I started this concrete guitar project almost
a year ago, when I was out in Joshua Tree
for the Makesgiving get together put on by
Ben Uyeda from Homemade Modern.
Unfortunately, I kicked off my trip to California
by crashing hard while riding a OneWheel,
so you’ll have to try and ignore the severe
lack of skin I have in these shots.
Anyway, the first step in building the concrete
guitar was creating a silicone mold for casting
the concrete, and I purchased a cheap guitar
kit to use for creating the mold.
Since the silicone would flow into any of
the holes or cavities in the guitar body,
I needed to seal up any areas I didn’t want
as part of my final casting.
I sealed the tremolo hole with heavy duty
packing tape and then sealed the other holes
with epoxy putty.
That said, if I had to do this again, I would have used the putty for the tremolo hole as well. But we’ll get to that later.
After sealing up the holes, I needed to create
the form for the silicone, and I did this
by adhering the guitar body, backside down,
to a scrap piece of melamine using silicone
caulk.
With the guitar stuck to the melamine, I could
then trace an offset around the body, where
I could use some aluminum flashing as the
walls of the form.
The flashing is too flimsy on its own, so
I used a technique I learned about on the
Smooth-On YouTube channel, and used pieces
of cardboard to reinforce the sides of the
flashing.
I attached the cardboard to the melamine using
hot glue, which was a little tricky as the
hot glue didn’t set up as quick as I needed
it to.
After seeing me struggling with the hot glue,
Ben’s sister Jessi lent me her hair dryer
which I used to help encourage the hot glue
to set up more quickly while adding the flashing,
and this worked great.
I used plenty of hot glue here, as the glue
not only provided the structure for the sides
of the form, but it also acted as the sealant
around the bottom edges of the form, to keep
the silicone from leaking.
Looking back, I should have tried to get the
sides of the form a lot closer to the guitar
body, and I had to use a lot more silicone
to create this mold because of the spacing
I ended up with.
Once the form was created, I could spray it
down with mold release, which would help the
silicone release after casting.
Speaking of silicone, next I could get my
silicone of choice, MoldStar 30 in this case,
mixed up, and I used this entire gallon kit
of silicone for this mold.
This kit cost close to $200, so you can see
why making the form smaller would have been
beneficial for a cost perspective.
Anyway, after mixing, it was time for the
first moment of truth, pouring the silicone
into the form, and there were definitely plenty
of spectators in the house for this.
This was my first time making this kind of
silicone mold but, based on what I’d read,
pouring the silicone in one corner and letting
it slowly fill in all of the voids really
helps to avoid air bubbles in your final mold,
and this seemed to work well for me.
After pouring, I kept an eye on the form,
looking out for any leaks, and luckily there
were only one or two, which I was able to
easily plug with more hot glue.
Once the silicone had a chance to cure, I
could demold it, which was another spectator
activity.
Also, that hot glue was way stronger than
I expected.
Anyway, luckily the mold turned out pretty
much perfect and, needless to say, I was pretty
excited.
The first guitar body I made after creating
the mold was made from TotalBoat’s ThickSet
epoxy, but I’m going to save that for a
future video, so you’ll have to stay tuned
for that.
After demolding the epoxy guitar body, I moved
on to the concrete body.
I started by mixing the concrete in a bucket
but, of course, I added way more than I needed,
so I moved the mix to a plastic mixing tub
so I could add enough water to get the concrete
to the right consistency, which was something
akin to pancake batter.
Next, I could get the concrete added to the
mold, and I did this slowly, making sure to
fill in areas where large voids could create
air pockets.
I scooped the concrete into the mold using
a mixing cup, and this really allowed me to
take my time and add concrete where I needed
it.
After filling the mold, I came back with a
reciprocating saw with no blade installed
and ran it along the outside edge of the mold,
to help vibrate out as many bubbles as I could.
Finally, I screeded the surface of the concrete
with a straight piece of wood, which just
helped to remove any excess concrete and level
out the surface.
After that, I let the concrete cure for a
few days and then I had to fly back home,
and I shipped the concrete guitar body, still
in the mold for added protection, back home
to Asheville as well.
Once the guitar body arrived safely, it was
time to demold it, and the concrete looked
pretty incredible right out of the mold.
As you can see, the concrete was still wet,
so I left it to cure, and I unfortunately
got busy with other projects and let the body
sit for another 10 months.
After taking the body back out after its long
hibernation, it luckily still looked great
and was certainly well cured at this point,
so I could move on with getting the rest of
the guitar finished up, starting with a quick
dry fit of
the parts.
The first thing I wanted to get out of the
way was flattening the area where the tremolo
cavity was located on the original guitar
body, which ended up as a slight hump on this
concrete body.
Fortunately, it was extremely easy to knock
down this area with a diamond sanding block,
and I just sanded the area until it was nice
and flat.
With that done, I moved my attention to the
neck, which came as part of the guitar kit
I had ordered.
I first wanted to shape the headstock which
started as a large rectangular shape, and
this gave me plenty of room for shaping.
I decided to go with a classic design and
just traced the headstock of another Strat
I had, and then I rough cut the shape with
my jigsaw.
I used my oscillating belt sander to clean
up the shape, swapping over to the spindle
attachment to shape the inside corner of the
shape.
If you don’t have a spindle sander, you
could certainly do this shaping with a rasp,
and this is one of the few tools you’d really
need for this project.
After getting as close as I could with the
spindle sander and belt sander, I switched
to hand sanding, and I pulled out these little
Rockler contour sanding grips, which were
perfect for this.
Once the edges were cleaned up and sanded,
I sanded the faces of the headstock and then
I could prep for finishing the neck by taping
off the fretboard.
I decided to try Tru-Oil for the finish on
this neck, which I’ve heard is a great option,
and it turned out really nice.
Tru-Oil is super simple to apply, I just wiped
on a light coat using a shop towel, let it
dry, and then repeated the process a few times,
scuffing up the finish with some synthetic
steel wool between coats.
While the finish cured on the neck, I could
work on getting the various components mounted
to the body, which was a little tricky.
I tested the technique I came up with on the
two mounting screws for the input jack plate,
and this involved first drilling holes with
a masonry bit and my hammer drill and then
using some TotalBoat 5 minute epoxy to glue
the dowels into the holes.
I should mention that this 5 minute epoxy
was the real MVP on this build and I used
it a ton, as you’ll see, and I’ll link
to it in the video description below, as I
was super impressed with how well it worked
and how strong of a bond it created.
After the epoxy had a chance to set up, I
used a self-centering drill bit, also from
Rockler, to pre-drill the holes, and then
I drove in the screws through the jack plate.
This worked like a charm and, as long as I
didn’t drill the holes too large, all of
the extra wooden areas were covered by the
components themselves.
I could repeat the process for the pickguard,
which obviously has quite a few screws, and
I also had less wiggle room since the screw
holes were so close to the edge of the pick
guard.
To help with this, I swapped to a smaller
masonry bit to drill the holes.
Unfortunately, I couldn’t find any dowels
that were small enough for these holes, so
I whipped up a quick dowel plate by drilling
a series of holes in a piece of scrap steel.
After drilling the holes, I rounded off the
end of the dowel with my belt grinder, cut
off a length with my flush trim saw, and then
pounded the dowel through the hole, which
scrapes off any wood larger than the hole
opening.
As you can see, this worked extremely well
and I ended up with a dowel that was perfectly
sized for the holes in the body.
I continued creating more dowels using this
method, but I did figure out that I needed
to add a few more holes to the dowel plate
so I could ease the dowel down to its final
size, which helped keep it from breaking while
I was driving it through the dowel plate.
After creating the dowels I needed for the
pickguard holes, I repeated the process of
gluing them into place with the TotalBoat
5 minute epoxy, and then, after the epoxy
cured, I trimmed the dowels flush with my
flush trim saw, adding a piece of painter’s
tape to help keep the teeth of the saw from
scratching the concrete.
Next, I needed to locate the hardtail bridge,
which I chose to replace the tremolo bridge
that came with this kit.
To help add more strength, I bumped back up
to the larger masonry bit for these holes
so I could add a larger dowel, and made sure
to drill the holes deep enough so the screws
could be driven to full depth.
I created more dowels using my homemade dowel
plate and then epoxied them in place with
more 5 minute epoxy.
The last two mounting locations on the body
were for the strap buttons, and I repeated
the same process to add dowels to those locations,
again using the larger drill bit since these
strap buttons would be supporting the pretty
sizable weight of this boat anchor of a guitar.
The last hole to drill in the body was a simple
through hole between the electronics cavity
and the cavity for the input jack, and this
didn’t need to be very precise, it just
allows the wires to run to the jack.
With all of the mounting locations dealt with,
I could start on finish prep on the body,
starting by cleaning up the front of the guitar
with a diamond sanding block.
My main goal here was to blend in the area
where that piece of tape had left a seam near
the bridge, and I ended up having to sand
the entire face of the guitar to get this
to match.
After sanding the front, it was time for the
moment I had honestly been dreading, cleaning
up the back face of this guitar.
To clean up this ridge, I used a diamond cup
wheel on my angle grinder and I was expecting
this process to take forever but, much to
my surprise, this wheel cut through this concrete
like butter and I was able to feather in that
edge between the back and edges of the guitar
fairly easily.
The inside edges of the horns were definitely
a little tricky and I didn’t get these as
clean as I wanted, but I was able to really
blend those areas with that diamond sanding
block.
All in all, this whole process took less than
10 minutes start to finish, and then I could
go home and take a much needed shower to clean
off all of that concrete dust.
The next morning, I could work on getting
the concrete sealed, which will help it resist
staining but will also give it a more even
color and sheen.
I used this Cheng countertop sealer and starting
by wetting the entire body with water, so
the sealer wouldn’t be absorbed too quickly.
Next, I diluted the sealer with water and
then soaked the surface of the body with it,
keeping it wet for roughly 5 minutes.
As you can see, this process is a huge mess
and I’d definitely recommend doing this
outside if at all possible.
After soaking the surface with the sealer,
I wiped off the excess and let the sealer
dry for about 20 minutes before repeating
the process.
In total, I applied four coats of sealer,
and I let the body dry for 24 hours after
the last coat.
As a final layer of protection, I added a
coat of countertop wax to the guitar, which
I just wiped on with a damp paper towel and
then buffed off.
I did make sure to avoid getting wax into
the neck pocket, as I’d be gluing the neck
in place with epoxy.
Speaking of which, now that the neck and body
were finished, I could get the neck glued
into the neck pocket.
I started by scuffing up the heel of the neck,
where it would come into contact with the
epoxy, to help with adhesion and to remove
the Tru-Oil from that area.
To glue the neck to the body, I once again
called on the TotalBoat 5 minute epoxy.
I then slid the neck into the pocket, cleaned
up some of the squeeze out, and then clamped
the neck in place while the epoxy cured.
I did make sure the neck was coming off of
the body nice and straight, which it was,
and then I could let the epoxy cure for a
few hours.
After the epoxy cured, I could start to get
the guitar put back together, starting by
adding the bridge.
I had waited until the neck was glued in place
to do this, as I still had a little wiggle
room due to the size of the dowels I used.
Once I located the bridge, I started the holes
with the self-centering drill bit and then
drilled the holes to full depth with a longer
bit.
Before mounting the bridge, I added a little
paste wax to the screws and went ahead and
ran them in and out of the holes, to essentially
pre-cut threads into the holes.
Finally, I mounted the bridge, which looked
pretty much spot on thankfully.
While I had some much nicer tuners and electronics
on order, I couldn’t help myself and decided
to get the guitar partially strung up to make
sure the neck and bridge had ended up in the
right place, so I installed the crappy kit
tuners and strings, consequently breaking
two of the strings in the process, but I could
still try out the guitar and was super impressed
with how it was playing even with no setup
work.
Next, I got the strap buttons installed, and
I made sure to use locking buttons here so
I don’t have to worry about my strap losing
its hold on this guitar.
I 
did go ahead and weigh the guitar and even
before I installed the electronics, it clocked
in at over 19 pounds.
Speaking of which, next I could work on getting
the electronics dialed in and I decided to
go all out on this project and upgraded to
this awesome loaded pickguard setup from Mad
Hatter Guitar Products.
Ed over at Mad Hatter makes a really cool
system of pots and switches he’s dubbed
the “Terminator", and the system is totally
solderless, making assembly super simple.
Before getting the Terminator system installed,
I needed to drill one more hole for running
a ground wire to the bridge, and then I also
added copper shielding tape inside of the
cavities, which helps reduce interference
in the electronics.
With that done, I could get the pickguard
and electronics installed.
I started by loosening the two set screws
holding the two wires coming from the input
jack, and then I fed those wires through the
hole between the input jack and control cavities.
After that, I just put the wires right back
where I had just removed them, tightened down
the set screws, added the ground wire from
the bridge to another location with another
set screw, and the wiring was done.
No soldering, no mess, and it’ll be super
easy to adjust things later if needed.
Unfortunately, I ran into a little bit of
an issue fitting the electronics into the
control cavity, probably because the guitar
kit I used doesn’t match Fender specs, but
after a little tweaking, I got the pickguard
installed, and then I was in the home stretch.
Next, I oiled up the fretboard and got the
strings installed, realizing I hadn’t installed
the string trees yet.
As with the other hardware that came with
this kit, these string trees were garbage
and I ended up replacing them after this.
Finally, all that was left was a little setup
work, and with that, it was time for the moment
I’d been waiting for for close to a year
now, trying the concrete guitar out for the
first time.
I know a lot of you are probably asking how
a guitar made of concrete sounds vs. a guitar
made of wood and, honestly, I don’t think
it sounds any different.
I’m in the camp of people that think tone
wood doesn’t really make any difference
in electric guitars, it’s all about the
pickups, amp and the player.
I’ll have a longer sound demo video on my
second channel if you want a more in-depth
look at how this guitar sounds.
Hopefully you guys enjoyed this video, I had
a ton of fun building this project.
If it’s your first time here, go ahead and
get subscribed and ring that little notification
bell so you don’t miss my future videos.
Also, I’ll have links to all of the tools
and materials I used in the video description
below.
Last, while you’re here, why not check out
another video of mine that YouTube thinks
you’ll enjoy.
Alright, thanks for watching everybody and,
until next time, happy building.
