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Post by strat80hm on Aug 24, 2015 12:02:05 GMT -5
Hey all - i d like to submit my plans your way before i commit. This Yamaha Flamenca - top solid spruce, back & sides cypress, with a thick polish layer (polyurethane probably) - has a crack on the top, along the bracing: Here s the crack Full crack is more visible with a light inside: Here s the bracing Fixing Top: Crack is a couple of years old now, though the table top doesnt really move much if i press on it vertically. - my plan is to fill it up inside/outside with titebond so that it doesnt get worse, would this do the trick? Top refinish - unglue the golpeador (that thin plastic guard to protect from percussive playing) using a heat gun - sanding top with steel wood and apply lacquer to obtain a nice dark red result - OR sanding to bare wood, apply dye and some natural finish protection (danish oil) note: i d like to avoid to sand down to barewood as i m sure that thick polish keeps the guitar sturdy (i play i lot of percussion on it) Back & Sides refinish I d like to change that yellow finish, darken the back and sides - deep brown chocolate - while keeping some wood pattern/transparency. So the plan is: - sand the glossy finish with steelwood - apply with a rag several thin layers of lacquer on top until it looks fine. Could you please share your thoughts? Thank you
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Post by strat80hm on Aug 24, 2015 21:38:37 GMT -5
Update: about the crack, i m planning on doing like this:
- apply water around/under the bracing with a brush - apply generous titebond glue - hold it all with a stick inside and some heavier weight on top - then i would fill up the crack with some light viscosity CA glue
I still have to remove that golpeador and i m uncertain about how to treat the top, though i just know i m a bit fed up with that bright yellow haha
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Post by cynical1 on Aug 24, 2015 23:23:29 GMT -5
The first thing I'd want to know is what caused the crack? I've steered clear of acoustics because from experience, nothing on them is an easy straight forward fix...
A trick I've seen luthiers use from time to time is to make a veneer size wedge, score the crack so you have a clean wood surface for the glue to bond to, and then press the wedge into the crack with the appropriate amount of glue.
Granted, this technique requires some sanding and refinish work, which is always a pain in the butt with poly.
Good luck.
HTC1
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Post by Deleted on Aug 25, 2015 3:48:36 GMT -5
Clean up the dust/dirt inside the crack, then a small amount of strong wood glue with a syringe along the crack, then some small amount of wood putty of ideally identical color along the crack, then some very light sanding.
Just an idea.
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Post by strat80hm on Aug 25, 2015 10:51:48 GMT -5
The first thing I'd want to know is what caused the crack? HTC1 Hey Cynical, thanks for input: it all started as a classic "winter crack" (caused by heater and dry air), and got worse on tour as i kept on banging the top pretending i was a bongo player in between chords. It got wider and larger, until i decided (now) to do something about it. As always, i m tempted by the easy way out when it comes to fix guitar haha
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Post by strat80hm on Aug 25, 2015 10:53:20 GMT -5
Clean up the dust/dirt inside the crack, then a small amount of strong wood glue with a syringe along the crack, then some small amount of wood putty of ideally identical color along the crack, then some very light sanding. Just an idea. ef̱charistó̱ GD, i m hoping for something along these lines yup
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Post by Deleted on Aug 25, 2015 15:22:19 GMT -5
γιου αρ γουελκομ! : (that sounds : you are welcome!)
btw, it is nice to have someone here who actually plays music for a living. I feel respect!
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Post by cynical1 on Aug 25, 2015 22:13:43 GMT -5
The syringe glue trick works like a charm. Any farm supply store will have an assortment to choose from. IE: Fleet Farm, Farm & Fleet, Coastal's, AGWest, Wilco...etc... I use a #18 or #20 x 1/2" syringe. (Same thing you use on alpaca, BTW), but 3/4" or 1" will work, too. A trick to make the glue flow better is to heat a pan of water on the stove. Not boiling, but hot. Let the glue bottle soak for about 10 minutes so it's hot all the way through. This will allow it to flow better through the syringe without having to water down the glue. Plain old TightBond II works best from my experience. The first 5 minutes out of the pan is the best time to get the glue in and out of the syringe. Resist the temptation to water down the glue. Anything more than a 5% dilution will have a significant effect on the bond strength. Remember, all this repair will do is cosmetically seal the crack. It will not have any effect on any potential bracing issues. Happy Trails - Cynical One PS: Check out this article on fixing an old Martin. Some of the content applies to your situation: Serious damage at the bridge area, and epoxy mess to an otherwise fine 1940 Martin D-28link
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Post by strat80hm on Aug 26, 2015 10:49:52 GMT -5
A trick to make the glue flow better is to heat a pan of water on the stove. Not boiling, but hot. Let the glue bottle soak for about 10 minutes so it's hot all the way through. Resist the temptation to water down the glue. Anything more than a 5% dilution will have a significant effect on the bond strength. Remember, all this repair will do is cosmetically seal the crack. It will not have any effect on any potential bracing issues. PS: Check out this article on fixing an old Martin. Some of the content applies to your situation: Thanks for reminding me of heating the glue - i indeed was about to dilute it. Titebond3 was fluid enough to be used as is in the syringe when i glued a bracing yesterday - i removed the needle though I m planning on addressing the understructure of the crack today. Good tips on that articles, thanks again!
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Post by strat80hm on Aug 26, 2015 10:52:09 GMT -5
γιου αρ γουελκομ! : (that sounds : you are welcome!) btw, it is nice to have someone here who actually plays music for a living. I feel respect! Thank you! I have no choice as i m too lazy to do anything else. Worked well for the past 25 years though! Is your work related to guitars at all?
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Post by strat80hm on Aug 26, 2015 13:46:16 GMT -5
That s what is up so far: - fixed a loose bracing - fixing crack with wood glue for now This is drying, hopefully it ll work..
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Post by cynical1 on Aug 26, 2015 23:03:34 GMT -5
Looks good. And you saved yourself a pretty pile of coin doing it yourself.
So, have you investigated case humidors yet?
HTC1
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Post by Deleted on Aug 27, 2015 2:13:08 GMT -5
Thank you! I have no choice as i m too lazy to do anything else. Worked well for the past 25 years though! Is your work related to guitars at all? Lazy but courageous! My work is to seat in an office and direct some small software development team, less lazy but not so brave I guess.
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Post by strat80hm on Aug 27, 2015 11:19:42 GMT -5
Lazy but courageous! My work is to seat in an office and direct some small software development team, less lazy but not so brave I guess.[/quote] Brave, courageous? Haha thanks i ll take that! Admittedly i m quite happy with my choice - been actively avoiding what i didnt want in favor of what i wanted - to discover new things regularly. I ve never known any steady paycheck on the other hand - except for that time when i wanted to discover the Broadway world and went on that tour all over the USA with a musical theater show for 1 year and a half!! Was fun to discover all those places, being treated like a rock star and have money in the bank when it was over. But it got old too haha
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Post by strat80hm on Aug 27, 2015 11:24:14 GMT -5
So, have you investigated case humidors yet? HTC1 No, do you mean humidifying-gig-cases or sarcophagus-shaped guitar-closet?
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Post by strat80hm on Aug 27, 2015 11:30:27 GMT -5
Here s what i got after removing the clamp: Rough but flat Testing with the light: no sign of open crack apparently Obviously i m gonna have to address the finish If this is it, cool, though it seemed a bit too easy - can titebond actually be strong enough to hold it together without any extra bracing?
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Post by cynical1 on Aug 27, 2015 12:40:26 GMT -5
Titebond 3 is rated at 4000 psi, it's waterproof and the odds are the top will split into a million pieces in every place...except where it's been glued. I think if you find some case humidifier the problem will likely not recur. Now for the ugly part... The seam did not join as originally glued. This may or may not present a stress at the other joints, but unless it's a $15,000.00 Martin you're probably not losing sleep about it. I'd take it with me on the road, but if it's a significant part of your show make sure you have a backup. You mentioned you were not terribly enamored with the light yellow top. If this is the case, the fix is easy. Have any talented airbrush artist friends? If so, just fill the crack flat, let them do their thing, and you have a pretty cool stage guitar. Mentioning who did the work on the road may help knock down the price. Another option may not be beautiful up close, but works fine on stage. Take a thin marquetry strip and glue it over the crack. Something like this: A little sanding after the fact, a bit of lacquer to protect it, and you're on the road again. A decent brush lacquer will level very thin and polish up like a mirror. Granted, this is the cheap and dirty way out. You can labor over this more if the mood strikes you I doubt that the original finish is lacquer. If the guitar is old enough a coat of lacquer over the top won't lift the finish. To test, take some cheap nail polish remover (acetone) on a Q-Tip and see if the finish lifts. If not, it ain't lacquer. Let me know what you have in mind. This was not a terribly expensive guitar, so feel free to go nuts. Happy Trails Cynical One
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Post by strat80hm on Aug 27, 2015 15:05:10 GMT -5
Thanks for following up Cynical1 I d love an acoustic guitar that wouldnt need much care, like an electric basically - i tried a humidifier once, but i always forget to fill it up, or even to put it back in. And all my guitars live outside of any case in my studio, ready for grabs at any moment. Granted this is probably what caused cracks on the acoustics (i have another on to fix actually..) I appreciate the suggestions too: i might not want a guitar with a motif on it, but for sure a nice dark wood top would look fine. (no it doesnt react to acetone, it s the usual thick yamaha finish (polyurethane?). I was thinking light woodsteel sanding, then colored lacquer (reddish on top - brown on sides) hopefully this would sustain? I dont mind the guitar to look beatup (it actually make the audience think i m kinda of a big deal i noticed hahaha) though like these marquetry strips too: => wondering if i could use those should i want light colored binding with the red and brown? This is where i am - i like the matte finish too.. Also there is that big chip (which helped me get that guitar for cheap!) I m still open to suggestion as for how to finish this.
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Post by strat80hm on Aug 27, 2015 16:10:10 GMT -5
I m not sure i m actually done with the structural part of the fixing, though i m wandering into the decoration part: From that yellow spruce/cypress look, m aiming for that sort of taint, no idea how to go there yet. For the top: Or also For the back/sides I like those
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Post by cynical1 on Aug 28, 2015 11:34:01 GMT -5
Well, that divot on the edge really changes things. As far as fixing it...there's the right way...then there's the cheap and dirty way... The right way is to remove the entire top and install a new one. More than likely more work than you want, requires more tools then you own and can go South on you in a skinny minute if you don't have enough experience to complete the job. So, lets go to the cheap and dirty side... The easiest thing to do is just leave it. If it's made a road trip already and come back alive, then the odds are it'll live to play another day. One look at Willie Nelson's old guitar proves that one out... You could use a plain wood filler. I'd steer away from epoxy wood fillers, as they really require a power sander to remove the bulk of the material to even the repair out. It'd be real easy to blow right through that plywood top while removing the epoxy filler. A company called Satellite City ( www.caglue.com/) makes a product called "Special T" ultra thick CA adhesive. I use this stuff to fix bad chips and cracks in a finish. It's cleaner than wood fillers and you can spray anything over the top of it. It sands out well with a 320 grit dry paper and smooths out to invisible with wet sanding. If it were my guitar, that's how I'd go. As far as the finish options... Lacquer levels very well, dries in very thin coats and buffs up to a mirror finish. It will have less of an effect on the tone of the guitar then the catalyst soup that's on there now. As far as the wood grain showing through after you use lacquer to tint in...probably not going to happen. You can reduce the lacquer with thinner 50%, which will require twice the number of coats, but if you split the coat between color and clear you might get pretty close. On an average, 2 mils is as thick as you want to go with lacquer. A wet film thickness of 3 mils will give me about .375 mils of dry film. So you're already at 6-8 coats unsanded and buffed without reducing it. For the record, red covers about the worst, so for your purposes it may be the best option Resist the temptation to tape the binding. The process is actually to scrap the painted binding clean with a special tool or knife prior to the clearcoat. I use a very old tool that I sharpen to a "V" shape. There is an art to it. Here's a cheap and dirty video to explain what I'm talking about: There are more involved videos on YouTube that detail the tooling and process, but I'll leave you to your own Google Fu on that one. More than likely, the finishes you posted as examples are wood dye with a clear coat. I love wood dye. You can mix it with water or denatured alcohol. I prefer the alcohol as water based dyes tend to lift the grain. You have a longer working time with water, so there is a trade off. Spraying the dye works better than rubbing it, but you use what you've got. You will need to remove ALL of the old finish in order to use wood dye. With an acoustic guitar this likely means you'll be removing all of the old finish by hand, as most strippers strong enough to cut poly\catalyst coating will potentially melt the glue on the binding, bridge and top. This has probably gotten long enough already, so I'll resist my natural verbose tendency and quit now. Let me know if I need to clarify anything here. Happy Trails Cynical One
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Post by strat80hm on Aug 29, 2015 12:35:54 GMT -5
As far as the finish options... Lacquer levels very well, dries in very thin coats and buffs up to a mirror finish. As far as the wood grain showing through after you use lacquer to tint in...probably not going to happen. Spraying the dye works better than rubbing it, but you use what you've got. You'll be removing all of the old finish by hand, as most strippers strong enough to cut poly\catalyst coating will potentially melt the glue on the binding, bridge and top. Let me know if I need to clarify anything here. Thanks for sharing all this Cyn, your verbose is under control, all s right on point. I m all for letting it look the way it does visually, chipped and scratched, but with a warmer tint - love Wilie Nelson s nylon string guitar - i would not articially "relic" a guitar but i dont intend on making is look any newer. I would not mind a natural wood finish - like on my LaPatrie, natural, no polish - though here that would mean sanding to barewood: regardless of the time it d take, would it really be smart to do that structure-wise since i already had that crack? Any success removing a thick layer of poly with a heat gun and scraper? This might hurt the biding too though. Will bring the guitar as-is to the art shop by Pratt institute and see what i find there - yes i d love to do this rubbing, less tools. Thanks for the tip about the binding: indeed that was the next question on my list. So you re saying to just lacquer away and THEN scratch the layers along the binding, got it. More soon..
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Post by cynical1 on Aug 29, 2015 19:30:03 GMT -5
So you re saying to just lacquer away and THEN scratch the layers along the binding, got it. Yep, that sums it up pretty good. Another option, which I probably should have though of off the bat, is aging the lacquer before applying. CRS... What is aged lacquer? One of the simplest and best kept secrets out there. If you ever have to match an old darkened finish on a neck, respraying new lacquer over a repair looks like a neon Fish Fry sign in a cemetery. Aging lacquer is easy as breathing. Just find a clear glass jar with a good seal on the lid. Fill it with lacquer and put it in a South window. The sun will darken it with no intervention on your part. The longer you leave it the darker it gets. There is a limit, based on the lacquer you use, but the results when sprayed give a remarkably convincing "vintage" look to light wood. The best part is, if the lacquer doesn't lift the original finish, you don't have to strip a thing and can bypass the binding scraping entirely. If the acetone didn't lift the finish you're probably good. You can test the theory a bit further by taking any decent brush lacquer and dabbing a bit in an inconspicuous spot. Ain't this fun? Happy Trails - Cynical One
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Post by strat80hm on Sept 4, 2015 14:36:52 GMT -5
Another option, which I probably should have though of off the bat, is aging the lacquer before applying. CRS... Brain seems to remember things pretty well Cyn1, thanks for tip. I m still researching options, at the moment, Aging the lacquer or tinting it before sounds like the good direction, i m starting to consider a middle way: - light sanding of sides/back, then lacquer (aged or colored or both) with hopefully a dark chocolate shade to it. - full sanding of the top, reddish dye then natural (danish oil) finish Hopefully the binding can survive this?
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Post by cynical1 on Sept 4, 2015 19:45:22 GMT -5
I m still researching options... The enemy of good is better... Let me toss one more thing into the mix. You can use TransTint dye right in the lacquer. Works pretty well, actually. You can make it semi opaque to almost transparent. Just make sure you measure each coat equally in the pot, as your results may vary wildly if you swag it. It comes in more than a few colors: You can even pull off a burst with the right gun. Realistically, if the original finish is stable and still adheres well to the guitar about the only thing you need to do is knock off the rough spots and re-spray. I would recommend using the "Special T" CA adhesive to fill in everything necessary to allow for a smooth level surface when applying the lacquer. Lacquer dries very thin and will betray every blemish left behind. I would have to lean against this option, as the time involved in hand sanding down to the wood is more work then you probably want. You also run the risk of sanding into the lower plys on the top. This problem becomes even more likely if you use a power sander. If the binding is solid now, over spraying probably won't create a problem. I'd be more concerned it'd get shanked while power sanding. If you're concerned about the lacquer lifting the binding you might want to consider spraying a couple light coats of shellac prior to the lacquer. The shellac acts as a barrier between the original finish and the fresh lacquer. This is old school, but it works So, are the waters muddy enough for you yet? Happy Trails Cynical One
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Post by strat80hm on Sept 12, 2015 19:00:45 GMT -5
You can even pull off a burst with the right gun. If you're concerned about the lacquer lifting the binding you might want to consider spraying a couple light coats of shellac prior to the lacquer. The shellac acts as a barrier between the original finish and the fresh lacquer. This is old school, but it works So, are the waters muddy enough for you yet? Indeed this is helpful Cyn I ve read, discussed, researched and am gonna start with tinted shellac. - as of now, i experimenting - on scrap wood and on the back of the guitar itself - with Shellac and pigments. - found the right reddish tint i m after, really promising. - experimenting with adding denatured alcohol trying to find the right consistence. - have no spraying gun so am perfecting manual technique to apply this evenly. Obviously this is not very easy to obtain something even haha I might wanna try with a brush and thin thin layers at a time maybe. More soon..
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Post by cynical1 on Sept 13, 2015 0:45:14 GMT -5
- have no spraying gun so am perfecting manual technique to apply this evenly... Easy to work around. It's just a jar that affixes to a disposable pressurized can. A quick Google search for your area will turn one up. Granted, it's not like a professional gun, but you can get very decent results with a little practice. And experiment away. Remember one thing, the shade will vary in your final result as the substrate for your experiments is different from the substrate on the guitar. But hey, have fun. When you're done you can be certain no one else in the world will have the same guitar as you do. Happy Trails Cynical One
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Post by cynical1 on Sept 13, 2015 10:33:46 GMT -5
CAVAET:Shellac can be sprayed, but it more commonly is brushed. Since there is no real chemical reaction, like poly or catalyst finishes, as it dries and hardens, the more you thin it with alcohol the longer it takes to harden. Wiping or brushing is more common. Since it hardens by an evaporation process you'll want to give it plenty of time to harden up if you spray it. De-waxed shellac is preferable, but it's hard to find that information detailed on the cans anymore. Shellac has become somewhat of a dinosaur since the introduction of varnish and poly (which is really just plastic varnish)finishes.
If you use the TransTint dye in shellac, they recommend 1/4 - 1/2 ounce concentrate per quart. If you make smaller size pots adjust accordingly. If you feel the need to thin it out, only use denatured alcohol, and not too much of it. The denatured alcohol will retard the hardening process, not the drying process...if that makes any sense. Since you're probably going to overspray the shellac with lacquer make sure you've allowed the shellac to harden, fine sand with 400 grit, 1000 grit and 0000 steel wool before shooting the lacquer.
Figured I better toss this information out there before bad things happened.
HTC1
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Post by strat80hm on Sept 13, 2015 12:06:56 GMT -5
CAVAET:Granted, it's not like a professional gun, but you can get very decent results with a little practice. Shellac can be sprayed, but it more commonly is brushed. HTC1 Interesting option, thanks for sharing this. I didnt know it existed - I was thinking of getting a empty spray bottle at the hardware store (the ones used to spray water on plants) and do test with it. I m gonna keep on experimentating with the manual technique first though - wiping and/or brushing; albeit uneven, i guess i like the hand-made look to it - it actually looks like some real reddish wood. More soon
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Post by strat80hm on Sept 14, 2015 16:00:51 GMT -5
Quick update: - found some promising shade - had fun mixing pigments (liquids AND solid) - tried it on the back (3 layers and thin steel-wool ligtht sanding in between - no rag, i finally i adopted the brush, help create some "wood" pattern - it seems that the solid pigment didnt dissolve totally, though it help with that raw "open pore" wood aspect, which i like much. [/URL
Plan is to go on with sides and top - keep on sanding/layering and end with clear coat as suggested.
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Post by cynical1 on Sept 15, 2015 12:23:58 GMT -5
Looking good! Having the time and guinea pig around to experiment on can be fun.
Yeah, I never had a lot of use for solid pigments. As you said, they may, or may not, fully dissolve and keeping them consistent through multiple batches can be challenging.
Just give the shellac plenty of time to harden and the clear coat, once buffed out, will polish up nicely. One caution, trying to simulate wood grain with brush strokes always works best with a matte finish. A mirror polished final clear coat will betray every imperfection and magnify attempts at a faux finish.
Looking forward to the next installment.
Happy Trails -
Cynical One
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