Kristin Huff | Blackstone Laboratories

About Kristin Huff

Kristin deviated from the family flock by attending Indiana University, earning an English degree. She worked as an editor and writer in Colorado and Michigan before the siren call of Blackstone brought her back to Indiana. Kristin started at Blackstone in 2002 and has since learned to love the intoxicating world of oil analysis. When she’s not working on the website, creating newsletters, doing HR stuff, or writing reports, Kristin enjoys running, swimming, gardening, and working on visiting all 50 states with her husband and kids.

Blackstone and the Post Office

(TL;DR: You can use the labels that are on your kits now, but if you’d like new ones, you can print one here.)

“I am FED UP,” said the customer on the phone. “Do you even have my sample? I mailed it a month ago.” I looked up his tracking number and he wasn’t exaggerating – he mailed it September 15, and we had just received it that day, October 15. Sound familiar?

Why is it taking so long for samples to arrive? And what are we doing about it? Read on, Blackstone fans. Have we got a story for you.

The Post Office makes some changes

“I think the post office isn’t charging us enough.” Ryan Stark, Blackstone’s president, and my brother and business partner, said to me one day last November after reconciling the checkbook. He’d noticed that for the last few months, the amount we were paying in postage had dropped significantly.

Stick with me, this is all going to tie together.

Last summer, just as we were all realizing the pandemic was not simply going to disappear, I learned the post office was ending their Merchandise Returns program. Because our samples came back to us on MR labels, we needed to create a new one, so I had my printer start working on it.

A major part of that process is getting approval from the USPS at various points along the way. And that’s where the process slowed…then slowed down some more…and then, like molasses on a winter sidewalk, came to a creeping halt.

We called USPS. How’s the label going? No reply. We emailed. How’s the label coming along? Nothing. Time passes. Months go by. Sometimes we’d get a reply – “We should have an answer for you soon!” But then…nada.

Back to the money

Meanwhile, the issue of not paying enough postage was still a problem. What do you do when you think the USPS isn’t charging your business enough? You call them – so I did.

I first contacted my local post office – the ones who deliver us samples every day, the ones who know who we are and what we do. “I think we’re not being charged enough,” I explained. “Nope, that’s not me,” she said. “They take care of that in Indianapolis now.” She gave me a number, so I called down to Indy. “Huh,” the Indy person said. “Let me look into it.”

Reader, you can see where this is going.

I got nowhere in November, so I called again in January. “Hey!” I said. “I still don’t think we’re getting charged enough!” “Hmmm” said the voice on the line. “Let me ask my supervisor about that.”

Time marches on. After calling and emailing various USPS representatives throughout February and March, I got fed up in April and sent an email blast to every single USPS contact I had, including the ones in Washington, D.C.

That one got some attention.

They started looking into what was going on, and to make a long story short, the issue culminated in a conference call with several USPS bigwigs. “Well,” said Bigwig #1, “you owe us (insert a huge amount of postage here. Nope, it was more than that).

It turns out that when the USPS stopped their Merchandise Returns program, our local post office stopped charging us for our incoming samples. We were still being charged for outgoing mail, but we hadn’t paid postage on incoming samples since the MR program ended in August.

After much gnashing of teeth and some heated words on my end (would they ever have caught the problem if I hadn’t kept after them? We’ll never know), we settled on a plan to pay the outstanding postage.

As part of this reconciliation, one of the USPS Bigwigs suggested we have samples returned to us in a Tyvek envelope, to help catch spills. Well, oil spills aren’t really the problem with getting samples delivered, but I tucked the idea away for the future.

Back to the labels

Meanwhile, the new label still had not been approved. And people still needed kits. While all this was going on, we continued to print and send out hundreds of thousands of old labels on kits. What choice did we have? Now those old Merchandise Return labels are now on kits that are sitting in garages, hangars, and marinas all over the country.

So when did we get it resolved? We officially started printing our new, USPS-approved labels more than a year after the old label was officially discontinued. The thing is, the post office reassured me that it would be fine to continue to use our old label – we would just have to pay more when people returned them.

Which is fine. Fine, fine, fine. Except, for some post offices, it’s not so fine. Most of those old, Merchandise Return-labeled kits get here no problem. But occasionally, a post office will hold on to it and not deliver it because it’s the old label, even though they said we could keep using them.

At this point, there’s nothing we can do about the thousands of old labels that are in circulation except try and get the word out. So that’s why you’re reading this. If you have old labels on your kits (they say Merchandise Return right on them), click here to ask for new ones. We really do want to receive your samples. And we don’t want you to have to wait for a month to get your results.

But wait, there’s more!

So while all of that was going on, Travis – a long-time Senior Analyst-turned-coder – had an idea. “What if,” he said to me one day, “we do a test to see if putting samples in a Tyvek envelope helps with the return postage time?” Because although oil spills aren’t a significant problem, it does seem to be a problem that the mailer is 1) small, and 2) clearly headed for a laboratory. Putting the oil into a Tyvek envelope might solve both issues. So we started a test – for one month, we sent all outgoing kits with a labeled Tyvek envelope for returning the sample to Blackstone.

The results were immediate and striking: this was a winner. We didn’t even run the test for the full month. The data Travis put together showed that return times were cut in HALF (from an average of 8.74 to 3.48 days) when samples came back to us in the Tyvek envelope. (See the sidebar.) We stopped the test and immediately started including Tyvek envelopes with each kit order, for return samples.

USPS supporters

Despite the problems, we are proud supporters of the United States Postal Service. No other carrier offers service to every single part of the US, no matter how remote. Lots of people don’t have access to UPS or FedEx, though if you want to use them to send in your samples, that’s absolutely fine.

The changes we’ve made to our label and the return package are already paying off in getting samples to us in a timely fashion. If you need new return envelopes and labels for your kits, let us know – we’re happy to send them out!

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Update! The Post office has discontinued their First Class Return labels (my new mantra: change is good…change is good). We are now using Ground Advantage labels. All the same things in this article still apply. You can use the First Class return labels, but your sample will arrive faster with a Ground Advantage label. You can print one off right here.

By Kristin Huff|2024-09-19T10:15:59-04:00July 19, 2023|Aircraft, Articles, Gas/Diesel Engine, Industrial, Marine|Comments Off

Pre-Ignition and Detonation

The information (and harrowing pictures!) that follows is reprinted courtesy of the FAA.

Pre-ignition. Detonation. Both can be deadly. But what’s the difference? And how can you avoid them?

This engine is from a Beech S35 Bonanza’s fatal accident. The #6 piston was eroded and began to melt. The rings and piston skirt were compromised by thermal expansion and metal transfer. Note the deep pitting and erosion of the piston face. This caused combustion gases to bleed into and over-pressurized the crankcase, forcing engine oil out the breather. The connecting rods then failed due to the lack of lubrication and smashed holes in the crank case, causing loss of power and engine failure.

Normal combustion vs. pre-ignition

Normal combustion is an orderly, progressive burning of the fuel-air mixture in the cylinders. The gasses within the cylinders are ignited from the top. The flame then travels down in an organized way. This combustive force, equally applied to the piston in a stable manner, pushes the piston down. The downward motion of the piston is then mechanically transferred to the propeller. This makes pilots very happy.

In a pre-ignition event, combustion is abnormal. It happens when the air-fuel mix ignites before the spark plug fires, while the piston is still moving up in the compression cycle. The ignition can be caused by a cracked spark plug tip, carbon or lead deposits in the combustion chamber, a burned exhaust valve, an ignition system fault, or anything that can act as a glow plug to ignite the charge prematurely.

When this happens the engine works against itself. The piston compresses and at the same time the hot gas expands. This puts tremendous mechanical stress on the engine and transfers a great deal of heat into the aluminum piston face damaging the piston. Engine failure can happen in minutes.

Detonation

As the name suggests, detonation is an explosion of the fuel-air mixture inside the cylinder. It occurs after the compression stroke near or after top dead center. During detonation, the fuel/air charge (or pockets within the charge) explodes rather than burning smoothly. Because of this explosion, the charge exerts a much higher force on the piston and cylinder, leading to increased noise, vibration, and excessive cylinder head temperatures.

The violence of detonation also causes a reduction in power. Mild detonation may increase engine wear, though some engines can operate with mild detonation. However, severe detonation can cause engine failure in minutes. Because of the noise that it makes, detonation is called “engine knock” or “pinging” in cars.

High heat is detrimental to piston engine operation. Its cumulative effects can lead to piston, ring, and cylinder head failure and place thermal stress on other operating components. Excessive cylinder head temperatures can lead to detonation, which in turn can cause catastrophic engine failure. Turbocharged engines are especially heat sensitive.

Some causes of detonation include:

improper ignition timing
high inlet air temperature
engine overheating
oil in the combustion chamber
carbon build-up in the combustion chamber

A combination of high manifold pressure and low rpm creates a very high engine load, which can also cause detonation. In order to avoid these situations:

When increasing power, increase the rpm first and then the manifold pressure
When decreasing power, decrease the manifold pressure first and then decrease the rpm

Pre-ignition and detonation results

The explosion of pre-ignition and detonation is like hitting the piston with a sledge hammer. The automotive term for the sound it makes is “ping” (something pilots cannot hear in aircraft). The ping sound is the entire engine resonating at 6400 hertz. It sounds like a ping, but it is an explosion with enough power to make the engine resound like a gong.

Both pre-ignition and detonation put tremendous mechanical stress on the engine and transfer a great deal of heat into the piston deck. This can cause the piston to melt (EGT is 1600 degrees; aluminum pistons melt at 1200 degrees). The force of these explosions can knock holes in pistons, bend connecting rods, overcome the lubrication film in the rod bearings, and hammer the babbitt out of rod bearings. Engine failure can happen in minutes.

The bent connecting rod at the start of the article is a good example of the damage pre-ignition and detonation can do.

These cylinder #2 spark plugs are packed with melted piston material.

Here’s what happens

This is a cylinder head showing signs of pre-ignition or detonation.

The carbon coating that normally lines the head dome is knocked off. There is melted piston material in the head and the cylinder sleeve is scored by the overheated piston.

This is the same piston , but note that the piston deck is eroded.

The rings are broken. The piston skirt is scuffed from rubbing on the cylinder wall. A piston in this condition allows combustion gases into the crank case. This over-pressurizes the crankcase and blows engine oil out of the crank case breather — all of the engine oil, in minutes.

Soon after the engine oil departs the connecting rods try to make a break for it, resulting in giant holes in the crank case.

How do I detect pre-ignition?

A rough-running engine can be the first sign of pre-ignition or detonation. High EGTs or CHTs can be a sign of a problem so be sure to keep an eye on that if you can.

Below are common indications of detonation. You should have increasing oil temperature, not pressure. The top left gauge is RPM. The top right is manifold pressure.

What do I do when it happens?

Since excessive heat can be so damaging, your main priority is to cool the engine:

Reduce power
Increase airspeed
Enrich the fuel mix
Open the cowl flaps.
Land immediately!

Preventing Pre-ignition

Do not take off unless the run-up is perfect
Maintain the ignition system
Pay attention to cylinder compression tests
Use the proper heat range spark plugs
Make sure cooling baffles are in good repair

Preventing Detonation

Lean the engine per the flight manual
Keep engine load to a minimum
Do not over boost
Use only the recommended fuel grade
Make sure engine timing is properly set
Make sure cooling baffles are in good repair
Be wary on hot, dry days
If in doubt, run rich

By Kristin Huff|2024-09-18T13:48:58-04:00July 18, 2023|Aircraft, Articles|Comments Off

Particle Count Test

The ISO Code (also known as the particle count test) is a system for representing particle concentrations in oil. The test is commonly referred to as the particle count. Without the use of the ISO Code, a confusing series of numbers would have to be examined to determine how clean an oil is.

In oil laboratories, automatic particle counters determine the ISO code. Below is a particle count report for hydraulic oil.

The particles are counted in six different size ranges (see the sample Particle Count test results below). Every particle count test by Blackstone is reported in ISO 4406 (2- and 3-number codes), NAS 1638, and SAE AS4059 formats. The left column shows the size in microns. The right column is the number of particles per mL of sample that were found to be larger than each micron size. In the chart below, the number of particles larger than 14 microns in size was 169.2.

The ISO 3-number Code in this example is 18/17/15. These three numbers (18, 17, and 15) identify a range of particles counted in the size above 4, 6, and 14 microns, respectively.

The ISO 2-number code in this example is 17/15. Those two numbers (17 and 15) identify a range of particles counted in the size above 5 and 15 microns in size. The chart does not list the actual number of particles counted at 5 and 15 microns.

The higher the ISO Code, the dirtier the oil. However, different oils can have different allowances for what we deem “clean” or “dirty.” The chart below shows the clean to dirty ranges for four types of oil:

But wait! How do we arrive at the 18/17/15 or 17/15 range? Using this chart:

Confusing, right? That’s why we use the code. Most equipment manufacturers will list guidelines as to what cleanliness code is acceptable, and that’s all you need to know.

By Kristin Huff|2024-09-19T10:32:30-04:00July 13, 2023|Articles, Industrial, Lab Tests|Comments Off