A benchtop experiment (or is it a laundry room experiment?)

[longcruise]

Wandering through Wally World the other day and got looking at some potential patch material.  I'm getting to be a "collector" of various patch stock which makes it easy to come up with something when trying out a new load.

Anyway, came across some "duck" that was in a variety of colors which the white haired lady at the counter assured me were all the same.  Decided to try a piece.

Since I always wash my patch material at least twice it seemed like an opportunity to test the changes in thickness as the material was put through the wash and dry cycles.  Starting out the material measure .022.  After one wash and dry, it measured .023 and finally after a second wash and dry it came in at .025.

I don't usually measure my patch material.  Just try various combos until a good fit is found and then stick with it.  I always keep track of which is which so it can be repeated (repurchased).

[Daryl]

Interesting, Longcruise - Have you shot that fabric yet?

I find denim fabric I use grows .001" after a wash or two.  I use a micrometer to measure patch thickness as it gives me identical readings. With calipers, I find how hard you squeeze the jaws and where you place the material, makes a big difference in the readout.

It is always a good idea to keep a record of shooting and load particulars, ball size, powder type, charge & lot # if possible, patch material, thickness and weave - maybe even vent size, shot dirty or cleaned twixt shots, etc, etc. The more 'data' the more accurately you can duplicate the load at a later date.  We do this quite accurately with the BP ctg. guns to allow up to precisely duplicate the best shooting load when the testing is over.

[Roger Fisher]

Thats another reason to wash the stuff!

Good tight thread count is also important.  Since I run out of fingers and toes when counting warp and woof threads my test is to stretch a strip of it tween my fingers hold up to the bright sun and if I can see light thru it I reject it. (for shootin that is)

[hanshi]

Hmmmm....velly intawesting.  I guess I always assumed the patching material would get a bit thinner after being washed.  I stand corrected.

[Daryl]

The fibers seem to fluff a bit, with the sizing and ironing gove from them.

[Gene Carrell]

I have always washed  my patching because it seems to hold lube  better after washing. I have also found about 0.001 increase in thickness through the wash.

[longcruise]

I use a micrometer to measure patch thickness as it gives me identical readings. With calipers, I find how hard you squeeze the jaws and where you place the material, makes a big difference in the readout.

I'd be the last to vouch for my ability to measure with a precision instrument.   I used the full length of the jaws and as equal of pressure as possible.  Have several micrometers but find it more difficult to repeat the pressure and hold with them.  OTOH, the calipers are used often and I've more confidence in my ability to use them.  No dought though that a micrometer would be more precise.  Maybe I should whack off a piece and send it to you.  Would be interesting to see what you come up with using a micrometer.

No, have not shot it yet but will try it next time out.

[Daryl]

As long as a fellow uses the same measuring system for all his fabrics, he can be assured of accurate results with checking thicknesses.  This is why I gravitated to using the mic.  It works for me and gives repeatable results, spinning the ratchet 1/6 dozen times or so.  Actual thickness isn't important, as long as it's measured with accuracy, or is it precision?

The different systems used by shooters, is why I've started listing the materials by their 'pound' designation, ie: 6 pound, 8 pound, 10, 12, etc.  With .400" balls in the .398" bore of my .40, I can use both 8(.017") and 10(.020" & .0215") pound denim, while the undersized .395" balls get 10 pound. Each loads easily with those numbers.  One of these days, I'll get around to trying the 12 pound(.025") with the .433" balls, both pure lead and WW metal in the .45 longrifle.

[longcruise]

Yes, "pounds" is my method of making sure it's the same as the last batch.  But, what I see is that it's measured in ounces rather than pounds.  Think we're talking about the same thing but you folks have that foreign language of yours.<g>

[hanshi]

Speaking of denim, I have some old blue jeans.  Is that denim close to what has been described?  What "weight" would it be?  If so, I like to use it for patching.

[longcruise]

Speaking of denim, I have some old blue jeans.  Is that denim close to what has been described?  What "weight" would it be?  If so, I like to use it for patching.

I tried that once, but the thickness varied a lot from one wear area to the next.  Did have good luck with one of my daughters discarded denim skirts.  Course they wear those three or four times and they are done!

[Daryl]

Flintr - if you use the pure cotton denim from the backs of the legs and below the knee all around, it's usually consistant.  Most denim is either 8 or 10 ounce, but there is some 12 in there as well - sometimes in the heavier weights of jeans.

Ed - perhaps you are right - it could be ounces per yard or meter - or weight for a bolt in pounds as I thought - doesn't really matter, it's the 6,8,10 or 12 that's important.