Heat Box Madness

This turned out to be more of a hack-job adventure than I ever imagined. My brain hurt thinking about this stupid thing, until finally I just stopped thinking and started duct taping.

"Don't think, duct tape," works good for this job. And I wouldn't try it yourself until I report back next week to let you know if it got hot enough (I'm hoping for 160F) without melting (because it's made out of styrofoam, duct tape, foam insulation, and reflective plastic insulation).
I've read things like, "for every 10 degree increase in temperature the epoxy composite will cure twice as fast", and also that the composite gets harder the faster you cure it. So I built myself a "heat box", which is a box full of heat.

This is a view of the inside of the heat box. What you are seeing is a reflective insulation that I got at a big box home improvement store; it's like two thin layers of aluminum sandwiching a 1/4" layer of bubble wrap. The bottom of the box is hardboard, the kind of thing you can buy perforated to hang tools from. In this case it's non-perforated; more like the kind of thing you might layer a workbench with. I'll be sliding the clamped-up guitar neck around on that, so I wanted something that wouldn't tear.

The inside dimensions of the box are 48" long, about 14" high, and about 24" wide. Why? It's about the size of the material I had and could buy. The top of the box is 2" foam block insulation like you'd buy to insulate a basement, I suppose. I already had that. The sides are some cruddy styrofoam insulation from a kit full of 14" x 48" x 1" sheets - I would avoid that next time, because it crumbles. I put a layer of that on the hardboard floor of the heatbox, as well.

Note: you can sort of see how duct tape does not stick to styrofoam. It's really just serving as a binding around the outside. Fortunately, I bought some heavy-duty actual aluminum reflective tape (what I like to call "real" duct tape) to seal the inside corners. This stuff is great; hyper adhesive (almost annoyingly so) and strong in the long direction.


That's the front view, with the materials I'm going to use for a door on top of it: three layers of that reflective bubble wrap and two very junky hardboard sheets I laminated together. I figure I'll secure the door to the opening with a duct tape hinge of some kind and some mini bungee cords.

Finally we've got the "heat" part of the heat box. I've seen some trick setups on the internet involving water heater heating element controls with hysteresis whatnot optimization. I, on the other hand, am going to stick four incandescent light bulbs on this contraption, slam a meat thermometer through the top of the box, and turn the light bulbs on and off by means of a two prong plug. That's why I AM GOING TO CURE MY LAMINATE OUTDOORS IN THE DRIVEWAY, FAR AWAY FROM ANYTHING FLAMMABLE. You do what you want with your heat box; I'm scared of mine.

This is a flat, thin bar of plain soft steel like you'd make a strap out of to hang a garage door opener with. It's got holes drilled in it already, but I had to widen two of them to put the bulb fixtures in. The bulb fixtures are secured through these holes with brass lamp nuts, where are their own sort of beast. I will wire a two-prong extension cord to the black and white wires and secure the connections with wire nuts and electrical tape. I will fasten the steel bar to three pieces of 1" pine to hold it off the floor of the heat box and allow room for the lamp nuts and wiring.

Next weekend I fire this thing up, OUTSIDE IN THE DRIVEWAY. Wish me luck.

Materials list for the heat box:

• 2" x 48" x 24" blue hard foam insulation - had it already, leftover from an attic insulation job
• 11oz adhesive spray - $4.58
• 55yd all-purpose duct tape - $4.98
• 3/4 poly (styrofoam) pane kit - $13.70 (wouldn't use this again, in favor of blue hard foam)
• 2" x 50yd aluminum tape - $11.99

Materials for the heat lamp setup:

• 3/4" x 60ft blue electrical tape - $3.79
• 1-3/8" flat bar, slotted - $6.59 (this is the bar the bulb outlets bolt to)
• 7ft extension cord - $4.99 (will become the cord for the lamp setup)
• 2 weird dual lamp sockets - $5.98 + $5.98
• 2 brass lamp nuts to secure the lamp sockets to the flat bar
• 3 1" x 4" x 4" white pine segments - found in the basement
• wire nuts - already had them

TOTAL OUTLAY FOR THIS STEP: around $77
TOTAL OUTLAY SO FAR: already $200. Oh my.

Here we go

I've always wanted to build a guitar from nearly scratch, which to me means constructing the neck as well as the body. I've finally decided to do it. I've already started buying materials and assembling some of the materials I'll need to build the neck. I am making this up as I go along, although I have done a bunch of internet research.

I was going to build the neck from a laminate of carbon fiber and epoxy, plus some kind of fancy tone wood - initially, I was thinking mahogany. Then I checked out the price of mahogany and settled on basswood. Basswood? That's for making guitar bodies! Well, please consider a few things:

1. It's cheap - I got it from National Balsa Wood Company; here is the page for 36" long basswood sheets; mine are 1/16" x 4"
2. I just read yesterday that Parkers have composite-wrapped basswood necks, and people seem to like those alright
3. There's a good chance I'll mess up and have to try again, and like I said, it's cheap

In the picture of the basswood sheets, with my Samick jazz box for a size comparison (a good guitar, but I have no idea why I own it), you can see a stack of 16 sheets, each 1/16" thick. I measured the thickness of several guitar necks and they always come in under an inch (minus the fingerboard layer). Only after I ordered the wood did I realize that after I laminate stuff between the basswood, it's going to be thicker than an inch by some as-yet-unknown amount.

Next, after I checked the price of carbon fiber cloth ($30+/yard) I decided to go with fiberglass. Here's why:

1. It's cheap - I got it for about $7/yard from US Composites; here is the page for fiberglass cloth; mine is the 8.9oz S-glass, which is an upgrade from the "regular
2. There's a good chance I'll mess up and have to try again, and like I said, it's cheap

In the picture of the fiberglass, from left to right is the 635 epoxy, the medium duration hardener, a little jar of blue dye (my idea is to stain the neck blue, so maybe this will help tone down the epoxy stripes), some measuring cups, and the fiberglass itself - 3 yards of it.

Here's my parts list so far, along with cost:

Basswood from National Balsa:

Code	Item	Qty	Price	Total
116436B	1/16 x 4 x 36 basswood sheets	16	$1.76	$28.16

Fiberglass and epoxy from US Composites:

EPOX-635313 Medium 635 1/2 gallon,
  21.3oz $34.25
FG-6781-38  8.9oz S Glass -
Satin Weave Thickness: 0.0097"
4 yards @ 13.95/yd
TRA - PB001 1oz transparent blue tint
   (< .25oz/gallon) 5.95
CON-C08 25x 8oz graduated plastic cups 5.5

Total: I'm about $130 into this thing already. Wow.

NEXT: A "heat box" to cure the laminate!