Is there anything I can use to thin CA. I have about 2 oz. of the stuff that has started to thicken up on me, hate to waste it , 2 oz, goes a long way. Any one tried MEK or acetone ?

Acetone will work O-P-Nut but it's not worth the effort. Just shaking it up takes forever so you actually have to stir it somehow. Save it for use on some non-critical areas (NO HINGES) and bite the bullet for some fresh stuff.

I haven't tried this but I do know that nitromethane is the best solvent for cured CA so it should thin it down as well. I suspect it would slow down the cure time, though.

I agree with Vinnie, chunk it in the roundfile and buy some more! I buy the smaller sizes and keep it refrigerated so I don't lose any due to old age.

Save yourself some grief down the road and consider it already wasted.

When it starts to thicken it's going off. You can try to thin it but it won't work well as a glue as the chemical action that cures the glue has been compromised. CA glue hardens using a chemical reaction rather than a drying action so it's not something that you can thin to restore like PVA or solvent based glues.

Just toss it. Or at least use it for VERY non critical areas but don't expect anything good from it.

Try Microwave and let me know...

I don't think anything will thin it. Tried acetone that just set it off, don't anyone try this, just a few drops into the bottle and it got warm, won't try that anymore. As for the microwave forgetaboutit sounds like a bad idea.
I will just buy more.
Fred

Really,... just go get you some brand new CA so that you have the confidence that you project won't fail in flight.

This all reminds me of something funny that happened to me back in the early 80s when I first discoved Ca or Zap as I knew it back then. This was before I realized that it all was pretty much what everybody called "Superglue" during that time.
I figured it shared pretty much the same qualities as epoxy but was just much faster setting. I wanted to apply some cloth reinforcement to a foam wing like I had done in the past with thinned epoxy...so I poured alcohol into about half a bottle of Ca, thinking that I could just shake it up and brush it on.
Wrong! It cured instantly in my hand with a LOT of heat and actually split the bottle wide open. Scared the bejesus out of me. I was holding a solid lump of white Ca glue. It was just like a rock.
This is the incident that taught me that alcohol works just fine as kicker.

I store mine in the freezer. It helps prolong the shelf life.

The last thing you really want to do is add something to the CA that will react with it. Nitromethane is a debonding agent, so it will just break down the CA without actually giving you any more to work with. And as mentioned, alcohol will tend to speed up the reaction, probably not what you want

A bottle of thin CA is much cheaper than a new plane

I've got some thin CA that has "amazingly" transformed into thick for sale cheap if anyone is interested.

Nitromethane is part of the mix of chemicals in the glue, so it should thin it. Not sure of the strength afterward, but it would work. Course mixing a bottle of debonding agent might work also. The reason alcohol kicks it off is that alcohol has some water in it. And the alcohol helps to mix the water into the glue.

I gotta try that alcohol trick next 4th of July!

Just wanted to say that reading these threads provides some of the best humor!! Good Story Greg.

Someday, somebody is going to dip their cookie in the wrong milk. Please take caution when you hear "some of this with some of that, will do the trick". C/A is DANGEROUS stuff. I remember an article about a well known RC'er who died in his basement when some CA reacted with some curing epoxy on the airframe and started a fire. I keep all my C/A's in a Tupperware container on the bench just in case they topple and spill. The stuff can start a fire with the heat generated from a simple spill. I ran some excess thin C/A down the inside of a sheeted leading edge one time and had smoke pouring out the end of the d-tube. I had to drop the wing it was so hot. Think how the whole bottle reacts to mixing with something that kicks it off.