Originally Posted by
bruceward51
I think we need to be careful talking about CA glue being a single product. I suspect that like other adhesives, there are probably many formulations and products based on cyanoacrylic acids. I know that they use a form of CA as a medical adhesive, and have done so since the Vietnam War, and I have been told that CA is the basis for things like Loctite thread lockers.
The properties of each formulation are likely to be very different. On of the main things I use CA for is filling small holes when turning. I overfill the hole with fine sawdust then dribble on thin CA glue. I also use the thicker (medium) formulation for small worm holes etc. But last year I ran out bought a blister pack from one of the big hardware chains. It turned out to be a gel product, and would not work at all for my normal purposes. I also had some black CA a few years ago and found that it remained rubbery even after curing, Quite different to the clear product that I use that is almost brittle when cured.
I cannot comment on the use of CA as a finish on flat projects, such as guitars, but I suspect that the drying time would be a big limitation and would make application tricky over even small areas. I used a but on a camphor laurel bowl the other day and the timber worked as a very effective accelerator. Within two seconds of application it crackled, smoked and set like a rock.
Everything I have seen about CA as an adhesive and as a finish says that it is waterproof. I have a razor kit and shaving brush that I turned about seven years ago. They have been in daily use since then and while they are both covered in soap residue, the finish is unaffected by the constant moisture. (I would take a photo, but they are too disgusting to share in public.)
The largest project that I remember using CA for was a handle for an ice-cream scoop. I think any larger than that might be difficult to apply using the methods I use.
My normal application method is the run the lathe slowly (maybe 100 rpm). I either wet a piece of paper towel and wipe that along the project, or gently dribble a few drops direct on the project and wipe it along the project with a piece of paper towel. You just want a thin smear of product, and re-coat several times. if you lay it on too thick, you can get ridges. In my experience, you can get away without accelerator if you are patient. After application, I apply triple E with the lathe stopped, work in it at slow speed then speed up to buff at high speed.
Bruce