Britbike forum Forums British Motorcycle specific Brands Vincent forum 1950 Black Shadow: Total Rebuild

Might be better to use Grappa, just in case and residual alcohol condenses in the lungs.


By the way, perhaps you should be harvesting those rattlers. Scarfing down their still beating hearts will put lead in your pencil.

I should probably head back to the garage before I offend anyone further.


As for your earth…. just make sure the ground rod is 100ft+

Since you're from the Northwest, you use the words "dirt" and "mud" interchangeably, so you have no concept of the word "dry."

Instructions for grounding an electron beam gun (hang in there, you'll see the relevance shortly), call for driving two metal rods in the ground, and if the resistance between them is less than 25 Ohms, the rf ground will be fine. I did that test when I installed an electron beam gun in my university lab years ago, but the resistance was hundreds of kiloOhms. Further instructions in the case of a too-high resistance, were to dig holes around the stakes and pour in some electrolyte whose name I no longer remember. The resistance remained thousands of times too high. The solution to the problem was having a commercial company install "self-watering" electrodes containing a hydroscopic chemical that leached the tiny amount of moisture from the air to use to dissolve some other chemical. The resistance was still very much higher than the gun's manufacturer recommended, but it worked OK despite that.

Anyway, a stake 100 ft. into the ground around here would still leave the booth ungrounded.

Brilliant. You could "water" your ground rod with used Guinness "electrolyte" and save a trip inside the house. I'd say that's a win win, maybe even a three-fer. The Guinness first steadies your hand for painting and later provides a sure ground to lessen the odds of a paint vapor explosion touched off by a stray spark.

That is...... as long as no stray voltages are present in the ground circuit.

My personal preference would be Raki. However in MM's vicinity maybe he could use Tequila.

At times in the past, when a specification called for a certain Earth resistance, I have had to employ specialists with drilling rigs to drill very deep holes to get to the required resistance. And thats in the UK which is considerably less dry than Arizona so I believe you.

These days we just take readings on a rainy day.

John

Dirt has a very high resistance, but the reason it's able to get to, say, 25 Ohms between a pair of stakes is there is a lot of dirt connecting those stakes.

Current doesn't just flow directly between the stakes. A small fraction of it takes a longer path of, say, an arc down to a depth of 50 ft. and back up to the other stake. An even smaller fraction goes down 100 ft. Another fraction takes an arc near the surface 25 ft. to the right of the line connecting the two stakes. And so on. The sum of an infinite number of paths between the two stakes, each carrying an infinitesimal amount of current, but extending through the entire depth and width of the high resistance Earth in all possible directions, results in a finite resistance. Or, in the case of the desert, a very high finite resistance.

The problem with that plan is I would have to install a refrigerator powerful enough to sustain warm-ish Guinness temperatures at times when the booth is in direct sunlight, which surely would require more than 20 Amps.

With a wiring system sketched out that would make Joe Lucas proud, I turned to the heart of a clean-air paint booth, the clean air. I need a few sockets and such for the wiring, but I probably will need a few HVAC components as well, so waiting to finish the wiring might save me one trip to the store.

After giving it fully 3 seconds of careful consideration, I decided to install the air flow system somewhat above the center line of the booth, on the premise that very few parts will be hung such that they reach floor level. Also on the premise that I could install a second inlet below the present one at sometime in the future, should I be so inclined.

I marked the location with a Sharpie, used a hole saw to make openings, and attacked the wall with a Sawzall. The next photograph shows the 12"×12" register held in place by ten 10-24 socket head screws, and caulked around the edges, inside and out.



The next photograph is a view from the outside.



The register has an 8"-diameter inlet, so what you see is an 8"-to-6" reducer installed from the inside to keep the projection outside as short as possible.

In what seems like a lifetime ago I bought a pop-up tent that I originally planned to use for my painting (can you say 'mission creep'?...), along with a 10-ft. length of flexible 6" pipe for its air system. The next photograph shows that pipe attached to the outlet, providing a more, ahem, flexible way to attach the fan than rigid HVAC pipe.



The next photograph shows the inside of the booth, with the 10"×10" outlet to be located on the back wall oppose the 12"×12" inlet.



The registers are designed to be mounted flush with the wall, as I did with the 12"×12" inlet register. If I do that with the outlet, it will project 5½" into the "alley" between the booth and the garage wall.



The "alley" is 23" wide, so that still leaves room to slip by to get to the water harvesting tank (which also can be reached by walking around the front of the booth). However, If I mount the register on its back surface, so it projects only 3", that would leave more room for a deflector of some kind to keep paint from reaching the garage wall.

I'm taking the day off because dilated pupils from my annual eye exam this morning makes working on the paint booth in the bright sunlight, and with limited depth of field, too uncomfortable.



Regularly-scheduled programming will resume tomorrow.

In my personal (professional ) experience a couple of gallons of water with a good dose (1/4 lb?) of magnesium sulphate (Epsom Salts) mixed in and poured on the stake will ensure a good connection between the ground stake and the mass of earth. This makes next-to-no difference in the actual ground resistance, it just ensures that your ground stake makes a good connection. I used to do it all the time when doing earth tests, especially in dry areas.

Re pictures of roof on page 25: I am sure you followed the construction directions, but for a metal roof, one is not supposed to put the screws in the valleys (channels) but rather on the tops of the ridges (which typically have a bit of flat width to them). This is to prevent leaks when it rains, which is admittedly rare in your area but does happen on occasion. I do hope they provided something to seal around the screws.

Unfortunately, I had no choice, because the panels came pre-drilled for screws in those locations. Although the screws have plastic washers that might seal them, I added a glop of RTV to each to provide an actual seal.

This is one of those practical compromises .
they put them on the flats where there will be metal to metal contact with the purlins underneath
so a lighter gauge material can be used ... and there's less chance of owner installation error ,
... where over torquing the screws
can collapse and spread panel ridges , because there is an air space is underneath

in either case "sealing washers" are called for .
and will last longer on holes where less water is seen or pooled .

... but we're forgetting that once complete
Magneto man will be able to travel back in time
to the day before the roof started to leak

What makes you think I haven't already observed the future leak and returned to fix it?

Didn't you run into yourself and be told, no need, it's already fixed?

People give you strange looks when you talk to yourself, so I try to avoid doing that.

As the first photograph shows, I added an electrical outlet on the inside.



It leads, via a very fat cord, to a plug on the outside, to which one of many extension cords will be attached to supply power to the inside of the paint booth.

The next photograph shows a 4 ft.-long LED light fixture leaning against the back wall that is supposed to have the equivalent brightness of a 2-bulb fluorescent fixture.



I'll hang it from a simple pair of brackets that I'll run between the two purlins below the roof (nb. new-to-me vocabulary word that makes it seem I know what I'm doing; thanks, quinten). I expect the single LED fixture to be bright enough, especially given the relatively reflective walls but, if not, there is room between the, ahem, purlins to add two more of the same lights.

As the third photograph shows, I also installed the outlet for the cross-flow air system today.



With the cross-flow clean air system and wiring installed, all that remains with the booth itself is to hang the light and duct-tape the roof seams. Which means, I'm getting close to the finish line. However, I'm sure minor -- I hope -- details will reveal themselves that will need addressing before the booth will pass its sea trials, such as installing a few paving blocks outside the door to make a clean-ish area for changing into Tyvek.

Interestingly, other than the lack of a TV, this isn't far off:

You should probably install a shower right outside the door, so you can decontaminate before you leave Rattler Gulch and head into the house.

That would need to be sealed as well to avoid unpleasant surprises snoozing in the towel.

The Adventure of the Speckled Band comes to mind.

I have replaced two of similar type LED ceiling fixtures.

Be careful, you will turn the immediate area blue when it only half lights up.
Both were repurposed to mood lighting in the shop,
from the origional bed room lighting use.
Life time was less than 3 years/100 hours (WAG).

When we moved in to our new (to us) house last year there were several two bulb fluorescent fittings in one of the barns. However there were a couple of gaps with no lights in them so I purchased an LED equivalent. The LED is massively brighter than the tubes. OK, the tubes are probably about 15 years old so that will be a factor but I was very surprised and pleased at how much light the LED produced.

Hopefully you wil have a similar experience and I will be interested to see what you think of yours.

John.

I can see where this is going. MM will have to wear sunglasses like the ones issued at Los Alamos and he'll end up with Ultra Violet paintwork.

It's rapidly rising to a predicted high of 100 ℉, but will be cooler the following week, so whether I'll brave the heat to install the light later today remains to be seen. That's the last thing that needs to be done before the paint booth will be functional (duct-taping the roof seams is a belt-and-braces item that doesn't affect functionality).

Note that even with today's high, it will drop to 90 ℉ at 7:00 pm, which is why painting will be possible even during the worst of summer. For you in the rest of the world who probably think otherwise, because of the low desert humidity 90 ℉ is quite comfortable when not in direct sunlight. Also, during the worst three summer months the rule-of-thumb is 80 by 8, 90 by 9 and 100 by 10, so painting first thing in the morning also is possible.

In any case, while a paint booth that only is usable a few hours a day for a third of the year wouldn't be commercially viable, it is all that I need for my non-commercial purposes.

Just a skosh more temperature and you could cure powder coating.

Good looking project.

It serves double duty as an enamel stove. Apply the paint before 6am, then beat the snakes at the door away, seal it up, and let nature take its course.
If not fully cured by the evening, just send it back to 10am until it is fully cured.

Against my better judgement (the same better judgement that caused me to "invest" time and money building this paint booth), I joined the mad dogs and Gila Monsters in the midday sun to install the light. Actually, I only intended to make the brackets for it, since most of the effort on those would take place in the AC'd garage, but mission creep took over.

As the first photograph shows, I was able to repurpose two Al brackets left over from some forgotten project into brackets between the two purlins (again, thanks quinten).



Thanks to springiness of the brackets and purlins I was able to slip them into place, and they are held without any Fasteners.

I used the mounting holes in the light fixture to mark the brackets, drilled the holes, then attached them with ¼-20 bolts. It was then an easy matter to slip the entire unit into place, as shown in the next photograph.



An extension cord was essentially the same cost as a separate length of wire and plug, with the advantage of not having to find a clerk to cut and price the wire, and the photograph shows it draped over the light. Plugging the cord into the socket will be the on/off switch. I used the excuse that I might want to install a second light to quit working inside the booth for the day while I pondered that issue.

Turning to the exhaust, conservation of mass means the air flow coming out of the exhaust will be the same as that directly in front of the fan. This means that any paint that makes it through the exhaust filters would hit the garage wall unless diverted. The next photograph shows how I will divert it downward so that it will paint the rocks, not the wall.



I'll also tape plastic to the garage wall until I determine whether or not any paint still manages to make it that far. When not in use, I'll remove the 90-degree fitting and replace it with the cap that's on the ground below it, which will seal the paint booth as well as allow me to walk the full length of the 'alley' to reach the water harvesting tank.

I plan to take a multi-layer approach to filtering the exhaust, that likely will get refined in light of experience with the system. I'll have a loosely-woven rag or towel in front of the MERV 8 exhaust filter, but if the filter clogs too fast I'll revise the filtering system,

Connecting the cord to the light (or lights, if I decide to add another, which I probably won't, but there's room for two more if I want to, ...) will bring the construction phase to an end. Phase II will be tests and adjustments, which should take a lot less time and money than Phase I did.

You might also want to consider draping some plastic sheets over the floor as in my experience any over-spray invariably ends up on the floor as a kind of fine dust. Alternately, you could also mop the floor clean before each spray session and this is generally the recommended course of action to keep dust at bay.

With any luck, the ventilation system will remove any paint mist before it has a chance to settle, and I guess you would have to test various air flows to see which works best.

That's a good idea. I'll also hang a plastic sheet on the wall behind the objects since buildup of paint anywhere will eventually flake and become a potential problem.

With the paint booth finished, I mustered the courage to add up the bill. At the risk of it being used as evidence to commit me at a sanity hearing, I spent $1755.

[img]https://cdn.shopify.com/s/files/1/0...-bbc3-b0517aa2df92_510x.jpg?v=1571611175[/img]

What ~$1750 got me is a paint booth of inside dimensions 5'9½" × 7'3¾" (42.4 sq. ft, approx. volume 266 cu. ft.), with lights, filtered cross-flow air, and supplied air respirator. That is, squandering this amount got me all the equipment I need in order to paint motorcycle parts in a dust-free environment. Other than the compressor, regulator, filters, hose, and spray gun, that is.

Stated differently, $1750 is the difference between painting outdoors on a calm day and hoping a breeze doesn't come up, or that a fly doesn't land, before the paint dries, and painting in a dust-free, insect-free, environment where the parts can be safely left to dry as long as necessary.



How "dust-free" does a spray booth need to be in order to meet professional standards? I'm glad you asked. Certainly, my spray booth provides a much cleaner environment than any home-made booth I've seen on youtube or anywhere else on the web. And, for reasons I'm about to discuss, it's even cleaner than a professional spray booth. I base this statement on paint booth specs plus knowing how clean rooms are constructed.

Commercial paint booths are built to stop most particles of size greater than 10 µm, for which they use MERV 10 filters for the incoming air, which are 85% efficient for particles >10 µm. In contrast, the MERV 13 filters I will use capture >90% of particles of size >1 µm. Construction details of the spray booth as well as air filtration matters, and Class 10 (ISO 4) clean rooms are what are used for the most stringent semiconductor production. This allows for no more than 10 particles/cu. ft. of size ≥0.5 µm. I had a ~250 sq. ft. Class 10 annex as part of my university lab's main Class 1000 clean room so I know how it was constructed, and I used this knowledge in constructing and configuring my spray booth.

A clean room is under constant positive pressure, as is a professional paint booth much of the time, so they actually don't have to be sealed as well as my paint booth in order to keep dust out. As I mentioned in an earlier post, my major reason for sealing it as well as I did is to keep dust and insects out during long periods of inactivity when it won't be under positive pressure. Given how well I sealed it, the limitation on the cleanliness of the flowing air will be the air filtration, not the sealing of the booth itself.

As for the financial justification of this booth, that's easy. Amortized over just three motorcycles, the cost it will add to painting each of them only will be... oh, never mind. Even given that nothing I do with old motorcycles makes any financial sense, this paint booth might seem to make even less sense. However, once I decided I would have to paint the Vincent myself in order to restore it to the high standard I'm aiming for, I had no choice but to build a professional-quality spray booth.

To put this paint booth in the context of the cost of rebuilding a Vincent, following are a few prices from the Coventry Spares list:

kickstart lever, $539
unpolished timing cover, $1012
front brake, $2755
Upper Frame Member (UFM), $4892

Someone could buy a basket case BSA or Triumph for the price of just the front brake, or a running one for the cost of a UFM. While it's unlikely a $1750 spray booth would return its cost in the form of added value to a BSA M20 restoration, it's possible it might for a Gold Star, and not unlikely it would return even more than its cost for a Vincent Black Shadow. In this context, $1750 spent on a 'tool' that only will be used a few times might even qualify as "quite reasonable."

But, even with the booth, will I be able to do at least as good a job as a professional painter?[*] It remains to be seen if it's just hubris talking, but if I didn't have good reason to believe so, I wouldn't have gone to all this expense and trouble.

[*]Or, perhaps my work will be even better than that of a professional painter. I'm not paid by the job, so I can take all the time I need to produce the best work possible, rather than quickly and efficiently produce what might be merely a good job. Not being paid by the job means I can take the time to carefully research the most appropriate paints for a particular motorcycle so I will use the "right" paints rather than a one-size-fits-all base of a 'close-enough' color plus clear coat that most painters insist on using for all their jobs. Also, I have the instruments for accurately determining color, gloss, and haze.

Other than a small piece of metal for the bulkhead connectors for the air inlets, an electrical outlet box, a small number of machine screws, and a few extension cords, I can't think of any materials I already had on hand that went into the paint booth's construction, so the many receipts accumulated over recent weeks tell the full story. This means $1750 is a good estimate of what such a structure would cost someone else to duplicate. Note that at several places in this thread actual builders have offered useful suggestions of a few alternative materials and professional construction techniques that should be considered by anyone who builds their own paint booth along the lines of mine.

On the subject of construction materials, at the cost per square foot of the plywood I used for the floor, the plywood for a complete shed of the same size would have been ~$45 less than the price of the steel shed. However, with the additional cost of just the 2×4s required for the frame, a wood shed easily would have been more expensive, not to mention more time-consuming, to build.

Some of the prices that follow are exact, while others are rounded off. However, this only affects the total by a few dollars. I overbought a few items, but the following list only includes what I actually used on the paint booth. Finally, getting to the point, the list contains everything needed to duplicate my paint booth, other than the gasoline for at least a half-dozen trips to the store.

Shed and Floor
(1) 6'×8' shed, $466
(1) painting rack, $82
(1) 4 ft. LED light, $38
(1) 110 V socket, $1
(1) 1l0 V plug, $3
(14 tubes) grey, white, and clear silicone outdoor caulk @ $8.98 ea. = $125.72
(1 tube) construction adhesive, $6.58
(10 ft.) ¾" OD clear vinyl tubing, $9.96
(1 roll) 2.5"×60 yards premium HVAC foil tape, $18.24
(1 roll) 1.9"×120 yards high temperature duct tape, $15
(2) 4'×8'×15/32" plywood @ $51.25 ea. = $102.50
(1 qt.) exterior wood primer, $12
Vinyl floor covering, 12 ft. wide × 6 ft.= 8 sq. yards @ $5.20/sq. yd = $41.60
(1 gal.) vinyl floor glue, $26
(2) 36" door seals @ 13.61 ea. = $81.66 27.22
(1 box of 175) ¾"-long self-drilling screws, $8.50
(1 box of 100) ½"-long #10 self-tapping sheet metal screws, $9.25
(1 box of 25) ⅜"-long #8 sheet metal screws, $3
(1 box of 100) ½"-long #6 self-tapping sheet metal screws, $8.50
(4) ⅜"×1 ft. rebar stakes @ $2.47 ea. = $10
Sub-total: $1004.07

Foundation
(20) 12"×12" pavestones @ $1.58 ea. = $31.60
(2) 0.5 cu. ft. bags pebble stones @ $4/bag = $8
(14) paving bricks, $8
(1) 7'×9' heavy-duty 7 mil tarp, $8.99
Sub-total: $56.59

Filtered Air System
(1) 600 cfm fan $65
(1) 8" duct cap, $7
(1) 6" duct cap, $7.22 ea.
(1) 10"×10"×8" ceiling register box, $20
(1) 12"×12"×8" ceiling register box, $22
(1) 12"×12" 4-way adjustable air register, $64
(1) 8" to 6" reducer, $14
(1) 6" 90-deg. elbow, $7.47
(3) 12"×12 MERV 13 air filters for inlet @ $10 ea. = $30
(3) MERV 8 air filters for outlet @ $3 ea. =$9
(1) 6"×5 ft. metal duct pipe, $12.50
Sub-total: $258.19

Compressed Air and Supplied Air Systems
(1) Hobbyair supplied-air respirator, $397
(1) 10' drinking-water hose, 12.98
(1) ¼"×¼" male-male water hose connector fitting, $5.62
(2) air quick connects, male and female @ $4.99 = $9.98
Sub-total: $425.58

Total: $1755.

Other:

Whether or not a spray booth is used, the following equipment also is required for painting at a professional level:

Compressor with appropriate capacity, ~$1000
Pressure regulator, ~$150
Particle and moisture filters, ~100
Air hose with fittings, $40
Spray gun, ~300
Chroma meter, ~$500
Haze/glossmeter, ~$500
Sub-total Other: ~$2600

So, someone starting from scratch would need to spend ~$4500 to be fully equipped to paint at a professional level behind their garage. On the other hand, a reasonable job can be done using just a $5 rattle can, so how is this expense justifiable? As Lord Kelvin said, "Large increases in cost with questionable increases in performance can be tolerated only in race horses and fancy women [...and paint booths]”. As an aside, Lord Kelvin is best known for his work in thermodynamics, but this quote implies his expertise in the physical realm extended outside the laboratory.

In any case, with this paint booth completed I now can add painting to my other motorcycle restoration equipment, for measuring, machining, honing, welding, magnafluxing, frame straightening, engines, heads, gearboxes, clutches, carburetors, flow benching, magnetos, electrics, media blasting, lifting, and hauling.

Unless I've overlooked something, and with the exception of decorative plating (Cd, Cr, and Ni), thanks to a life-long obsession with tools I find myself equipped to do everything up to full concours-level nut-and-bolt restorations completely in-house of just about any motorcycle ever made irrespective of its initial condition.



Although, to what end, I don't know, because I never had a Grand Plan to end up here.

If you have the money, knowledge and ability to paint, you do not need any justification for it, I don't have any of it so I would never attempt to build one.