portable black light

[wearwolfss]

Newbie here went to my local gun shop to check out a ss side cap that look to good to be true and it was my brand new portable black light showed all of th evil doings my question how about when it has been washed in todays modern soap does anybody know how to tell the differnce

[tempelhof]

modern laundry detergent contains phosphorous and related compounds that can cause anything washed with this stuff to glow.

such an item should show an evenly distributed and slight glow across the entire piece with little variance across changes in fabric if there are any. in a piece that would have glowed whether washed or not, i would think the glow would be a little more intense and you'd see that intensity change across fabric types such what you might see coming from piping as compared to what you might see coming from a label on the same piece.

this isn't always true and i'd have to make this determination as to whether a glow is coming from detergent or use of contemporary fabrics on a case-by-case basis with the item in hand.

maybe you could wash it again without detergent and see if the glow fades? i've never tried that before, but from the perspective of chemistry, i'd think if a glow was coming from the use of detergents, washing it again a second time without detergents would remove some of the phosphorous compounds and thus remove some of the glow.

in addition, there are solutions used by hunters sometimes which will greatly subdue any glow found in a modern fabric.

simply put, the black light is not a magic bullet. it is part of a much larger armamentarium of other tools, chief of which are experience and knowledge.

[tempelhof]

basically, the correct use of a black light for me is to determine whether there is a glow. if there is, i'm done. i'm not interested in the item.

if there is not, i might be interested. there is further research to be done.

they are most useful for paper items, and less useful for cloth. but not entirely useless.

[wearwolfss]

Thank you Templhof that makes sense all the way around.

[stonemint]

It works for white materials on visors--the gauze (cheesecloth) behind the visor lining; the threads used to attach the lining; white piping; the thread "core" of bullion insignia (to include chincords),etc.

However, colored piping will glow--try it on Panzer pink.

[CARL]

I agree with Templehof, the black light test is superb for testing paper items, but with cloth pieces it is something that can help (sometimes), nothing more.

Regards,

Carl

[MD Helmets]

Black lights are a tool in our collecting tool boxes. Don't rely totally on it, but use it to piece together your evaluation of an item.

[wearwolfss]

Thanks to all for the Knowledge and insight
regards Robert.

[wearwolfss]

One more Question guys is there any way to make modern fabric not glow under uv light just want to know and if there is can you tell that it has been done to fabric paper anything
best regards Robert

[tempelhof]

yes. there are ways to do this.

as i pointed out earlier, there are products (UV Killer, Sport-Wash etc.) used by hunters especially that, when applied to fabrics, will bind to them and prevent UV glow under black light.

this is just one more reason UV is not a final answer.

again, it can not be said enough: if there is a glow, i'm done. if there is no glow, further investigation is warranted. this is my personal "motto", if you will, for the practical interpretation of black light results.

this does NOT mean every interpreted result will be correct. however, it errs to the side of caution such that an error costing money based on the over-reliance of UV results becomes close to impossible. you need not know every situation in which something might glow or not glow. you need only know that a glow is a deal killer. i guess what i am saying is that why an item does not glow is not important. what is important is the realization that, if an item does not glow, no guarantee of period manufacture is implied per se. you simply have further work to do.