FrankenHead and FrankenCabinet build

[Paul P]

I hate finger joints. They're about the only joint where you can't apply
clamping pressure inline with the glue joint so you have to resort to strap
clamps and cauls to keep the straps away from the joints. There's just so
much glueing surface that you have to apply copious amounts of glue so it
doesn't dry out on you, which then drips everywhere, especially where you
don't want it. Definitely not for the weak of heart.

The box wasn't quite square at first, nothing a few whacks with a sledge
hammer couldn't fix...

Other than that, things are coming along nicely.

Paul P

[black_labb]

looking good.

[Paul P]

I glued up the cabinet which went quite well after practicing on the first box :

While that was drying I rough sanded and rounded over the edges of the
head :

Here's a close-up of a finger joint. To be honest they don't look this nice
everywhere but then, as the saying goes, a good craftsman is not one who
can do a perfect job but one who's good at fixing his mistakes... I repeat
this to myself everytime I do something stupid.

Paul P

[tubeswell]

Here's a close-up of a finger joint. To be honest they don't look this nice
everywhere but then, as the saying goes, a good craftsman is not one who
can do a perfect job but one who's good at fixing his mistakes... I repeat
this to myself everytime I do something stupid.Paul P

Hi Paul P, I have the same confession about using my new router, (its really easy to make tiny little slips when you get tired) so this time I'm going to cover the whole (5G9) box with tweed fabric again.

[Paul P]

I'm drowning in details... Besides the two boxes there are a bunch of small
pieces that go inside that have to be made. These are for the head, and
don't include the decorative faces :

I plan on using a piece of 1/8" plexiglass to cover the front and rear
panels which will be inset in rebates (rabbets) cut in the 1" square strips :

Starting to look like some sort of an amp :

The tape is holding on a patch to repair a chip that popped out while
rounding over the edges.

Now to do the same for the speaker cabinet.

Paul P

[trevorus]

What is the circuit you're using? knobs a'plenty

[Paul P]

What is the circuit you're using? knobs a'plenty

That's a long story .

Here's the front panel with labels :

I originally planned to have reverb and tremolo on channel 2, so the panel
reflects this, but I've since put the reverb on channel 1. The range rotary
switches for the tremolo were so I could use quality pots which I could only
find in 1M and lower values.

As I mentioned somewhere else I plan to print out the panel on paper, glue
that to a piece of formica/arborite (countertop stuff), then put that behind
1/8" clear plexiglass (acrylic).

Paul P

[trevorus]

You might spray the paper/formica thing with laquer to seal it.

Of course, there is always this place: http://www.bnplasers.com/

They can do custom work.

[Paul P]

The cabinet with the baffle for my 12" speaker :

The baffle was cut from a piece of recycled 1/2" poplar
plywood that'd been painted beige. It'll be painted flat
black.

Still have to make the frame for the grillcloth.

Paul P

[Paul P]

I made the front and rear decorative frames out of cherry. The pieces were
doweled together then rounded over in a jig I threw together for the occasion.



Paul P

[Paul P]

I got these really big rubber feet from Antique Electronic Supply when I
ordered my grill cloth. They're 1-3/4" at the wide end and 1-3/8" at the
small end. They're quite soft so they should offer the head at least some
isolation from the cabinet's vibrations.

I routed some depressions in the cabinet top to receive the head's feet :

Paul P

[Paul P]

The one thing that I've been pretty nervous about up until now has been
the grill cloth for my cabinet. My plan was to create a removable frame
that would hold the grill cloth sandwiched between two layers, a wider plywood
frame underneath with a narrower decorative frame on top.

I bought my grill cloth from Antique Electronic Supply, part number S-G297.
This is a pretty thick brown and black basket weave. One side is more black
while the other has large bands of brown visible (not shown in AES's picture).
I decided to have the brown on the outside. The brown doesn't show
well in the pictures below.

I've been afraid I'd have trouble getting enough tension in it to remove
wrinkles but it turned out to be pretty easy. I did a partial dry run of
assembling the frame without glue to see how it would go. I started
by marking the center of top, bottom and sides of the frame. I then
screwed one screw at the top center, followed the line in the cloth to
the bottom and screwed another screw in the center while pulling on the
cloth. I then did the same at the sides.

When I checked to see if the weave lined up with the frame at the ends
I found out that I had more of a parallelogram than a rectangle and redid
the sides. I put in a few more screws and found out that it was pretty
easy to tighten the cloth as I went, going back and forth to opposite sides
and ends working towards the corners.

I then traced around the plywood frame with chalk on the grill cloth and
disassembled everything. I then reassembled everything after having placed
a bead of glue on both halves of the frame.

The cabinet itself is almost finished. I just have to trim the grill cloth and
put a partial panel on the back to hold the jack. The speaker will be installed
from the front of the baffle using machine screws with T-nuts on the inside.

Paul P

[Paul P]

Most of the woodwork is done. The rounding over of the panels has to be
worked by hand in the corners to blend the curves where they meet. I use
mainly half-round files for this :

The wood is yellow birch and I finished it with a sort of oil finish like that
found on scandinavian teak furniture where there isn't really any finish
visible. I use this on just about everything I make because it looks great
and is extremely easy to apply.

I first applied a quick coat of shellac (just the white liquid stuff you can
get at a hardware store) because of all the end grain due to the finger
joints which tends to turn really dark if too much oil is absorbed. I sanded
the shellac with 150 grit sand paper changing often because the shellac
quickly gums up the paper.

I then mixed up 1/3 mineral spirits (paint thinner), 1/3 pure tung oil (mine's
from LeeValley) and 1/3 satin polyurethane. I brush it on liberally and keep
all the surfaces wet for maybe 15-20 minutes. I then wipe it all off with
flannel cloths. I keep wiping until it feels almost dry. You have to wipe it
down often for a day or two because some of the oil seeps back out of
the wood and then it's hard to remove if it dries.

It would normally take about a week for the first coat to cure properly but
I didn't want to wait that long so I applied a second coat after two days
but this time I first added an equal part of polyurethane to what was left
of the mixture, greatly increasing its proportion. I applied as before but this
time it started to cure fairly quickly so I had to be quick in wiping it off
once it started. I wiped it down every hour or so until the finish stabilized.

That's all there is to it. It creates a fairly waterproof finish that is so soft
and smooth and has no visible film. It can always be waxed if you want
a more glossy surface.

One important thing : oily rags can catch fire by spontaneous combustion
if left in a pile. I believe what happens is that heat is generated by the
curing process and if this is concentrated in a wad or garbage pail it can
get hot enough to ignite, and there goes your house. I lay each rag out
on the concrete floor of my garage until it's dry.

My wood has a bit of figure to it, which shows up better under an incandescent
light :

Here's a close-up of the cherry frames for the front and back of the head :

I'm starting to think that I may just finish everything this weekend.

Paul P

[black_labb]

looking excellent, want to see it all together.

[Paul P]

Things are starting to move now that all the little pieces are done.

Here's the front frame with a piece of grillcloth to cover the upper
opening :

The front control panel made from paper stuck to Formica for the labels
and plexiglass to protect it (I may do something a bit more elegant later
on) :

The front with the pieces installed :

I'm a little bit worried about static electricity from the plexiglass.

Paul P