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| Rant - Porous EIRW anyone? http://w-ww.luthiersforum.com/forum/viewtopic.php?f=10102&t=4665 |
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| Author: | Tim McKnight [ Sun Jan 22, 2006 8:52 am ] |
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I brushed a coat of shellac on an EIRW back/sides and it soaked through the back. The inside is a real mess. I have had it happen before in a couple of pin head size places on other woods but never EIRW or at this magnitude. It looks like the entire interior was finished (by a two year old). I had the soundhole covered and didn't notice it for a while. Lots of RW bleed / stain on the the spruce braces and linings. I am bummed! Sorry for the rant, back to the shop... |
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| Author: | Mario [ Sun Jan 22, 2006 9:06 am ] |
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Wow! How much shellac do you apply!?! |
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| Author: | Terry Stowell [ Sun Jan 22, 2006 9:18 am ] |
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wow's right. Shellac is solvent based though.... Spruce center strip & braces? That's gonna be tough I'd tape off the spruce with solvent resistant tape, and start wiping till it's all leached out. You may have to "stain" your spruce though 
Let us know. WE know you'll come up with something |
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| Author: | guitarjtb [ Sun Jan 22, 2006 10:12 am ] |
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How thin do you sand your backs,Tim?? 
Seriously, I have never had any finish bleed/soak through. Sorry I can't help. |
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| Author: | Dave-SKG [ Sun Jan 22, 2006 11:57 am ] |
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Tim, just put some tape over it and tell people that's there to hide the crayon! 
seriously...Sorry to hear bout this...what lb cut were you using?...must have been very thin. |
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| Author: | Tim McKnight [ Sun Jan 22, 2006 12:01 pm ] |
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I use a 2" brush and apply a 2lb cut coat over the entire box prior to pore filling. The back on this one is .085" and I have gone down to .070" before with no problems. This was just a really strange experience that I have never encountered before. If you look at the back under magnification there are hundreds of tiny pinholes all over the surface. I didn't notice them before I applied the finish. There are four like sets of EIR in this batch and it only happened on one set. If I pick up a quart of brown floor enamel, pour it inside the box & shake it around, MAYBE no one will notice 
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| Author: | Dave Anderson [ Sun Jan 22, 2006 1:46 pm ] |
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I've never heard of such a thing. The shellac soaking thru the pinholes taking rosewood dust with it staining your spruce. Hope it will clean up somehow.Good luck with it. |
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| Author: | Dickey [ Sun Jan 22, 2006 2:11 pm ] |
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Tim, look on the bright side, here is an opportunity in brace shaving. bummer, I know. |
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| Author: | Paul Schulte [ Sun Jan 22, 2006 5:38 pm ] |
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Tim, sorry about your expierience. Must be an unusually porous piece of rw. As a French polisher I think you may have better results by padding on the shellac instead of brushing. A 2 lb cut is still pretty thin and a brush can hold a lot of shellac. By padding I mean just a quick swipe around the bindings to prevent color bleed and then a swipe with the grain everywhere else. You could pad on as many coats as you want, start fairly dry for an initial seal then gradually wetter with sucessive coats. |
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| Author: | Pwoolson [ Mon Jan 23, 2006 2:01 am ] |
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Tim, I had a similar, though not as bad, experience with a set of EIR. The good news is that all of the RW dust was suspended in shellac which is very easy to sand. Though it IS inside a box and not so easy to get at. Luckily for me, the top split on that box so I had to cut it off. While it was in boat form, I was able to sand of the shellac much better. Paul S had a good point in that you probably should have put on several thin coats of a thicker cut first. Then paint it on afterward. But since you have never had this problem before, hindsight is 20.20. |
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| Author: | John How [ Mon Jan 23, 2006 3:05 am ] |
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Bummer, I have not had this problem however I have wiped rosewwod with naptha and had it come completed thru the rosewood of course this evaporates away quickly and doesn't cause a problem. I think in the future I'd fill the pores before using anything else. It seems that some sets of EIR are more porous than others. |
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| Author: | Rod True [ Mon Jan 23, 2006 4:31 am ] |
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How about spraying the shellac instead of brushing it on. This would alow for a thinner coat. Maybe you've tryed this in the past and don't like this method. |
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| Author: | Steve Kinnaird [ Mon Jan 23, 2006 4:48 am ] |
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I always wonder in a case like this (and something like this has happened to me), how much gravity was aiding and abetting the enemy? For instance, if you had suspended the guitar over your head, and painted this while underneath it, would gravity then have helped--at least a bit--to keep the shellac from running straight downward through those pores? Kept it more on the surface where you wanted it? Don't laugh too hard--I once read how Dana Bourgeois would paint a solid colored guitar, then suspend the painted surface upside down so that dust could not settle on the surface. So my thoughts are merely a dubious extension of that sound principle. You could clamp the guitar to extend out from your bench--lie down on one of those mechanics "crawlers"--roll under the instrument, and paint away like Michelangelo. I'm sorry, I was up way too late last night.... Steve |
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| Author: | Brock Poling [ Mon Jan 23, 2006 7:51 am ] |
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The other option might be to spray the first couple coats of shellac. |
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| Author: | Mario [ Mon Jan 23, 2006 9:14 am ] |
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The other option might be to spray the first couple coats of shellac. May I ask why so much shellac? A simple light wipe or a misting spray, will suffice as a sealer. A few coats aren't needed unless we're trying to build up a layer of shellac to sand down and rub into the pores. Dana Bourgeois would paint a solid colored guitar, then suspend the painted surface upside down so that dust could not settle on the surface. I have my bodies set up so that I can roate them while spraying, and I always leave them with the top facing the floor for that very reason. Dust on a dark back isn't much of a problem, but on a light-colored top, it is terrible. |
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