Patch thickness measuring question

[tonykarter]

When measuring patch thickness what is the proper technique to get accurate thickness indications: How tight do you dial down on the micrometer? The reason I ask is that different people may get variation thickness readings on the same piece of fabric due to how tight they dial the adjusting screw. Your .015 reading might be .018-.020 if I did it. Is there an agreed best method? Thanks!

 

[coloradoclyde]

I prefer to use a dial or digital Calipers with a friction wheel.. because it measures the fabric over a broader area. allowing for more consistent readings, and the friction wheel prevents me from over or under crushing the fabric..
An actual fabric micrometer is very different than an standard micrometer, it has large measuring pads and is spring loaded for compression.
People get different reading because they measure differently and use different tools....
A standard micrometer is designed to measure solid objects that are spherical in nature..

I use the tool that gives me the most consistent readings when compared against known values.

 

[mzloder]

Take a look at this thread, I just went through a similar situation:
http://www.muzzleloadingforum.com/fusionbb/showtopic.php?tid/297629/

 

[coloradoclyde]

The amount of spring force used on a Kafer thickness gauge is: 3.6 ozf or 1 newton.

This gauge is designed to measure the fabric as it is moving.

A static gauge is listed at less than 1.4 newtons

Here's what a static one looks like... http://www.checkline.com/product/500-FD

 

[Claude Mathis]

Your .015 reading might be .018-.020 if I did it.

Consistency plays a major role in accuracy. Consistency is based on what you do each time, not how you compare to someone else. As long as you use the same pressure each time, you should be fine.

The same goes for how you load your gun. IMO

 

[tonykarter]

I understand more now. I will use my caliper to determine the thinnest to the thickest material among those suggested. Regardless of the their actual thickness, which I am not equipped to accurately determine with the caliper, I will at least know the progression of thicknesses, and one will end up performing better than the rest. That is all that I really care about anyway. That other thread was great. Thanks Mzloder.

 

[Vaino]

I use a 1" micrometer and pull the fabric through until the friction is what I deem is consistent. This eliminates compressing the cloth....Fred

 

[necchi]

Is there an agreed best method? Thanks!

Simply stated,, Nope.
We can't,, if all of us where to gather at the same place and pass around the same sample of fabric, we'd come up with several different measured thickness. We could maybe all learn on the day we gathered how much pressure each individual needs to use to come up with the same,, maybe.
Claude nailed it with this;

Consistency is based on what you do each time,
The same goes for how you load your gun. IMO

What your doing is comparing different fabrics for your use.

You'll probably get several different answers in the thread and none of them are wrong, because like Claude said each method works for each individual,, and all that matters not.
You just do it your way,(the same each time), the comparison only matters to you.

 

[Stumpkiller]

I use my Starrett 230 micrometer and tighten with the clutch until I get three clicks. That is the same way I calibrate it when empty to zero. I measure three different spots on the bolt and can get three different reading 0.001" +/- of what I am looking for.

I have no idea the force the ball puts on the lubed material against the bore, so IMHO a compressed measure doesn't make sense, anyway.

The key is to get the same results as the last batch you used; if that is what worked well.

 

[hanshi]

This works for me. I put the material in the jaws of my caliper and squeeze it down with thumb and index finger as far as it will go. I do this three or four times and when I release it the fourth time whatever setting it springs back out to is the thickness of the material. An example: some material I use for patches measures .030". After I squeeze it down a few times it levels out at .024".

 

[Rifleman1776]

I understand more now. I will use my caliper to determine the thinnest to the thickest material among those suggested. Regardless of the their actual thickness, which I am not equipped to accurately determine with the caliper, I will at least know the progression of thicknesses, and one will end up performing better than the rest. That is all that I really care about anyway. That other thread was great. Thanks Mzloder.

You need to invest in a micrometer that has a friction rachet thingy in the adjusting knob. I use one that is older than I am. And that is really old. :shocked2: As you have seen in other responses, how you do it is not as important as doing it the same way each time and finding what works best for you.

 

[jferguson]

How about this? Making a single measurement of anything is always prone to some degree of error. How about we fold the fabric 2 or four thicknesses, take the measurement, and divide by 2 (or four) and in this way, we are "averaging" out the errors and reaching a more accurate figure. Has anyone ever suggested this, and any reason why this would not be an improvement?

 

[necchi]

any reason why this would not be an improvement?

Sure, just off the top of my head,
Fabric will "squish", it compresses.
Some fabric may compress 3%, some might go 10%, or even more,
If you start folding the stuff your not only multiplying the thickness your multiplying the compression percentage.
You idea would work but only as a comparison if you had a machine that compressed the folded material to a set pressure, say 10 or 20psi. We have measuring machines at work that do just that.

Again, it doesn't matter if we all do it the same,, the measurement of fabric thickness as comparison only matters to the individual and his needs.
As long as a person does his measurement the same way each time he will see a difference in fabric thickness and be able to make the choice he needs.

 

[coloradoclyde]

Has anyone ever suggested this, and any reason why this would not be an improvement?

Just you.... :grin:

Folding the fabric 2 or 4 times won't give you an average measurement... What it will do is amplify your degree of error in measuring.... :td:

Simply take multiple measurements of a single thickness and then calculate your average...this way you reduce the variance in your measuring...
Good measuring tools and practice also help....

 

[Maven]

Sound advice co clyde! :bow:

 

[swathdiver]

As long as a person does his measurement the same way each time he will see a difference in fabric thickness and be able to make the choice he needs.

:thumbsup:

I do it as taught by Dutch Schoultz's "The System".

 

[zimmerstutzen]

As stated, consistency is the key. It is necessary to adequately seal the bore. There is so much more to the consideration. Tightness of weave, knapp, type of rifling, etc. Many people swear by pillow ticking and lubed ticking does stand up to the heat of heavy charges. Over the years I found that cotton flannel worked best in my target barrel. I know a bench shooter who swears by pure linen and pays a premium for a thick course weave linen. I was surprised that it almost resembled fine weave burlap. I tried some and it worked as good in my gun.

Getting a patch material that is so heavy that you need to bruise your haND or even a mallet, is probably deforming the ball. It may work at some distances but probably detracts from accuracy at longer distances.

 

[coloradoclyde]

As stated, consistency is the key. It is necessary to adequately seal the bore. There is so much more to the consideration. Tightness of weave, knapp, type of rifling, etc. Many people swear by pillow ticking and lubed ticking does stand up to the heat of heavy charges. Over the years I found that cotton flannel worked best in my target barrel. I know a bench shooter who swears by pure linen and pays a premium for a thick course weave linen. I was surprised that it almost resembled fine weave burlap. I tried some and it worked as good in my gun.

Getting a patch material that is so heavy that you need to bruise your haND or even a mallet, is probably deforming the ball. It may work at some distances but probably detracts from accuracy at longer distances.


Worth reading twice....[/quote]

 

[azmntman]

Has anyone ever suggested this, and any reason why this would not be an improvement?

Just you.... :grin:

Folding the fabric 2 or 4 times won't give you an average measurement... What it will do is amplify your degree of error in measuring.... :td:

Simply take multiple measurements of a single thickness and then calculate your average...this way you reduce the variance in your measuring...
Good measuring tools and practice also help....

Exactly :thumbsup:

 

[Billnpatti]

We may never get to the place where we both get the same exact measurement on anything as soft as a piece of cloth. The problem is exactly as you stated with regard to how tight do you tighten the micrometer on the fabric. If we were to both measure the thickness of something solid such as a piece of steel, we would likely get the same exact measurement every time but fabric is soft and we are not likely to tighten the micrometer to the same exact degree of torque. However, we can come close if we agree on a technique. My technique is to measure both the uncompressed thickness and the compressed thickness. In reality, I think the compressed thickness is the more accurate way of measuring because it more closely represents the thickness of the fabric when it is compressed between the ball and inside of the bore. The way I measure the uncompressed thickness is to place one layer of fabric into my micrometer and close the micrometer onto the fabric using only the ratchet. When it clicks three clicks, I stop and take my reading. the three clicks is just the way I do it. You can pick as many clicks as you like just use the same number of clicks for all of your measurements. consistency is important. Okay, that gives you the uncompressed thickness. To get the compressed thickness you will be doing this by feel and you will have to develop the feel for how much torque you put on the stem of your micrometer. It is a precision instrument so you don't want to get too "King Kong" with it. Just snug the micrometer down on the fabric using only your thumb and forefinger on the stem of the micrometer. Good and snug but, like I say, not King Kong snug. You are not tightening head bolts. Admittedly, how tight you tighten will never be exactly how tight I tighten but as long as you do it consistently, the measurement will be relevant for your needs. The precise measurement is too elusive but once you find a fabric thickness by your measurement that works best in your rifle, that is the thickness you want all the time. You may find a fabric that by your measurements is .010 but I may measure it to be .015. So long as you use fabrics that you measure to be .010 and they work for you, it doesn't matter what I measure them to be. For you, that fabric is .010. It works and that's all that matters.

I've had my say. :hatsoff: