearance that I don't like.

Cheers,
David

I typically fill larger cracks and voids with epoxy that's been mixed with something (occasionally something colorful), but for thin cracks I usually just try to use some sanding dust from the same type wood I'm turning. In this case, the cracks were actually so thin, the sawdust didn't really stay put because it was too thick to act as filler in such a thin space. This is why I think for this bowl I should have left them alone completely. I don't think they would have grown any (the wood is already dried and probably won't move much), and the CA didn't do anything for the final look of the bowl. I never thought about using oil to restrict it from soaking into the wood. I might try that. Do you suppose the type of oil makes a difference?

[Aaron Craven]

Thin your epoxy slightly with acetone and use a palette knife or paddle to push it into the cracks.

These cracks were too thin to use anything to push the epoxy in, but maybe if I can thin it enough with acetone it would flow in like thin CA does?

[Aaron Craven]

I finish my turnings with WOP and if I have any small cracks to fill I put the first coat of WOP on then fill the cracks before I put the remaining coats on. That way none of the CA soaks into the wood.

I'll keep that in mind. I frequently try to do a simple oil finish, but I sometimes use WOP too.

[Rob Grindler]

Thin cracks that I know are not going to crack further or take away from the integrity of the piece and weaken it, using tung oil or danish oil , wet sand across the crack and it will fill in with fine wet dust and harden as the oil sets .Otherwise it's CA glue for me with sawdust rubbed in,

[Greg McClurg]

I just use a shellac sealcoat around the area which dries very quickly. Then I fill the crack with CA. Since the shellac doesn't soak in it stops the CA but sands out very easily. I've never had a stain using this method.

[John K Jordan]

I use very thin CA glue both to fill hairline cracks and harden soft, punky wood.

How I use it for cracks depends on the color and figure of the wood. I can often make what you refer to as a "stain" invisible by adding a "microscopic" drop directly into the crack with one of the extremely fine capillary tips made for thin CA glue bottles. I immediately wipe any excess in the direction of the figure with a piece of paper towel or somethings. This often blends invisibly into the figure. I have done this many, many times without a visible stain. Note I usually only fill these hairline cracks when fine sanding (say with 400-600). I also use this method to fill tiny pits - apply a tiny drip to a sawdust-filled pit, wipe, sand, and repeat if needed. A couple of time and the defect is invisible. The "wiping" method may not work so well with bland wood without interesting figure.

If the wood is soft in places I often flood the entire surface of the wood with thin CA glue, whether or not there are hairline cracks present. This prevents any edge stain AND stabilizes the wood. I turned a 3-corner box from a cube of beautiful but very soft, punky spalted yellow poplar using this method. This wood was so soft it could not possibly be turned without serious, un-sandable tearout. The end result was a perfect surface with a glass-like smoothness.

When I use the flooding method I apply the glue, let cure (NEVER use accelerator), make a very fine cut, then reapply the glue. Repeat as needed.

BTW, I almost never use thin CA glue any more without the fine tips. With them the drop of glue is extremely small. I usually just tip the bottle and watch until the glue reaches the tip then touch the tip without squeezing the bottle. To clear the tip I hold the bottle vertically and squeeze until air blows through. I sometimes run a very fine wire down the tip but after a few weeks the tip may still clog and I put on a new one.
I've bought these tips several places but they are here:
http://www.amazon.com/gp/product/B000H7H4NW

[Kyle Iwamoto]

Have you tried as the others and CA after you put that first coat of walnut oil? I've also used rattle can Deft lacquer to seal off the wood. It's pretty neutral and the coat sands off easily. Deft is pretty neutral in color.

[robert baccus]

Try spraying several light coats of lacquer or SC around the crack--prevents ca glue stain.

[Ron Rutter]

I fill cracks with CA after giving the crack a swipe over with WAX. No stain.

[Aaron Craven]

...BTW, I almost never use thin CA glue any more without the fine tips....

Thanks for the information! Those tips would be great! I actually have a fairly wide tip on my bottle which sometimes leads to me getting much more glue than I want. I'll be looking for these!

[Aaron Craven]

Have you tried as the others and CA after you put that first coat of walnut oil? I've also used rattle can Deft lacquer to seal off the wood. It's pretty neutral and the coat sands off easily. Deft is pretty neutral in color.

I haven't; that's definitely a take-away for me here that I plan to try.

[Aaron Craven]

To everyone who's answered, thank you very much for the tips. I've definitely got a number of great ideas to try!

[Stan Calow]

These cracks were too thin to use anything to push the epoxy in, but maybe if I can thin it enough with acetone it would flow in like thin CA does?
Wouldn't thinned epoxy have the same disadvantages as the CA?

[Prashun Patel]

+1: Seal your wood or crack with a coat of your finish, THEN put in the CA or epoxy. A drop or two of acetone in the epoxy will thin it.