Filling small knots and voids

Hmm...the pictures I added disappear on the post.  Trying again here. 

I think you’d probably be fine with CA and sawdust on those Barb, but epoxy is easy to use too. Do they go all the way through? 

Ryan- none of these go all the way through.  With the superglue, do you mix in sawdust immediately?  And is the thick type better for this application?

I’d probably use the medium. Sand up a pile of dust from those boards (so it’ll match), drop in some CA glue to mostly fill the voids, the scoop on some dust and kinda work it into the voids. Don’t be stingy. The glue will soak right into the dust. May need to add some more glu and more dust to top it out. You want it to end up a little proud of your surface, it’s ok if it’s not smooth or is a bit wonky, you just want to make sure there aren’t any gaps. Once it drys, then sand it back. I don’t use activator when I fill voids, just let it dry on its own. 

Some guys will pack the voids with sawdust, then add thin CA across the top to permeate the dust. I think this probably works just fine too, and maybe keeps you from glueing your fingers together! If you do this, something the liquid of the CA will settle the dust down a little and it’ll recess a bit into the void, leaving a hollow that needs to be addressed before sanding back. 

I use the medium for this because the thin is SO thin it finds ways to leak out of the wood sometimes. Anyway, that’s what I do. I’m sure there are a hundred YouTube videos too!!

Thanks Ryan.  I'll need to practice I think before trying on my project boards...and need to buy some CA glue first!  

Barb, I pack such voids with sawdust first and then dribble in thin CA. Putting the glue in first, and then attempting to rub sawdust in has generally left me with my blue nitrile glove glued to the wood and sawdust glued to my shirt or jeans.

I will also use Gorks Goodfilla if I don’t have sawdust handy. They have a variety of colors, but I generally buy the neutral in a bag (the powder lasts forever as long as you don’t get it wet) and then mix dyes to get a match, but sawdust and CA will be a good match (a little darker than the wood, usually) with less fussing around.

Dave - thanks for that insight.  The glove glued to the board sounds like what I would encounter (or my finger glued there!). 😬 I need to dig in my scraps to find some boards I can do some test runs.

Starbond black ca glue is made for that. I used it on live edge tables to fill small voids and knots.
I can't find the pics, but I did post it as a project over at the other place.

Hairy - thanks you for that note.  A colored CA would be nice.  Will have to check into that.  

I use the Starbond colored CA for that as well.  They have both black and brown tones and different viscosities too.  For fine cracks the thin is better.  I generally prefer the brown because it looks more natural than the black with most woods.   If the hole does go all the way through, a piece of tape on the bottom is advised.  For deep cavities, I usually pack some saw dust in the bottom for filler but not all the way up to the top because I don't like the particle board effect that sawdust sometimes creates.  You can use clear CA for the sawdust and then just top it off with the colored CA.  Let the CA with the sawdust cure before you top it off with the colored CA.  You can use an accelerator to speed up the cure.  

i agree with starbond black it looks classy if you wait and see what i made for swap package you can see it  LOL

I probably need to get some of the black. It’s got several uses…

Thanks for the recommendations on the Starbond - I think I will order some of that.  Does everyone use the accelerator too (one "kit" I found had the black, brown, and accelerator)?

I usually use accelerator for CA glue, but not when filling voids. Sometimes the accelerator causes the glue to bubble up. It dries fast enough on its own for void filling, for me. Others may feel differently. Regardless, you can use the accelerator for regular CA gluing down the road if you get it…

When I’m filling voids with sawdust and CA, I use the accelerator. Pack the void, dribble in thin CA, zap with accelerator, then sand smooth. Lather rinse repeat. 

I don’t use accelerator with medium or thick CA because that will bubble it out of the void, and mean more work. 

Yes, the accelerator will cause the CA to bubble, but with sawdust and thin CA, it’s mostly set immediately and the accelerator just sets any drips that ran across the surface so I don’t put my hand in it. 

The accelerator is nice to have.  It can cause the surface to bubble but I typically overfill slightly anyway and have to sand it flat regardless so not really any more work.  For a relatively deep fill, it can take a while for it to completely set and the accelerator makes sure that the top at least is set and sealed before you sand.  I have waited for over 10 minutes when I didn't use the accelerator only to find that the CA was still wet when I tried to sand which made a mess and I had to use some acetone to get it off my hands.  

+1 with black starbond.....I use it on bowl voids works great...I use accelerator most of the time, altho I am not a huge accelerator fan for gluing non wood things and such.....I have used a lot of epoxy colored...I really do think it may work better than starbond for flat surfaces like yours, but a lot of messing around and you must purchase the color to mix with the epoxy and you must wait over night and usually involves a fair amount of sanding.  So all in all the starbond is easier and very close in results....

The other trick if you have CA and accelerator is that you can use the combo like contact cement. Put CA on one surface, and spray the other surface with the accelerator. Press together, and they’re stuck, almost instantly.

I was cutting dovetails in some oak this morning, and ran into a void like you have, plus some punky wood. Thin CA to the rescue. I soaked it into the end grain where the wood was punky, and that firmed it up some. Also filled the void using the sawdust from cutting the dovetails and then soaked it with the thin CA and a zap of accelerator. Looks good as new. No photos though, since I was making good progress.

Fun thing was that I got the CA fumes / smoke coming out of the punky end-grain. There was something in there that was causing the CA to set almost instantly, similar to what happens if you dribble it into aluminum powder or baking soda (check out Adam Savage’s superglue video for more fun).

So wow. I watched Adam’s video through for the first time in years, and I’m completely unlike him. I use almost nothing but thin CA glue. I don’t leave my 1 and 2 oz bottles open (they have caps for a reason, Adam), and medium is the glue I almost never use. The thin tips he talks about as necessities with thin CA? I have dozens of those and use them almost never. That said, it’s a fun video, and the baking soda trick is hugely useful, especially when you realize that sawdust can be used the same way. Anyway. It’s worth a half hour of your time, but you might find that thin is more useful for you than medium or thick (I use thick for gluing tubes into pens - that’s about it).

Thanks for the added info Moke and Dave.  
I've been watching several videos on CA and I think I'll be ordering some of the Starbond.  I saw a recommendation to store it in the refrigerator.  Is that suggestion for when it has been opened?  I am a bit worried to order as it is super hot here in Missouri right now and I doubt I'll find it locally.  Would exposure to high temperatures in shipping impact the product?