Official Luthiers Forum!

I caught a bit of flack a long while back (not here) about using CA as a high gloss neck finish. well I paid no attention and did 4 proto-type test pieces and they are approaching a year old and doing fine. They polished out to a very high gloss and have a very lo friction coefficient. Slick as bat guano. It is cheap finish as well. Less than 1.5 oz of Med CA will do a neck and peg head. That is less than $3.00 a neck if you buy Starbond in 16oz bottles.

Interesting thing is this afternoon I got a news letter form Woodworker’s journal promoting just such a thing, CA as a turned part finish.

Michael,

I have seen CA used as a finish for turned pens. Very shiny! Wonder if it is flexible enough for a guitar body?

Chuck

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Michael -

First, good to see your name again. Short retirement?

How about an overall finish? How do you think it would look? (I wish Z-poxy would be good as an overall finish, but everyone says it would break down under UV with no additional overcoating.)

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Jim Kirby
kirby@udel.edu

I never said I retired I said I had to steep away for a while due to my day job and that I may be moving to boot I just stopped in to say high while waiting to change planes.

As far as a body finish on an acoustic I have some concern with flexibility but I have a body test going on because I too was curious. I will let you know in a year how it is doing.

As far a looks it is as clear as or even clearer than any finish if done right. It takes a buff in my opinion better equal to or better than nitro but that is a subjective statement. I was concerned with possible yellowing but after a year I have none, and on of the test necks has been exposed to a non air conditioned room in the shop for most of a year with extremes from 20F to 115F and no yellowing or hazing so far.

Michael,

CA sounds promising. Have you had any issues with CA as a pore filler? I am thinking of switching from z-poxy.

Chuck

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I have used CA as my sole pore fill for over two years. it is quick and efficient but fumes must be dealt with my means of proper PPE (Personal Protection Equipment) and ventilation. Same true for finishing with it.

Here is a tip if you want to try it. I found the best way to apply to a "neck" is by wearing high quality nitrel gloves (you want a good tight fit) and applying a small amount to the index finger and wiping it on. This means you will go through several gloves one for each coat. Use the medium thick CA for the long cure time.

I have had good success applying with 1” wide polypropylene brush but have had a hard time finding a steady supply. Plus the brush waist a lot more CA than the finger wipe method. If you are able to find polypropylene brushes squeeze out the excess into a cheap plastic bowl the place the brush into acetone and you can reuse the brush between coats a couple times. But I find this really to expensive and too hard to find the polypropylene brush suitable for finish brushing. But they would be and advantage on bodies if it works out.

Michael,good to hear from you.So how many coats of CA did you put on the neck?,and how many would it take for the body?Also did you seal with shellac first? And next time you come to Nashville,look me up.
James

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James W Bolan
Nashville Tennessee

Thanks Michael, just might have to give it a try.

Chuck

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Four coats of medium thick applied just less than sag weight allow to set hard between coats sand to level between coats.

For this test body I have 6 coats of medium (not medium thick) on it.

Hi, everybody; first post. Please allow me to jump in here as finishes have been a specialty of mine for a few decades.

I've been using CA as a wood finish (not for guitars) for 23 years, on and off.

The stuff they made 23 years ago DID yellow; took 5-7 years. It wasn't really intended as a finish material, and had no UV inhibitors. UV did seem to break it down slightly as well. I don't think formulas have changed significantly since then, either.

If you're looking for larger quantities of CA, might I suggest ZCorp. They sell a thinner grade of CA in a "premium" and "economy" grade. The premium is Z-Bond 101, and one pint is $150.00. The economy is Z-Bond 90, and 2-one pint bottles are $170.00. Their phone # is 781-852-5005.

The ZCorp CA is used in our 650 3D Printer to catalyze the printed parts.

I don't smear, but use a brush. It takes two coats of this stuff to seal, but it really penetrates spruce, redwood, and cedar. It darkens the latter two substantially.

A total of 6-8 coats is about right. It does sand and buff out very well. I've not seen a checking problem with older finishes, but these were smaller parts. YMMV

Paul, welcome to the forum! And thanks for the info.

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Formerly known as Adaboy.......

I bought a few different viscosities of CA from star bond on the west coast, , its been awhile but I dont think I paid anywhere near the prices mentioned here . they also threw in some of those little pipet bottles and some extra bottles, which was a nice perk . Jody

Well, I for one am glad to see you have not fully retired (I too thought you had). I read your "off topic" post and was sure you meant you were hanging up the shingle.

Please stick around, your posts are informative and helpful.

Mike

Where do you get your brushes the only bristel I have found to work is polypropalene and they are near impossible to find in a finish grade brush. Also $170 for 2 pints (16oz per pint) that is $5.31 per oz I pay $32 per pint for Starbond in any viscosity or 16oz that is $2.00 per oz

Just wondering if there are any touch-up problems with a CA finish? I've never used it,but might try.I use FP or Nitro because they are so easy to touch-up.

I have had no problem on necks It burns in well I have had no witness lines from one coat to the next if the surface is cleaned dust free. Keep in mind I sand to level between each coat. And so far only necks have been completed but if it was a problem it would have shown on the necks I have done. I am absolutely sure that if you do not clean a repair area that you would get witness lines but I think that is just common sence.

Thank you so much for doing the ground work on this one, Michael! It's great to see someone really putting the time in to test a new method!

I've used CA on flat things (chessboard) and to seal pieces of wood, but haven't 'gone all the way' to try it as a finish on a neck or body. I'm thinking I'll do exactly that very soon!

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Bob Garrish
Former Canonized Purveyor of Fine CNC Luthier Services

my pleasure Bob

For those looking for a good price on large (16oz) bottels of cyanoacrylate (CA) in various viscosities here is a link where I get mine

http://www.ptscoshop.com/starbond_cyanoacrylate_(super_glue).htm

Are those fumes with CA dangerous in any way? I know they are irritating, but in the volumes needed to do larger pieces, I was wondering if there were exposure level concerns. Of course, wear a mask. Just wondering.

Mike

I haven't tried it yet, but here is a Dan Erlewine article I saved on the subject:
(I don't have the 'Fig' images that go along with this)


Safety warning: Wear protective vinyl or latex gloves (any kind will do) to keep from getting stuck to your work. Expect to have to change gloves often as they get covered with glue and stuck to the sandpaper, so have fresh pairs at the ready. Work in a well-ventilated area and wear eye protection. Avoid spills or touching superglue—the glue won’t hurt you if you get it on your skin, but it will stick you to anything you touch.

Fig. 1 Using paper along with low-tack draftsman’s tape (blue painter’s tape will also work), I masked off the neck, leaving only the fingerboard un-masked. I left the fingerboard’s rounded edge unmasked (I taped right up to it). Note: Any tape can leave chemical marks and imprints in solvent-based finishes. When you are at your hardware store buying tape, if you notice that a particular tape has a chemical odor, sniff some others. (The less chemical smell a tape has, the more likely I am to buy it.)

To make sure the fingerboard was clean and dust free, I wiped it with a rag dampened with acetone. Notice the dark and light areas—it’s lighter where the finish has been sanded through.

Fig. 2 I poured a small pool of No. 20 superglue onto the backside of a piece of fine-grit wet-sanding paper and quickly wiped it onto the fingerboard surface, back and forth and from end to end. I wiped in circles and figure eights, too. The trick is to not stop; otherwise, the sandpaper—or your hand—might stick. I changed gloves often.

Why are we using the backside of a piece of sandpaper? Wet-or-dry sandpapers are relatively waterproof so that they don’t get soggy and fall apart. Those same properties allow them to be used with superglue. I like to use fine-grit sandpapers for this purpose because they let me feel the work better.

Fig. 3 This is what an application of No. 20 looks like when dry—shiny and a little lumpy. Don’t worry, the dried glue sands and levels easily. In oblique light I could see if I missed an area—see the dry area on the E-string side near the 12th fret?

Fig. 4 Since it was a nice spring day, I did my gluing and sanding outdoors to avoid the fumes. I wiped on two coats of No. 20, stopping for ten minutes in between.

Fig. 5 After the second coat had dried for ten minutes, I sprayed some superglue accelerator onto the backside of a clean piece of wet-sanding paper and quickly rubbed it over the surface, from end to end and sideways. This hardened the glue as I burnished it, because of both the accelerator’s action and the friction of rubbing.

Fig. 6 I lightly sanded the two coats with 220-grit Fre-Cut nonloading paper and a rubber sanding block (to keep the surface flat). I just barely leveled the finish. I applied two more coats, burnished with accelerator, and sanded with 320-grit until the surface appeared powdery.

Now, for a final coat, I poured a silver dollar-size pool of No. 20 glue into a dish and added about one-quarter as much of No. 10 to it—this is the thin finish coat. I applied a couple of these coats and let them dry. After 20 minutes I repeated the accelerator/sandpaper/burnishing steps.

Fig. 7 Now there were about six coats of thin superglue on the fingerboard that needed to be sanded level and polished. I quickly sanded through several grits—400-, 600- and 800-grit gold Fre-Cut nonloading paper.

Fig. 8 Then I switched from dry-sanding to wet-sanding with 1,000-, 1,500-, and 2,000-grit Unigrit paper. Finally, I jumped to Micro-Mesh micro-polishing papers, wet, in 3,400, 4,000, 6,000, and 8,000 grits. (You can skip the Micro-Mesh and still get a nice-looking “wet” look.)

Fig. 9 I enjoy hand-rubbing the finish to a satiny shine; in this case I used medium-grit rubbing compound. This is the same compound I use on my power-buffing machines for large finish work. I applied this finish in less than two hours. That’s a remarkably short time for a finish that’s so goodlooking and durable—and you don’t have to be a pro finisher to apply it, either.

by Dan Erlewine

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Tom Krebs

Just the irritation. The burning from the fumes is actually the sensation of it curing on your eyes/throat/other mucous membrane, but it doesn't actually have any toxic effects besides the irritation (ie: neither the fumes nor the cured glue are poisonous or carcinogenic). A small number of people are allergic to CA, but that's a different thing altogether.

In one of the safety articles I read on CA they had under 'ingestion' that it was essentially impossible to ingest it since it would cure in the mouth before you could swallow. I thought that was a funny one

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Bob Garrish
Former Canonized Purveyor of Fine CNC Luthier Services

As Bob said the fumes are an irritant but not toxic (watch out here comes the EW calvary charging down on me)
Now it is possible to aquire an acumulative sensitivity alergy to anything. this will happen to some people not to the majority. Proper PPE and enviromental percautions should ALWAY be used. You should always keep a copy of the MSDS on file for any chemical you use. if for no other reason than to know the proper first aid procedures in case of an acidental respratory or internal exposure.