Expanding Foam For Filling Post Holes

So, the reason I'm posting these is that there's apparently a new-to-me use for the expanding polymer foam that we use in our polymers labs: filling post holes.

I've always heard of using cement - or quickcrete - for setting fence (or mailbox or basketball goal) posts, but I guess expandable foam could be strong enough to work.

There are multiple options, however, not just Sika's product.



The above video - made by Secure Set - demonstrates that their product is far superior to Sika's and that Sika's product container while convenient can be explosively dangerous (2:54).



Admittedly, the Secure Set videos just might be a little biased toward their product.

Then again, so is the Rainbow Foam video. Though I like their clinical narration and reasonably consistent tests.



I do with they would name what product P and product B are. I have to assume those initials were chosen because they fit the product names that I just don't know.

Oh, and there is a bit of blood in this video as the mute demonstrator cuts himself in the video cut between 9:10 and 9:14. It's not spurting blood or anything, but I thought I'd warn you.

And I am kinda glad we get to finally see the demonstrator's face at 16:35.

Admittedly, that last video is way too long, but I appreciate that they show that the tests have to be performed on each of the products with reasonably repeatable precision.

Updated cKit manual!!!!!

Edit: 3/15/25 - NACE is now AMPP. Their links have changed.

• Ckit labs and resources - link

We've been giving out cKits from the National Association of Corrosion Engineers (actually, they're just NACE now) at our ASM summer teachers camps for quite a few years now. The Kit is outstanding, and contains a lab manual, a comic book of Inspector Protector, a set of electrodes, a multimeter, a booklet about NACE, and a CD of the lab manual.

All of which is great...

...except the lab manual.

Which was great once but has been recently showing its age. The labs were developed by some of our ASM master teachers for NACE, and you can see their students in the lab photos. Since the labs were developed nearly twenty years ago now, however, our procedures have been refined and adjusted to be more successful, more portable, and often less wasteful. During the summer camps, then, we've been sharing the adjusted procedures and telling our campers to make those adjustments in spite of what the lab manual says.

But now we won't have to do that anymore because the lab manual has been updated.

I'll admit that I'm going to miss the iPhone-commercial-like graphics, but I'm thrilled that the manual now includes our procedure for brassing a penny.

In case you've taken our camp already and have the old version, a pdf version of the new manual has been posted by NACE on their website.

Material Science Girl's website

Material Science Girl is one of our ASM, summer camp, master teachers. She's at Tolles High School on the far west side of Columbus, a vocational high school that teaches two years of material science.

Her curriculum - created and taught along with another master teacher at Tolles - started out being pretty similar to our summer camps but has grown and evolved from there.

As a way to share documents and videos with her students - and with you and us - she made a website (matscigirl.weebly.com).

On the site, she has absolutely no personal information about herself, but she's pretty awesome. She does have individual sections about...

• ASM summer camps
• Solids
• Metals
• Ceramics & glass
• Polymers
• Composites

Sadly she doesn't have photos of the outstanding projects that her students made, but she does have a whole bunch of articles, worksheets, and lab instructions that she uses in class.

Plus she's used only her own in-class photos to mark the website sections.

How is plastic recylced?

The short answer to Andy Brunning's question, of course, is that it's recycled badly and far too infrequently.

I'm typing this up on Earth Day - though it won't post for a month or so now - and am just torn up that less than 20% of the PETE is being recycled, but I watch my students through water bottles away all the time even though the recycling bin in two inches to the left of the trash can.

I don't have any idea why recycling is so infrequent because it just seems like an automatic thing to me at this point. I'm the one carrying cans away from meetings because there aren't recycling bins in our meeting rooms.

Why Concrete Needs Reinforcement

It's the jorts (2:39), the New Balance shoes, and the pasty, white legs of one Grady Hillhouse that really endear this video to me.

Yes, Grady's style is a little dry, but he does a marvelous job showing very basic concepts of engineering as they apply to our everyday world and not just talking about the concepts but rather by building and showing small, graspable demonstrations.

In this video, Grady shows...

• how much force it takes to break two 'identical' concrete cylinders - one under tension, one under compression
• concrete beams (fairly thick beams) tested to failure with a four-point break test - a beam with no reinforcement, with 'rebar' reinforcement, and with pre-stressed 'rebar' 

Dissimilar metals and Galvanic Action - Acorn to Arabella

A little background first, the YouTube channel Acorn to Arabella...

We are building a 38’ wooden sailboat designed in 1934 by William Atkin. Atkin calls this particular boat “Ingrid” but our vessel will be named “Arabella”, once built we intend to take her to the most far flung corners of the world. We are documenting every aspect of the build as we go, we hope to inspire and educate people along the way and to experience as much of this wonderful world as possible in the process.

In this week's episode (or rather the episode from April 13, 2018), Steve (the guy with the awesome beard) is looking at using various metals as fasteners on the boat. Apparently it matters whether the metal is very reactive (less noble) or not very reactive (more noble).

Specifically, Steve puts various metal samples in salt water alone and in various combinations to see which metals should and should not share fasteners in the boat.

I haven't yet checked out the follow-up where Steve looks at the effects of the metal corrosion on various woods.

You Can Hear The Difference Between Hot and Cold Water

The title of the video, "You Can Hear The Difference Between Hot and Cold Water," is clearly wrong and stupid.

There's no way that you can hear the difference between hot and cold water at all.

Except that the video makes clear that you can...because of viscosity.