guitar finsihing problems (Full Version)

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Haithamflamenco -> guitar finsihing problems (Mar. 23 2014 8:48:28)

Dear all,

I am refenshing some guitars, totaly and some rethicknessing the neck and refinish it again,

I facing a problem with tung oil and polyurethane, I add the tung oil on the bare wood, three coutsm then I added the poly to seal it, it seems that the poly will never dry and it is still sticky little bit,

so , is ok to top coat the tung oil with poly?!?!

when I added the tung oil I j ust wait until it dryes ( 15 minutes ) or should I wait a couple of days?!?!

here how did I do it:

1. spoke shaving the neck
2. sanding.
3.cleaning
4. tung oil ( 15 minutes waitting )
5. wet sanding
6. tung oil ( 15 minutes waitting )
7.wet sanding
8.tung oil ( 15 minutes waitting )
9.wet sanding
10. poly ( 20 minutes )
11.wet sanding
12.poly ( 20 minutes )
13.wet sanding
14.poly ( 20 minutes )


i belive my waitting ( dryinh time ) is very short, and the tung oil is still not dry enough ot cure??

need your help



Sr. Martins -> RE: guitar finsihing problems (Mar. 23 2014 13:19:10)

15 - 20min is barely enough time to cook a meal [:D]



pjn -> RE: guitar finsihing problems (Mar. 23 2014 16:03:53)

Ah, another of your usual witty and informed responses.



Anders Eliasson -> RE: guitar finsihing problems (Mar. 23 2014 16:17:13)

Haitham:
Why do you put polyurethane over tung oil. Who told you to do that and did you test on some scrap wood first?



Haithamflamenco -> RE: guitar finsihing problems (Mar. 24 2014 6:59:11)

quote:

Haitham:
Why do you put polyurethane over tung oil. Who told you to do that and did you test on some scrap wood first?


andress, because I want to mach the meranti color to the body color,

no boy told me, I just did it, then i discover that not all finsihs can bond togother!!!!

I am facing a problems with poly!!!!

oil based poly is what is availave around with its sealer and stain,

water based poly is availbe but only in one place and one company minwax,

lecqure is also availab from minwax,

but the yamaha finsihs I belive its polytherne or polyster I am not sure what is the different,

I tray to make my own wipe on poly, by adding 50% thinner,

its seem like it didnt work,



Anders Eliasson -> RE: guitar finsihing problems (Mar. 24 2014 7:11:57)

I think tere´s only one way out. Take off all the poly, let the guitar dry for a LONG time and try finish it with Tung oil.
Remember to try on scrap wood first that when you do things like you this, . Sorry if I sound like your dad[&:] But you forgot to think things over.

There´s also a possibility that when you´ve taken off all finish, and after drying, you can seal the the guitar with shellack and then cover it with polyurethane. Shellack is neutral to almost everything.



krichards -> RE: guitar finsihing problems (Mar. 24 2014 9:19:56)

I'm not sure about oils. I have never used them.
But for all solvent based finishes shellac is the ideal base/primer. It sticks to anything and works well with polyurethane, polyacrylics etc



estebanana -> RE: guitar finsihing problems (Mar. 24 2014 12:20:32)

I agree with Anders. wipe off or take off as much poly as possible.

You can actually make a Tung oil only finish on a guitar, it was getting some trials about 20 years ago or in the 1980's by a few classical makers.
You need to get the poly off and let the Tung oil dry, then reapply Tung oil very carefully and thinly three or four more times. It will buff out with a soft cloth.

The problem is that now the wood is saturated with Tung oil and only another oil based finish will stick to it. You might be able to get Shellac to stick if the Tung oil dries really well, but finishing it with Tung oil seems most natural and safe.

The thing is once you coat something with Tung oil it's hard to find a product to stick to it, and if you do there is no way you can predict if it will peel off later. That's why I say strip the poly and only go with Tung oil. It will give a low sheen, but durable finish that you can touch up later if it wears thin.

Let us know how it goes, looks like Anders can help you if I miss your next post, but let us know what happens or if you need more help.

Another idea is you might be able to coat it with a long oil spar varnish, but you would need to do some tests. Guitar makers advise against using spar varnish, but I have done it a few times with excellent results. The thought it that it is not tough enough for guitars, but a high quality well formulated long oil varnish will varnish a guitar if applied thinly. No problem, it is used on masts and guitars don't get that much abuse.



Sr. Martins -> RE: guitar finsihing problems (Mar. 24 2014 12:23:48)

quote:

Ah, another of your usual witty and informed responses.


No, that ain't the case here.

You're just too dumb to understand that what I said means "Not enough time to dry".



constructordeguitarras -> RE: guitar finsihing problems (Mar. 25 2014 20:48:06)

After following Anders' advice to take the poly off and let what's left dry, I would suggest sealing with shellac. Everything bonds to shellac, and we can't say this of anything else. Oh, he basically said that, didn't he. Well, I agree.



estebanana -> RE: guitar finsihing problems (Mar. 25 2014 23:53:20)

I would test it to make sure, shellac does not adhere to every other finish, I have to disagree.



Anders Eliasson -> RE: guitar finsihing problems (Mar. 26 2014 7:36:19)

Make a test on scrap wood. Thats standard procedure when mixing finishes.
Give it a couple of layers of tung oil and wait som days or a week and give it a couple of layers of shellack to check out things.
I´ve never worked with tung oil, but if it dries, then I´m 99,9% sure that shellack will stick and dry on it and seal it for another finishing.. If the tung oil doensnt dry out completely, then shellack wont stick. Shellack is 100% compatible with true oil both on top and underneath, but true oil is not an oil finish but an oil based lacquer.



constructordeguitarras -> RE: guitar finsihing problems (Mar. 26 2014 14:43:21)

I agree--always test everything. If the Tung Oil doesn't dry by itself in air, some Japan Drier will make it dry. Yes, that's really what it's called. It is a solution of organometallic salts that oxidize the oil quickly.

Hey, I just noticed I'm a " fellow" now.



n85ae -> RE: guitar finsihing problems (Mar. 26 2014 14:49:20)

Minwax polyurethane can take up to 1-2 months to fully harden, I finished a sewing
machine table with it, and it took a very long time to harden fully. Now that it has it
is VERY tough, however if you are expecting satisfaction in mere days, you might want
to rethink your process.

Regards,
Jeff



estebanana -> RE: guitar finsihing problems (Mar. 27 2014 4:34:51)

Happy fellowdom.

Hey guys I'm only be a schickler because we have a guy who does not know much about finish work, so I just don't want to send him on some bad path.

Usually commercially prepared Tung Oil already has a siccative in it- But the Japan drier will work, but my experience in Japan is that it is wetter here. Rains.

______

I've worked a lot with Tung Oil here's the problem, it saturates deep into the wood and it's questionable whether or not it is a surface you can cover with another material. And what's more because Tung Oil penetrates deep, you may not be able to sand back far enough to expose fresh wood without significantly changing the thickness of the top.

A solution like sanding back all surfaces except the top and applying shellac to fresh exposed wood might work. Then cleaning the top of poly carefully and finishing the top with Tung Oil.

But to really get an idea of how to treat this issue you would have to see it in person. It's not realistic to give a perfect or safe solution to a situation like this unless you can see it yourself. It's got too many unknowns.

I really think the poster should find some local help in his area.



Haithamflamenco -> RE: guitar finsihing problems (Mar. 30 2014 6:41:34)

thanks guys,

I will post photos,

I should test the finsihes on scrap wood pieces first,

I couldnt find shellac in our area,

the only finishing prodcut is woorking with me now is the lacquer ,

poly will take a hick of long time to dry.

I am just wondring if I acan use an oild basded stain or water based stain under the lacquer!?!?!

all my photos are in my instegram: bahrainguitarshop

where I am starting to repair and modfy classical and flamenco guitars



Haithamflamenco -> RE: guitar finsihing problems (Apr. 2 2014 6:20:25)

Dear all,

I think that my problem was that I used tung oil ( which is actully contain no tung oil) its myabe a wipe on varnish, and I did not really leave it to dry for so long, then I applied a layer of stained polytherne in a hurry, and as you know polytheren will take a hick of time to dray, i absolotly hate it.

I have no paithent for drying time, I tried lacqure on some scrap sample as andress advice me to do,

its the best result and I am so stasfied with it, after trying for about 1 month plent of prodcuts such as: minwax wipe on poly, tung oil, water base stains, NC stainds, and lacqure.

after asking and reading in the net, I try the superglue lacqure method, its was absoutly fantastic results ,

after spoke shaving the neck, I sand the neck untill smothe and desire shape,

then I stained the neck with NC stain ( NC stands for Nitrocellulose based Wood Stain ) let it dry, sanded with fine grade 1200 with water,

then apply two layer of super glue , thin layer with a piece of clouth in fast way cause it gets dry too fast, wanding between the tow layer with fine snad papper ,

then I applied for layer of lacquer then wet sanding ,buffing and polishing,

all of that was hand applied, except for the lacqure was in spray can











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keith -> RE: guitar finsihing problems (Apr. 7 2014 16:54:31)

Haithamflamenco--nice job. i just finished re-shaping and re-finishing a cordoba classical guitar neck. i stripped the mile thick poly and re-shaped the the neck and used wood stain (sedonia red) and then semi-gloss poly. i put on one coat of stain with a rag and then 4 light coats of poly with a sponge brush. i have to say the neck feels a lot "faster" with the semi-gloss than the glob of poly or whatever was on it.



Ruphus -> RE: guitar finsihing problems (Apr. 7 2014 19:03:20)

quote:

ORIGINAL: keith

i have to say the neck feels a lot "faster" with the semi-gloss than the glob of poly or whatever was on it.


Certainly.
Glossy surfaces can only work like a brake to the skin. Which is why I expect optimal neck finishes to be either oiled, waxed or satin finished.

Ruphus



jshelton5040 -> RE: guitar finsihing problems (Apr. 7 2014 23:52:20)

quote:

ORIGINAL: Ruphus

Certainly.
Glossy surfaces can only work like a brake to the skin. Which is why I expect optimal neck finishes to be either oiled, waxed or satin finished.

Ruphus

why not coat it in sandpaper and make it really fast?



estebanana -> RE: guitar finsihing problems (Apr. 8 2014 0:18:41)

quote:

why not coat it in sandpaper and make it really fast?


Hi John,

Is the weather getting warmer up there? Mark Twain said the coldest winter he ever faced was the summer in San Francisco, but he as wrong. It's because he never spent the winter in Oregon or Japan. He wore white suits after all, he looked Col. Sanders.

There's got to be a neck joke in there somewhere, but I'm shivering too much to laugh.



constructordeguitarras -> RE: guitar finsihing problems (Apr. 8 2014 1:53:00)

Another reason it may feel faster is because you shaved off a bunch of wood, making it thinner. I always find that a thinner neck feels faster somehow.



Ruphus -> RE: guitar finsihing problems (Apr. 8 2014 10:28:20)

Should there be doubts on a humble circumstance like of how a mat surface distinctively allows for less friction to the skin than a glossy one, then ... Why not experiment a bit?

Can´t be an experience that hard to make, can it?

Ruphus


PS:

And to John.
I have news for you.
Not all parameters will keep evolving linear.
Some conditions have an optimal realm beyond of which things develop sub-optimal again.

That is why you must have observed that sandpaper wouldn´t do.

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keith -> RE: guitar finsihing problems (Apr. 8 2014 11:25:37)

ethan, undoubtly a well shaped neck will be faster than a clunky shape. my "speed" test was with the guitar on its' belly and sliding my thumb across the back, up the neck and up the headstock. cordoba finishing goop-poop provides a slow surface--especially with higher humidity where, as ruphus mentions, there is more friction.



jshelton5040 -> RE: guitar finsihing problems (Apr. 8 2014 14:23:36)

quote:

ORIGINAL: keith

ethan, undoubtly a well shaped neck will be faster than a clunky shape. my "speed" test was with the guitar on its' belly and sliding my thumb across the back, up the neck and up the headstock. cordoba finishing goop-poop provides a slow surface--especially with higher humidity where, as ruphus mentions, there is more friction.

Sorry Keith, I didn't mean to impune your analysis. I was responding to the absurd statement by the "expert".



Ruphus -> RE: guitar finsihing problems (Apr. 8 2014 14:53:47)

The expert must be you, who has not yet noticed such an obvious matter, but finds it even "absurd" to hear of it.

Comes to show that being involved into something will not inevitably equal covering related basics.
Too bad, actually.

Otherwise parents on default would be skilled in pedagogics, as pet keepers be versed in whereabouts of their owned species, and every cook be serving refined cusine.

... And maybe I after decades would had figured out by now how to treat a ficus benjamina.

Ruphus



keith -> RE: guitar finsihing problems (Apr. 8 2014 14:57:19)

john, no reason to be sorry as you did not impune my analysis. i think your sandpaper comment was funny. ethan's comment about the shape was on target and i believe he made his as i did not clearly describe my "speed" test. long story short--goop poop kills sound when applied to the sound board and kills free mobility on the neck--especially in humid conditions.



jshelton5040 -> RE: guitar finsihing problems (Apr. 8 2014 18:03:51)

quote:

ORIGINAL: estebanana

Is the weather getting warmer up there? Mark Twain said the coldest winter he ever faced was the summer in San Francisco, but he as wrong. It's because he never spent the winter in Oregon or Japan. He wore white suits after all, he looked Col. Sanders.

There's got to be a neck joke in there somewhere, but I'm shivering too much to laugh.

Actually we're experiencing one of those rare spring warm periods. It was 76 degrees yesterday and it's supposed to continue for the whole week. I spent the afternoon driving the tractor with the belly mower cutting the deep grass and sweating. After that I sat on the porch with a nice stiff bourbon and admired the blooming cherry trees. It was a lovely break from the normal shop work. Too bad you couldn't join me for a libation and some porch sitting[:D].



Anders Eliasson -> RE: guitar finsihing problems (Apr. 8 2014 19:50:30)

quote:


quote:

ORIGINAL: keith

i have to say the neck feels a lot "faster" with the semi-gloss than the glob of poly or whatever was on it.


Certainly.
Glossy surfaces can only work like a brake to the skin. Which is why I expect optimal neck finishes to be either oiled, waxed or satin finished.

Ruphus


I agree that glossy finishes feels sticky and slow. There´s some kind of logic in it. Imagine the neck being a tyre, then a glossy finish will be like a slick tyre which is more sticky.
I personal prefer a neck that has been slightly rubbed with 0000 steelwool and i finish many of my guitars neck that way



jshelton5040 -> RE: guitar finsihing problems (Apr. 8 2014 23:03:31)

quote:

ORIGINAL: Anders Eliasson

I agree that glossy finishes feels sticky and slow. There´s some kind of logic in it. Imagine the neck being a tyre, then a glossy finish will be like a slick tyre which is more sticky.
I personal prefer a neck that has been slightly rubbed with 0000 steelwool and i finish many of my guitars neck that way

"Feels" is the key word. If you clean the neck and apply a coat of good wax it will not feel sticky anymore than pavement with ice on it is more sticky than dry. I prefer necks with ultra high gloss and silicon wax. If I had the capital to invest in the expensive equipment I'd probably switch to polyester instead of lacquer.



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