First Build, so many lessons learned

[beltjones]

24 minutes ago, Prostheta said:

 

They're being very emphatic with that response, and it involves a LOT (hah) of distinct claims which might not stand up for many reasons. Even pure copper tape over 30 yards will show a lot of voltage drop/resistance, so how they claim this stuff is better than that is puzzling.

Perhaps you should ask them if anybody in fact HAS (hah, more caps) painted two thirty-yard lines and tried to light a bulb. I would say that this is unlikely.

Additionally, re-read the last bit in the voice of Trump. It possesses many of the 3rd grade aspects of one of his tweets. 

That last sentence about trump is exactly what I thought when I read the email. 

My in-laws are in town, coincidentally, and they're both retired electrical engineers. I showed them the bottle of shielding paint which specifies 105 ohms of resistivity per square inch. They were both confused by the specs. I'm going to go try to find a light bulb with two posts and a nine volt battery and do a science experiement with my f-i-l.

[Prostheta]

I'm unsure as to how one might come up with that value. Is it a square of paint measured edge to edge for resistivity, or corner to corner? Also, what is the film weight? No doubt they're confusing, since they make little sense.

[ScottR]

30 minutes ago, Prostheta said:

No doubt they're confusing, since they make little sense.

You need to make a plaque that says that...maybe print it on a t-shirt.

SR

[CDH]

On 4/15/2018 at 7:50 PM, beltjones said:

 

The shielding paint looks good to me, but I can't get a read with my multimeter on it at all. I used www.guitarfetish.com's shielding paint, and it specifies 105 ohms per square inch of resistivity (not sure how that differs from resistance), but if I set my multimeter to 200 ohms it doesn't show a resistance reading at all. Anyone know about this stuff?

 

I'm trying a similar paint I bought from Stewmac. Set your meter to check continuity and touch your probs together. They should read zero. Now touch both probs to the paint in the cavity. If it's conductive you will get some kind of a reading.

By the way, love the work you're doing on this build!

[beltjones]

44 minutes ago, CDH said:

I'm trying a similar paint I bought from Stewmac. Set your meter to check continuity and touch your probs together. They should read zero. Now touch both probs to the paint in the cavity. If it's conductive you will get some kind of a reading.

By the way, love the work you're doing on this build!

Right, I'm getting nothing. 

I emailed guitarfetish.com again asking about how thick the liquid is supposed to be. Mine is super thin - I think maybe they didn't homogenize before aliquoting into the little bottles.

Edited April 17, 2018 by beltjones

[curtisa]

It's a shame Guitar Fetish gave you that response. Unfortunately it makes them look like they don't understand the product they've sold you. If you can get current to flow from a 9V battery to a lamp via their shielding paint, of course you're going to measure resistance with your multimeter. The meter works on the same principle - apply a small voltage between the two probes, measure the current flowing between the two and do the math to display resistance.

 

12 hours ago, Prostheta said:

I'm unsure as to how one might come up with that value. Is it a square of paint measured edge to edge for resistivity, or corner to corner?

It's probably the resistance measured from one edge of a painted 1" square to another. From any opposite edge (or opposite corner) it should behave like an infinite number of resistors in parallel within the boundaries of the 1" square. The thickness of the film may have an impact. It's possible that the most conductive bit is just below the surface of the dried paint too, so pressing your probes hard into the paint to break through the surface may yield better measurements.

The label on the tin of the Stewmac equivalent paint suggests applying a minimum of four coats.

[Norris]

Going back to my school physics lessons, the thicker the paint the less resistance. As @curtisa says it's like lots of parallel resistors, and this applies in all 3 dimensions. However if there's no graphite in your substrate it's not going to conduct much electricity.

You could maybe try applying a couple of blobs of paint on your test piece and measure the resistance while it's still wet

[beltjones]

I made cavity covers out of some left over black limba.

[Stu.]

On 16/04/2018 at 6:53 PM, Prostheta said:

 

I wouldn't use either. Mostly because those bits grind rather than cut/slice, but also because they move waste from the centre outwards which produces a ragged edge. Forstner bits or lip n' spur. Nothing else.

My bad!

Feel free to ignore my previous post. I'll give a sharp 10mm forstner a try next time.

[beltjones]

I've asked guitarfetish twice how thick this shielding paint is supposed to be, and they emailed a response that didn't address that question at all. They did offer to send me another bottle, but I'm reminded of the time I was in high school driving around with my buddy, Mike. We stopped at a convenience store to grab a snack, and Mike bought some beef jerky. We got back on the road and he ate a piece, and it turned out to be pup-peroni, a jerky treat for dogs. He turned around and went back to the store to ask for his money back, but they refused, and instead gave him more pup-peroni sticks, which he ate (and it made him sick). The moral of the story is that more of bad thing is not as good as cutting your losses and trying something else. 

Edited April 18, 2018 by beltjones

[Prostheta]

Wow, that's a pretty bad warning sign. I gather that a lot of people buy from them as well.

[beltjones]

This is how the paint is described on their website: "DO NOT CONFUSE this with the lame watered down stuff they sell elsewhere- This is the best.

I package a 1 ounce bottle with a nice stiff brush. This is water soluble so cleanup is a snap! This stuff is so thick and adheres so well I think you'll be able to do 4,5 or even 6 guitars with one bottle!"

So I asked how thick it's supposed to be, which should be an easy question to answer. Something like, "About the same as latex house paint," or, "Like maple syrup," or "Fluid, but dense, like Mercury," or any kind of description or comparison, really.

This is what I got back: "In answer to your question, its fluid, its not especially thick or thin in nature. Again I am not sure what your issue might be. As I stated before we sell a ton of this stuff and have very few complaints whatsover."

I guess I should read the rules here as they relate to talking about bad suppliers, but I figured someone else might save themselves from the same mistake I made.

[curtisa]

Make a couple of tests on some scrap. Paint a few coats and see if you can get it to measure anything. If you have a factory-made guitar that has the conductive paint applied in the cavity, use your multimeter to see if it shows up as conductive.

The only things I can think of is user error with the multimeter, a faulty multimeter or the paint is bad.

[Prostheta]

It sounds like their bullshit is also fairly fluid, requiring several layers. 

[beltjones]

Ok, I took off the masking tape because it's about time to finish sand and apply the oil finish to this thing, but first I'm going to string it up and test it out before I go through all that. I figure it would be a real bummer to spend ~25 hours applying finish, sanding it back, and repeating only to find out that I have to plug and redrill the bridge and ruin the finish, ya dig? In the meantime I snapped a picture.

I also wiped it down with some mineral spirits to remove some adhesive left behind by the cheapo masking tape, which is why parts look wet and other parts look dry.

[Prostheta]

It certainly sounds like the right time to be doing that, yes!

[beltjones]

I strung it up just to see if it played reasonably well, and even without a proper setup it played well. The action was too high at the nut and I need to radius the bridge, and with the strings on suddenly the neck felt huge, like a baseball bat, but otherwise we're in good shape. 

Edited April 20, 2018 by beltjones

[Andyjr1515]

3 hours ago, beltjones said:

I strung it up just to see if it played reasonably well, and even without a proper setup it played well. The action was too high at the nut and I need to radius the bridge, and with the strings on suddenly the neck felt huge, like a baseball bat, but otherwise we're in good shape. 

That is so good by any standards. For a first build it's simply off the scale!

Your comment about the feel of the neck rings true. It's why I personally do the final shaping actually strung up like this. After getting the neck profile broadly right with my templates, I string it up and sit the guitar on the floor between my knees like a back-to-front cello. I then draw a scraper up from heel to nut, taking the excessive curve away, being careful not to touch the fretboard edge or neck spine.  At frequent intervals, I pick the guitar up over my knee and play it.  For me, it's the only way I can really tell.

I'm not at all sure if any other builders do this, but it works for me

 

[Prostheta]

Shaping a neck can be a real back-and-forth job unless you're aiming for a specific profile and have good templates to work from. Oftentimes, string feel from a high action in test fit can exaggerate the size of the profile, so it might be wise to give it a second test feel with a capo on first and the saddles adjusted to simulate a realistic action to get a new bead on it.

[ShatnersBassoon]

On 4/19/2018 at 8:02 PM, beltjones said:

Ok, I took off the masking tape because it's about time to finish sand and apply the oil finish to this thing, but first I'm going to string it up and test it out before I go through all that. I figure it would be a real bummer to spend ~25 hours applying finish, sanding it back, and repeating only to find out that I have to plug and redrill the bridge and ruin the finish, ya dig? In the meantime I snapped a picture.

I also wiped it down with some mineral spirits to remove some adhesive left behind by the cheapo masking tape, which is why parts look wet and other parts look dry.

I really love the look of this Wenge stuff (especially as a fretboard material) I don’t remember seeing it in guitars throughout the last 20 years...maybe it’s because I was never involved in building. I take it that it’s a lot more popular these days? Amazing looking build by the way!!

Edited April 26, 2018 by ShatnersBassoon

[mistermikev]

jeez this forum... I've got the but and based on all the cool guitars I see I'm going to have about 900 guitars if I build all the ones in my head now...

very cool.  now I need one with wenge.  Looks sort of like the neal schon model as I remember it.

what you did with the dots - so simple, but the effect is really classy.  very creative.  love it.

[beltjones]

I was out of town for a few days, and at this point all of the progress is small stuff that you wouldn't necessarily notice in a photo, like sanding. I did re-bleach the top after finish sanding to 400 grit paper, and next it's time to start applying the final finish. I also made a little cover for the truss rod access hole with some curly maple off-cut I had lying around. I'm going to dye and sand it back a couple of times to hopefully pop the grain a little bit.

[beltjones]

I applied the first coat of tru-oil yesterday afternoon. My plan is to only do one sort of "matte" coat on the fretboard and neck, and to do multiple coats with an attempt at grainfilling on the body. Later I'll level and polish the body and see how it looks. I'm not sure how many coats I'll do, but the number will be somewhere south of ScottR's 30 on his stripy doublecut. I don't think I have that much patience, skill, or tru-oil. 

The oil on the fretboard really made the padauk come to life with some really amazing, almost iridescent, lines and stripes. 

 

Edited April 29, 2018 by beltjones

[Prostheta]

A lot of woods gain a sense of depth when you've prepared them nicely. Quartersawn white Oak, Zebrano and others get rays and flecks that seem translucent and move in the light. Wood is awesome.

[beltjones]

I've been putting on a coat of tru-oil pretty much every day for the last week and a half, minus a few days when I have been traveling. It's starting to look good.



Also, this happened. 


The one on the right is four-piece book-matched Bubinga, and the one on the left is quartersawn purpleheart, tigrillo, and wenge.