How to make the crack disappear ?

[kkmm]

I got an acoustic guitar that fell on the carpet floor and the headstock got a crack.
I fixed the crack by fill in HHG then clamp it (standard procedure). The joint feels smooth to the touch. Depending on the view angle, the crack is more or less visible.
Pls see photos below.



Are there any good way to make the crack even less visible (or disappear would be best) ?

[sunburst]

There is not real way to make it less visible at this point. Perhaps alignment could have been better when it was glued but I can't really tell from looking at pictures. If so, that would have improved the look, but even with hot hide glue that ship has sailed. We get one good shot at making a near-invisible repair and if we miss that one, for whatever reason, we must settle for a good repair that is visible.

The finish looks to be less-than-high-gloss so finish touch up followed by buffing is not an option. Refinishing the neck would probably do it, but that's getting rather extreme just to make a crack less visible. Matching the sheen of the finish with a touch up is close to (but not completely) impossible. Probably the best thing to do now is observe rule #1 for finish touch up/repair; 'It is always easier to make it look worse than to make it look better'; and just accept it as is.

[kkmm]

I guess I have to accept it that way. Have tried to make repaired cracks disappear for years but look like it is not possible. Just hoping someone came out with a novel technique. I have practice the alignment without glue about 5 or 6 times, using only finger touch to ensure the joint is smooth. After gluing (and clamping), it is indeed very smooth. Unfortunately, it is visible.
Thanks anyway for the "final" verdict.

[HoGo]

It's hard to tell from the photo, but it appears like a poly finish. Even if the crack is well aligned when glued, the chipped finish at the crack will be visible. On gloss I've had good luck with CA filling and buffing but on satin you can either buff the whole thing, or fill level sand the neck smooth and spray thin coat of satin over whole neck.

[mirwa]

To make it invisible would require a complete neck refinish, if that is done well you would never see it

Steve

[Timbofood]

There is not real way to make it less visible at this point. Perhaps alignment could have been better when it was glued but I can't really tell from looking at pictures. If so, that would have improved the look, but even with hot hide glue that ship has sailed. We get one good shot at making a near-invisible repair and if we miss that one, for whatever reason, we must settle for a good repair that is visible.

The finish looks to be less-than-high-gloss so finish touch up followed by buffing is not an option. Refinishing the neck would probably do it, but that's getting rather extreme just to make a crack less visible. Matching the sheen of the finish with a touch up is close to (but not completely) impossible. Probably the best thing to do now is observe rule #1 for finish touch up/repair; 'It is always easier to make it look worse than to make it look better'; and just accept it as is.

John, that is one of the best quotes ever!
I may have to change my signe!

[rcc56]

The only cracks that I've been able to completely hide were on rosewood or mahogany that had been finished with nitro or French polished shellac, and that takes a lot of luck and patience.

An alternative would be to grind down the back of the head 1/16", install a veneer, and apply a satin finish. If done well, it would be prettier, but still visible. But it's a lot of work. I might go to that kind of trouble on a '50's D-18, but not on a recent issue guitar, unless it was a high-end model.

[mirwa]

Yes, rosewood is easy to hide cracks

[Br1ck]

Finish repair is an art form. One could easily make a specialty career out of it. And yes, that quote was very true. Easier to make it worse. I just did some finish work on an electric guitar a friend bought cheap because it fell off a hanger at a store. First thing I told him was it could look a whole lot worse. Well, it was a thick poly and I filled it with super glue, scraped it flat and sanded. It looks better, but far from good.

[mirwa]

Finish repair is an art form. One could easily make a specialty career out of it.

Yep,

Before


After

[HoGo]

It makes things simplier when there is clear nitro over unstained rosewood.
Violin makers would in never touch up more than the minimal bare spot, even FP over larger area is frowned upon these days, and yet the best can hide quite ugly mess completely invisibly. I've seen cello that was cut down (shortened) in 19th century when large cellos went out of fassion and subsequently enlarged decade or two ago and the added wood was almost undetectable - talking about 1" of wood added to top and bottom end of instrument.
In crack touch up the trend is to make them invisible under both daylight AND UV light as well.
I used to have some incredible before/after pics of such work (not mine) but I cannot find them now.

[mirwa]

It makes things simplier when there is clear nitro over unstained rosewood..

Actually its about knowing how to do finish work, being nitro, poly, uv, acrylic, enamel is irrelavant.

Punched hole in top


Hole repaired


Coloured and refinished

[belbein]

Mirwa, that first post of the hole in the side is a beautiful repair. I'm very impressed.

[Jeff Mando]

We certainly have some talented members here. Great job, Steve!

[Mark Gunter]

This:

Actually its about knowing how to do finish work, being nitro, poly, uv, acrylic, enamel is irrelavant.

Not a professional luthier, but I've made a 40 year career out of finish work and finish repair work ... I wouldn't totally refinish a neck to make a crack disappear. The go-to method in your case, for me, would probably be french padding with matching pigments rubbed in, possibly followed by a little toner, then topped and adjusted with proper topcoat spot finishing for protection and sheen adjustment. Its amazing what you can achieve with that.

Anyone can learn to do this, but it helps if you have all the ingredients and use them in your daily business.

I discussed this method in this thread, using a piece of furniture as an example: https://www.mandolincafe.com/forum/t...french+padding

Here is a little tutorial from one of my old websites via the wayback machine: http://web.archive.org/web/200805090...omahogany.html

Most of my work is done on Architectural Millwork, but as a lifelong musician and sometime amateur luthier, I've used the same techniques on musical instruments many times. Unfortunately, you need to know about French padding, have the right color pigments, and be pretty familiar with the original finishes to make easy work of it, but it can be done without refinishing the neck.