Chemists in the house?

[Sam Fleisher]

Long story long........ I was filling some shallow checking with some ca glue and didn't have any accelerator/activator and didn't want to wait 2-3 days for amazon and definitely didn't want to brave the holiday shoppers in any store so Google being my friend I looked up diy activator.

Many suggestions and recipes. I tried the one with water and baking soda and it worked in a way but seemed to harden the top and still soft inside. And it was rough with a whitish surface which I'm guessing was too much baking soda. It did work to keep it from running until it hardened though and since I was going to sand it anyway I considered it somewhat of a success.

The actual activator dries quickly and I read on the Starbound site that theirs is acetone based.. Any chemist know what that recipe would be or what to mix with the acetone if anything?

Other recipes said isopropyl alcohol some even said just straight water if it had a lot of minerals and a high pH.

So since I'm sure someone has been in the same situation I thought I'd ask here.

This experiment was on another 12 inch snowman so it's not exactly a critical structure thing, just cosmetic.

 

[Brian Gustin]

CA glue cures in the presence of moisture so a humid environment would accelerate curing vs air conditioned dry environment (I often leave my CA glue uncapped, it doesn't cure simply due to air..) Moist/green wood will cure it faster that kiln dried wood will, also. Baking soda or any other Alkaline can neutralize the acid in CA glue which also rapidly accelerates cure time. However baking soda (or excess accelerator) applied heavily over top of a thick bead of CA will do what you describe- It crystalizes over top, but then the inner uncured CA will take a long time to harden (Same reason green wood cracks - outsides dry faster than insides) Just takes a little understanding (Ask Bing Bot perhaps) of how CA glue works and cures.. I'm no chemist by any means, but I have a fairly rudimentary understanding of Acids and Alkalines (Same principles can be applied to test your garden soil, and deal with battery acid spills & corrosion.. Hint: 7-up makes a good battery cleaner!...)

There was a YouTube video I remember where someone did an experiment trying to start a fire using a large amount of CA glue and pile of baking soda.... the rapid reaction of the alkaline soda on the acidic CA in a large volume did cause some very high temperatures, as I recall.

As far as DIY accelerator, I've tried several including brushing a bit of diet Pepsi over the wood on one piece while putting CA on the other, with limited success (But it was only for a quick temporary hold on a jig I was fabricating, so I can't speak to how strong a bond it might have been) I don't use CA glue a lot, so YMMV as far as any of the above.

 

[Brian Nowak-Thompson]

I have a chemistry degree and did a little digging. It looks like CA polymerization is initiated by alkaline compounds like baking soda or the tolulidine they put in the commercial accelerators. I also saw some reference to peroxides being used. But like Brian alluded to, the powered baking soda is not in solution so it won't diffuse into the CA itself forming the crust you saw. Look up Goobertown Hobbies on youtube for an in depth but understandable chemistry lesson.

 

[Sam Fleisher]

I have a chemistry degree and did a little digging. It looks like CA polymerization is initiated by alkaline compounds like baking soda or the tolulidine they put in the commercial accelerators. I also saw some reference to peroxides being used. But like Brian alluded to, the powered baking soda is not in solution so it won't diffuse into the CA itself forming the crust you saw. Look up Goobertown Hobbies on youtube for an in depth but understandable chemistry lesson.

Well, I made it roughly half way through the epoxy video before my eyes glazed over.

 

[Dean Center]

Cellulose seems to accelerate CA. A paper towel is the easiest way to get cellulose in contact with the adhesive, but that probably won't work well in cracks. For surface use, make a pad of paper towel, very lightly apply to wood, turn on to spin and in 20-30 seconds, it's setting up. Gotta get the paper off quickly at that point (roughly when your eyes start to burn but before your fingers feel warm)

 

[robo hippy]

Well, how fast it sets up also depends on how thick and deep you are trying to fill. If it is a deep crack, I will chase with thin CA first, then apply some medium CA on top of that, and the thin seems to wick in the medium. If you are going very deep, then when you apply the accelerator, the outside cures, but the inside does not, and it can take days for it to cure no matter what you do.

robo hippy

 

[Matt Meadows]

Pen makers use boiled linseed oil on a clean cloth and the lathe spinning to cure CA glue into a satin finish. You probably can do the same with the lathe off, just use medium or thick ca and keep the cloth moving and don't let dry cloth touch the uncured CA, keep the cloth wet with oil.

 

[Dave Mueller]

CA is cured by any basic chemical. The pH of an acidic solution is less than 7 and a basic solution is greater than 7. Pure water is neutral at 7 . Baking soda (sodium bicarbonate) is basic at a pH of 9, which is why it cures CA. You could try a dilute water solution of baking soda on a test piece, which might should slow the curing process and prevent the crystal formation of the CA. However, the water is probably not good for the wood. Why risk your piece with homemade accelerator? Just borrow some commercial accelerator from a fellow woodturner.

 

[Sam Fleisher]

Why risk your piece with homemade accelerator? Just borrow some commercial accelerator from a fellow woodturner.

First sentence in my first post.
And then last sentence for the second part.

Now that I'm not in a hurry I ordered some. But I'd still like to have a back up plan for if I run out again.

 

[Neil S]

If you are going very deep, then when you apply the accelerator, the outside cures, but the inside does not, and it can take days for it to cure no matter what you do.

With deep/thick applications I have had some success with applying the accelerator first and adding the CA to that, just don't apply the CA direct from the bottle or the next time you go to use it the remaining contents will have also set...