CA finish

I just spent 5 days trying to get good results using CA for a gloss finish. It’s good that this stuff is forgiving and fully reparable in a short period of time, because it was definitely trial and error at first. Here’s what I found out:

CA goes on very thin and is easy to sand through unless you use about ten coats of thick gel after filling the pores. Thick gel builds faster than thin or medium, and allows more time to spread before it hardens. It also gives off fewer fumes than thin or medium.
The CA must be applied evenly and sanded with 220 between coats. I made some paper towel spreaders after going through a lot of little folded paper towels. These work a lot better and give you more control (see picture). They’re made by gluing a sheet of paper towel to corrugated cardboard with spray adhesive, then cutting them into little squares

Even with ten coats, the CA is much thinner that ten coats of lacquer, and it’s easy to sand through three or four coats when final sanding from 400 to 1000. I was surprised to find out that it does shrink, and takes about two days to shrink about as much as lacquer would in about four weeks, so it’s good to let it rest a couple of days before final sanding. If you do discover a sand-through after polishing, it has to be scuffed back to 400 or less before making the repair.

The other pictures are of the results on two new ukuleles I’m trying to get done. It was really tough getting them to this point, but I think now that I know more about it, it can become a three day finishing process (with two days to rest) which is a lot better than lacquer.

I'm an old fart and I like the old rule of thumb to spell out acronymns and abreviations on first usage in a written piece.
Are you finishing your ukes with ten coats of Cyano Acrylate (superglue?)
OMG!
WTF!
-Vinnie

Well the results certainly look pretty good. Question: Do you think the results were worth the learning curve and are you going to use this finish instead of lacquer from here on out? Just curious.

Yeah, superglue. If you count the number of times you've seen "ca"used on this forum, you would already know. BTW, I'm an OF too.

Not ready to throw out the lacquer. It's good to try new things so you can have a better understanding of all the possibilties.

Hluth said:

It's good to try new things so you can have a better understanding of all the possibilties.

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That's a quote that should be burned into wood and hung over the bench. Thanks Hluth.

look like it buffs up good! Good to know

I have used CA for a finish on my wood turnings (bottle stoppers, appliance handles, etc.) and have had great results. Larger items like a whole uke have scared me up until now. That looks great!

There's nothing not to like about that body. Nice work!

Looks great. I hope it holds up over time....I always wondered if CA was too brittle to work as a finish
How did you manage the fumes while working with it?

I've seen too many things turned on a lathe that are finished in CA that don't stand the test of time. Far to inflexible and brittle I suspect. No way ever I'd be doing anything other than a pore fill that's only left in the pores.

Allen said:

I've seen too many things turned on a lathe that are finished in CA that don't stand the test of time. Far to inflexible and brittle I suspect.

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You have me worried now. I was acting on Ken's comment about using CA. He does great work and I don't think he would be using a finish that would be anything less than acceptable. You can see some of his finishes here: http://www.franklinguitars.com/Site/Ukuleles.html

This is a soprano uke I made twenty years ago. It's been from Hawaii to very dry and cold NY state to hot and humid Florida in its twenty years with nary a problem. It was glued entirely with CA glue (Satellite City, the medium thick stuff), including the bridge.

I kept it because a day after it was finished, the huge crack in the back happened, and rather than fix it right and sell it or throw it away, I filled the crack with, you guessed it, CA glue. I play it once in a while. It sounds pretty good, and it still has the original black nylon strings I put on it twenty years ago.

I did a very unscientific test to see if I could cause a crack in CA. Two pieces of binding tape were coated, one with CA and the other with lacquer (I used un-spread thick CA and it turned out to be thicker than 4 heavy coats of lacquer). They were then stretched as far as possible to see if the finishes would stretch along with the tape (photo 1). Next, both pieced of tape were tightly folded in half (photo 2). I couldn't get either finish to crack. I know from my experience with steel that it will always have a balance of hard and tough depending on it's composition and heat treating. Hard steel is easier to break than tough, but tough is more wear resistant. I found the CA more difficult to buff out, possibly indicating that it is more wear resistant (more tough than hard). It also scratches a little easier indicating possible lack of hardness. Food for thought.

I have been experimenting with using CA as a pore filler (not a complete finish) and I have to say that those little paper towel spreaders are a great invention. So much more control, particularly towards the edges.