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Andyjr1515

Dreadnought Acoustic

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1 hour ago, ScottR said:

I was thinking about this build and your egg whites this weekend. I had a little bit of tear out in some zebra wood around some holes drilled for dowels and made a wood filler out of sanding dust and a water based sanding sealer. It dried very nearly the same color as the wood and did a bang up job filling pores. I wondered how your egg whites would react with some sanding dust mixed in as a thickener and used as a pore filler? It didn't appear to darken the wood it was on as you used it.

I didn't really have any voids big enough to warrant trying a slurry with it, but I will try it with some scrap.  I suspect that it would work well as it seems to be non-reactive but dries hard.  I'll let you know how it goes.  Colour-wise, it seems to do no more than the change when you wet wood,  What's nice is that it seems to hold that depth of colour from pretty much the first  coat.

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It has been my understanding that raising a slurry with egg whites is the advantage behind their use. There'll be a limit on the amount of filling they can achieve on their own, however I have a gut feeling that the shear resistance of protein-based binders is pretty high. I'd have more confidence in them working than as not, let's say.

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OK - I might have a bit of an issue with the egg-white.

First is a bit of a schoolboy error.  Egg white is remarkable tough and rigid when it's set.  But it is instantly water soluble.  So on early coats of the finishing varnish, the usual wet n dry used wet is NOT an option!!!  Any breakthrough allows the water to get to the eggwhite which immediately disappears!  The result is a series of 'snail trails' wherever that has happened:

hqNzrCpl.jpg

 

That is fixable.  Just sand back down to the eggwhite and start again, remembering to sand dry.

 

The second is a much more serious concern and may well lead to me abandoning the technique on this project.  Here's what it looks like from the top:

B0UtI2xl.jpg

 

...and from most angles, it looks the same.  Very pleased :)

But I caught a glimpse of it from THIS angle and wow!  :

P3YgFDYl.jpg

That's really not good.  These areas had not got down through the varnish with the wet sanding so I don't think it's the same issue, but it maybe a moisture issue of some nature.

This particular project is too important to risk it, so I'm going to strip it all back to the wood and start again with more modern methods.  I'll carry on trialling egg white in other contexts, but on something a little more disposable.

 

On the other hand, I tried thinning down Z-poxy with acetone for the first time to get it to be able to wipe-on to the pickguard.  That appears to be a bit more successful!.  I think denatured alcohol is the recommended (and probably healthier) way of thinning but I had acetone and didn't have any alcohol.  I made sure the windows were open and let the cloth dry outside to avoid any spontaneous combustion stuff!!! :

jE2DUTvl.jpg

Edited by Andyjr1515

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Wow, well that's news. I mean, I guess that the water thing makes easy sense, however I didn't think it would mess up that badly. I mean, I'm completely new to egg white work myself since I tend to rely on shellac or thixotropic/shear-resistant fillers normally. Perhaps this is where @ScottR insistence on dry sanding throughout would pay off?

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1 hour ago, Prostheta said:

Wow, well that's news. I mean, I guess that the water thing makes easy sense, however I didn't think it would mess up that badly. I mean, I'm completely new to egg white work myself since I tend to rely on shellac or thixotropic/shear-resistant fillers normally. Perhaps this is where @ScottR insistence on dry sanding throughout would pay off?

Yes - this is where the schoolboy error came in.  I dry sanded for the initial grain flattening and surfacing.  I'd forgotten, though, how thin a coat of varnish I'd put on before the flattening sand on that and just went into mental auto-mode.

That other discolouration is something else though.  The weird thing is that from all other angles it is completely undetectable.  In fact, from all other angles it looks absolutely great!  But there's something not right and I can't be sure it isn't highlighting a faulty bond that will give me problems in the future...

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14 minutes ago, Prostheta said:

It does look very strange. Water sounds as likely an answer as any.

I know what you mean - and it does look like sanding marks. The odd thing though is those areas are not consistent with where I did the most flattening.

On the positive side, I found a link to a guy who does an egg white slurry approach on his acoustics with rosewood ( I think I remember) back and sides and it looks very good indeed.  I'll post the link when I get a mo'. 

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I'm wondering if they're a consequence of adhesion issues or witness marks? That they appear from one angle only would imply that the wood has something to do with it since varnish doesn't have "a direction" as such. Perhaps the water in the egg white has played hell with the grain? I too am clutching at straws. Throwing ideas out and seeing what sticks....very unscientific....

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Perhaps the egg white absorbed to different degrees in different areas of the top? It almost looks like some area have flaked off when viewed from that angle.

SR

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I've had a really really close look under bright light and subdued light and I think you are right - it's definitely a grain direction issue rather than an adhesion issue.  From the top or across the grain, however close you look,  there is no discernible issue.  In fact it shimmers like a great tight piece of proper vertically grained lacquered spruce does.  

However, if you look obliquely from either end along the grain, the areas of difference are as plain as the stripes on a freshly lawn-mowered and rolled lawn.

Clearly, I have sanded differently or to a different level or finished in a different direction in those areas somewhere in the grain levelling process.  Whether the egg white has caused or exacerbated the issue, I can't tell.

The back and sides look OK, so I will continue with those as normal.  (the Lacewood is a very smooth tight grained, almost formica-like, wood so no grain issues there).  The top will be sanded down to the wood, maybe this evening, and re-done.   

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The top's stripped and a tru-oil slurry has been applied.  I'll see what it's like in the morning.

On another topic, on one of the other forums I dip in and out of, a question has been raised about the lacewood pickguard.  The pickguard will be the last thing I fit and won't fit it until I can see how the whole thing looks fully assembled and strung. 

But in terms of, at first glance above, whether it enhances or detracts, what's the consensus here?  Bear in mind I'll do what I like anyway :lol:, but I am interested in everyone's views in any case!  :D

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5 minutes ago, ScottR said:

I quite like the look, but wonder if it will dampen the top any.

SR

Yes - it might do....but doesn't a plastic one do so also?

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I probably should have mentioned in your earlier thread regarding the egg white pore filler - I've also only seen the technique mentioned when the finish being applied is French polish, where the film build is done without sanding between coats - water never forms part of the finishing process in that situation.

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2 hours ago, Prostheta said:

I dislike pickguards on acoustics. Babies however, do require bibs.

:)   Me too.

 Trouble is, you are right...and this baby needs a bib!  Our vocalist smacks the top with his pick almost every time he does a down stroke.  He had a 5 minute go on my OM when I'd just finished it (and that doesn't have a pickguard) and I spent the next couple of evenings steaming out the gouges :lol:

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17 minutes ago, Prostheta said:

Ah, well it sounds like he's far beyond learning then.

Well this 'special birthday' is his 70th!  So, unless you really can teach old dogs new tricks, I think it is a lost cause :D 

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Just now, Prostheta said:

Would a film pickguard be ineffective? Does he genuinely hack away?

I did consider this.  I have one on my 1970s Yairi flamenco (quite progressive for that age) and it's unobtrusive, but has been very well done. Never done one, though, and would hate to  wreck the look.

and yes - he hacks away.  He doesn't even know he's doing it (he would be mortified if he knew he'd gouged my top). He does a sweeping full arm stroke on a trajectory where the pick brushes the bottom strings, digs in progressively into the treble strings and finishes its travel on the top.  It sounds an odd addition to a blues/rock band but in the mix it's not a bad sound.

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....and the reason he doesn't know he's doing it is that his old hacker acoustic has a standard teardrop pickguard so there are no gouges on the top itself.

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16 hours ago, Andyjr1515 said:

Yes - it might do....but doesn't a plastic one do so also?

Probably. I honestly don't know enough about acoustics to speak intelligently on the subject. I've been studying up on mandolins recently, though, and my eyes have been opened widely. It makes me look at things and ask questions that never would have occurred to me before.

It's a classic case of you don't even know what you don't know.....until you learn enough to realize you don't know squat!:D

SR

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I don't think it's a case of realising that you don't know squat, but one of reminding yourself that you're always learning. If you're not making mistakes, you're not challenging yourself.

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That's true as well.

Every now and then I come across a subject, that I never had cause to learn anything about previously. And when the need arises, I'll dig into it. And those times where my reaction is Holy Cow! that's fascinating--I had no idea!--well, that's almost like Christmas in the summer. Now I've got a whole new thing that makes me happy.:)

SR

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Ah man, I love to learn. I wish I was able to learn metal lathework and milling for one. That pushes SO many of my buttons.

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