Too True, or not to Tru?

[stubhead]

I am ALL READY - the walnut bod is all drilled for controls, wiring, the threaded inserts for the back plate are in, the threaded inserts for the front pickup mounting cover are in; the threaded inserts for the bridge(s) are in, one bridge is a Schaller string-through, the other is a topmount Schaller 475, because you can run the strings out the back, into the Hipshot Trilogy - who's threaded inserts are also in.... all sanded to 220-smooth.

Hoo-ray?  :hello2: HELL no, because -

The gol dang-nabbit humidity is hitting 55 and 60 at it's absolute driest, afternoons, and it's blowing up every night to at least 95%! I live on the inside edge of the Chesapeake Bay on that gob of land that's hanging off northern Maryland/Delaware, in an area often referred to as "Satan's armpit" (referred to by me, at least, as often as I can). Dorchester County is the largest so-called land mass county in Maryland, "so-called" because half the "land" is under a greasy friggin' swamp. Those clever people who think about stuff like this call it "Wetlands", indeed I'm only a few miles north of the largest "wetlands" wildlife preserve outside of Louisiana.

"Wetlands" = clever, because it's really just a big ol' SWAMP, and somehow "Preserve the Wetlands" sucks out more grant money & goony tree-huggery than "Save the Endangered Swamp Mosquito!" Of which we have, ahem, plenty, thank you. Where's Joni Mitchell and that paving machine just when you need 'em :icon_scratch:

It doesn't even have to be a good Tru-Oil finish, this is the hardest slab of walnut I've even seen and I just want to thin the Tru-Oil way down with naptha or mineral spirits (whichever tastes the worst, I guess) and hit it five or so thin coats just to suck up.... then maintain it down the road with wax and orange oil, whatever's lying around. As far as "protection" the world has far more to fear from this old chunk of walnut than the walnut has to fear from the world, I tried to use a wood rasp on it and it just bounced off... and laughed at me, Go, Woody Go! Mike Curd is a guy who has cut quite a few bods for the Texas-based luthier crowd (when they say "hand-crafted" it don't necessarily mean their own hands :laughing3. And he's working his way through some old-growth Appalachian walnut - it's harder than hard rock maple, but also a bit lighter?  :icon_scratch: Dunno how that works, but my spider sense is really a-tingling over this one. My waterlogged spidy-sense. I may get a tiny WOOP* around Friday, Saturday...

Glub, glub, glub. :sad1:


*(Window Of OpPortunity)

 

[Cagey]

55%-60% humidity? What a luxury! My L5S is languishing for the same reason, only the numbers have been worse and I don't even live near a swamp. Of course, I've got the Great Lakes to think about, but still. It's been a surprisingly humid year so far.

Something you might consider is going to a water-based filler to get the wood to finish-ready. It's a low-VOC solution that allows you to bring the body indoors where the AC is sucking the moisture out of the air. Then at least you have half a chance of it curing and you don't have to worry about making the house smell like a 3M plant or the Love Canal.

Once the surface is perfect, you need very little finish as you're not relying on repeated sand/fill iterations to level things out to where they're polishable and pretty. At that point, you can pick a target of opportunity. One fine day, you do as much as you can, which may be all of it.

 

[alterbridgefan]

Get that sucker done...

There's a package coming your way. :glasses10:

Insert pics of 007 looking cheesy. Or Michael Buble, doesn't really matter.

:blob7:

 

[Johnfv]

I've spent a lot of time in the Chesapeake area so familiar with that humidity. I live in Austin TX and it's plenty HOT and humid here. I'm no expert but I've done hand rubbed finishes on several necks (only one body) with Formby's "Tung Oil". I always did it inside with air conditioning (in a spare bedroom), I found the fumes to be minimal. YMMV...

 

[Day-mun]

I was thinking of getting a dehumidifier for the garage for this reason (-and to dry out the basement so laundry area doesn't start getting musty, of course... -at least that is how I would pass the expense report to "the commitee".), -would something like that help? Not sure where everyone's pieces are hanging up to dry...

 

[Cagey]

Dehumidifiers are almost as expensive to run as A/C units, since they're similar in design. The only real difference is A/C units vent the waste heat, while dehumidifiers don't.

I suspect trying to dry out a garage would present the same problems heating or cooling one would. They're often pretty porous structures with little or no insulation. Then, you've got this huge bay door that when opened essentially blows away everything you've done to the interior atmosphere in no time flat. Imagine knocking out a wall in your living room. How long would it take to lose all the warm or cool air you paid so much to get? 30 seconds? It's like shooting a 12ga in an aircraft at 30,000 feet. It vents pretty quickly.

But, as long as you know those things on the going-in side, you can mitigate them. Insulate the garage and put up drywall to close things off. Better window(s), insulated bay door with good weather stripping, etc.

Of course, then you're left with ventilating the thing if you're going to spray paint in there. Make no mistake - ventilation is crucially important. It can't be just any old ventilation equipment, either. If you're shooting lacquer, you're going to put a lot of acetone in the air, which isn't just flammable, it's combustible. Without explosion-proof ventilation, you can be whistling a merry tune while shooting some candy apple red on your latest fiddle when suddenly the house/garage looks like something Micheal Bay would be proud of.

Good thing I was wearing my safety glasses...​

All that said, if you live in an area that's constantly humid, you don't have a lotta choice unless you want to send things off to get finished. But, considering the amount of work finishing can be if you want something fine, that's often the better choice unless you have an artistic bent that won't be satisfied any other way, or you don't mind working for $2/hr.

As for why everybody's hanging pieces up to dry, they're not. Most finishes "dry" pretty quickly. Lacquer, for instance, is touchable within minutes. They're hanging them up to cure, which takes time. Molecules are doing things, and they need their privacy.

 

[Day-mun]

Dry. Cure. -Need we mince words?

Here I thought the problem was molecules don't like "doing things" when they're wet. That would be water-wet from the humidity in the air, -just to clarify for you sticklers out there that may think I'm confused about the finish still being partially in solution with their respective solvent carriers before those said carriers can evaporate.

I work in the chemical industry, and use XP (eXplosion Proof) everything; ventilation equipment, mixers, hell even the cell phone I use for work is XP (and about as big is as a paving stone form home depot). So because of that training and background, of course I wouldn't think of generating combustable fuel/air mixtures in the proximity of any open electrical circuits, or spark-producing tools/equipment. But glad that these safety concerns got brought up for those who may not be so savvy.

but what about for the curing (and not drying, since this technically only takes seconds) stage? I thought this was the part of the process that was so sensitive to humidity. I guess this is my real question, and the one I should have asked the first time.

 

[Cagey]

Within realistic numbers, which is to say what humans will tolerate over time, most finishes are not really sensitive to humidity outside of dewpoint at spray time. I mean, it matters, but it doesn't hurt anything. It just changes the cure time. But, if the humidity is too high to spray in the first place, you may never get to the cure stage.

When I say "dewpoint at spraytime" I mean where things are immediately after the paint leaves the gun. The pressure shift there changes things dramatically from where they are in the surrounding area. It can cause moisture to precipitate in the spraystream and get embedded in the finish. This shows up in lacquer as a milky "blush", and will cause you to spontaneously invent new cuss words.

You can mitigate that somewhat by using an HVLP sprayer, as the pressure differential is not very big. They typically run about 4 psi above ambient, while a standard atmosphere at sea level is about 14 psi. On more traditional spray rigs, you often ran 35-40 psi. Big shift there, coming out of the gun. Rainclouds form in your spray stream.

But, even at 4 psi, you can still get blush if it's too humid. I had it happen yesterday, and the humidity was only 52% at 78 degrees. Luckily, I was able to clear it or I might have done something I'd later regret.

 

[stubhead]

I thinned out the Tru-oil 50/50 with naptha and got five very thin coats on in five slightly-dry hours Sat. no blush.... I almost avoided it entirely, once it stops stinking I'm gonna matte it out with 000 plastic steel wool and from then on, just beeswax & orange oil for maintenance. This particular piece of walnut is in no danger of oversensitivity giving it the vapors, this is the kind of stuff they used to build clubs to kill dinosaurs with. You can just wax, oil & (if wanted) turpentine wood, they did it for several centuries before anyone discovered that spraying delicate "nitro" over ACRYLIC CAR PAINT made you feel good about yourself.... but there are those who say that the raw oil that sinks in never really cures, and of course once that's in your head, it'll worm into your ears, and forever.... :icon_scratch:

 

[Day-mun]

So longer cure times are no big deal, aside from chewing my own nails off even shorter in anticipation of getting to play with the new toys. I get it now; the rapid depressurization occurring at the nozzle of the sprayer lowers the temperature and causes condensation... in the stream of whatever is being sprayed. Yeah. That would be bad.

Thanks for clearing that up for me, -here I thought the humidity made it suck after-the-fact, but now I get how it screws up the finish before it even gets on the piece.

 

[Cagey]

Well, there's a little more to it. You get moisture in the paint, but the deviltry takes place when the lacquer skins over on the surface and won't let things evaporate. That happens real fast with lacquer, which is why you sometimes need to use "retarder", which is a mixture of solvents that don't evaporate as quickly as acetone. Slows down the vehicle evap and lets it breathe for a few minutes. It's especially important when the temperature is higher. The boiling point of acetone is only like 135°F, so at higher temperatures lacquer is almost drying before it hits the part.

 

[ale_alle]

I am in the process of building my first strat and decided to go with tru oil for my finish.  Learned a lot!

1. Steel wool can be oily and leave behind tiny hairs of steel that would rust and ruin the finish.. I've been using a scour pad in between coats instead.
2. Most old t-shirts or lint free rags STILL have lint in them.  I finally switched to coffee filters.  Folded edges make for less streaks when applying.
3. Let the Tru-Oil dry completely before trying to scour or wetsand.  I've been using Boiled linseed oil to wetsand, wiping the excess off completely for a smooth surface before any more coats.

I've lost track of how many super thin coats I've applied.  Apparently, this causes more of the 3D or moving of the grain effect because every layer refracts the light uniquely due to the streaks that are left behind in each coat.  I don't know how to polish it so that it will have no streaks but I'm sure I'll read about a way in one of these forums.

 

[Cagey]

Wow! That looks really nice! Don't often see Tru-oil over colors. Usually, people use it for natural finishes.

The coffee filter trick is a good one. Back when Intel and AMD were making stoves instead of CPUs, I used to buy these huge Zalman copper heatsinks and polish the base to a mirror finish to make better contact with the processor die. Helped heat transfer tremendously. Anyway, I used coffee filters for cleanup on those to keep from getting any lint on the surface. It was amazing how much impact even a tiny flaw in the mating surfaces would have on the temperature.

 

[dmraco]

I am in the process of building my first strat and decided to go with tru oil for my finish.  Learned a lot!

1. Steel wool can be oily and leave behind tiny hairs of steel that would rust and ruin the finish.. I've been using a scour pad in between coats instead.
2. Most old t-shirts or lint free rags STILL have lint in them.  I finally switched to coffee filters.  Folded edges make for less streaks when applying.
3. Let the Tru-Oil dry completely before trying to scour or wetsand.  I've been using Boiled linseed oil to wetsand, wiping the excess off completely for a smooth surface before any more coats.

I've lost track of how many super thin coats I've applied.  Apparently, this causes more of the 3D or moving of the grain effect because every layer refracts the light uniquely due to the streaks that are left behind in each coat.  I don't know how to polish it so that it will have no streaks but I'm sure I'll read about a way in one of these forums.

dude...did you hand apply that color?  Nice job.

 

[dmraco]

I am in the process of building my first strat and decided to go with tru oil for my finish.  Learned a lot!

1. Steel wool can be oily and leave behind tiny hairs of steel that would rust and ruin the finish.. I've been using a scour pad in between coats instead.
2. Most old t-shirts or lint free rags STILL have lint in them.  I finally switched to coffee filters.  Folded edges make for less streaks when applying.
3. Let the Tru-Oil dry completely before trying to scour or wetsand.  I've been using Boiled linseed oil to wetsand, wiping the excess off completely for a smooth surface before any more coats.

I've lost track of how many super thin coats I've applied.  Apparently, this causes more of the 3D or moving of the grain effect because every layer refracts the light uniquely due to the streaks that are left behind in each coat.  I don't know how to polish it so that it will have no streaks but I'm sure I'll read about a way in one of these forums.