How to fix these flaws?

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Eric Knapp
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How to fix these flaws?

Post by Eric Knapp »

Hello. When I did the bindings on the back of my first guitar I used a glue I hadn't used before. That was a mistake. I tried the CA glue method of gluing bindings and the glue turned white in some gaps. I have no idea how this happened and I'm looking for advice on how to fix it.

Here's what they look like. I really like to improve this but I'm nervous about making it worse. The only think I can think of is to gouge out the white glue and fill it with something that mostly matches the wood. If that would work what kind of filler should I use?
white-lines-1.jpeg
white-lines-2.jpeg
white-lines-3.jpeg
Thanks,

-Eric
Freeman Keller
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Re: How to fix these flaws?

Post by Freeman Keller »

My experience with CA is that it really does not show up under lacquer like wood glues do - that is one of the reasons I use it for binding. It floods into the wood and I try to scrape/sand as much as I can but if a little is left it doesn't seem to matter. CA is even used for drop filling. In your case have you tried wiping naphtha on it to see if the white stands out? You might also try to duplicate it with some scrap and put a bit of your finish on to see what it is going to look like.
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Peter Wilcox
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Re: How to fix these flaws?

Post by Peter Wilcox »

If you can duplicate it on scrap, try wiping it with acetone and see if that makes it less noticeable.
Maybe I can't fix it, but I can fix it so no one can fix it
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Bryan Bear
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Re: How to fix these flaws?

Post by Bryan Bear »

I was thinking acetone too but definitely practice on scrap!
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Marshall Dixon
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Re: How to fix these flaws?

Post by Marshall Dixon »

Try finding a colored felt tip marker to match the color of the wood. Mask the areas as needed. See if the glue will stain. Practice on scrap, of course.
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Barry Daniels
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Re: How to fix these flaws?

Post by Barry Daniels »

As Marshall suggested a felt marker is a versatile tool. Therefore, it is not necessary to dig out the white glue, just colorize it. A brown, fine tipped Sharpie is my choice. It it goes on too dark, hit it quickly with a mineral spirits dampened cloth. The Sharpies are somewhat permanent ink so the stain will last.
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Eric Knapp
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Re: How to fix these flaws?

Post by Eric Knapp »

Thanks for the suggestions, guys. I tried using a sharpie on some scrap. I am using shellac for the finish and the alcohol removed the sharpie immediately. It has been suggested by a woodworker friend that I could try liquid hide glue as a filler. It is very close to the color of the woods I'm using. I am going to try to dig out some of the white glue and fill with hide glue. I'll still tape around the area and then scrape the glue down to the tape after it's hard. If nothing works well I will just live with it. I consider this my learning guitar and It's not going to leave the house. I'll just move on to the next one.

-Eric
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Barry Daniels
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Re: How to fix these flaws?

Post by Barry Daniels »

Ummm, I don't think I agree about the hide glue as a filler. I think there are better options.
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Randy Roberts
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Re: How to fix these flaws?

Post by Randy Roberts »

Eric,

The white areas are where too much CA flashed too fast. You are looking at the tiny bubbles that were created when the liquid CA turned solid while boiling. The CA turning solid is an exothermic reaction and if there is enough of it still liquid when this process occurs it essentially boils the CA that is still liquid, and the boiling CA turns solid while boiling, trapping the hundreds of tiny bubbles permanently. It's kind of a China Syndrome nuclear reaction thing (am I dating myself?).

It is permanent and the only way of getting rid of the white is removing the glue itself. It usually extends to the depth of the glue, so digging all that set CA out would be quite a job and probably make the side and binding look worse.

Unless you are in a big hurry with this guitar, I think your best bet would be to re-route your binding channels a hair deeper and put new binding on. The width of the gap between the binding and the side looks kinda large anyway, and getting the edges flush together would lessen the space there and prevent having so much of a pool of glue there to possibly boil in the first place

I've only ever used CA for bindings, and this is an inherent risk of using it if you try to hurry the job. The CA is fast enough already compared to other glues for the job, so slow the process down and take your time with the glue. Just 3-4 drops at a time, let it harden, then do a few more drops. The other inherent risk with CA is on your top be sure to seal the walls of the binding's ledge with shellac before gluing in the binding. Otherwise the CA will wick down the "tubes" of the soft wood of the top and discolor the wood, especially the end grain areas.

You want to glue small areas at a time and let it set before moving on down the way. I found that tack gluing the binding every couple inches, and then going around and filling in the spaces in between works well, but I usually just slowly work my way around, pressing the binding in place with my fingers, and holding it pressed in until the CA is hard (I put a little bit of myself, or at least my fingers, in every guitar<g>) Just don't use a bunch at once.

Some CA accelerants can increase this boiling risk, some don't seem to. If I use an accelerant, I go with one of the spray types, and just the tiniest of puffs of it.
Alan Carruth
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Re: How to fix these flaws?

Post by Alan Carruth »

Baking soda is an accelerant for CA. When I'm using the stuff on an acid wood like walnut, that will slow the set down, I like to rub some baking soda into the surface, wiping off any excess. What's left in the pores is not enough to show up white, but will start the CA kicking over. So with walnut purfling I'll rub the soda into the walnut, and apply the CA to the ledge so that there's no chance of it kicking while you're putting the purfling in place. I also use a slower cure CA, rather than the 'instant' stuff, which gives a nit of time to get things aligned.

CA and epoxy harden by a chemical reaction, and thus don't shrink as they set up, or not much. Wood glues, such as Titebond, hide glue, and fish glue, do shrink, so they're less likely to leave a visible glue line. I like to use liquid fish glue for binding, but, of course, the slow setup means you have to clamp it for several hours. For that I use a strip of rubber cut from a truck inner tube. It takes a bit more time overall to do the binding that way, but I'm never sure that I can get everything is as tightly as I want with CA. I do use that for the more flexible purfling, though.
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Bryan Bear
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Re: How to fix these flaws?

Post by Bryan Bear »

Another thing to consider is that these gaps will be a record of your progress. You will always have flaws. Often you will be able to fix them or hide them before you move on. In this case you could go as far as routing it all off and doing it again. That would be more practice and move you a bit closer to honing this particular skill. There is nothing wrong with doing that. Working hard to hide or minimize them can be a good skill too. But moving on is a third option.

For me, I struggle with never getting anything done because I get too focused on the errors. I had to teach myself to move forward with the best job I am able to do at the time. Since this is a hobby for me, it is a safe place to do that. There is something rewarding about looking back at my older efforts. I’m party embarrassed but mostly just proud of how far I have come.

We have a group that gets together once a year here in St. Louis. A couple years ago, we all agreed to bring our first efforts to show. It was really neat for all of us to see and show how far we have each come.
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Marshall Dixon
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Re: How to fix these flaws?

Post by Marshall Dixon »

I don't know how many of these spots you have to deal with, but they do stick out like a sore thumb. I've dug them out with a dental tool that is a basically a high tempered curved needle. Or I've used the tip of a No. 11 scalpel blade up against a flexible metal rule as a micro chisel. You need to preserve the straight line of the binding and remove enough to make a shallow channel to fill as camouflage. You've got lighter and darker elements in the side wood so you can get away with a bit of a mismatch there. A sewing needle with the tip ground to a chisel point guided by a straight edge.

Or try some super glue remover. Maybe put that on before surgery.
Alan Carruth
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Re: How to fix these flaws?

Post by Alan Carruth »

Light spots tend to show up more than dark ones. If you can make the filler about a half a shade darker than the lighter wood on either side that's good. A sliver of wood is usually better than dust and glue.
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Eric Knapp
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Re: How to fix these flaws?

Post by Eric Knapp »

Here's an update. I dug out the white glue with an Xacto blade that I ground to a chisel point. I then filled the spots with liquid hide glue. The results are much better and do not stick out like a sore thumb. There are still flaws but I expect that on guitar number 1, and 2, and 3, etc. I'm hoping to improve and make a good guitar some day. I posted some photos in a new post on finishing. I'm satisfied with the look for now.

Thanks for all your input, it was very helpful in understanding how this happened and how to avoid it in the future. There's always something to learn, eh?

-Eric
Clay Schaeffer
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Re: How to fix these flaws?

Post by Clay Schaeffer »

Coming late to the party, but one way you can fill those areas is to scrape the CA to slightly below the surface and then cover it with a mixture of sanding dust from the same wood and the finish material you will be using (in your case - shellac). The finish material will act as a binder and often keep the wood dust about the same shade as the rest of the wood. One advantage of this, rather than using markers, is that the fill will take on the same patina as the rest of the wood as it ages. Markers often become more conspicuous with time.
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