creating rusty bolts for an experiment

[pippo]

People,

 

Can one create/prepare UNIFORMLY rusty bolts siezed into a steel block for an experiment where all the bolts rusted in will be exactly of the same degree of rust? In other words, say one wanted to test different rust penetrating fluids, and apply different fluids on the bolts as "control " bolts, assuming that in the experiment you would have exactly the same conditions for an unbiased test.

 

I guess there is so many factors that could alter one bolt from another rusty bolt. I mean, the threads themselves, so much can change inside threads affecting "rust" development.......

 

Thanks!

[swansont]

I suspect not, since the bolts themselves will not be identical and rust may preferentially occur (or not) owing to imperfections. You could do a test to see if identically prepared samples are close enough to identical in performance — you need to do a large enough sampling to get statistics to see what the variation is. That will tell you if you can get away with small sample numbers for each fluid.

[pippo]

Thanks, swan. Makes common sense. Well, common to scientific approach, of course, which is what I strive to adhere to. Sample should be as large as possible to arrive closer to a top of bell curve distribution(?), I figure.

[swansont]

Thanks, swan. Makes common sense. Well, common to scientific approach, of course, which is what I strive to adhere to. Sample should be as large as possible to arrive closer to a top of bell curve distribution(?), I figure.

The initial test should be large enough to tell you how much variation there is in the prepared bolts. That will tell you how many samples you need for the subsequent tests. Let's say you find the torque that is required to unstick the bolts and it's a bell curve with a standard deviation of 10%. If the variation between the fluids is only a few %, you need a lot of statistics (conversely, you'd conclude they are indistinguishable within your uncertainty if you didn't get a lot of statistics). But one or two bolts would be enough if two fluids differed by 25% of the original torque.

[pippo]

Good point, on the large difference requiring just a few bolts, swan. Overwhelms the tiny differences between them.

[alpha2cen]

In this case, you can do the experiment by using this experiment design method.

When you want to know the cause of the corrosion or to fix a corrosion degree as a factor, 2nd method is useful.

You can obtain more detail knowledge from experimental design book.

Edited December 3, 2012 by alpha2cen

[Externet]

Uniformly creation of rust under equal torques is one of those things that may work well in the laboratory and papers, but the real penetrating fluid evaluation should be outside in the real world.

I would go to a seaside marina or industrial plant and look at their junk piles, take your time looking for old equipment with many equal rusty bolts -say a boiler- to perform your tests.

Am sure that someone there would appreciate the 'free' dismantling of some old stuff around.

 

By the way; you want an unbeatable penetrating fluid ? Plain transmission fluid + acetone 50/50. I never buy that WD something nor any other 'liquid wrench' products.

Penetration ability and rust 'freeing' are different properties of a fluid, if a bolt head seats hermetic for the applied fluid to reach past it into the threads, tests can be of uncertain effectivity.

[John Cuthber]

"By the way; you want an unbeatable penetrating fluid ? Plain transmission fluid + acetone 50/50."

 

Perhaps you would like to tell us how you did that testing.

[Externet]

Since at least 20 years ago, every time I needed to loosen rusty anything, works great !

Pour both in a container and shake vigorously, applied immediately before settling.

 

Edited - added : You got me curious... Just checked wikipedia for Acetone, before the 'Safety' paragraph.

And surprised of the Google hits on "transmission fluid acetone"

 

Edit 2 : 30 years ago, I used 'Marvel mystery oil' My household "3 in 1" can refilled has only ATF in it.

I use it for lubrication too, and as a wood furniture surface rejuvenator - Without the acetone !

Edited December 4, 2012 by Externet

[alpha2cen]

To choose the factor, using SSPC standard is useful for practical usage.

[pippo]

thanks, people. yes, I have heard of the ATF + acetone, 50/50. Also heard of old/used motor oil.

oh- I no like new website. I resist change- old chemist. but, things happen.