I'm trying to source my pool equipment o-rings by trade sizes and material.
I've figured out all the trade sizes; but does anyone know the material?

Buna? Viton? Nitrile? Silicone? Butyl?
Does it matter?

If nobody knows, I'm going to go with Viton; but it would be better to
know for sure what the OEM material is for pool pump o-rings.

On Sat, 25 May 2013 06:56:48 +0000, Danny D. wrote:

I've figured out all the trade sizes; but does anyone know the material?
Buna? Viton? Nitrile? Silicone? Butyl?

Of the zillions of o-ring reference for pool pump parts on the web,
this is the only one I've found, so far, that mentions the material.

http://www.ebay.com/itm/Sta-Rite-O-R...-/190660713317

On Sat, 25 May 2013 08:19:11 +0000, Danny D. wrote:

This listing also mentions pool o-ring material; but it is confusing at best.
http://tinyurl.com/nojnt73
http://www.theoringstore.com/index.p...ducts_id=18551

24850-0009 Sta-Rite Tank O-Ring - System 3 Filter, 25 inch diameter
Alladin O-486
The o-rings listed are made from Buna, Viton or EPDM compounds.
All pool o-rings are made from Buna unless otherwise stated.
If you are running a chlorine system and can not locate the Viton o-ring
that you need, please contact us to make sure one is available.

From that, I can't tell if pool o-rings are buna or viton.

On Sat, 25 May 2013 08:30:21 +0000, Danny D. wrote:

From that, I can't tell if pool o-rings are buna or viton.

This pool o-ring blog implies they're EPDM (but they seem to have
their facts wrong on Buna-N so I can't really trust their advice).

http://blog.poolcenter.com/article.aspx?articleid=6082
"Swimming pool pump and filter o-rings are typically made with EPDM rubber,
while chlorinator o-rings are usually made of a Fluorocarbon, Viton or FKM.
Some more expensive types are made with a Nitrile rubber, used in Buna type o-rings."

On Sat, 25 May 2013 10:46:58 -0400, gfretwell wrote:

I doubt it really makes much difference.

I tried calling Aladdin Equipment (941-371-3732) today (http://www.aladdin1950.com)
to ask what they make their kits out of, since they use trade sizes in their kit
descriptions; but they're not open on Saturdays.

Swimming pool water is about as benign a fluid as you can find.

I was thinking sunlight + water + chlorine + acid was the environment.
Note: Sunlight might be eliminated once installed though.

This is a reference
http://www.grainger.com/tps/pumps_ch...patibility.pdf

Wow! Thanks. Comprehensive. A keeper! Mostly for metals though.
They list Buna-N (aka Nitrile) & Viton, & maybe Silicone; but not EPDM, nor Kalrez.
Note: They list "Silicon" in the rubber section, so maybe that's a typo?

Googling for o-ring materials, it seems the material choices go in this order:
a. First see if Buna-N (Nitrile) will work (because it's the cheapest solution).
b. If that won't work, use Silicone,
c. If that won't work, use Viton (Fluoro-elastomer),
d. If that won't work, use EPDM,
e. If that won't work, use Kalrez (perfluoro-elastomer).
REF: http://www.metrogasket.com/o-rings/m...tion_guide.htm

On May 25, 7:46*am, wrote:
On Sat, 25 May 2013 06:56:48 +0000 (UTC), "Danny D."

wrote:
I'm trying to source my pool equipment o-rings by trade sizes and material.
I've figured out all the trade sizes; but does anyone know the material?

Buna? Viton? Nitrile? Silicone? Butyl?
Does it matter?

If nobody knows, I'm going to go with Viton; but it would be better to
know for sure what the OEM material is for pool pump o-rings.

I doubt it really makes much difference. Swimming pool water is about
as benign a fluid as you can find.
When I lived in DC my city water tested "ideal" on a 2 bottle pool
tester.

If you are actually in the chlorinator itself, that is a more hostile
environment.

This is a reference

http://www.grainger.com/tps/pumps_ch...patibility.pdf


http://www.grainger.com/tps/pumps_ch...patibility.pdf
Swimming pool water is about as benign a fluid as you can find.
+1

DDD-
If you want to educate yourself to reasonable level about O-rings &
O-
ring material apps,' go to McMaster Carr catalog and search on O-
rings.

If you REALLY want to learn about O-rings

http://www.parker.com/literature/ORD...g_Handbook.pdf

Hint.... my dad & I used o-rings in pools for many years without ever
researching materials.
Pool O-rings ain't rocket science or PhD work.

"I was thinking sunlight + water + chlorine + acid was the
environment.
Pool water is nearly drinkable except for the salts / hardness level.

KISS

Calm down....you're over thinking (& incorrectly at that) nearly
everything you approach.

Ya know...your calls to all the mfr's may seem "free" but the true
cost is coming out of the shareholders or owner's pocket.
Reduce the clutter......

Get some Buna-N's from McMaster & be done.
If they fail (which they won't) replacement with EDPM.

On Sat, 25 May 2013 11:44:42 -0700 (PDT), DD_BobK
wrote:

researching materials.
Pool O-rings ain't rocket science or PhD work.

Nope. They are not. A kit for his pump is ~ $25, local.

Danny is showing his "Accountant" attributes. Counting beans...

Sausage is good with eggs. Not something you would see being made.

Danny stop complicating a minor concern.

Danny:

No. If nobody knows, then go with nitrile rubber because it's the most widely used rubber for making O-rings, and so not only will every O-ring you ever need to buy be available and in stock in nitrile rubber at any place that sells O-rings, but nitrile rubber O-rings are very much cheaper than any other kind of rubber O-ring. An O-ring that costs 12 cents in nitrile rubber will cost 2 dollars in EPDM rubber, and it's not because EPDM rubber will last 20 times as long. It's because there's 20 nitrile rubber O-rings made and sold for every EPDM rubber O-ring made and sold, and it's mass production and greater availability from competitors that brings down the cost of nitrile rubber O-rings.

Read my post in the thread by PeteCresswell entitled "Enhancing an O-ring Seal" just about 10 threads below yours. That will explain everything you need to know about O-rings.

Maybe print off that post and show it to the manager of any place that sell's O-rings in your area to get his comment.

On Sat, 25 May 2013 11:44:42 -0700, DD_BobK wrote:

Get some Buna-N's from McMaster ...

OK. Makes sense. Pool water is practically drinking water.
I'll go with the basic 50-cent Buna-N (aka Nitrile) o-rings then.

For accuracy, the one thing I need to better understand are
what the trade sizes actually indicate.

The trade sizes don't seem to follow any obvious rhyme
or reason.

For example, the tiny drain plug o-ring is a 0-39 but the
much larger basket cover o-ring is a 0-12 while the slightly
larger seal plate housing o-ring is a 0-240 and the hugely
larger filter body o-ring is a 0-486.

They don't follow any order that I can discern.

Is the o-ring trade size merely from an arbitrary lookup table,
or is there a definable logic to the trade-size designation?

- ~1" drain plug o-ring (x2) U9-359; trade size O-39
- ~3" diffuser o-ring, U9-37A; trade size O-83
- ~3" filter union o-ring U9362, trade size unknown
- ~2" pre1998: Insert o-ring U9-376; trade size O-113
- ~10" trap cover o-ring, U9-375; trade size O-12
- ~12" seal plate housing o-ring, U9-228A; trade size O-240
- ~25" filter body o-ring 24850-0009; trade size 0-486

I looked at the diagram for the pool pump you posted. In my experience, that large and small O-ring together shouldn't cost any more than $2 or $3 in nitrile at any shop that sells O-rings. The manufacturer will charge you $25 for those two O-rings as a repair "kit", but only people that are scared to buy anything but OEM repair parts would ever pay that much. Maybe just take your old O-rings down to any place that specializes in pneumatic and hydraulic seals, and they'll size the O-rings for you. EVERY O-ring meant for plumbing applications I've ever come across has been 70 durometer hardness, and so if you buy 70 durometer nitrile rubber O-rings to replace what you have, they should work fine for you.

On Sat, 25 May 2013 12:13:55 -0700, Oren wrote:

Danny is showing his "Accountant" attributes. Counting beans...

I'm still shocked you know I'm an accountant!
(I must start counting Huckleberries when you say they're in season!)

The problem with the kits, by the way, is that they're incomplete.
http://www.aladdin1950.com/index.html

For example, the Aladdin GO-KIT38-9 for my pump is missing the drain
plug o-rings; and there doesn't seem to be a filter o-ring kit for
the 25-inch diameter Sta-Rite System 3 Model S8M150 filter tank.

On May 25, 3:45*pm, Danny D wrote:
On Sat, 25 May 2013 11:44:42 -0700, DD_BobK wrote:
Get some Buna-N's from McMaster ...

OK. Makes sense. Pool water is practically drinking water.
I'll go with the basic 50-cent Buna-N (aka Nitrile) o-rings then.

For accuracy, the one thing I need to better understand are
what the trade sizes actually indicate.

The trade sizes don't seem to follow any obvious rhyme
or reason.

For example, the tiny drain plug o-ring is a 0-39 but the
much larger basket cover o-ring is a 0-12 while the slightly
larger seal plate housing o-ring is a 0-240 and the hugely
larger filter body o-ring is a 0-486.

They don't follow any order that I can discern.

Is the o-ring trade size merely from an arbitrary lookup table,
or is there a definable logic to the trade-size designation?

- ~1" drain plug o-ring (x2) U9-359; trade size O-39
- ~3" diffuser o-ring, U9-37A; trade size O-83
- ~3" filter union o-ring U9362, trade size unknown
- ~2" pre1998: Insert o-ring U9-376; trade size O-113
- ~10" trap cover o-ring, U9-375; trade size O-12
- ~12" seal plate housing o-ring, U9-228A; trade size O-240
- ~25" filter body o-ring 24850-0009; trade size 0-486

Homework assignment....

Did you visit McMaster?
Attempt to investigate trade sizes?
Or are you asking more questions before doing any due diligence?

I get the strong impression you were the guy (characterization
skipped) who asked a ton of questions in class in lieu of thinking.

On May 25, 3:54*pm, "Danny D." wrote:
On Sat, 25 May 2013 12:13:55 -0700, Oren wrote:
Danny is showing his "Accountant" attributes. Counting beans...

I'm still shocked you know I'm an accountant!
(I must start counting Huckleberries when you say they're in season!)

The problem with the kits, by the way, is that they're incomplete.
*http://www.aladdin1950.com/index.html

For example, the Aladdin GO-KIT38-9 for my pump is missing the drain
plug o-rings; and there doesn't seem to be a filter o-ring kit for
the 25-inch diameter Sta-Rite System 3 Model S8M150 filter tank.

The guys who regularly post on AHR are pretty sharp....

It would take a major brain injury for most to forget that you're an
accountant......
Especially since your ongoing behavior reinforces the image MANY times
per day.

The plant manager where I work has a saying about "stepping over
dollars to pick up dimes"... ponder that.

I think Danny just wants to take the time to make sure he's doing things as correctly as he can. That's what a university education and the principles of accounting drive into a person. I find I'm the same way whenever I start dabbling in anything I've never done before, such as when I started rebuilding my own laser printer toner cartridges. I wouldn't fault the guy for it, he's just wanting to partially compensate for not being formally instructed on how to rebuild that pump by using the best parts he can when rebuilding it. His only other option is to buy a "repair kit" for the pump, and that means paying $25 for $5 worth of O-rings. That's always the case cuz the company making the repair kit knows it's customers don't know anything about O-rings and would be scared they'd buy the wrong ones.

Danny:
Your best bet would be to take the O-rings out of your pump down to any place that sells O-rings to the hydraulic and pneumatic cylinder and valve repair shops in your area, tell them they're from a swimming pool pump and follow their advice. My guess is that they'll sell you the same 70 durometer nitrile O-rings that are what everything in plumbing uses, and you'll have everything you need for less than $5.

I have 66 faucets in my building; 21 kitchen faucets, 21 bathroom sink faucets, 21 Tub & Shower faucets and three laundry room sink faucets. I can't remember the last time I bought an O-ring in a hardware store or plumbing wholesaler. I buy all of my O-rings from Kepco Sealing Supplies in Winnipeg, and they primarily cater to the hydraulics and pnuematics industries, not to the plumbing industry. But all the plumbing hardware you buy in North America uses standard size O-rings, just like the hydraulics and pneumatics sector of the economy does, so they're completely interchangeable. The manufacture doesn't know which O-ring is going onto a kitchen faucet spout and which one is going into a pneumatic cylinder, he just makes them to the standard size out of the same rubber, and the O-rings he sells can be used equally well in either application.

On Sat, 25 May 2013 16:48:19 -0700, DD_BobK wrote:

Attempt to investigate trade sizes?

I have read the o-ring charts and PDFs, e.g., this chart:
http://www.allorings.com/size_cross_...nce_framed.htm

And this PDF (starting on page 7):
http://www.callapg.com/downloads/oring_catalog.pdf

In these charts, the O-### goes up with increasing size of
the o-ring; yet, in the list of O-rings I'm trying to doublecheck,
that relationship does *not* hold true.

If nobody can easily explain why, in a single sentence or so,
that means that they actually don't understand this any more
than I do.

That's OK; but for you to intimate otherwise, without
actually providing that single sentence, implies that you're
in the same boat that I'm in on this sizing discrepancy.

On Sun, 26 May 2013 06:06:57 +0000, Danny D wrote:

In these charts, the O-### goes up with increasing size of
the o-ring;

I should clarify that statement, by saying that for o-ring sizes
from O-001 to O-050, the designation increases as the size of the
O-ring increases.

Then the size designation jumps, to O-102, where it starts all
over again, tracking size up to O-178.

Again, there is a discontinuity, until we get to the range
of O-201 to O-284, where, again, increasing size tracks
increasing number.

Another discontinuity; and then we start at O-309 to O-395
for the next set ... until we jump to O-425 to O-475 for the
penultimate set ... and finally, we have O-901 to O-932 for
the final range.

Within a range, the o-rings increase in size with increasing
O-### designation. There are six ranges.

I'll have to dig deeper to see what the variants are that
determine the six ranges. Probably it's a ratio thing of the
key measurements to themselves.

If anyone knows offhand, why the six ranges - let us know
in a single sentence if it's not a ratio thing.

On Sun, 26 May 2013 06:17:26 +0000, Danny D wrote:

If anyone knows offhand, why the six ranges - let us know
in a single sentence if it's not a ratio thing.

Ah, digging deeper, I find the six "groups" are numbered
1, 2, 3, 4, 5, 9 (go figure) corresponding to the O-1##,
O-2##, O-3##, etc., designations, for a total of 369
standard sizes.

The first five groups are (mostly) based on cross-sectional
diameter (ranging from 0.040 to 0.275 inch). Within any one of
those cross-sectional groups, inside diameters range from
0.029 to 25.940 inches, counting upward.

Just to confuse you, the sixth group is organized by outside
diameter in 1/16 inch increments.

REF: SAE Aerospace Standard AS568B

On May 25, 11:06*pm, Danny D wrote:
On Sat, 25 May 2013 16:48:19 -0700, DD_BobK wrote:
Attempt to investigate trade sizes?

I have read the o-ring charts and PDFs, e.g., this chart:
*http://www.allorings.com/size_cross_...nce_framed.htm

And this PDF (starting on page 7):
*http://www.callapg.com/downloads/oring_catalog.pdf

In these charts, the O-### goes up with increasing size of
the o-ring; yet, in the list of O-rings I'm trying to doublecheck,
that relationship does *not* hold true.

If nobody can easily explain why, in a single sentence or so,
that means that they actually don't understand this any more
than I do.

That's OK; but for you to intimate otherwise, without
actually providing that single sentence, implies that you're
in the same boat that I'm in on this sizing discrepancy.

Sometimes it takes more than a sentence or two to explain stuff.
Sometimes people who know aren't willing to spend the time.

Sometimes systems that appear to have no consistency .... really do
have consistency & sometimes they don't.

A lot of the time you try to "delve" into things to look for meaning
where none exists.

Sometimes things just have to be believed / accepted....

think about the spelling of lots of english word, no rhyme or reason
(sometimes) just have to accept it.

On May 25, 11:06*pm, Danny D wrote:
On Sat, 25 May 2013 16:48:19 -0700, DD_BobK wrote:
Attempt to investigate trade sizes?

I have read the o-ring charts and PDFs, e.g., this chart:
*http://www.allorings.com/size_cross_...nce_framed.htm

And this PDF (starting on page 7):
*http://www.callapg.com/downloads/oring_catalog.pdf

In these charts, the O-### goes up with increasing size of
the o-ring; yet, in the list of O-rings I'm trying to doublecheck,
that relationship does *not* hold true.

If nobody can easily explain why, in a single sentence or so,
that means that they actually don't understand this any more
than I do.

That's OK; but for you to intimate otherwise, without
actually providing that single sentence, implies that you're
in the same boat that I'm in on this sizing discrepancy.

DDD-

When it comes to O-rings or anything related to O-rings.....
we're not in the same boat, not even on the same continent.

If you think I'm going to waste my time giving you an education (for
free) about O-rings,
you're even more of a DDD than I imagined.

On May 25, 11:38*pm, Danny D wrote:
On Sun, 26 May 2013 06:17:26 +0000, Danny D wrote:
If anyone knows offhand, why the six ranges - let us know
in a single sentence if it's not a ratio thing.

Ah, digging deeper, I find the six "groups" are numbered
1, 2, 3, 4, 5, 9 (go figure) corresponding to the O-1##,
O-2##, O-3##, etc., designations, for a total of 369
standard sizes.

The first five groups are (mostly) based on cross-sectional
diameter (ranging from 0.040 to 0.275 inch). Within any one of
those cross-sectional groups, inside diameters range from
0.029 to 25.940 inches, counting upward.

Just to confuse you, the sixth group is organized by outside
diameter in 1/16 inch increments.

REF: SAE Aerospace Standard AS568B

WGAF?
You focus on the silliest things......
And how many angels can dance on the head of a pin?

On Sun, 26 May 2013 00:08:05 -0700, DD_BobK wrote:

Sometimes it takes more than a sentence or two to explain stuff.
Sometimes people who know aren't willing to spend the time.

OT warning

My dad taught me that if it can't be explained, it isn't
understood. For example, what a tangent?

Last week, a friend of mine wanted to doublecheck drawings
for trapezoidal-shaped windows where he needed an overlap
of 1/2 inch all around for the window glass dimensions:
http://www4.picturepush.com/photo/a/...g/13133012.jpg

He had the numbers - he just wanted to doublecheck them.

He asked me how, and I came up with this simple formula
for the upper overlap (all other dimensions being purely
additive) given the symmetry of parallel lines, geometric
angles, & high-school trig:
Side1=tangent of (90° + angle°)/2 * 1/2 inch overlap
Side2=tangent of (90° - angle°)/2 * 1/2 inch overlap

He checked all his drawings with a calculator proclaiming
the answer correct. He then googled what a tangent was,
and apparently he got the answer that it's the slope at
any point of the curve.

He called me back, asking "What's a tangent?" because
the fact that it's the slope of a curve doesn't help
him understand what it is. Sure, he saw the graph of
a tangent on the web - but that didn't help him understand.

You know what I told him?

I said draw a one-inch right triangle with a 45° angle &
note the sides have a ratio of 1:1. The tangent of 45°
is simple the ratio of the opposite side over the adjacent
side. Now change the angle to 34° (which was his angle),
and you'll see the same ratio holds true. So you have
an equation where if you know two of the three components,
you can solve for the third. He understood.

I could have waxed and waned with using unit circles and
definition of the slope and describing sines over cosines
(like math teachers do); but, the answer (for him) was as
simple as the relationship of an angle to a ratio.

Note: He then tried to apply the tangent to degrees in
Microsoft Excel, which only uses radians, so I had to
explain radians to him; but I'll just leave that
explanation to your imagination.

Point is:
If it can't be explained simply - it's not understood.

Back on topic, now that I know the O-ring sizing scheme,
I can doublecheck my numbers.

More importantly, for the o-rings that I don't already
have the trade size for, I first measure the cross section
and that already tells me the series (as long as it's not
a boss seal). Then I measure the ID & I have the trade
size. It's that easy.

Plus, this method works for all o-rings in the household!
Learning is all the fun (the rest is just work).

On Sun, 26 May 2013 00:08:05 -0700, DD_BobK wrote:

A lot of the time you try to "delve" into things to look
for meaning where none exists.

You're forgetting that some people love to learn!

In fact, learning is more fun than actually doing the work.

For example, learning about how unions sealed using boss o-rings
while NPT threads seal with goop was more fun than getting that
goop all over my fingers.

Specifically, learning that the union o-rings are measured
differently than the sealing o-rings is more fun than twisting
unions together and not having them leak.

The meaning is in the learning - not in the work itself.

On Sun, 26 May 2013 00:08:05 -0700, DD_BobK wrote:

think about the spelling of lots of english word, no rhyme or
reason (sometimes) just have to accept it.

You'll note that I strive to not misspell words in my posts,
and that I punctuate my sentences as well as I can - and that
all my posts are readable & responsive (if a bit verbose).

So, even if I'm asking about something as mundane as how to
properly plumb a shower stall, I take pains to use the English
language as properly as I know how to use it.

It's all part of the enjoyment of understanding what is
being said and done.

In fact, you'll notice that I even have an ancillary thread
on the English-usage newsgroups asking how the word "plumb"
came about; it's interesting that the term comes from
hanging lead balls (i.e., plumbum) on the end of a string.

Learning just *that*, was more fun than the actual plumbing
of the shower stall.

On Sun, 26 May 2013 14:49:55 +0000, Danny D wrote:

My dad taught me that if it can't be explained, it isn't
understood. For example, what a tangent?

Ooops. "What's a tangent?"

Typos *do* creep into my text, so I apologize for making it
harder to read (I generally edit mistakes out before posting;
but sometimes I am remiss).

On Sat, 25 May 2013 22:54:25 +0000 (UTC), "Danny D."
wrote:

On Sat, 25 May 2013 12:13:55 -0700, Oren wrote:

Danny is showing his "Accountant" attributes. Counting beans...

I'm still shocked you know I'm an accountant!

Why?

(I must start counting Huckleberries when you say they're in season!)

(you have time now since you retired


The problem with the kits, by the way, is that they're incomplete.
http://www.aladdin1950.com/index.html

For example, the Aladdin GO-KIT38-9 for my pump is missing the drain
plug o-rings; and there doesn't seem to be a filter o-ring kit for
the 25-inch diameter Sta-Rite System 3 Model S8M150 filter tank.

Kits are from different companies, I guess. Filter canister O-ring on
the filter is usually sold as a single item or include an O-ring for
the strainer basket on the pump housing (my experience).

Pump kits may fit different models, whereas, a filter O-ring is
specific to the style of the filter housing.

On Sun, 26 May 2013 15:01:53 +0000 (UTC), Danny D
wrote:

In fact, learning is more fun than actually doing the work.


“Tell me and I'll forget; show me and I may remember; involve me and
I'll understand.” ( Chinese Proverbs quote)

"We the unwilling led by the unknowing are doing the impossible for
the ungrateful, have done so much for so long with so little we are
now qualified to do anything with nothing!" (from an office desk)

On Sun, 26 May 2013 00:52:20 +0200, nestork
wrote:


I looked at the diagram for the pool pump you posted. In my experience,
that large and small O-ring together shouldn't cost any more than $2 or
$3 in nitrile at any shop that sells O-rings. The manufacturer will
charge you $25 for those two O-rings as a repair "kit", but only people
that are scared to buy anything but OEM repair parts would ever pay that
much.

Yes, this is true to some degree. You can also spend hours on end
"learning" about O-rings.

You'll note the kit for his pump includes the ceramic seal, etc. What
he needs to stop the pump leak, all in one package.

If I had a deadline, I'd get the kit, fix the leak and be done with
the project. Study the history of O-rings later.

"**** or get off the pot", as they saying goes.

On Sun, 26 May 2013 09:05:56 -0700, Oren wrote:

(I must start counting Huckleberries when you say they're in season!)
(you have time now since you retired

I never said that, but it's basically true.
You really (really) scare me!

On May 26, 8:13*am, Danny D wrote:
On Sun, 26 May 2013 00:08:05 -0700, DD_BobK wrote:
think about the spelling of lots of english word, no rhyme or
reason (sometimes) just have to accept it.

You'll note that I strive to not misspell words in my posts,
and that I punctuate my sentences as well as I can - and that
all my posts are readable & responsive (if a bit verbose).

So, even if I'm asking about something as mundane as how to
properly plumb a shower stall, I take pains to use the English
language as properly as I know how to use it.

It's all part of the enjoyment of understanding what is
being said and done.

In fact, you'll notice that I even have an ancillary thread
on the English-usage newsgroups asking how the word "plumb"
came about; it's interesting that the term comes from
hanging lead balls (i.e., plumbum) on the end of a string.

Learning just *that*, was more fun than the actual plumbing
of the shower stall.

Huh?

IMO total non sequitur

plus....when did you plumb a shower stall, I missed that?

On May 26, 8:01*am, Danny D wrote:
On Sun, 26 May 2013 00:08:05 -0700, DD_BobK wrote:
A lot of the time you try to "delve" into things to look
for meaning where none exists.

You're forgetting that some people love to learn!

In fact, learning is more fun than actually doing the work.

For example, learning about how unions sealed using boss o-rings
while NPT threads seal with goop was more fun than getting that
goop all over my fingers.

Specifically, learning that the union o-rings are measured
differently than the sealing o-rings is more fun than twisting
unions together and not having them leak.

The meaning is in the learning - not in the work itself.

DDD-

You're assuming facts not in evidence

"You're forgetting that some people love to learn! "

I'm a life long learner & I appreciate that in others.
It is my impression that in your case the slope of the learning curve
is so flat as to be indistinguishable from zero....

Now that Oren has divined that you are retired .....all I can say is
"oh goodie".

My former Strength of Materials professor used to tell us:

"Nature is simple. If someone can't explain something to you in simple terms so that you understand it well enough to explain it to someone else, then it's only because they don't understand it themselves."

And, I've always found that to be true. Whenever anything seems complicated, it's only because we don't fully understand it. If we did, we'd see that it's simple.

Before Newton, asking why something fell when you dropped it was considered a stupid question. And, the orbits of the planets around the Sun were considered to be circles. That's because the Heavens are perfect, and a circle is a perfect shape, and so the only "correct" shape for a planetary orbit would be a circle. Then, Isaac Newton discovered the piece of the puzzle called "gravity", and we realized it wasn't a stupid question and why planetary orbits should be elipses instead of circles. That puzzle went from incomprehensible to simple with the discovery of gravity.

The cure for cancer is going to turn out to be simple. It seems complicated now only because we don't have all the pieces of the puzzle, or at least we don't know which pieces we're missing or which one's we're overlooking, and so we don't understand the process. Once we understand cancer better, we're going to have all the pieces and they're going to fall into place in a simple and understandable way, just like we now understand the causes and cures of cholera, leproscy and the Bubonic plague. Everything seems complicated until you understand it, and then it turns out to be simple after all. The greatest clue we have to understanding is that Nature always favours simplicity.

On May 26, 7:49*am, Danny D wrote:
On Sun, 26 May 2013 00:08:05 -0700, DD_BobK wrote:
Sometimes it takes more than a sentence or two to explain stuff.
Sometimes people who know aren't willing to spend the time.

OT warning

My dad taught me that if it can't be explained, it isn't
understood. For example, what a tangent?

Last week, a friend of mine wanted to doublecheck drawings
for trapezoidal-shaped windows where he needed an overlap
of 1/2 inch all around for the window glass dimensions:
*http://www4.picturepush.com/photo/a/...g/13133012.jpg

He had the numbers - he just wanted to doublecheck them.

He asked me how, and I came up with this simple formula
for the upper overlap (all other dimensions being purely
additive) given the symmetry of parallel lines, geometric
angles, & high-school trig:
*Side1=tangent of (90° + angle°)/2 * 1/2 inch overlap
*Side2=tangent of (90° - angle°)/2 * 1/2 inch overlap

He checked all his drawings with a calculator proclaiming
the answer correct. He then googled what a tangent was,
and apparently he got the answer that it's the slope at
any point of the curve.

He called me back, asking "What's a tangent?" because
the fact that it's the slope of a curve doesn't help
him understand what it is. Sure, he saw the graph of
a tangent on the web - but that didn't help him understand.

You know what I told him?

I said draw a one-inch right triangle with a 45° angle &
note the sides have a ratio of 1:1. The tangent of 45°
is simple the ratio of the opposite side over the adjacent
side. Now change the angle to 34° (which was his angle),
and you'll see the same ratio holds true. So you have
an equation where if you know two of the three components,
you can solve for the third. He understood.

I could have waxed and waned with using unit circles and
definition of the slope and describing sines over cosines
(like math teachers do); but, the answer (for him) was as
simple as the relationship of an angle to a ratio.

Note: He then tried to apply the tangent to degrees in
Microsoft Excel, which only uses radians, so I had to
explain radians to him; but I'll just leave that
explanation to your imagination.

Point is:
If it can't be explained simply - it's not understood.

Back on topic, now that I know the O-ring sizing scheme,
I can doublecheck my numbers.

More importantly, for the o-rings that I don't already
have the trade size for, I first measure the cross section
and that already tells me the series (as long as it's not
a boss seal). Then I measure the ID & I have the trade
size. It's that easy.

Plus, this method works for all o-rings in the household!
Learning is all the fun (the rest is just work).

And this counts as a "simple explanation"?

Even your explanation of "tangent" (if correct, I didn't bother to
read it carefully) hardly qualifies as "simple".

No disrespect to your dad but...he was wrong.

"My dad taught me that if it can't be explained, it isn't
understood."

I fully understand fourier transforms (classical & FFT's).
Can I easily / simply explain them? to you?
No... that's why there's a multi-week course on them AFTER a couple
years study of math.

I suppose I could explain them to you in a few dozens of hours?
Would that count?

On Sun, 26 May 2013 17:00:19 +0000 (UTC), Danny D
wrote:

On Sun, 26 May 2013 09:05:56 -0700, Oren wrote:

(I must start counting Huckleberries when you say they're in season!)
(you have time now since you retired

I never said that, but it's basically true.

You eluded to it.

You really (really) scare me!

Why?!

On Sun, 26 May 2013 10:56:22 -0700 (PDT), DD_BobK
wrote:

You're assuming facts not in evidence

"You're forgetting that some people love to learn! "

I'm a life long learner & I appreciate that in others.
It is my impression that in your case the slope of the learning curve
is so flat as to be indistinguishable from zero....

Now that Oren has divined that you are retired .....all I can say is
"oh goodie".

Upon retirement; he took up DIY home repair, not a bad thing, though.

When I retired I needed some refresher remedial stuff.

On Sun, 26 May 2013 11:05:16 -0700, Oren wrote:

You really (really) scare me!

Why?!

I strive to be totally anonymous on the net, giving out only the
information needed to solve the problem.

You seem to be able to discern more than I intended others to
know about me and my personal life...

On Sun, 26 May 2013 11:04:52 -0700, DD_BobK wrote:

I fully understand fourier transforms (classical & FFT's).
Can I easily / simply explain them? to you?

I understand them, and can explain them (to the level that
I need to).

To me, it's simply the ability to mathematically break down a
complex periodic wave into its component sine waves of various
frequencies.

For example, if I take a square wave, I can break it down
into component sine waves of different frequencies; and vice
versa, if I mix the right frequencies of sine waves together,
I get back my original square wave.

I suppose I could explain them to you in a few dozens of hours?
Would that count?

I think I know Fourier transforms as well as I need to know,
but if you want to correct my simplification above, I'd be
glad to be the recipient of your largess.

On Sun, 26 May 2013 10:56:22 -0700, DD_BobK wrote:

Now that Oren has divined that you are retired .....all I can say is
"oh goodie".

I like Oren. I really do. But he still scares me!

On Sun, 26 May 2013 11:37:13 -0700, Oren wrote:

Upon retirement; he took up DIY home repair, not a bad thing, though.

I never worked on a home before.

In the beginning, I rented. Later on, I didn't have the time, so I paid.
Then I left my life-long profession (good riddance) and bought a run-down
fixer-upper hidden deep in the mountains, so now I've got the three
incredible ingredients for DIY home repair:

I. An old house
II. No money
III. Lots of time!

If you didn't have the first, there'd be nothing to fix; if not the
second, I'd just pay someone else to have all the fun; and the third
is a prerequisite to spending more time learning how to do the job
than doing the job itself.

PS: The fourth thing you need is an nntp newsreader & server and
good friends who care about and understand you!

Don't worry.

Prolly none of us have ever stolen anyone's identity, and we don't intend to start with yours.

I even put my web site up on the internet so everyone knows where I live, and so far no one's tried to kill me.

On May 26, 12:10*pm, Danny D wrote:
On Sun, 26 May 2013 11:05:16 -0700, Oren wrote:
You really (really) scare me!

Why?!

I strive to be totally anonymous on the net, giving out only the
information needed to solve the problem.

You seem to be able to discern more than I intended others to
know about me and my personal life...

"I strive to be totally anonymous on the net, giving out only the
information needed to solve the problem."

Are you embarrassed?


but you have seem to have no problem attempting to reveal all sorts of
information (correct or incorrect) about others.

hmmm that seems more than a bit duplicitous......