I wouldn't know a Erlmeyer flask from a Van de Graaff Generator. But a picture is worth a thousand words!
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| Author: | Brock Poling [ Tue Nov 13, 2007 9:32 am ] |
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I thought I would share this since it worked out so well. I mix a fair amount of shellac and mainly use it to seal parts during my building process -- the top when I inlay the rosette and before I bind (cuts down on the little fuzzies) and I seal the outsides of my sides before I laminate them (retards epoxy coming through the short grain on highly figured sets) Anyway... I would mix this up in left over jars and I always had a big clump of flakes at the bottom, even after a few days of waiting and shaking and occassionally stirring. I would just filter this mess out and all was fine. But, I bought one of those small magnetic stirrers from a lab supply house and a couple 1L erlenmeyer flasks. I then mixed up a batch, shined 2 halogen lights on the mix (from about 30" away) and within 1 hour the flakes were completely 100% dissolved and ready to strain. I just thought I would pass that on for those who mix their own shellac... It didn't even leave a residue in the flask. |
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| Author: | Don Williams [ Tue Nov 13, 2007 10:36 am ] |
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I wouldn't know a Erlmeyer flask from a Van de Graaff Generator. But a picture is worth a thousand words!
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| Author: | burbank [ Tue Nov 13, 2007 10:47 am ] |
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[QUOTE=Brock Poling] <snip>... always had a big clump of flakes at the bottom, even after a few days of waiting and shaking and occassionally stirring. I would just filter this mess out and all was fine.[/QUOTE] I had this problem with two batches of Hock flakes from WoodCraft. Dumped it and got some from LMI. The LMI stuff dissolved completely overnight, not a trace of residue. Old Hock flakes? I dunno. Another thing that helps is grinding flakes in a coffee grinder, as long as it's real clean inside. |
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| Author: | PaulB [ Tue Nov 13, 2007 10:47 am ] |
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Brock I do the same thing. Luckily, I work in a lab so I don't have to buy this stuff. We have a magnetic stirrer with a heating element built in, they are a little more expensive but worth the money. We also have a large oven - great for baking tops. I get my wood sent to work, bake it, then take it home. |
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| Author: | bob J [ Tue Nov 13, 2007 10:57 am ] |
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How many tops do t=you bake at at time; 1hr. 200 degrees? |
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| Author: | GregH [ Tue Nov 13, 2007 11:18 am ] |
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Erlenmeyer Flask  |
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| Author: | PaulB [ Tue Nov 13, 2007 11:42 am ] |
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Bob, I think the most I baked at one time was 5, 'cause that's the most I've bought at one time. |
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| Author: | Dave Bamber [ Tue Nov 13, 2007 5:33 pm ] |
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Pardon my newbie ignorance, but why do you 'bake' you tops? I'm assuming you're not talking about drying them... |
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| Author: | Rick Turner [ Tue Nov 13, 2007 6:25 pm ] |
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It's generally thought to drive off VOCs and "set" the resins. |
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| Author: | stan thomison [ Wed Nov 14, 2007 5:48 am ] |
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Dave yes some or maybe even most will put tops and backs into a kiln with low heat for an hour or so for drying them. I was told in school this made sure dry and eliminated movement in the wood. I did it and didn't see any difference or movement, so figured Bryan gave me a good sets of really dry wood. Make a mark of few thou on wood and measure before and after "baking" and may see it moved some. Don't have to do sides as get them pretty hot anyway in the bender. Some put in house oven,some make a small enclouser with a space heater (what we had at school). |
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| Author: | Brock Poling [ Wed Nov 14, 2007 9:51 am ] |
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If you bake a well quartered top it will shrink in all directions, after it cools and becomes reaclimated it never recovers fully to its original size. The idea that this "pre shrinking" prevents some of the cracks that occur from guitars that are too dried out. IIRC I saw Bob Taylor go on and on about this in a video clip, but I can't seem to locate it. |
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| Author: | FishtownMike [ Wed Nov 14, 2007 11:53 am ] |
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I always thought undisolved shelac flakes was a sign of old flakes. |
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| Author: | Brock Poling [ Wed Nov 14, 2007 2:27 pm ] |
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Yeah, I heard that too, but I tried new flakes and ran into the same issues. Changed the alcohol... no dice. I put it in the mag stirrer and they all dissolved very fast. I just figured I couldn't be the only person experiencing this. |
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| Author: | Kahle [ Wed Nov 14, 2007 4:38 pm ] |
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I lost all my flasks when they raided my meth lab 
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| Author: | TRein [ Fri Nov 16, 2007 1:36 am ] |
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If all you are doing is sealing with shellac, I can recommend SealCoat as a very convenient alternative. I made a test on half of a rejected soundboard with SealCoat and the other half with blonde flakes dissolved in ethyl alcohol. There was no difference in sandability after initial sealing. I then French polished each half with the respective shellac. Again, no difference in application, hardness, ease of polishing. After the sample had cured for a week, I heated up a damp rag in the microwave to about 90-100 degrees and laid it across both halves. Neither side imprinted. I bought a quart of SealCoat at Lowe's for about $9. For all intents and purposes, SealCoat can be considered a drop in replacement for blonde shellac. |
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| Author: | JJ Donohue [ Fri Nov 16, 2007 1:57 am ] |
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Ditto on the Zinnser Bullseye De-waxed Seal Coat. I've FP'd 4 guitars so far with this material and I'm now totally flake-free...except for befriending a few of our fellow members!
BTW...our resident experts (Michael P. & Colin) on FP issues use this product (or UK equivalent) as well and have reported similar results. Nonetheless...those magnetic stirrers are the most convenient and effective mixers you can use for relatively low viscosity liquids. |
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| Author: | Barry Daniels [ Fri Nov 16, 2007 2:09 am ] |
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I am getting ready to do my first FP on a top. I normally use the clear pickguard material that is applied with water to prevent air bubbles. Do you FP guys think this would cause blushing problems on a fresh FP surface? |
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| Author: | JJ Donohue [ Fri Nov 16, 2007 2:42 am ] |
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Barry...My uninformed and untested reaction would say "yes" if applied over a fresh surface. I would err on the side of caution and wait as long as possible before applying the PG...2 weeks minimum. Since I don't use pickguards, I'd wait for others to chime in. Also...this should be easy enough to test on scrap. Then again...the nice thing about FP'd shellac is that if it does discolor, you can always repair it so easily. |
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