CA Glue on Crack

[Luke Maddux]

I've recently been turning some larger stuff and I've made my first few attempts at filling cracks with CA glue. Cracks have been a mil wide max. I've been successful, but not as successful as I would like. I have the medium viscosity and high viscosity Hot Stuff glues and the Hot Stuff accelerant.

I seem to have a lot of trouble sanding off the glue stains. I have even used 60 grit and, as we all know, that's just not fun for anyone...

I've ultimately gotten frustrated and just gone back to shear scraping. This works, but tends to go a bit too deep and open up some microgaps in the glue fill that were otherwise not there when I was previously attempting to sand. I then have to refill, reapply accellerant, wait, and then go again with the sanding/scraping, sometimes several times and, well...

345453

Anyone got any pointers for me?

Thanks a lot,
Luke

[jay h]

Hi Luke, I think a try of thinner CA may help on the smaller cracks. Jay

[Luke Maddux]

Hi Luke, I think a try of thinner CA may help on the smaller cracks. Jay

Noted. I guess it couldn't hurt to have one of each.

[Willy Nelson]

Mate
I fix cracks all the time in my Jarrah burls.
Here is a list to choose from:



Don't use accelerator, sends the CA white
Sand and seal the area, then repair the crack
Use sawdust mixed with CA
I only use thin CA, and rarely the med
Take the item off the lathe whilst still attached to the chuck, do your repairs at an angle which assists the CA using gravity


Good Luck
Willy

[dai sensei]

I always use thin CA to start with, to penetrate, then medium or thick depending on how wide the cracks are for clear casting. For 1mm cracks you will need the medium and thick as the thin will struggle to fill it without going white from the ponding. CA penetrates a fair way and so you apply it before your final cuts. That way you cut/sand through the any sideways penetration.

For the larger cracks I use sawdust, but it is never the same colour as the original timber, so tend to more often use coffee grinds that then look like bark inclusions or spalting. Alternatively you can use crushed stone or glitter etc with thin CA to make them into features

[Christos]

I have used thin CA to fill small cracks. I try to avoid getting too much CA on other parts of the turning as it is hard to sand out, as you have been discovering.

I leave this to cure overnight and add more CA if needed. As mention gravity is key to getting the CA into the crack.

If this is a bowl and has developed cracks I used epoxy and in particular a brand called Techniglue. When mixed this is a paste consistency to begin with and for me it is easier to apply. If the hole is deep the epoxy will sink and you need to apply more which means another 24 hours to wait. :C

As both of these processes require me to wait 24 hours I usually add some colour making it a feature.

[Drillit]

Noted what all have said. You may find that if you use lemon oil with cotton bud and
rub over and around crack that it will allow you to sand later without leaving any marks, including the wick
after you have used the CA. I find that this works. I also pack in the sawdust before I put on the glue.
But I find that after the lemon oil putting the accelerator on after packing the sawdust then the CA glue
will give you a better and more effective repair. You can sand immediately. A small bottle of lemon oil (pure) costs about $10/15 on Ebay,
but using a cotton bud, will last forever. Hope this helps. Drillit.

[hughie]

I use a lot of CA on cracks etc. But 1 mm its a bit large and depending on what effect you want to achieve. Do want to make the crack disappear or do want to make it a feature? Both will require differing techniques.

If its too big I would suggest you try and make it a feature. But before you start with the CA you will need to seal the surface to stop the CA stain and there are many products to use.

Heres a few that I use


Floods Penetrol, it dries in a few minutes and is colourless and does not darken the timber
BLO but it will darken and it take a few days to dry
Sanding sealer
One coat of DO or similar
any varnish you can add thinner to so its like water


Feature cracks need to be filled and again there quite a few out there, heres a few I use

Milo
coffee grounds
wood dust from the piece your working on, although it wont look anything like the original
CA just keep filling it over a few hours
Coloured CA

At the end of the day its pretty hard to make the crack go away and it will be somewhat frustrating as you try, thats why I like feature idea.

[Ron Rutter]

You can also apply wax to the area around the crack. I use more thin than med & usually sprinkle sawdust on then immediately rub in wearing rubber gloves. You can also try running in thin & then immediately sanding. Why would you use accelerator?

[Drillit]

You can also apply wax to the area around the crack. I use more thin than med & usually sprinkle sawdust on then immediately rub in wearing rubber gloves. You can also try running in thin & then immediately sanding. Why would you use accelerator?

Hello Ron,
The reason I recommend this approach is because the CA is often not fully cured immediately and if the crack/split is deep you will have to
leave at least overnight for it to dry properly. In my experience the accelerator overcomes this problem and resultant mess and allows immediate use. However, my point
was using lemon oil to avoid any CA stains/wick. It definitely works, as I am sure other alternatives do. One thing that CA is very good at, is
as a sealer over green timber timber when you have finished a piece. If you smother it in thin CA it will definitely NOT crack but it may warp,
which quite often enhances the piece anyways. You can then finish as you wish, but if you intended to stain/dye you would have to do this before
you added the CA and after it dried. Therefore spirit stain works well with quick drying. Hope this helps a little, Drillit.

[Dalboy]

You can also use metal powder and thin ca to fill gaps cracks etc, This is a piece I have on the lathe at the moment luckily I had already taken some photo's of the filling part.

This shows the lid section of the box which has not yet been hollowed, after the filling has been done I will skim it to its final size to clean it up.

[NeilS]

Why would you use accelerator?

Because we are always in a hurry and we don't want CA all over our visor...:U

[Mobyturns]

Shellac is also a good sealer to use.

Please stay safe turning items with those sorts of cracks.

[Ron Rutter]

[QUOTE=Mobyturns;1860938]Shellac is also a good sealer to use.

I agree with the shellac solution as well.

Neil. I am retired so no need to hurry!! Go for a coffee!!!

Cheers. Ron.

[NeilS]

[QUOTE=Mobyturns;1860938]

I am retired so no need to hurry!! Go for a coffee!!!



......:U