TTSH, gettin’ sticky wit it
Alright on to some finished surfaces with the TTSH build.. This entry is all about tolex, from someone with zero previous experience on applying / handling technique. If you ended up here looking for some kind of advice, this may (or may not) be a good read. You’ve been warned! :)
Do also check out what has happened in this project previously, links are at the bottom.
Ok so for the totally uninitated, tolex is waterproof vinyl fake-leatherish fabric that has this nice textured surface. It’s most often used on guitar amps to make the plywood case look like something that someone might even shell out money for. How tolex is applied is:
- Measure & sketch out the shape (of item to be covered) on reverse side of tolex sheet.
- Cut sheet down to the shape.
- Apply adhesive (contact glue) to both case & cut piece of tolex.
- Wait <x> minutes for the glue to dry.
- Join the two surfaces, shaping corners etc. as you go.
But of course there’s more to this only goes so far. I started looking into applying techniques way early this year, around the time when I started making parts for version 1 of the road case. Guess I wanted the tuts to sink in or whatever, thinking I’d be all prepped when the time comes (eek!). In the end it was mostly the hands-on experiences that truly helped me to get a feel for handling tolex.
For the adhesive I was able to find two choices; a) the spray-on, solvent-based stuff which needs ~10 minutes to dry before joining and is toxic to breathe AND b) the brush-on, water-based stuff which needs like minimum of 45 minutes to dry, but is non-toxic. I chose to try both starting with latter, just to rack up some experience. For spray I had Adam Hall’s 01360 and for brush-on, Casco Contact 3880. I’ll refer to these by the friendly names of Adam & Casco from now on :)
I found that tool-wise the most essential things to have are a sharp knife and a heat gun. The former is obviously required for clean cuts, while the latter is great aid for shaping. While tolex is soft enough to be worked around corners even without a heat gun, I found that using one allowed for perhaps a bit more sharper / tighter shaped cornering (perhaps due to vinyl shrinking). For other tools & work instructions, check out eg. the beginning of this video by Reliable Hardware:
As it turned out the heat gun was also neat for stretching and shrinking elsewhere than just forming around the corners. For example I tried gluing one of the flat sheet parts only near the edges: This left (unglued) middle part sort of loose so that it would slightly flap against the sheet. But carefully applying heat over the full surface the tolex shrunk slightly, tightening away the flappy middle parts. For some stretching stuff, check the inner frame snaps further down.
The adhesives I would short-list as follows:
- Toxic to breathe, work environment needs good ventilation.
- Quick to dry, surfaces joinable in 10 minutes after applying.
- Medium open time (to full grip) after initial contact.
- Strong grip.
- With non-porous surfaces treating only either one is enough.
- Often makes quite the mess, but..
- Spills are often easy to clean with rag dipped in solvent (eg. isopropyl alcohol).
- Non-toxic, good for working with in common household places.
- Dries up to form a gummy like stretchy film over the surface.
- Slow to dry, surfaces joinable after minimum of 45 minutes after applying.
- Very short open time (to full grip) after initial contact.
- Super strong grip.
- Both surfaces need to be treated regardless if it’s porous / non-porous.
- Rarely makes a mess.
- Spills are either easy or annoying to clean; tolex = no problem (rubs off), plywood = PITA.
For me what needed the most hands-on practice was adjusting to the open time before full grip. As in how large a segments should be worked on at a time, how much time do you have for correcting alignment errors etc. Tolex is quite a soft material so any big, floppy pieces have a tendency to flex wherever the weight & shape of fabric allows for. So by treating too a large segments with glue it was easy to run into accidental initial contacts when the loose tolex would erratically flex/flop, eg. while rotating the case part being worked on.
This became problematic especially with Casco due to its near-instant time to full grip. Basically Casco just begged to be applied over small segments at a time. Add to this the lengthy drying period and fully treating each frame part turned into a lengthy multi-session task. In practice it made sense to only apply Casco to max. two surfaces at a time, let it grip and only then proceed to following segment. For instance folding over an edge would require two separate sessions, as I couldn’t afford lengthier ones than perhaps two hours tops.
So yeah to sum it up, I preferred Adam over Casco despite all the spray mess. It just was easier to work with wherever tolex needed more handling than just a single press to apply. On the other hand, Casco provided a good instant grip over the larger surfaces without the need to use a respirator and have a well-vented work space. Something which I totally appreciate, not having access to any proper workshop these days.
Now then, the build snaps!
No surprise I chose to start learning tolex with the side panels. The obvious easy parts, even for someone with zero experience :)
One idea I had for hiding some of the seams was, these side panels could have a Marshall / Vox guitar amp style vinyl piping stapled around the edges. Both outer frames will then have a support sheet (or rails) on the inside to which the side panel will attach. This is also allows for less visible screws on the exterior. So yeah bought some white piping off Ebay and:
Here’s one shopping tip: Besides guitar amps, the same style vinyl piping is also used on boat & automobile textiles. It’s often cheaper to buy if you look up something like “Marine Piping” instead of “Marshall Piping” or “Guitar Amp Piping”. Great variety of colors too! :)
Without giving any thought what might be the sort of intermediate wrapping practice, I next moved on to the inner frame.. And what a bad idea it was! On this part the difficulty stepped up quite a bit, as the sides have angled edges to match the tilted the TTSH front panel. And working with Casco, this lead to a total disaster on the first go. Had tons of fun times removing all the gummed up glue <3.
Continuing on the visible seams theme, to have as little as possible of them I decided to wrap the inner frame in alternate direction than the to outer frame. So instead of using one long sheet to first wrap around the frame and then edges (eg. like in Reliable Hardware video above), I instead chose to cut a more rectangular piece, start from the front and wrap to the sides. Going about it this way would only leave visible seams to the bottom, and that was like practically screaming “yay you can f**k up the cuts as much as you like”. Least visible section and all that.
To go about the angled sides I decided to do slits along the edge of tolex, then heat & stretch the tolex to shape. This left quite a bit of ugly kinks towards the edge, not that it matters really. They either got cut away or are sandwiched out of sight between the two frames once assembled.
Not much to it here, sort of school book wrap following about any tutorial online.
I had no idea how to wrap around the side dish cutouts, but here’s what I did:
Knowing the outer corners of the case will get corner protectors installed (=hiding what’s underneath), I decided to experiment a bit by heat-forming (=stretching) one corner seam instead of making miter cuts:
This did result in quite a nice looking seam, but it was more work than the miter cuts. So I went with the latter for all remaining corners. Similar to inner frames, I left quite a bit of excess tolex which can be cut away after wrapping over the edges.
Initially I was planning to install the side panel with the piping bulging out. But by the time I actually got to testing this style for looks, it turned out to be quite the fugly little thing:
Making the piping flush with the outer frame pushed both side panel inwards about 5mm more than in my original design. This called for the inner frame to be cut by the same amount. I thanked myself quite a few times for designing the case with such loose internal dimensions that thinning down the internals didn’t cause yet another full re-design / rework of the case.
Didn’t plan this part much. Figured it would build & wrap the part pretty much like the outer frame.
One minor difference in design was that instead of using screws to affix the side panel I chose to use strong rare earth magnets (10 pcs sth like 3 USD from DealExtreme). How this works out is both the inner & outer panels have thin (but strong) rare earth magnets glued to them, and inside the case is a support board with matching through-holes on it. This gets sandwiched between inner & outer panels which grip together with magnets. The support board is installed to grooves plunge-routed inside frame parts. Kind of like some drawer box design.
‘Why all this magnet trickery’ you might ask? Well, not to have any visible screws to the sides.
Coming as bit of a surprise this magnet scheme worked quite well. I was well-prepared that the whole design would go all tits up, after which I would use screws instead. But it didn’t. I then had a beer to celebrate.
One build annoyance was that the support board is 3mm thick whereas the router bit I had was 6mm. To work around this without buying expensive adapters etc. I chose to cut these long thin 3mm thick sticks out of the same board. Glue these inside the grooves with the support board = 6mm router bit all good to use. So like:
The Magic Moment
With all the above sorted out it was time for the fun part: Install the case hardware and see how the damn thing turned out. The hardware being corner brackets, rubber feet, carrying handle and drawbolt catches.
I have to mention I was very very VERY determined to get all the case hardware in BLACK, mostly because it looks nicer with purple than the regular shiny metal parts do. And oh boy was it a total pain in the rectal region to find one shop which could deliver all the parts suitable for the project!
Funny enough even the biggest manufacturer of (flight) case hardware, Penn-Elcom, didn’t have everything I needed at their webshop! But Swanflight did.. despite their p+p costs more than doubled the price of all the hardware I needed for the build :P
Minus the carrying handle which was affixed with countersunk screws & t-nuts, I chose to use black rivets for rest of the hardware. Rivets are way more lower profile than screws and thus they look nicer than screws in my opinion.. Even despite the hole in the middle. Ebay for black countersunk screws, and a local awesome hardware store, Ruuvi-Säve, for black rivets. Osssooooom!
Similar to original Arp 2600 (afaik) the rubber feet come in two sizes. Taller pair to bottom of inner and shorter to outer frame. The taller pair also doubles up as a cheapo lock mechanism for the front cover, securing the bottom edge and thus requiring drawbolt catches to be installed only on top of case.
How I wrapped the tolex around the rubber feet through-holes turned perhaps the ugliest part of the whole job. For reasons x, y and z I just could get Adam to grip despite applying on both surfaces etc. A while later I just gave up and used hot glue, which of course made the usual mess it does. But nevermind that, the case was now all sorted out!
Damn that was a lot of work! This post included :)