rockstar.esq

I see a lot of articles with some version of the following in them; "Expert who predicted XYZ says this will happen next". Every time I see that, I think about a statistics class where we went over the prediction accuracy of some pretty basic stuff, weather, stocks, sports. The most popular and published experts in every one of these fields was less accurate than random chance. In fact, in most cases, a person would have better odds of success by opposing whatever the expert predicted. Yet in the past fifteen years or so, there's this incredible situation where we have experts who accurately predicted quite a few things in print, yet they seem to be inconsistent when placed under the spotlight. What is going on? I think the short answer is human nature, which is often ridiculous. I believe the first fundamental of this whole thing is publishing standards. Journalists cite facts from respected agencies and individuals in their articles. Since people often disagree, it's entirely possible for a journalist to find an expert or agency which supports their story. There doesn't seem to be much investigating into whether or not the marketable expert or agency is consistently worthy of respect. The second fundamental I've noticed is the absolute absence of effective peer review. An individual speaking for an agency is often quoted as the respected agency. This same individual can do an interview where they render their own, opposing opinion or prediction. Peers often treat this as a protected free-speech issue, without considering the individual's scientific, or moral integrity. This practice works against public trust because "both sides" of any issue can claim the same experts testimony. The third fundamental is what I call the time value of information integrity. Since the individual in question is obviously predicting two different outcomes, they have to time their predictions such that they are close enough to claim credit for the success, but far enough apart to claim that "new information came to light" to excuse the failure. With the narrative in place, these "experts" are able to compile a mighty list of accurate predictions, all of which were published in the media. The fourth fundamental seems to place everything is a zero-sum (existential) crisis. In my industry (construction), it's fairly common to schedule new ground-up construction for late spring starts. This minimizes weather delays, and generally allows the building envelope to be closed in before rain or snow become an issue. Yet every trade publication treats the seasonality like it's an industry destroying boom or bust. We're either dying from no work, or we're starving for new hires. I can't help thinking that if the industry would quit panicking, they might apply themselves differently. The fifth fundamental I see is the "precautionary principle" which is an approach to innovations with considerable risk when available scientific information is lacking. Very simply put, it's advocating for corrective action which might prove harmful, to forestall a perceived threat, in a situation where there is insufficient science to confirm the threat, or the corrective action. "Shoot first, ask questions later", and "better safe than sorry" are a pithy summations of this principle. I think this is a last-ditch approach that tends to assume that any action has even odds of success. Life doesn't work that way. Every action has a consequence, but the outcome is not always limited to good or bad. I've found that unintended consequences cause most of humanities crises. It's incredibly tragic how often our panic-driven action in an imaginary crises generates a real crisis as an unintended consequence. With all that said, I think the reasonable individual has to take a few steps back. In most cases, there is no crisis, and it's actually pretty rare that we get inflection points that clearly swing one way or the other. In my industry, I can say with some confidence that the trade associations can rarely be expected to see anything that contradicts their preferred worldview / marketing narrative. These human herds tend to be pretty dumb, even by herd animal standards. I've reduced my stress significantly by focusing less on the advertised crisis, and more on the actual challenges in my life. I've seen quite a few crises go from constant coverage to total silence without ever encountering the most fervently predicted outcomes. For what it's worth, I've also noticed how frequently there are order of magnitude math errors on all sides, all along. On some level, I have to wonder if the goal is to separate the crisis from the facts so that people can abuse the precautionary principle to advance their tribal preferences.

JME, They are the "national account" holder for the client so contractors have no choice but to purchase from these people. Their performance is generally better after the quote but they have had some of the most spectacular screw-ups of any firm I've ever worked for. One time they went through all the paperwork to confirm every detail about some pole lights. Then, when it came time to place the order, they changed the paint color from black, to smurf Blue! That wasn't even a standard option which means they had to custom order that color which includes additional paperwork acknowledging that there are no returns on custom painted fixtures. The custom color delayed the fixture delivery, which they never told us until they missed their original delivery deadline. Then, when the lights finally did arrive, their delivery guy slid them off his truck scratching the paint for the full length of each individual pole. He also tossed the light heads, severely damaging the packaging, but not the fixtures. It took a few weeks of wrangling, but eventually they ordered the right fixtures at no extra expense, however they had no resources to pick up and remove the scratched, smurfy fixtures. We ended up doing them a favor by hauling the parts to their warehouse. Oh, I almost forgot, the replacement fixtures were put on a truck in Texas, headed to Colorado. Their first driver drove straight through, arriving in Denver around Midnight when there was nobody at the fenced off construction site. Rather than waiting until everyone showed up at 6:00 a.m., or delivering it to the local warehouse, this driver just turned around and drove back to Texas with the lights! The driver didn't answer his phone, so everyone just thought he was running late to Colorado when he strolled into the Dallas factory office later that afternoon to ask where he should put the lights! George, the only time this firm is allowed to bid to me is when we're contractually obligated to use them. We've done less and less work for this client because the decision-makers in charge have changed. It took this client almost twenty years to recognize that corruption between design teams and lighting reps was making their projects too expensive. My work has exposed a great deal of this. Eventually they tasked a trusted adviser with finding a suitable firm to set up a national account, which comes with stipulated unit prices for every fixture they ever get. Sadly, their adviser was a volatile guy who'd just spent twenty years personally alienating every lighting rep in town. Every successful electrical distributor needs to stay on good terms with the lighting reps. I believe this is why their adviser eventually found himself talking to this little fly-blown outfit staffed with obstinate dullards. On the smurfy pole light job we had to explain what happened to the client and their adviser. We tried to be diplomatic about it, but we were truthful about their performance. This evoked howls of rage from the client and their adviser who wouldn't hear a word against their national account holder. I think on some level, they decided to have a partner that's honest and incompetent because they can expect subcontractors to fix the mistakes. They're still figuring out that this arrangement only works when they're willing to pay the going rate for better subcontractors.

Sorta funny thing I thought I'd share. There's a company I've worked with for going on eleven years now. In that time, they've gone through something like five different sales representatives. Every time the replacement rep told me it was because the previous sales rep made too many mistakes, and was upsetting their customers. Here's the thing. Over the last eleven years, I've asked this firm to bid hundreds of projects. There has not been a single occasion where their bid was correct on the first try. I'm not talking about default bid conditions, or piddly differences in phrasing. I literally provide the specifications and the quantities for everything they're supposed to provide. They unerringly fail to follow instructions, no matter how short the list is, or how easy it would be to do it right. Now all of that is pretty consistent, here's where it gets almost unbelievable. In eleven years, there has only been one bid where they fixed their first mistake, without making a new mistake! This company needs an average of five tries to quote a ten item list correctly.

Small diameter high carbon steel stock is good for tools like screwdrivers, small wrenches, etc. Many antiques use straight slotted screws which are monumentally easier to work with if your screwdrivers have a "gunsmith" hollow grind such that the tip fully fills the slot. After using a properly ground straight screwdriver, it's almost amazing that the taper tip "keystone" shaped ones ever took off. Another potential use is to make a wrench for those annoying "coin slot" caps that get used in battery and little C02 cylinder covers. While I'm thinking of it, a good blacksmith project would capitalize on germophobes. Make a finger loop at one end, with a short shaft ending with a blunt poker and hook. Size it so the blunt poker can be used to push buttons like the ATM keypad, size the hook so you can snag doors like lockers, restroom partitions, milk jugs, and gate latches.

I'm surprised nobody mentioned this, but if you drill a series of closely spaced holes, you can easily snap the remainder.

Hondo, Thank you for sharing some important life lessons. Seeing something through to the end is a valuable skill. I used to wonder why seemingly talent-less people got ahead. It turns out that a lot of talented people quit when things get difficult. I can relate to the frustration of being in a situation where current ability falls short of past performance. I think that frustration is proof that you're on the path to regaining your abilities. Since you know what to look for, you can be both the teacher and the student. You're recognizing progress which is essential to self-improvement. You're also showing people that it's OK to struggle in pursuit of your goals. I admire your tenacity, and hope that I can meet challenges with similar resolve. Keep up the good work.

Bonus cool points if you carve it out of ironwood!

Aside from the already mentioned ideas, here are a few more. If your anvil wobbles, it's especially tough to use struck tooling. If you are working alone, it's tough to use struck tooling on stock that doesn't want to lay flat (and still) on the anvil. Trying to chisel unrestrained round stock on your own is a rodeo, if you can keep it together for 8 seconds, you're a champion! If you're cutting thin metal, you might want to set the chisel in line with the edge of your anvil. If possible, you can tip the chisel such that one corner cuts before the other. This sets up a shearing cut which is very useful for trimming a strip off a larger plate. Broadly speaking, wider chisels will have more resistance while cutting than narrower chisels. You might find that a narrower chisel actually makes a longer cut faster because it achieves more cutting with every hammer blow. It's possible that part of the rebound you're experiencing is a function of the chisel slipping after the cut. There are top tools called "butchers" which are typically used to isolate stock. Some butchers have a working face that look a bit like a crescent shaped chisel. The advantage of this design is that the outside corners of the stock are "hemmed in" by the curve. That minimizes the distortion on the stock you're trying to leave alone. Since the edge is curved, it's only making contact at two small points on the stock to initiate the cut. That allows the first blow to really set the line. Generally, the butcher is then traded out for a different top tool depending on what you're trying to achieve. Finally, if you're using a chisel for hot-cutting, there's a few tips I picked up from Peter Ross. His chisels have a few features I haven't seen together anywhere else. First off, he shapes the edge like an axe, so that he can "walk" the chisel along a curved cut. This also reduces surface area when starting a cut so that first blow really sinks. Second, he blunts the edge such that it has a 1/16" flat. When cutting hot stock, this tends to reduce the ragged edges at the bottom of the cuts because it forges the rag outwards on either side of the cut. It also makes your "edge" tougher in use against hot metal. Third, he grinds what looks like a false edge on the leading edge of his chisel. It's used to sight down the tool so you can tell if your cutting edge is lined up without bending, or stooping.

Looks like it has a plastic plunger in the center of the threaded shaft. I'm guessing that it's a part or tool holder for something delicate like a sensor or a probe.

JHCC lots of good points as always. Your last sentence there can absolutely be applied to my point, which is that there are times that normal decorum allows bad-faith actors to appear legitimate, stall for time, and avoid resolution. I was thinking about this some more, and I realized that culture and local custom greatly affect what is considered rude. This has led to many situations where the offending party was as unfairly misunderstood, as the offended party was justified in taking offense. All of that is patently ridiculous in a setting where two (or more) parties are trying to resolve a conflict. If everyone was of the same mind on things, there would be no conflict to resolve. Your example perfectly illustrates how positive resolution for all, comes from good faith and objectivity. I've certainly seen plenty of conflicts resolved where both parties politely stabbed each other in the back. I've also seen plenty of conflicts that immediately resolved when all parties recognized the potential for mutually assured destruction. Now obviously those are two extremes, and negotiation normally requires considerable subtlety. My original point, greatly condensed, was to ask if anybody had noticed how light ridicule sends sociopaths into hysterics. If I'm on the right track, it would suggest that a little light ribbing during a difficult negotiation, might reveal that you're up against someone who is not capable of good faith or objectivity.

I work at the "management" end of the construction industry which often has different rules of decorum than the sites do. That being said, I came up in the trades and have many years of field experience. All of which is to say that I've seen quite a few arguments in a lot of different settings. In that time I've spotted a few folks who were very good at resolving conflicts in their favor. Doing what I can to improve myself, I've learned by their example. The other day I was talking with a colleague and he commented on how rude this person was. Now I've watched that person for some time now, and it's doubtlessly true that they aren't always polite. That being said, this person has a remarkable record of making intractable parties live up to their promises. Looking beyond the bluster, it's very clear that this person gets results. Then I remembered a project a few years back where we were working for a client that may well be a sociopath. This client's actions were consistently adversarial, even in situations where events were going in their favor. The only thing that seemed to matter to this client was "winning" the argument. They would pick a fight any time there was a chance that something productive might get done. I recall that there were only two ways to immediately extinguish these fights. The first was to immediately capitulate, give them whatever they asked for, and accept that you'd never get anything done. That only bought you temporary quiet in exchange for productivity. The second way to extinguish the fight was humor. This person absolutely could not handle any form of ridicule. I want to be clear that I'm not talking about mean-spirited put-downs here. By way of example, I was at the job walk prior to bidding the job. We were inside this facility that was supposed to stay open during construction. Most of their equipment was mounted to or powered by electrical coming out of a wall that was going to be removed during the project. I pointed this out to the client and asked them if they wanted us to include temporary power set up on an adjacent wall to avoid interrupting their operations. This person talked for fifteen minutes straight without answering the question. At the end, they asked me if that answered my question. I replied "Honestly, no. I just need to know if you want temporary power or not". The other people in the room giggled a bit at that. This client launched into a twenty minute tirade about absolutely everything except whether or not he needed temporary power before turning on his heel and walking outside. Everyone stood in silence for a few minutes to let them cool off before we followed them out to continue the walk. Anyhow, I got to thinking about how my colleague thinks this "rude" person is a problem. Then I got to thinking about how most people that I'm interacting with have lots of experience arguing over things. I've seen lots of arguments that involved foul language and unpleasant behavior, but it's pretty rare for someone to simply flip out because the other party was rude. In those rare cases, I can see a lot of similarities to that crazy client. My admittedly superficial understanding of sociopaths is that they don't have feelings or empathy. They have to mimic emotions to "pass" in civil society. When I consider the range of emotional reactions to ridicule, it's a long list. Shame, anger, fear, frustration, and humor to name a few. Again, just guessing here, but what if they flip out because they can't fake such a complex interaction in a situation where they stand to lose something? I feel like it's important to point out that the ridicule I'm talking about here is where the joking party is making a factual argument with humor. These jokes wouldn't be funny if the facts they referred to, were false. The whole thing got me to wondering if maybe my colleagues sensitivity to decorum is more acutely tuned than objectivity. What do you think?

Thomas, I figure that worrying about a Yellowstone eruption is pointless. It would end everything out here before we knew what happened. It would likely end everything for most of the world, but they'd suffer longer than I did.

Anvil isn't joking. Two weeks ago Northern Colorado could have served as a film set for Mars! Every single day I'm grateful for those firefighters.

Thomas, Just guessing here, but there was a properly massive Amazon warehouse facility going up at the South end of Colorado.

I can't answer for blacksmiths, however I can say that "essential" construction trades out here are in desperate shape right now. Developers cancelled or postponed basically everything since March. The only commercial market segments that are moving forward with work are schools, clinics, and big empty buildings known in the industry as "Core and Shells". I hear that homebuilders are booming, but it's predominately single family homes, not multi-family. There are rumors going around among firms with large metro offices that they expect to stop remote working and mandate a return to offices in mid November. Of course, that may be wishful thinking among contractors who build offices for a living. After six months of struggle, I can honestly report that the "just in time" procurement channels are still in chaos. Every job in the last nine months has required extensive re-specification for fixtures because short notice to proceed coupled with long material lead times were making it impossible to meet the schedules. Nine out of ten re-specification efforts took long enough that the lead times doubled on the replacement specifications. Factories either couldn't or wouldn't provide accurate information on lead times because their suppliers, and their workforce are interrupted by new regulations that come with immediate effect, and without an expiration date. We were recently informed that the tropical storms that hit the US in conjunction with large orders from overseas have put certain resins in short supply. PVC conduit cost has more than doubled in the past week, and the lead time to get significant quantities is now measured in months. We were forced to buy large stocks early to protect slow-moving projects that involve large quantities of PVC conduit.

George, I see this as a good example of surivorship bias. The difficulty of repair vs longer mileage comparison is still working from the assumption that all vehicles will last that long. It's also framing the vehicle's value in only two dimensions; repair difficulty versus longevity. This thread also seems to be steering towards the assumption that there's a correlation between vehicle longevity, and the difficulty to repair. I recently bought a used car and shopping around revealed some important points. First, it's absolutely incredible how coordinated the price-pointing is on used vehicles. There isn't even 5% of difference between dealer lots spanning a 200 mile radius for comparable vehicles. Seriously, if you pick a make model, year, and mileage threshold in Colorado, the only significant price difference is either warranty or tax. "Certified pre-owned" vehicles that come with warranties were 10% more than those without. Otherwise, the car will be the same price wherever you go. Dealers won't reduce their online price by more than $200 on the nicer (under 30K miles, one owner, no damage) cars. That price-pointing was a huge factor as the average mileage goes up. At the $9-7K price point, nearly all the available inventory I found needed repairs that cost at least 20% of the purchase price. Mileage at that level was between 90K and 200K. Once we got down to the $5K price point, the repair costs were anywhere from 30% to 100% of the purchase price. We found a lot of cars with salvage titles at this level. Mileage at this level was almost always above 150K, often going 200K for economy cars. $2K and down vehicles were all either above 250K miles, or they were being sold as "parts cars". As I shopped around, it was really remarkable how frequently the cost to repair negated the "discount" for higher mileage. All of that experience taught me that the "true" cost of a properly working used vehicle is artificially increased by two things that have no causal relationship to longevity. The first is that overpriced repairs are obviously creating a source of revenue for dealers who take used cars in trade, repair whatever is broken, then sell them as "certified pre-owned". 10% is a significant price hike, but it's also equivalent to the total costs for three average repairs in the first year. The second thing that doesn't cause longevity, is the fact that a very significant amount of the available inventory at the 100K mile level was salvaged. Those aren't incredibly built cars that stood the test of time, they're cars that were caught in a flood, a horrible crash, or something equally devastating to the integrity of the car. For the most part, it's not possible to get insurance or a title to legally drive these things on the road. Yet these vehicles are helping to set the price point for the used market because online advertisements don't typically put that information in the lede. That increases the suvivorship bias assumption that "newer" cars last longer. I think it's important to recognize that there's actually a market for people who would rather illegally drive a fatally damaged vehicle with less miles on it, than an older one. My best guess is that they figure there is less risk since they know what's wrong with the salvage car, but they're more afraid of the price to fix what they don't know about in the older one. If I'm right, that would suggest that the real barrier to vehicle longevity isn't the mileage or the resale value, but the cost of repairing it. Finally, I think it's really important to dispel the notion that longevity comes from design decisions to exclude the do-it-yourself owner. There are tons of manufacturers of electrical parts. All of them adhere to the same manufacturers standards which allows interchangeability, without preventing innovation or durability. Comparatively speaking, commercial fire alarm systems are heinously expensive because they're all proprietary. There's no reason that the auto manufacturers couldn't standardize even the most advanced systems and provide technical bulletins to allow owners to repair their own stuff. There's a huge legal fight between farmers and John Deere over this. I sincerely believe that "Right to Repair" is becoming a borderline civil rights issue. We are fast approaching the point where owners will need a subscription to use their own property. I recently read that BMW was proposing a subscription service for luxury functions like Air Conditioning. That way they can continue to collect revenue for the entire lifespan of the car. Tesla is already doing similar things with their vehicles. During the California wildfires last year, Tesla "unlocked" extra range in all the California Teslas to permit people to escape. Sure, that was a kind thing to do, but what if they decided not to be kind? What would you pay to escape in such a situation? This is the true cost of artificial price inflation, which is only possible when all the other options for consumers are traded away.

Thomas, I think your question has a few layers to it which can be addressed via the original point of this post. You're basing the longevity expectation of modern vehicles on the survivors which raises the question or whether or not the barrier to self repair is a good thing. This completely overlooks the fact that the barrier to self repair raises the cost of the repairs at a shop. That in turn, makes it less economically viable for owners to risk the expense of doing a costly repair, knowing that the vehicle may soon suffer more problems. I've owned eight vehicles in my life, and I've been provided with three company vehicles in my career. Out of that eleven, only two made it above 100K miles before encountering a "death spiral" of repair costs. I don't think I'm the only one who sees spending 50% of the vehicles current worth three to four times a year as a bad investment, especially when working a job that really requires a car. I will concede that those two vehicles could have been repaired, and it's theoretically possible that their pattern of breakdowns would have ceased for a while. I will also conceded that the annual cost of repairs on the worst of years was still lower than a year of new(er) car payments. That being said, it can be difficult to maintain your cashflow when the daily driver is randomly racking up huge bills. Timing alone can make these costs far more significant to a person who's barely getting by financially. This goes double when the breakdowns cost your working hours. If these cars weren't built to prevent owners from doing the work themselves, more people would be able to afford the repairs. I think the way to measure this would be to look at the salvage and trade-in inventory. It wouldn't surprise me if the repair costs became unmanageable for the majority of owners at around 150K miles.

Thomas, Your comment about "throw-away society" reminded me of something. If you peruse a typical survival manual, you'll likely find all sorts of information on how to convert resources into useful products for survival. A great example is how to make cordage which has a lot of survival applications. However, it's pretty rare for a survival manual to address preserving, maintaining, and and re-using cordage. This despite the fact that it's actually a lot of work to convert vegetation into viable cordage in most environments. As for the high mileage brag, I think there's an industrial movement playing a bigger role than social trends. Cars are significantly more difficult to repair with basic tools than they ever were before.

During WWII there was a statistician named Abraham Wald who took part in an analysis of bomber planes that had returned from combat. The military thinking to that point was to add armor to the parts that were getting hit since it seemed fairly obvious that was where the bullets were landing. Wald's group told the military to add armor to the parts of the bomber that were not hit. They reasoned that the damaged parts were obviously not critical because the only examples to inspect post combat had survived. This suggested that the difference between the planes that were shot down, and those that survived was that the survivors were not hit in critical areas. I read this and immediately recognized the utility of this thinking in business, specifically starting a businesses. Lots of new businesses fail despite having many of the same characteristics as ventures that were successful. In fact, the entrepreneurs tend to use successful businesses as a model for what their operation. Business schools spend a lot of time on case studies where they go over the surviving wreckage and make recommendations. We see a lot of emphasis placed on adding risk mitigating "armor" wherever the entrepreneur felt they took damage. I know a guy who's a perfect example of this. When he started, his entire business plan was mostly two slogans; "The first thing a business needs is a client" and "Pigs get fat, hogs get slaughtered". He spent his first six years in business painfully chasing one profitless job after another. He couldn't bring himself to admit that some clients are very bad for business, so he focused on constantly seeking a level of graft that was high enough to compensate, without attracting so much attention that he was kicked off the bid lists. Raising change order pricing was just adding armor where his "wings" were getting hit. The jobs weren't profitable in their own right, so the higher change order prices only brought it back to break-even. Meanwhile, the true key to his success was in the areas he paid the least attention to. His positive attitude, and excellent communication skills made him less stressful to work with than his competitors. Building trust with better clients never occurred to him, because his history of earning the trust of bad clients had no observable effect.

Jealdi, Steve beat me to it. He knows what he's talking about.

There's a purpose-built version of a 12" adjustable wrench with a hammer poll on one side. It's my understanding that miners would stick a 12" adjustable wrench in their back pocket. When they needed to set an anchor in the ceiling of a shaft, they rapped it home with the edge of the wrench, then tightened the bolt to expand the anchor with the wrench. Somebody noticed that the miners were breaking a lot of adjustable wrenches so they made the hammer version. I just checked, and McMaster Carr sells them under the name "adjustable wrench with hammer face". Interestingly, "hammer wrench" in their catalog refers to an open end wrench which has a striking block on the far end of the handle. Apparently you whack the striking block with a hammer to knock a fastener looser or tighter.

If you do decide to hire an electrician to bring you a new 240V circuit, I would recommend having them install a proper #12 CU SO cord instead of that NM-2 cable which is definitely not approved for that use.

Stone, You might ask your home insurance provider to quote it for you. Be advised that insurance is a tricky subject. I have a carpenter neighbor who had an insurance policy to cover all his tools which where in a trailer, parked on his property. One day he parked the trailer on the street right in front of his home. Some thief broke in and stole several tools. The insurance company denied the claim because the trailer wasn't parked in the driveway. The kicker was, that the insurance would have covered him if he'd parked the trailer any place between his driveway and his job sites. According to the agent, the only place he wasn't covered was the street in front of his home. That nasty little loophole wasn't mentioned when he priced the policy. Another thing that comes to mind is to be very, very, careful about having only listed equipment in your home shop. Most insurance policies have a provision which requires that only listed equipment be on the premises. Stuff like electrical forge blowers are almost always in violation. Hiring an electrician to hook it up won't make any difference. The problem in that case isn't the quality of the work, the problem is that there's no listing agency approval for the completed assembly. I've heard of insurance claims for stuff like flooding being denied for having an unlisted chandelier installed in the home. There are a lot of super-cheap import electrical tool makers who are not listed. Be sure you check.

Nodebt, It was my extremely superficial understanding that their extraction process was chemical as it involved volatile stuff like Benzine.

Nodebt, your comment reminded me of something I've only had a passing interaction with. According to several local authorities having jurisdictions, the process to extract THC from Marijuana must done in "explosion-proof" rooms. As one might expect, these rooms are terrifically expensive to build. From what I've seen of explosion proof rooms in this industry, there are no interlocks preventing (or even warning) someone from opening the explosion proof door when there are high concentrations of explosive vapors in the room. There are no airlock anteroom chambers either. The risk just wasn't worth it for us to take on those jobs.